Fix sign and conversion warnings (major)

This makes all integer type conversions that have potential data loss explicit with calls that do range checks and raise an exception. After this commit, qpdf builds with no warnings when -Wsign-conversion -Wconversion is used with gcc or clang or when -W3 -Wd4800 is used with MSVC. This significantly reduces the likelihood of potential crashes from bogus integer values. There are some parts of the code that take int when they should take size_t or an offset. Such places would make qpdf not support files with more than 2^31 of something that usually wouldn't be so large. In the event that such a file shows up and is valid, at least qpdf would raise an error in the right spot so the issue could be legitimately addressed rather than failing in some weird way because of a silent overflow condition.

Fix sign and conversion warnings (major)
This makes all integer type conversions that have potential data loss explicit with calls that do range checks and raise an exception. After this commit, qpdf builds with no warnings when -Wsign-conversion -Wconversion is used with gcc or clang or when -W3 -Wd4800 is used with MSVC. This significantly reduces the likelihood of potential crashes from bogus integer values. There are some parts of the code that take int when they should take size_t or an offset. Such places would make qpdf not support files with more than 2^31 of something that usually wouldn't be so large. In the event that such a file shows up and is valid, at least qpdf would raise an error in the right spot so the issue could be legitimately addressed rather than failing in some weird way because of a silent overflow condition.
Jay Berkenbilt
1 parent f40ffc9d
Showing 79 changed files with 882 additions and 694 deletions
ChangeLog
NOTICE.md
examples/pdf-create.cc
examples/pdf-double-page-size.cc
examples/pdf-invert-images.cc
examples/pdf-parse-content.cc
examples/pdf-split-pages.cc
fuzz/standalone_fuzz_target_runner.cc
include/qpdf/BufferInputSource.hh
include/qpdf/Pl_Count.hh
include/qpdf/QPDF.hh
include/qpdf/QPDFWriter.hh
libqpdf/BitStream.cc
libqpdf/BitWriter.cc
libqpdf/BufferInputSource.cc
libqpdf/FileInputSource.cc
libqpdf/InputSource.cc
libqpdf/InsecureRandomDataProvider.cc
libqpdf/JSON.cc
libqpdf/MD5.cc
 2019-06-20  Jay Berkenbilt  <ejb@ql.org>
+	* Fix all integer sign and conversion warnings. This makes all
+	integer type conversions that have potential data loss explicit
+	with calls that do range checks and raise an exception.
+
 	* Change out_bufsize argument to Pl_Flate's constructor for int to
 	unsigned int for compatibility with underlying zlib
 	implementation.
+	* Change QPDFObjectHandle::pipeStreamData's encode_flags argument
+	from unsigned long to int since int is the underlying type of the
+	enumerated type values that are passed to it. This change should
+	be invisible to virtually all code unless you are compiling with
+	strict warning flags and explicitly casting to unsigned long.
+
 	* Add methods to QPDFObjectHandle to return the value of Integer
 	objects as int and unsigned int with range checking and fallback
 	behavior to avoid silent underflow/overflow conditions.
@@ -10,8 +10,6 @@ Versions of qpdf prior to version 7 were released under the terms of version 2.0
 The qpdf distribution includes a copy of [qtest](http://qtest.qbilt.org), which is released under the terms of the [version 2.0 of the Artistic license](https://opensource.org/licenses/Artistic-2.0), which can be found at https://opensource.org/licenses/Artistic-2.0.
-The standalone fuzz target runner (fuzz/standalone_fuzz_target_runner.cc) is copyright 2017 by Google and is also released under the Apache license, Version 2.0.
-
 The Rijndael encryption implementation used as the basis for AES encryption and decryption support comes from Philip J. Erdelsky's public domain implementation.  The files `libqpdf/rijndael.cc` and `libqpdf/qpdf/rijndael.h` remain in the public domain.  They were obtained from
 * http://www.efgh.com/software/rijndael.htm
 * http://www.efgh.com/software/rijndael.txt
@@ -14,6 +14,7 @@
 #include <qpdf/Pl_Buffer.hh>
 #include <qpdf/Pl_RunLength.hh>
 #include <qpdf/Pl_DCT.hh>
+#include <qpdf/QIntC.hh>
 #include <iostream>
 #include <string.h>
 #include <stdlib.h>
@@ -30,15 +31,15 @@ class ImageProvider: public QPDFObjectHandle::StreamDataProvider
     virtual ~ImageProvider();
     virtual void provideStreamData(int objid, int generation,
 				   Pipeline* pipeline);
-    int getWidth() const;
-    int getHeight() const;
+    size_t getWidth() const;
+    size_t getHeight() const;
   private:
-    int width;
-    int stripe_height;
+    size_t width;
+    size_t stripe_height;
     std::string color_space;
     std::string filter;
-    int n_stripes;
+    size_t n_stripes;
     std::vector<std::string> stripes;
     J_COLOR_SPACE j_color_space;
 };
@@ -88,13 +89,13 @@ ImageProvider::~ImageProvider()
 {
 }
-int
+size_t
 ImageProvider::getWidth() const
 {
     return width;
 }
-int
+size_t
 ImageProvider::getHeight() const
 {
     return stripe_height * n_stripes;
@@ -111,7 +112,8 @@ ImageProvider::provideStreamData(int objid, int generation,
     {
         p = new Pl_DCT(
             "image encoder", pipeline,
-            width, getHeight(), stripes[0].length(), j_color_space);
+            QIntC::to_uint(width), QIntC::to_uint(getHeight()),
+            QIntC::to_int(stripes[0].length()), j_color_space);
         to_delete.push_back(p);
     }
     else if (filter == "/RunLengthDecode")
@@ -121,9 +123,9 @@ ImageProvider::provideStreamData(int objid, int generation,
         to_delete.push_back(p);
     }
-    for (int i = 0; i < n_stripes; ++i)
+    for (size_t i = 0; i < n_stripes; ++i)
     {
-        for (int j = 0; j < width * stripe_height; ++j)
+        for (size_t j = 0; j < width * stripe_height; ++j)
         {
             p->write(
                 QUtil::unsigned_char_pointer(stripes[i].c_str()),
@@ -155,9 +157,9 @@ QPDFObjectHandle newName(std::string const&amp; name)
     return QPDFObjectHandle::newName(name);
 }
-QPDFObjectHandle newInteger(int val)
+QPDFObjectHandle newInteger(size_t val)
 {
-    return QPDFObjectHandle::newInteger(val);
+    return QPDFObjectHandle::newInteger(QIntC::to_int(val));
 }
 void add_page(QPDFPageDocumentHelper& dh, QPDFObjectHandle font,
@@ -173,8 +175,8 @@ void add_page(QPDFPageDocumentHelper&amp; dh, QPDFObjectHandle font,
     // compression.
     ImageProvider* p = new ImageProvider(color_space, filter);
     PointerHolder<QPDFObjectHandle::StreamDataProvider> provider(p);
-    int width = p->getWidth();
-    int height = p->getHeight();
+    size_t width = p->getWidth();
+    size_t height = p->getHeight();
     QPDFObjectHandle image = QPDFObjectHandle::newStream(&pdf);
     image.replaceDict(QPDFObjectHandle::parse(
                           "<<"
@@ -335,8 +337,8 @@ static void check(char const* filename,
                 unsigned int mismatches = 0;
                 int tolerance = (
                     desired_filter == "/DCTDecode" ? 10 : 0);
-                unsigned int threshold = (
-                    desired_filter == "/DCTDecode" ? len / 40 : 0);
+                size_t threshold = (
+                    desired_filter == "/DCTDecode" ? len / 40U : 0);
                 for (size_t i = 0; i < len; ++i)
                 {
                     int delta = actual_bytes[i] - desired_bytes[i];
@@ -34,7 +34,7 @@ static void doubleBoxSize(QPDFObjectHandle&amp; page, char const* box_name)
 				 " is not an array of four elements");
     }
     std::vector<QPDFObjectHandle> doubled;
-    for (unsigned int i = 0; i < 4; ++i)
+    for (int i = 0; i < 4; ++i)
     {
 	doubled.push_back(
 	    QPDFObjectHandle::newReal(
@@ -7,6 +7,7 @@
 #include <qpdf/QUtil.hh>
 #include <qpdf/Buffer.hh>
 #include <qpdf/QPDFWriter.hh>
+#include <qpdf/QIntC.hh>
 static char const* whoami = 0;
@@ -56,7 +57,7 @@ ImageInverter::provideStreamData(int objid, int generation,
     unsigned char ch;
     for (size_t i = 0; i < size; ++i)
     {
-	ch = static_cast<unsigned char>(0xff) - buf[i];
+	ch = QIntC::to_uchar(0xff - buf[i]);
 	pipeline->write(&ch, 1);
     }
     pipeline->finish();
@@ -6,6 +6,7 @@
 #include <qpdf/QPDFPageDocumentHelper.hh>
 #include <qpdf/QPDFPageObjectHelper.hh>
 #include <qpdf/QUtil.hh>
+#include <qpdf/QIntC.hh>
 static char const* whoami = 0;
@@ -72,12 +73,12 @@ int main(int argc, char* argv[])
 	pdf.processFile(filename);
         std::vector<QPDFPageObjectHelper> pages =
             QPDFPageDocumentHelper(pdf).getAllPages();
-        if ((pageno < 1) || (static_cast<size_t>(pageno) > pages.size()))
+        if ((pageno < 1) || (QIntC::to_size(pageno) > pages.size()))
         {
             usage();
         }
-        QPDFPageObjectHelper& page = pages.at(pageno-1);
+        QPDFPageObjectHelper& page = pages.at(QIntC::to_size(pageno-1));
         ParserCallbacks cb;
         page.parsePageContents(&cb);
     }
@@ -8,6 +8,7 @@
 #include <qpdf/QPDFPageDocumentHelper.hh>
 #include <qpdf/QPDFWriter.hh>
 #include <qpdf/QUtil.hh>
+#include <qpdf/QIntC.hh>
 #include <iostream>
 #include <stdlib.h>
@@ -24,7 +25,8 @@ static void process(char const* whoami,
     inpdf.processFile(infile);
     std::vector<QPDFPageObjectHelper> pages =
         QPDFPageDocumentHelper(inpdf).getAllPages();
-    int pageno_len = QUtil::int_to_string(pages.size()).length();
+    int pageno_len =
+        QIntC::to_int(QUtil::uint_to_string(pages.size()).length());
     int pageno = 0;
     for (std::vector<QPDFPageObjectHelper>::iterator iter = pages.begin();
          iter != pages.end(); ++iter)
-// Copyright 2017 Google Inc. All Rights Reserved.
-// Licensed under the Apache License, Version 2.0 (the "License");
-
-// Except for formatting, comments, and portability, this was copied
-// from projects/example/my-api-repo/standalone_fuzz_target_runner.cpp
-// in https://github.com/oss-fuzz
-
-#include <cassert>
+#include <qpdf/QUtil.hh>
+#include <qpdf/PointerHolder.hh>
+#include <qpdf/QIntC.hh>
 #include <iostream>
-#include <fstream>
-#include <vector>
+#include <string>
 extern "C" int LLVMFuzzerTestOneInput(unsigned char const* data, size_t size);
+static void read_file_into_memory(
+    char const* filename,
+    PointerHolder<unsigned char>& file_buf, size_t& size)
+{
+    FILE* f = QUtil::safe_fopen(filename, "rb");
+    fseek(f, 0, SEEK_END);
+    size = QIntC::to_size(QUtil::tell(f));
+    fseek(f, 0, SEEK_SET);
+    file_buf = PointerHolder<unsigned char>(true, new unsigned char[size]);
+    unsigned char* buf_p = file_buf.getPointer();
+    size_t bytes_read = 0;
+    size_t len = 0;
+    while ((len = fread(buf_p + bytes_read, 1, size - bytes_read, f)) > 0)
+    {
+        bytes_read += len;
+    }
+    if (bytes_read != size)
+    {
+        throw std::runtime_error(
+            std::string("failure reading file ") + filename +
+            " into memory: read " +
+            QUtil::uint_to_string(bytes_read) + "; wanted " +
+            QUtil::uint_to_string(size));
+    }
+    fclose(f);
+}
+
 int main(int argc, char **argv)
 {
     for (int i = 1; i < argc; i++)
     {
-        std::ifstream in(argv[i]);
-        in.seekg(0, in.end);
-        size_t length = in.tellg();
-        in.seekg (0, in.beg);
-        std::cout << "checking " << argv[i] << std::endl;
-        // Allocate exactly length bytes so that we reliably catch
-        // buffer overflows.
-        std::vector<char> bytes(length);
-        in.read(bytes.data(), bytes.size());
-        assert(in);
-        LLVMFuzzerTestOneInput(
-            reinterpret_cast<unsigned char const*>(bytes.data()),
-            bytes.size());
+        PointerHolder<unsigned char> file_buf;
+        size_t size = 0;
+        read_file_into_memory(argv[i], file_buf, size);
+        LLVMFuzzerTestOneInput(file_buf.getPointer(), size);
         std::cout << argv[i] << " successful" << std::endl;
     }
     return 0;
@@ -54,6 +54,8 @@ class BufferInputSource: public InputSource
     virtual void unreadCh(char ch);
   private:
+    qpdf_offset_t const bufSizeAsOffset() const;
+
     bool own_memory;
     std::string description;
     Buffer* buf;
@@ -48,6 +48,8 @@ class Pl_Count: public Pipeline
     unsigned char getLastChar() const;
   private:
+    // Must be qpdf_offset_t, not size_t, to handle writing more than
+    // size_t can handle.
     qpdf_offset_t count;
     unsigned char last_char;
 };
@@ -32,6 +32,7 @@
 #include <iostream>
 #include <vector>
+#include <qpdf/QIntC.hh>
 #include <qpdf/QPDFExc.hh>
 #include <qpdf/QPDFObjectHandle.hh>
 #include <qpdf/QPDFObjGen.hh>
@@ -859,7 +860,7 @@ class QPDF
     bool pipeForeignStreamData(
         PointerHolder<ForeignStreamData>,
         Pipeline*,
-        unsigned long encode_flags,
+        int encode_flags,
         qpdf_stream_decode_level_e decode_level);
     static bool pipeStreamData(PointerHolder<QPDF::EncryptionParameters> encp,
                                PointerHolder<InputSource> file,
@@ -1253,7 +1254,7 @@ class QPDF
     void dumpHPageOffset();
     void dumpHSharedObject();
     void dumpHGeneric(HGeneric&);
-    int adjusted_offset(int offset);
+    qpdf_offset_t adjusted_offset(qpdf_offset_t offset);
     QPDFObjectHandle objGenToIndirect(QPDFObjGen const&);
     void calculateLinearizationData(
 	std::map<int, int> const& object_stream_data);
@@ -1297,6 +1298,20 @@ class QPDF
 				  std::set<QPDFObjGen>& visited, bool top);
     void filterCompressedObjects(std::map<int, int> const& object_stream_data);
+    // Type conversion helper methods
+    template<typename T> static qpdf_offset_t toO(T const& i)
+    {
+        return QIntC::to_offset(i);
+    }
+    template<typename T> static size_t toS(T const& i)
+    {
+        return QIntC::to_size(i);
+    }
+    template<typename T> static int toI(T const& i)
+    {
+        return QIntC::to_int(i);
+    }
+
     class Members
     {
         friend class QPDF;
@@ -467,7 +467,7 @@ class QPDFWriter
     enum trailer_e { t_normal, t_lin_first, t_lin_second };
-    int bytesNeeded(unsigned long long n);
+    unsigned int bytesNeeded(long long n);
     void writeBinary(unsigned long long val, unsigned int bytes);
     void writeString(std::string const& str);
     void writeBuffer(PointerHolder<Buffer>&);
@@ -483,10 +483,8 @@ class QPDFWriter
     void writeTrailer(trailer_e which, int size,
 		      bool xref_stream, qpdf_offset_t prev,
                       int linearization_pass);
-    void unparseObject(QPDFObjectHandle object, int level,
-		       unsigned int flags);
-    void unparseObject(QPDFObjectHandle object, int level,
-		       unsigned int flags,
+    void unparseObject(QPDFObjectHandle object, int level, int flags);
+    void unparseObject(QPDFObjectHandle object, int level, int flags,
 		       // for stream dictionaries
 		       size_t stream_length, bool compress);
     void unparseChild(QPDFObjectHandle child, int level, int flags);
@@ -510,7 +508,7 @@ class QPDFWriter
 	char const* user_password, char const* owner_password,
 	int V, int R, int key_len, std::set<int>& bits_to_clear);
     void setEncryptionParametersInternal(
-	int V, int R, int key_len, long P,
+	int V, int R, int key_len, int P,
 	std::string const& O, std::string const& U,
 	std::string const& OE, std::string const& UE, std::string const& Perms,
 	std::string const& id1, std::string const& user_password,
@@ -554,7 +552,7 @@ class QPDFWriter
         qpdf_offset_t hint_length,
         bool skip_compression,
         int linearization_pass);
-    int calculateXrefStreamPadding(int xref_bytes);
+    int calculateXrefStreamPadding(qpdf_offset_t xref_bytes);
     // When filtering subsections, push additional pipelines to the
     // stack.  When ready to switch, activate the pipeline stack.
 #include <qpdf/BitStream.hh>
+#include <qpdf/QIntC.hh>
 // See comments in bits.cc
 #define BITS_READ 1
 #include "bits.icc"
-BitStream::BitStream(unsigned char const* p, int nbytes) :
+BitStream::BitStream(unsigned char const* p, size_t nbytes) :
     start(p),
     nbytes(nbytes)
 {
@@ -16,7 +17,7 @@ BitStream::reset()
 {
     p = start;
     bit_offset = 7;
-    if (static_cast<unsigned int>(nbytes) > static_cast<unsigned int>(-1) / 8)
+    if (QIntC::to_uint(nbytes) > static_cast<unsigned int>(-1) / 8)
     {
 	throw std::runtime_error("array too large for bitstream");
     }
@@ -24,21 +25,21 @@ BitStream::reset()
 }
 unsigned long long
-BitStream::getBits(int nbits)
+BitStream::getBits(size_t nbits)
 {
     return read_bits(this->p, this->bit_offset,
 		     this->bits_available, nbits);
 }
 long long
-BitStream::getBitsSigned(int nbits)
+BitStream::getBitsSigned(size_t nbits)
 {
     unsigned long long bits = read_bits(this->p, this->bit_offset,
                                         this->bits_available, nbits);
     long long result = 0;
-    if (static_cast<long long>(bits) > 1 << (nbits - 1))
+    if (static_cast<long long>(bits) > 1LL << (nbits - 1))
     {
-        result = static_cast<long long>(bits - (1 << nbits));
+        result = static_cast<long long>(bits -(1ULL << nbits));
     }
     else
     {
@@ -47,12 +48,21 @@ BitStream::getBitsSigned(int nbits)
     return result;
 }
+int
+BitStream::getBitsInt(size_t nbits)
+{
+    return static_cast<int>(
+        QIntC::to_uint(
+            read_bits(this->p, this->bit_offset,
+                      this->bits_available, nbits)));
+}
+
 void
 BitStream::skipToNextByte()
 {
     if (bit_offset != 7)
     {
-	unsigned int bits_to_skip = bit_offset + 1;
+	size_t bits_to_skip = bit_offset + 1;
 	if (bits_available < bits_to_skip)
 	{
 	    throw std::logic_error(
@@ -12,18 +12,18 @@ BitWriter::BitWriter(Pipeline* pl) :
 }
 void
-BitWriter::writeBits(unsigned long long val, unsigned int bits)
+BitWriter::writeBits(unsigned long long val, size_t bits)
 {
     write_bits(this->ch, this->bit_offset, val, bits, this->pl);
 }
 void
-BitWriter::writeBitsSigned(long long val, unsigned int bits)
+BitWriter::writeBitsSigned(long long val, size_t bits)
 {
     unsigned long long uval = 0;
     if (val < 0)
     {
-        uval = static_cast<unsigned long long>((1 << bits) + val);
+        uval = (1ULL << bits) + static_cast<unsigned long long>(val);
     }
     else
     {
@@ -33,11 +33,17 @@ BitWriter::writeBitsSigned(long long val, unsigned int bits)
 }
 void
+BitWriter::writeBitsInt(int val, size_t bits)
+{
+    writeBits(static_cast<unsigned long long>(val), bits);
+}
+
+void
 BitWriter::flush()
 {
     if (bit_offset < 7)
     {
-	int bits_to_write = bit_offset + 1;
+	size_t bits_to_write = bit_offset + 1;
 	write_bits(this->ch, this->bit_offset, 0, bits_to_write, this->pl);
     }
 }
 #include <qpdf/BufferInputSource.hh>
+#include <qpdf/QIntC.hh>
 #include <string.h>
 #include <stdexcept>
 #include <algorithm>
@@ -32,6 +33,12 @@ BufferInputSource::~BufferInputSource()
     }
 }
+qpdf_offset_t const
+BufferInputSource::bufSizeAsOffset() const
+{
+    return QIntC::to_offset(this->buf->getSize());
+}
+
 qpdf_offset_t
 BufferInputSource::findAndSkipNextEOL()
 {
@@ -39,7 +46,7 @@ BufferInputSource::findAndSkipNextEOL()
     {
         throw std::logic_error("INTERNAL ERROR: BufferInputSource offset < 0");
     }
-    qpdf_offset_t end_pos = this->buf->getSize();
+    qpdf_offset_t end_pos = bufSizeAsOffset();
     if (this->cur_offset >= end_pos)
     {
 	this->last_offset = end_pos;
@@ -48,7 +55,7 @@ BufferInputSource::findAndSkipNextEOL()
     }
     qpdf_offset_t result = 0;
-    size_t len = end_pos - this->cur_offset;
+    size_t len = QIntC::to_size(end_pos - this->cur_offset);
     unsigned char const* buffer = this->buf->getBuffer();
     void* start = const_cast<unsigned char*>(buffer) + this->cur_offset;
@@ -97,7 +104,7 @@ BufferInputSource::seek(qpdf_offset_t offset, int whence)
 	break;
       case SEEK_END:
-	this->cur_offset = this->buf->getSize() + offset;
+	this->cur_offset = bufSizeAsOffset() + offset;
 	break;
       case SEEK_CUR:
@@ -130,7 +137,7 @@ BufferInputSource::read(char* buffer, size_t length)
     {
         throw std::logic_error("INTERNAL ERROR: BufferInputSource offset < 0");
     }
-    qpdf_offset_t end_pos = this->buf->getSize();
+    qpdf_offset_t end_pos = bufSizeAsOffset();
     if (this->cur_offset >= end_pos)
     {
 	this->last_offset = end_pos;
@@ -139,9 +146,9 @@ BufferInputSource::read(char* buffer, size_t length)
     this->last_offset = this->cur_offset;
     size_t len = std::min(
-        static_cast<size_t>(end_pos - this->cur_offset), length);
+        QIntC::to_size(end_pos - this->cur_offset), length);
     memcpy(buffer, buf->getBuffer() + this->cur_offset, len);
-    this->cur_offset += len;
+    this->cur_offset += QIntC::to_offset(len);
     return len;
 }
@@ -130,7 +130,7 @@ FileInputSource::read(char* buffer, size_t length)
                           this->filename, "",
                           this->last_offset,
                           std::string("read ") +
-                          QUtil::int_to_string(length) + " bytes");
+                          QUtil::uint_to_string(length) + " bytes");
         }
         else if (length > 0)
         {
@@ -3,6 +3,7 @@
 #include <stdexcept>
 #include <qpdf/QTC.hh>
 #include <qpdf/PointerHolder.hh>
+#include <qpdf/QIntC.hh>
 void
@@ -35,7 +36,7 @@ InputSource::readLine(size_t max_line_length)
     this->seek(offset, SEEK_SET);
     qpdf_offset_t eol = this->findAndSkipNextEOL();
     this->last_offset = offset;
-    size_t line_length = eol - offset;
+    size_t line_length = QIntC::to_size(eol - offset);
     if (line_length < max_line_length)
     {
         buf[line_length] = '\0';
@@ -116,7 +117,8 @@ InputSource::findFirst(char const* start_chars,
         // Search for the first character.
         if ((p = static_cast<char*>(
-                 memchr(p, start_chars[0], bytes_read - (p - buf)))) != 0)
+                 memchr(p, start_chars[0],
+                        bytes_read - QIntC::to_size(p - buf)))) != 0)
         {
             if (p == buf)
             {
@@ -126,7 +128,8 @@ InputSource::findFirst(char const* start_chars,
             if (len != 0)
             {
                 // Make sure it's in range.
-                size_t p_relative_offset = (p - buf) + (buf_offset - offset);
+                size_t p_relative_offset =
+                    QIntC::to_size((p - buf) + (buf_offset - offset));
                 if (p_relative_offset >= len)
                 {
                     // out of range
@@ -198,7 +201,7 @@ InputSource::findLast(char const* start_chars,
         }
         after_found_offset = this->tell();
         cur_offset = after_found_offset;
-        cur_len = len - (cur_offset - offset);
+        cur_len = len - QIntC::to_size((cur_offset - offset));
     }
     if (found)
     {
@@ -30,7 +30,8 @@ InsecureRandomDataProvider::random()
 	// Seed the random number generator with something simple, but
 	// just to be interesting, don't use the unmodified current
 	// time.  It would be better if this were a more secure seed.
-        QUtil::srandom(QUtil::get_current_time() ^ 0xcccc);
+        QUtil::srandom(static_cast<unsigned int>(
+                           QUtil::get_current_time() ^ 0xcccc));
 	this->seeded_random = true;
     }
@@ -197,7 +197,7 @@ JSON::encode_string(std::string const&amp; str)
             }
             else
             {
-                result.append(1, ch);
+                result.append(1, static_cast<char>(ch));
             }
         }
     }
@@ -29,6 +29,7 @@
 #include <qpdf/MD5.hh>
 #include <qpdf/QUtil.hh>
+#include <qpdf/QIntC.hh>
 #include <stdio.h>
 #include <memory.h>
@@ -110,7 +111,7 @@ void MD5::init()
 // context.
 void MD5::update(unsigned char *input,
-		 unsigned int inputLen)
+		 size_t inputLen)
 {
     unsigned int i, index, partLen;
@@ -268,7 +269,7 @@ void MD5::transform(UINT4 state[4], unsigned char block[64])
 // Encodes input (UINT4) into output (unsigned char). Assumes len is a
 // multiple of 4.
-void MD5::encode(unsigned char *output, UINT4 *input, unsigned int len)
+void MD5::encode(unsigned char *output, UINT4 *input, size_t len)
 {
     unsigned int i, j;
@@ -282,7 +283,7 @@ void MD5::encode(unsigned char *output, UINT4 *input, unsigned int len)
 // Decodes input (unsigned char) into output (UINT4). Assumes len is a
 // multiple of 4.
-void MD5::decode(UINT4 *output, unsigned char *input, unsigned int len)
+void MD5::decode(UINT4 *output, unsigned char *input, size_t len)
 {
     unsigned int i, j;
@@ -308,7 +309,7 @@ void MD5::reset()
 void MD5::encodeString(char const* str)
 {
-    unsigned int len = strlen(str);
+    size_t len = strlen(str);
     update(QUtil::unsigned_char_pointer(str), len);
     final();
@@ -319,22 +320,27 @@ void MD5::appendString(char const* input_string)
     update(QUtil::unsigned_char_pointer(input_string), strlen(input_string));
 }
-void MD5::encodeDataIncrementally(char const* data, int len)
+void MD5::encodeDataIncrementally(char const* data, size_t len)
 {
     update(QUtil::unsigned_char_pointer(data), len);
 }
-void MD5::encodeFile(char const *filename, int up_to_size)
+void MD5::encodeFile(char const *filename, qpdf_offset_t up_to_offset)
 {
     unsigned char buffer[1024];
     FILE *file = QUtil::safe_fopen(filename, "rb");
     size_t len;
-    int so_far = 0;
-    int to_try = 1024;
+    size_t so_far = 0;
+    size_t to_try = 1024;
+    size_t up_to_size = 0;
+    if (up_to_offset >= 0)
+    {
+        up_to_size = QIntC::to_size(up_to_offset);
+    }
     do
     {
-	if ((up_to_size >= 0) && ((so_far + to_try) > up_to_size))
+	if ((up_to_offset >= 0) && ((so_far + to_try) > up_to_size))
 	{
 	    to_try = up_to_size - so_far;
 	}
@@ -343,7 +349,7 @@ void MD5::encodeFile(char const *filename, int up_to_size)
 	{
 	    update(buffer, len);
 	    so_far += len;
-	    if ((up_to_size >= 0) && (so_far >= up_to_size))
+	    if ((up_to_offset >= 0) && (so_far >= up_to_size))
 	    {
 		break;
 	    }
@@ -388,7 +394,7 @@ std::string MD5::unparse()
 }
 std::string
-MD5::getDataChecksum(char const* buf, int len)
+MD5::getDataChecksum(char const* buf, size_t len)
 {
     MD5 m;
     m.encodeDataIncrementally(buf, len);
@@ -396,16 +402,16 @@ MD5::getDataChecksum(char const* buf, int len)
 }
 std::string
-MD5::getFileChecksum(char const* filename, int up_to_size)
+MD5::getFileChecksum(char const* filename, qpdf_offset_t up_to_offset)
 {
     MD5 m;
-    m.encodeFile(filename, up_to_size);
+    m.encodeFile(filename, up_to_offset);
     return m.unparse();
 }
 bool
 MD5::checkDataChecksum(char const* const checksum,
-		       char const* buf, int len)
+		       char const* buf, size_t len)
 {
     std::string actual_checksum = getDataChecksum(buf, len);
     return (checksum == actual_checksum);
@@ -413,12 +419,12 @@ MD5::checkDataChecksum(char const* const checksum,
 bool
 MD5::checkFileChecksum(char const* const checksum,
-		       char const* filename, int up_to_size)
+		       char const* filename, qpdf_offset_t up_to_offset)
 {
     bool result = false;
     try
     {
-	std::string actual_checksum = getFileChecksum(filename, up_to_size);
+	std::string actual_checksum = getFileChecksum(filename, up_to_offset);
 	result = (checksum == actual_checksum);
     }
     catch (std::runtime_error const&)
@@ -4,6 +4,7 @@
 #include <assert.h>
 #include <stdexcept>
 #include <qpdf/rijndael.h>
+#include <qpdf/QIntC.hh>
 #include <string>
 #include <stdlib.h>
@@ -11,7 +12,7 @@ bool Pl_AES_PDF::use_static_iv = false;
 Pl_AES_PDF::Pl_AES_PDF(char const* identifier, Pipeline* next,
 		       bool encrypt, unsigned char const* key,
-                       unsigned int key_bytes) :
+                       size_t key_bytes) :
     Pipeline(identifier, next),
     encrypt(encrypt),
     cbc_mode(true),
@@ -22,11 +23,11 @@ Pl_AES_PDF::Pl_AES_PDF(char const* identifier, Pipeline* next,
     use_specified_iv(false),
     disable_padding(false)
 {
-    unsigned int keybits = 8 * key_bytes;
+    size_t keybits = 8 * key_bytes;
     assert(key_bytes == KEYLENGTH(keybits));
     this->key = new unsigned char[key_bytes];
     this->rk = new uint32_t[RKLENGTH(keybits)];
-    unsigned int rk_bytes = RKLENGTH(keybits) * sizeof(uint32_t);
+    size_t rk_bytes = RKLENGTH(keybits) * sizeof(uint32_t);
     std::memcpy(this->key, key, key_bytes);
     std::memset(this->rk, 0, rk_bytes);
     std::memset(this->inbuf, 0, this->buf_size);
@@ -68,7 +69,7 @@ Pl_AES_PDF::setIV(unsigned char const* iv, size_t bytes)
     {
         throw std::logic_error(
             "Pl_AES_PDF: specified initialization vector"
-            " size in bytes must be " + QUtil::int_to_string(bytes));
+            " size in bytes must be " + QUtil::uint_to_string(bytes));
     }
     this->use_specified_iv = true;
     memcpy(this->specified_iv, iv, bytes);
@@ -123,7 +124,7 @@ Pl_AES_PDF::finish()
             // specification, including providing an entire block of padding
             // if the input was a multiple of 16 bytes.
             unsigned char pad =
-                static_cast<unsigned char>(this->buf_size - this->offset);
+                QIntC::to_uchar(this->buf_size - this->offset);
             memset(this->inbuf + this->offset, pad, pad);
             this->offset = this->buf_size;
             flush(false);
@@ -166,7 +167,7 @@ Pl_AES_PDF::initializeVector()
     {
 	for (unsigned int i = 0; i < this->buf_size; ++i)
 	{
-	    this->cbc_block[i] = 14 * (1 + i);
+	    this->cbc_block[i] = static_cast<unsigned char>(14U * (1U + i));
 	}
     }
     else
@@ -106,7 +106,7 @@ Pl_ASCII85Decoder::flush()
     for (int i = 0; i < 5; ++i)
     {
 	lval *= 85;
-	lval += (this->inbuf[i] - 33);
+	lval += (this->inbuf[i] - 33U);
     }
     unsigned char outbuf[4];
@@ -27,7 +27,7 @@ Pl_ASCIIHexDecoder::write(unsigned char* buf, size_t len)
     }
     for (size_t i = 0; i < len; ++i)
     {
-	char ch = toupper(buf[i]);
+	char ch = static_cast<char>(toupper(buf[i]));
 	switch (ch)
 	{
 	  case ' ':
 #include <qpdf/Pl_Count.hh>
+#include <qpdf/QIntC.hh>
 Pl_Count::Pl_Count(char const* identifier, Pipeline* next) :
     Pipeline(identifier, next),
@@ -16,7 +17,7 @@ Pl_Count::write(unsigned char* buf, size_t len)
 {
     if (len)
     {
-	this->count += len;
+	this->count += QIntC::to_offset(len);
 	getNext()->write(buf, len);
 	this->last_char = buf[len - 1];
     }
@@ -2,6 +2,7 @@
 #include <qpdf/QUtil.hh>
 #include <qpdf/QTC.hh>
+#include <qpdf/QIntC.hh>
 #include <setjmp.h>
 #include <stdexcept>
@@ -213,7 +214,7 @@ skip_buffer_input_data(j_decompress_ptr cinfo, long num_bytes)
             "reading jpeg: jpeg library requested"
             " skipping a negative number of bytes");
     }
-    size_t to_skip = static_cast<size_t>(num_bytes);
+    size_t to_skip = QIntC::to_size(num_bytes);
     if ((to_skip > 0) && (to_skip <= cinfo->src->bytes_in_buffer))
     {
         cinfo->src->next_input_byte += to_skip;
@@ -283,15 +284,17 @@ Pl_DCT::compress(void* cinfo_p, Buffer* b)
     jpeg_start_compress(cinfo, TRUE);
-    int width = cinfo->image_width * cinfo->input_components;
+    unsigned int width = cinfo->image_width *
+        QIntC::to_uint(cinfo->input_components);
     size_t expected_size =
-        cinfo->image_height * cinfo->image_width * cinfo->input_components;
+        cinfo->image_height * cinfo->image_width *
+        QIntC::to_uint(cinfo->input_components);
     if (b->getSize() != expected_size)
     {
         throw std::runtime_error(
             "Pl_DCT: image buffer size = " +
-            QUtil::int_to_string(b->getSize()) + "; expected size = " +
-            QUtil::int_to_string(expected_size));
+            QUtil::uint_to_string(b->getSize()) + "; expected size = " +
+            QUtil::uint_to_string(expected_size));
     }
     JSAMPROW row_pointer[1];
     unsigned char* buffer = b->getBuffer();
@@ -326,7 +329,8 @@ Pl_DCT::decompress(void* cinfo_p, Buffer* b)
     (void) jpeg_read_header(cinfo, TRUE);
     (void) jpeg_calc_output_dimensions(cinfo);
-    int width = cinfo->output_width * cinfo->output_components;
+    unsigned int width = cinfo->output_width *
+        QIntC::to_uint(cinfo->output_components);
     JSAMPARRAY buffer = (*cinfo->mem->alloc_sarray)
         (reinterpret_cast<j_common_ptr>(cinfo), JPOOL_IMAGE, width, 1);
@@ -2,6 +2,7 @@
 #include <qpdf/QTC.hh>
 #include <qpdf/QUtil.hh>
+#include <qpdf/QIntC.hh>
 #include <stdexcept>
 #include <string.h>
 #include <assert.h>
@@ -52,22 +53,22 @@ Pl_LZWDecoder::finish()
 void
 Pl_LZWDecoder::sendNextCode()
 {
-    int high = this->byte_pos;
-    int med = (this->byte_pos + 1) % 3;
-    int low = (this->byte_pos + 2) % 3;
+    unsigned int high = this->byte_pos;
+    unsigned int med = (this->byte_pos + 1) % 3;
+    unsigned int low = (this->byte_pos + 2) % 3;
-    int bits_from_high = 8 - this->bit_pos;
-    int bits_from_med = this->code_size - bits_from_high;
-    int bits_from_low = 0;
+    unsigned int bits_from_high = 8 - this->bit_pos;
+    unsigned int bits_from_med = this->code_size - bits_from_high;
+    unsigned int bits_from_low = 0;
     if (bits_from_med > 8)
     {
 	bits_from_low = bits_from_med - 8;
 	bits_from_med = 8;
     }
-    int high_mask = (1 << bits_from_high) - 1;
-    int med_mask = 0xff - ((1 << (8 - bits_from_med)) - 1);
-    int low_mask = 0xff - ((1 << (8 - bits_from_low)) - 1);
-    int code = 0;
+    unsigned int high_mask = (1U << bits_from_high) - 1U;
+    unsigned int med_mask = 0xff - ((1U << (8 - bits_from_med)) - 1U);
+    unsigned int low_mask = 0xff - ((1U << (8 - bits_from_low)) - 1U);
+    unsigned int code = 0;
     code += (this->buf[high] & high_mask) << bits_from_med;
     code += ((this->buf[med] & med_mask) >> (8 - bits_from_med));
     if (bits_from_low)
@@ -94,7 +95,7 @@ Pl_LZWDecoder::sendNextCode()
 }
 unsigned char
-Pl_LZWDecoder::getFirstChar(int code)
+Pl_LZWDecoder::getFirstChar(unsigned int code)
 {
     unsigned char result = '\0';
     if (code < 256)
@@ -130,7 +131,7 @@ Pl_LZWDecoder::addToTable(unsigned char next)
     if (this->last_code < 256)
     {
-	tmp[0] = this->last_code;
+	tmp[0] = static_cast<unsigned char>(this->last_code);
 	last_data = tmp;
 	last_size = 1;
     }
@@ -144,7 +145,7 @@ Pl_LZWDecoder::addToTable(unsigned char next)
         }
 	Buffer& b = table.at(idx);
 	last_data = b.getBuffer();
-	last_size = b.getSize();
+	last_size = QIntC::to_uint(b.getSize());
     }
     else
     {
@@ -161,7 +162,7 @@ Pl_LZWDecoder::addToTable(unsigned char next)
 }
 void
-Pl_LZWDecoder::handleCode(int code)
+Pl_LZWDecoder::handleCode(unsigned int code)
 {
     if (this->eod)
     {
@@ -189,11 +190,11 @@ Pl_LZWDecoder::handleCode(int code)
 	    // be what we read last plus the first character of what
 	    // we're reading now.
 	    unsigned char next = '\0';
-	    unsigned int table_size = table.size();
+	    unsigned int table_size = QIntC::to_uint(table.size());
 	    if (code < 256)
 	    {
 		// just read < 256; last time's next was code
-		next = code;
+		next = static_cast<unsigned char>(code);
 	    }
 	    else if (code > 257)
 	    {
@@ -153,7 +153,7 @@ Pl_PNGFilter::decodeSub()
             left = buffer[i - bpp];
         }
-        buffer[i] += left;
+        buffer[i] = static_cast<unsigned char>(buffer[i] + left);
     }
 }
@@ -167,7 +167,7 @@ Pl_PNGFilter::decodeUp()
     for (unsigned int i = 0; i < this->bytes_per_row; ++i)
     {
         unsigned char up = above_buffer[i];
-        buffer[i] += up;
+        buffer[i] = static_cast<unsigned char>(buffer[i] + up);
     }
 }
@@ -190,7 +190,7 @@ Pl_PNGFilter::decodeAverage()
         }
         up = above_buffer[i];
-        buffer[i] += (left+up) / 2;
+        buffer[i] = static_cast<unsigned char>(buffer[i] + (left+up) / 2);
     }
 }
@@ -214,7 +214,9 @@ Pl_PNGFilter::decodePaeth()
             upper_left = above_buffer[i - bpp];
         }
-        buffer[i] += this->PaethPredictor(left, up, upper_left);
+        buffer[i] = static_cast<unsigned char>(
+            buffer[i] +
+            this->PaethPredictor(left, up, upper_left));
     }
 }
@@ -247,7 +249,8 @@ Pl_PNGFilter::encodeRow()
     {
 	for (unsigned int i = 0; i < this->bytes_per_row; ++i)
 	{
-	    ch = this->cur_row[i] - this->prev_row[i];
+	    ch = static_cast<unsigned char>(
+                this->cur_row[i] - this->prev_row[i]);
 	    getNext()->write(&ch, 1);
 	}
     }
@@ -85,13 +85,13 @@ Pl_RunLength::decode(unsigned char* data, size_t len)
             if (ch < 128)
             {
                 // length represents remaining number of bytes to copy
-                this->length = 1 + ch;
+                this->length = 1U + ch;
                 this->state = st_copying;
             }
             else if (ch > 128)
             {
                 // length represents number of copies of next byte
-                this->length = 257 - ch;
+                this->length = 257U - ch;
                 this->state = st_run;
             }
             else // ch == 128
@@ -491,7 +491,7 @@ QPDF::reconstruct_xref(QPDFExc&amp; e)
         this->m->file->seek(line_start, SEEK_SET);
         QPDFTokenizer::Token t1 = readToken(this->m->file, MAX_LEN);
         qpdf_offset_t token_start =
-            this->m->file->tell() - t1.getValue().length();
+            this->m->file->tell() - toO(t1.getValue().length());
         if (token_start >= next_line_start)
         {
             // don't process yet
@@ -610,7 +610,7 @@ QPDF::read_xref(qpdf_offset_t xref_offset)
         throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), "", 0,
                       "unable to find trailer while reading xref");
     }
-    int size = this->m->trailer.getKey("/Size").getIntValue();
+    int size = this->m->trailer.getKey("/Size").getIntValueAsInt();
     int max_obj = 0;
     if (! this->m->xref_table.empty())
     {
@@ -686,7 +686,7 @@ QPDF::parse_xrefFirst(std::string const&amp; line,
     {
         ++p;
     }
-    bytes = p - start;
+    bytes = toI(p - start);
     obj = QUtil::string_to_int(obj_str.c_str());
     num = QUtil::string_to_int(num_str.c_str());
     return true;
@@ -837,11 +837,11 @@ QPDF::read_xrefTable(qpdf_offset_t xref_offset)
 	    {
 		// Save deleted items until after we've checked the
 		// XRefStm, if any.
-		deleted_items.push_back(QPDFObjGen(i, f2));
+		deleted_items.push_back(QPDFObjGen(toI(i), f2));
 	    }
 	    else
 	    {
-		insertXrefEntry(i, 1, f1, f2);
+		insertXrefEntry(toI(i), 1, f1, f2);
 	    }
 	}
 	qpdf_offset_t pos = this->m->file->tell();
@@ -1006,7 +1006,7 @@ QPDF::processXRefStream(qpdf_offset_t xref_offset, QPDFObjectHandle&amp; xref_obj)
     int max_bytes = sizeof(qpdf_offset_t);
     for (int i = 0; i < 3; ++i)
     {
-	W[i] = W_obj.getArrayItem(i).getIntValue();
+	W[i] = W_obj.getArrayItem(i).getIntValueAsInt();
         if (W[i] > max_bytes)
         {
             throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(),
@@ -1014,7 +1014,7 @@ QPDF::processXRefStream(qpdf_offset_t xref_offset, QPDFObjectHandle&amp; xref_obj)
                           "Cross-reference stream's /W contains"
                           " impossibly large values");
         }
-	entry_size += W[i];
+	entry_size += toS(W[i]);
     }
     if (entry_size == 0)
     {
@@ -1023,7 +1023,7 @@ QPDF::processXRefStream(qpdf_offset_t xref_offset, QPDFObjectHandle&amp; xref_obj)
                       "Cross-reference stream's /W indicates"
                       " entry size of 0");
     }
-    long long max_num_entries =
+    unsigned long long max_num_entries =
         static_cast<unsigned long long>(-1) / entry_size;
     std::vector<long long> indx;
@@ -1063,20 +1063,20 @@ QPDF::processXRefStream(qpdf_offset_t xref_offset, QPDFObjectHandle&amp; xref_obj)
 	indx.push_back(size);
     }
-    long long num_entries = 0;
-    for (unsigned int i = 1; i < indx.size(); i += 2)
+    size_t num_entries = 0;
+    for (size_t i = 1; i < indx.size(); i += 2)
     {
-        if (indx.at(i) > max_num_entries - num_entries)
+        if (indx.at(i) > QIntC::to_longlong(max_num_entries - num_entries))
         {
             throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(),
                           "xref stream", xref_offset,
                           "Cross-reference stream claims to contain"
                           " too many entries: " +
                           QUtil::int_to_string(indx.at(i)) + " " +
-                          QUtil::int_to_string(max_num_entries) + " " +
-                          QUtil::int_to_string(num_entries));
+                          QUtil::uint_to_string(max_num_entries) + " " +
+                          QUtil::uint_to_string(num_entries));
         }
-	num_entries += indx.at(i);
+	num_entries += toS(indx.at(i));
     }
     // entry_size and num_entries have both been validated to ensure
@@ -1091,8 +1091,8 @@ QPDF::processXRefStream(qpdf_offset_t xref_offset, QPDFObjectHandle&amp; xref_obj)
 	QPDFExc x(qpdf_e_damaged_pdf, this->m->file->getName(),
 		  "xref stream", xref_offset,
 		  "Cross-reference stream data has the wrong size;"
-		  " expected = " + QUtil::int_to_string(expected_size) +
-		  "; actual = " + QUtil::int_to_string(actual_size));
+		  " expected = " + QUtil::uint_to_string(expected_size) +
+		  "; actual = " + QUtil::uint_to_string(actual_size));
 	if (expected_size > actual_size)
 	{
 	    throw x;
@@ -1103,7 +1103,7 @@ QPDF::processXRefStream(qpdf_offset_t xref_offset, QPDFObjectHandle&amp; xref_obj)
 	}
     }
-    int cur_chunk = 0;
+    size_t cur_chunk = 0;
     int chunk_count = 0;
     bool saw_first_compressed_object = false;
@@ -1112,7 +1112,7 @@ QPDF::processXRefStream(qpdf_offset_t xref_offset, QPDFObjectHandle&amp; xref_obj)
     // not overflow any buffers here.  We know that entry_size *
     // num_entries is equal to the size of the buffer.
     unsigned char const* data = bp->getBuffer();
-    for (int i = 0; i < num_entries; ++i)
+    for (size_t i = 0; i < num_entries; ++i)
     {
 	// Read this entry
 	unsigned char const* entry = data + (entry_size * i);
@@ -1129,7 +1129,7 @@ QPDF::processXRefStream(qpdf_offset_t xref_offset, QPDFObjectHandle&amp; xref_obj)
 	    for (int k = 0; k < W[j]; ++k)
 	    {
 		fields[j] <<= 8;
-		fields[j] += static_cast<int>(*p++);
+		fields[j] += toI(*p++);
 	    }
 	}
@@ -1137,7 +1137,7 @@ QPDF::processXRefStream(qpdf_offset_t xref_offset, QPDFObjectHandle&amp; xref_obj)
 	// based on /Index.  The generation number is 0 unless this is
 	// an uncompressed object record, in which case the generation
 	// number appears as the third field.
-	int obj = indx.at(cur_chunk) + chunk_count;
+	int obj = toI(indx.at(cur_chunk)) + chunk_count;
 	++chunk_count;
 	if (chunk_count >= indx.at(cur_chunk + 1))
 	{
@@ -1161,8 +1161,8 @@ QPDF::processXRefStream(qpdf_offset_t xref_offset, QPDFObjectHandle&amp; xref_obj)
 	    // This is needed by checkLinearization()
 	    this->m->first_xref_item_offset = xref_offset;
 	}
-	insertXrefEntry(obj, static_cast<int>(fields[0]),
-                        fields[1], static_cast<int>(fields[2]));
+	insertXrefEntry(obj, toI(fields[0]),
+                        fields[1], toI(fields[2]));
     }
     if (! this->m->trailer.isInitialized())
@@ -1395,7 +1395,7 @@ QPDF::getObjectCount()
     {
 	og = (*(this->m->obj_cache.rbegin())).first;
     }
-    return og.getObj();
+    return toS(og.getObj());
 }
 std::vector<QPDFObjectHandle>
@@ -1570,8 +1570,8 @@ QPDF::readObject(PointerHolder&lt;InputSource&gt; input,
                                   "an integer");
                 }
-                length = length_obj.getIntValue();
-                input->seek(stream_offset + length, SEEK_SET);
+                length = toS(length_obj.getUIntValue());
+                input->seek(stream_offset + toO(length), SEEK_SET);
                 if (! (readToken(input) ==
                        QPDFTokenizer::Token(
                            QPDFTokenizer::tt_word, "endstream")))
@@ -1641,7 +1641,7 @@ QPDF::recoverStreamLength(PointerHolder&lt;InputSource&gt; input,
     size_t length = 0;
     if (this->m->file->findFirst("end", stream_offset, 0, ef))
     {
-        length = this->m->file->tell() - stream_offset;
+        length = toS(this->m->file->tell() - stream_offset);
         // Reread endstream but, if it was endobj, don't skip that.
         QPDFTokenizer::Token t = readToken(this->m->file);
         if (t.getValue() == "endobj")
@@ -1652,7 +1652,7 @@ QPDF::recoverStreamLength(PointerHolder&lt;InputSource&gt; input,
     if (length)
     {
-	int this_obj_offset = 0;
+	qpdf_offset_t this_obj_offset = 0;
 	QPDFObjGen this_obj(0, 0);
 	// Make sure this is inside this object
@@ -1700,7 +1700,7 @@ QPDF::recoverStreamLength(PointerHolder&lt;InputSource&gt; input,
         warn(QPDFExc(qpdf_e_damaged_pdf, input->getName(),
                      this->m->last_object_description, stream_offset,
                      "recovered stream length: " +
-                     QUtil::int_to_string(length)));
+                     QUtil::uint_to_string(length)));
     }
     QTC::TC("qpdf", "QPDF recovered stream length");
@@ -2027,8 +2027,8 @@ QPDF::resolveObjectsInStream(int obj_stream_number)
 		      " has incorrect keys");
     }
-    int n = dict.getKey("/N").getIntValue();
-    int first = dict.getKey("/First").getIntValue();
+    int n = dict.getKey("/N").getIntValueAsInt();
+    int first = dict.getKey("/First").getIntValueAsInt();
     std::map<int, int> offsets;
@@ -2052,7 +2052,7 @@ QPDF::resolveObjectsInStream(int obj_stream_number)
 	}
 	int num = QUtil::string_to_int(tnum.getValue().c_str());
-	int offset = QUtil::string_to_ll(toffset.getValue().c_str());
+	int offset = QUtil::string_to_int(toffset.getValue().c_str());
 	offsets[num] = offset + first;
     }
@@ -2087,7 +2087,7 @@ QPDF::resolveObjectsInStream(int obj_stream_number)
 QPDFObjectHandle
 QPDF::makeIndirectObject(QPDFObjectHandle oh)
 {
-    int max_objid = getObjectCount();
+    int max_objid = toI(getObjectCount());
     QPDFObjGen next(max_objid + 1, 0);
     this->m->obj_cache[next] =
 	ObjCache(QPDFObjectHandle::ObjAccessor::getObject(oh), -1, -1);
@@ -2509,7 +2509,7 @@ QPDF::getExtensionLevel()
                 obj = obj.getKey("/ExtensionLevel");
                 if (obj.isInteger())
                 {
-                    result = obj.getIntValue();
+                    result = obj.getIntValueAsInt();
                 }
             }
         }
@@ -2733,8 +2733,9 @@ QPDF::pipeStreamData(int objid, int generation,
                      bool suppress_warnings,
                      bool will_retry)
 {
-    bool is_attachment_stream = this->m->attachment_streams.count(
-        QPDFObjGen(objid, generation));
+    bool is_attachment_stream = (
+        this->m->attachment_streams.count(
+            QPDFObjGen(objid, generation)) > 0);
     return pipeStreamData(
         this->m->encp, this->m->file, *this,
         objid, generation, offset, length,
@@ -2746,7 +2747,7 @@ bool
 QPDF::pipeForeignStreamData(
     PointerHolder<ForeignStreamData> foreign,
     Pipeline* pipeline,
-    unsigned long encode_flags,
+    int encode_flags,
     qpdf_stream_decode_level_e decode_level)
 {
     if (foreign->encp->encrypted)
@@ -114,9 +114,9 @@ QPDFAcroFormDocumentHelper::analyze()
     // bidirectionally to fields.
     std::set<QPDFObjGen> visited;
-    size_t nfields = fields.getArrayNItems();
+    int nfields = fields.getArrayNItems();
     QPDFObjectHandle null(QPDFObjectHandle::newNull());
-    for (size_t i = 0; i < nfields; ++i)
+    for (int i = 0; i < nfields; ++i)
     {
         traverseField(fields.getArrayItem(i), null, 0, visited);
     }
@@ -216,8 +216,8 @@ QPDFAcroFormDocumentHelper::traverseField(
     if (kids.isArray())
     {
         is_field = true;
-        size_t nkids = kids.getArrayNItems();
-        for (size_t k = 0; k < nkids; ++k)
+        int nkids = kids.getArrayNItems();
+        for (int k = 0; k < nkids; ++k)
         {
             traverseField(kids.getArrayItem(k), field, 1 + depth, visited);
         }
@@ -52,7 +52,7 @@ int
 QPDFAnnotationObjectHelper::getFlags()
 {
     QPDFObjectHandle flags_obj = this->oh.getKey("/F");
-    return flags_obj.isInteger() ? flags_obj.getIntValue() : 0;
+    return flags_obj.isInteger() ? flags_obj.getIntValueAsInt() : 0;
 }
 QPDFObjectHandle
@@ -4,6 +4,7 @@
 #include <qpdf/QPDFAnnotationObjectHelper.hh>
 #include <qpdf/QUtil.hh>
 #include <qpdf/Pl_QPDFTokenizer.hh>
+#include <qpdf/QIntC.hh>
 #include <stdlib.h>
 QPDFFormFieldObjectHelper::Members::~Members()
@@ -189,7 +190,7 @@ QPDFFormFieldObjectHelper::getQuadding()
     if (fv.isInteger())
     {
         QTC::TC("qpdf", "QPDFFormFieldObjectHelper Q present");
-        result = static_cast<int>(fv.getIntValue());
+        result = QIntC::to_int(fv.getIntValue());
     }
     return result;
 }
@@ -198,7 +199,7 @@ int
 QPDFFormFieldObjectHelper::getFlags()
 {
     QPDFObjectHandle f = getInheritableFieldValue("/Ff");
-    return f.isInteger() ? f.getIntValue() : 0;
+    return f.isInteger() ? f.getIntValueAsInt() : 0;
 }
 bool
@@ -245,8 +246,8 @@ QPDFFormFieldObjectHelper::getChoices()
     QPDFObjectHandle opt = getInheritableFieldValue("/Opt");
     if (opt.isArray())
     {
-        size_t n = opt.getArrayNItems();
-        for (size_t i = 0; i < n; ++i)
+        int n = opt.getArrayNItems();
+        for (int i = 0; i < n; ++i)
         {
             QPDFObjectHandle item = opt.getArrayItem(i);
             if (item.isString())
@@ -631,8 +632,8 @@ ValueSetter::writeAppearance()
         {
             // Try to make the found item the second one, but
             // adjust for under/overflow.
-            int wanted_first = found_idx - 1;
-            int wanted_last = found_idx + max_rows - 2;
+            int wanted_first = QIntC::to_int(found_idx) - 1;
+            int wanted_last = QIntC::to_int(found_idx + max_rows) - 2;
             QTC::TC("qpdf", "QPDFFormFieldObjectHelper list found");
             while (wanted_first < 0)
             {
@@ -640,7 +641,7 @@ ValueSetter::writeAppearance()
                 ++wanted_first;
                 ++wanted_last;
             }
-            while (wanted_last >= static_cast<int>(nopt))
+            while (wanted_last >= QIntC::to_int(nopt))
             {
                 QTC::TC("qpdf", "QPDFFormFieldObjectHelper list last too high");
                 if (wanted_first > 0)
@@ -650,8 +651,9 @@ ValueSetter::writeAppearance()
                 --wanted_last;
             }
             highlight = true;
-            highlight_idx = found_idx - wanted_first;
-            for (int i = wanted_first; i <= wanted_last; ++i)
+            highlight_idx = found_idx - QIntC::to_size(wanted_first);
+            for (size_t i = QIntC::to_size(wanted_first);
+                 i <= QIntC::to_size(wanted_last); ++i)
             {
                 lines.push_back(opt.at(i));
             }
@@ -672,13 +674,15 @@ ValueSetter::writeAppearance()
     // Write the lines centered vertically, highlighting if needed
     size_t nlines = lines.size();
-    double dy = bbox.ury - ((bbox.ury - bbox.lly - (nlines * tfh)) / 2.0);
+    double dy = bbox.ury - ((bbox.ury - bbox.lly -
+                             (static_cast<double>(nlines) * tfh)) / 2.0);
     if (highlight)
     {
         write("q\n0.85 0.85 0.85 rg\n" +
               QUtil::double_to_string(bbox.llx) + " " +
-              QUtil::double_to_string(bbox.lly + dy -
-                                      (tfh * (highlight_idx + 1))) + " " +
+              QUtil::double_to_string(
+                  bbox.lly + dy -
+                  (tfh * (static_cast<double>(highlight_idx + 1)))) + " " +
               QUtil::double_to_string(bbox.urx - bbox.llx) + " " +
               QUtil::double_to_string(tfh) +
               " re f\nQ\n");
@@ -693,8 +697,10 @@ ValueSetter::writeAppearance()
         // which doesn't seem really worth the effort.
         if (i == 0)
         {
-            write(QUtil::double_to_string(bbox.llx + dx) + " " +
-                  QUtil::double_to_string(bbox.lly + dy) + " Td\n");
+            write(QUtil::double_to_string(bbox.llx + static_cast<double>(dx)) +
+                  " " +
+                  QUtil::double_to_string(bbox.lly + static_cast<double>(dy)) +
+                  " Td\n");
         }
         else
         {
@@ -30,8 +30,8 @@ QPDFNameTreeObjectHelper::updateMap(QPDFObjectHandle oh)
     QPDFObjectHandle names = oh.getKey("/Names");
     if (names.isArray())
     {
-        size_t nitems = names.getArrayNItems();
-        size_t i = 0;
+        int nitems = names.getArrayNItems();
+        int i = 0;
         while (i < nitems - 1)
         {
             QPDFObjectHandle name = names.getArrayItem(i);
@@ -47,8 +47,8 @@ QPDFNameTreeObjectHelper::updateMap(QPDFObjectHandle oh)
     QPDFObjectHandle kids = oh.getKey("/Kids");
     if (kids.isArray())
     {
-        size_t nitems = kids.getArrayNItems();
-        for (size_t i = 0; i < nitems; ++i)
+        int nitems = kids.getArrayNItems();
+        for (int i = 0; i < nitems; ++i)
         {
             updateMap(kids.getArrayItem(i));
         }
@@ -26,8 +26,8 @@ QPDFNumberTreeObjectHelper::updateMap(QPDFObjectHandle oh)
     QPDFObjectHandle nums = oh.getKey("/Nums");
     if (nums.isArray())
     {
-        size_t nitems = nums.getArrayNItems();
-        size_t i = 0;
+        int nitems = nums.getArrayNItems();
+        int i = 0;
         while (i < nitems - 1)
         {
             QPDFObjectHandle num = nums.getArrayItem(i);
@@ -43,8 +43,8 @@ QPDFNumberTreeObjectHelper::updateMap(QPDFObjectHandle oh)
     QPDFObjectHandle kids = oh.getKey("/Kids");
     if (kids.isArray())
     {
-        size_t nitems = kids.getArrayNItems();
-        for (size_t i = 0; i < nitems; ++i)
+        int nitems = kids.getArrayNItems();
+        for (int i = 0; i < nitems; ++i)
         {
             updateMap(kids.getArrayItem(i));
         }
@@ -22,6 +22,7 @@
 #include <qpdf/QTC.hh>
 #include <qpdf/QUtil.hh>
+#include <qpdf/QIntC.hh>
 #include <stdexcept>
 #include <stdlib.h>
@@ -643,7 +644,7 @@ QPDFObjectHandle::isRectangle()
     {
         return false;
     }
-    for (size_t i = 0; i < 4; ++i)
+    for (int i = 0; i < 4; ++i)
     {
         if (! getArrayItem(i).isNumber())
         {
@@ -664,7 +665,7 @@ QPDFObjectHandle::isMatrix()
     {
         return false;
     }
-    for (size_t i = 0; i < 6; ++i)
+    for (int i = 0; i < 6; ++i)
     {
         if (! getArrayItem(i).isNumber())
         {
@@ -1013,7 +1014,7 @@ QPDFObjectHandle::getUniqueResourceName(std::string const&amp; prefix,
                                         int& min_suffix)
 {
     std::set<std::string> names = getResourceNames();
-    int max_suffix = min_suffix + names.size();
+    int max_suffix = min_suffix + QIntC::to_int(names.size());
     while (min_suffix <= max_suffix)
     {
         std::string candidate = prefix + QUtil::int_to_string(min_suffix);
@@ -1374,7 +1375,7 @@ QPDFObjectHandle::rotatePage(int angle, bool relative)
             if (cur_obj.getKey("/Rotate").isInteger())
             {
                 found_rotate = true;
-                old_angle = cur_obj.getKey("/Rotate").getIntValue();
+                old_angle = cur_obj.getKey("/Rotate").getIntValueAsInt();
             }
             else if (cur_obj.getKey("/Parent").isDictionary())
             {
@@ -1506,7 +1507,7 @@ QPDFObjectHandle::parse(std::string const&amp; object_str,
     bool empty = false;
     QPDFObjectHandle result =
         parse(input, object_description, tokenizer, empty, 0, 0);
-    size_t offset = input->tell();
+    size_t offset = QIntC::to_size(input->tell());
     while (offset < object_str.length())
     {
         if (! isspace(object_str.at(offset)))
@@ -1618,7 +1619,7 @@ QPDFObjectHandle::parseContentStream_data(
     QPDFTokenizer tokenizer;
     tokenizer.allowEOF();
     bool empty = false;
-    while (static_cast<size_t>(input->tell()) < length)
+    while (QIntC::to_size(input->tell()) < length)
     {
         QPDFObjectHandle obj =
             parseInternal(input, "content", tokenizer, empty, 0, 0, true);
@@ -1863,8 +1864,8 @@ QPDFObjectHandle::parseInternal(PointerHolder&lt;InputSource&gt; input,
 		    // Try to resolve indirect objects
 		    object = newIndirect(
 			context,
-			olist.at(olist.size() - 2).getIntValue(),
-			olist.at(olist.size() - 1).getIntValue());
+			olist.at(olist.size() - 2).getIntValueAsInt(),
+			olist.at(olist.size() - 1).getIntValueAsInt());
 		    olist.pop_back();
 		    olist.pop_back();
 		}
@@ -100,7 +100,7 @@ QPDFOutlineObjectHelper::getCount()
     int count = 0;
     if (this->oh.hasKey("/Count"))
     {
-        count = this->oh.getKey("/Count").getIntValue();
+        count = this->oh.getKey("/Count").getIntValueAsInt();
     }
     return count;
 }
@@ -117,7 +117,7 @@ QPDFPageDocumentHelper::flattenAnnotationsForPage(
         page.getObjectHandle().getKey("/Rotate");
     if (rotate_obj.isInteger() && rotate_obj.getIntValue())
     {
-        rotate = rotate_obj.getIntValue();
+        rotate = rotate_obj.getIntValueAsInt();
     }
     int next_fx = 1;
     for (std::vector<QPDFAnnotationObjectHelper>::iterator iter =
@@ -6,6 +6,7 @@
 #include <qpdf/QUtil.hh>
 #include <qpdf/QPDFExc.hh>
 #include <qpdf/QPDFMatrix.hh>
+#include <qpdf/QIntC.hh>
 class ContentProvider: public QPDFObjectHandle::StreamDataProvider
 {
@@ -236,7 +237,9 @@ InlineImageTracker::handleToken(QPDFTokenizer::Token const&amp; token)
                 b.finish();
                 QPDFObjectHandle dict =
                     convertIIDict(QPDFObjectHandle::parse(dict_str));
-                dict.replaceKey("/Length", QPDFObjectHandle::newInteger(len));
+                dict.replaceKey(
+                    "/Length",
+                    QPDFObjectHandle::newInteger(QIntC::to_longlong(len)));
                 std::string name = resources.getUniqueResourceName(
                     "/IIm", this->min_suffix);
                 QPDFObjectHandle image = QPDFObjectHandle::newStream(
@@ -391,8 +394,8 @@ QPDFPageObjectHelper::getAnnotations(std::string const&amp; only_subtype)
     QPDFObjectHandle annots = this->oh.getKey("/Annots");
     if (annots.isArray())
     {
-        size_t nannots = annots.getArrayNItems();
-        for (size_t i = 0; i < nannots; ++i)
+        int nannots = annots.getArrayNItems();
+        for (int i = 0; i < nannots; ++i)
         {
             QPDFObjectHandle annot = annots.getArrayItem(i);
             if (only_subtype.empty() ||
@@ -579,7 +582,7 @@ QPDFPageObjectHelper::getMatrixForTransformations(bool invert)
                         ? scale_obj.getNumericValue()
                         : 1.0);
         int rotate = (rotate_obj.isInteger()
-                      ? rotate_obj.getIntValue()
+                      ? rotate_obj.getIntValueAsInt()
                       : 0);
         if (invert)
         {
@@ -8,6 +8,7 @@
 #include <qpdf/QPDFExc.hh>
 #include <qpdf/QUtil.hh>
 #include <qpdf/QPDFObjectHandle.hh>
+#include <qpdf/QIntC.hh>
 #include <stdexcept>
 #include <stdlib.h>
@@ -715,7 +716,7 @@ QPDFTokenizer::findEI(PointerHolder&lt;InputSource&gt; input)
         {
             break;
         }
-        this->m->inline_image_bytes = input->tell() - pos - 2;
+        this->m->inline_image_bytes = QIntC::to_size(input->tell() - pos - 2);
         QPDFTokenizer check;
         bool found_bad = false;
@@ -19,6 +19,7 @@
 #include <qpdf/QPDFObjectHandle.hh>
 #include <qpdf/QPDF_Name.hh>
 #include <qpdf/QPDF_String.hh>
+#include <qpdf/QIntC.hh>
 #include <algorithm>
 #include <stdlib.h>
@@ -722,11 +723,11 @@ QPDFWriter::copyEncryptionParameters(QPDF&amp; qpdf)
         this->m->id1 =
             trailer.getKey("/ID").getArrayItem(0).getStringValue();
 	QPDFObjectHandle encrypt = trailer.getKey("/Encrypt");
-	int V = encrypt.getKey("/V").getIntValue();
+	int V = encrypt.getKey("/V").getIntValueAsInt();
 	int key_len = 5;
 	if (V > 1)
 	{
-	    key_len = encrypt.getKey("/Length").getIntValue() / 8;
+	    key_len = encrypt.getKey("/Length").getIntValueAsInt() / 8;
 	}
 	if (encrypt.hasKey("/EncryptMetadata") &&
 	    encrypt.getKey("/EncryptMetadata").isBool())
@@ -763,9 +764,9 @@ QPDFWriter::copyEncryptionParameters(QPDF&amp; qpdf)
 	setEncryptionParametersInternal(
 	    V,
-	    encrypt.getKey("/R").getIntValue(),
+	    encrypt.getKey("/R").getIntValueAsInt(),
     	    key_len,
-	    encrypt.getKey("/P").getIntValue(),
+	    encrypt.getKey("/P").getIntValueAsInt(),
 	    encrypt.getKey("/O").getStringValue(),
 	    encrypt.getKey("/U").getStringValue(),
             OE,
@@ -884,7 +885,7 @@ QPDFWriter::compareVersions(int major1, int minor1,
 void
 QPDFWriter::setEncryptionParametersInternal(
-    int V, int R, int key_len, long P,
+    int V, int R, int key_len, int P,
     std::string const& O, std::string const& U,
     std::string const& OE, std::string const& UE, std::string const& Perms,
     std::string const& id1, std::string const& user_password,
@@ -972,10 +973,10 @@ QPDFWriter::setDataKey(int objid)
         this->m->encrypt_use_aes, this->m->encryption_V, this->m->encryption_R);
 }
-int
-QPDFWriter::bytesNeeded(unsigned long long n)
+unsigned int
+QPDFWriter::bytesNeeded(long long n)
 {
-    int bytes = 0;
+    unsigned int bytes = 0;
     while (n)
     {
 	++bytes;
@@ -1121,7 +1122,7 @@ QPDFWriter::pushEncryptionFilter()
 	{
 	    p = new Pl_RC4("rc4 stream encryption", this->m->pipeline,
 			   QUtil::unsigned_char_pointer(this->m->cur_data_key),
-			   this->m->cur_data_key.length());
+			   QIntC::to_int(this->m->cur_data_key.length()));
 	}
 	pushPipeline(p);
     }
@@ -1356,7 +1357,8 @@ QPDFWriter::writeTrailer(trailer_e which, int size, bool xref_stream,
 		    writeString(" /Prev ");
 		    qpdf_offset_t pos = this->m->pipeline->getCount();
 		    writeString(QUtil::int_to_string(prev));
-		    int nspaces = pos - this->m->pipeline->getCount() + 21;
+		    int nspaces =
+                        QIntC::to_int(pos - this->m->pipeline->getCount() + 21);
 		    if (nspaces < 0)
                     {
                         throw std::logic_error(
@@ -1430,19 +1432,18 @@ QPDFWriter::writeTrailer(trailer_e which, int size, bool xref_stream,
 }
 void
-QPDFWriter::unparseObject(QPDFObjectHandle object, int level,
-			  unsigned int flags)
+QPDFWriter::unparseObject(QPDFObjectHandle object, int level, int flags)
 {
     unparseObject(object, level, flags, 0, false);
 }
 void
 QPDFWriter::unparseObject(QPDFObjectHandle object, int level,
-			  unsigned int flags, size_t stream_length,
+			  int flags, size_t stream_length,
                           bool compress)
 {
     QPDFObjGen old_og = object.getObjGen();
-    unsigned int child_flags = flags & ~f_stream;
+    int child_flags = flags & ~f_stream;
     std::string indent;
     for (int i = 0; i < level; ++i)
@@ -1687,7 +1688,7 @@ QPDFWriter::unparseObject(QPDFObjectHandle object, int level,
 	    if (this->m->direct_stream_lengths)
 	    {
-		writeString(QUtil::int_to_string(stream_length));
+		writeString(QUtil::uint_to_string(stream_length));
 	    }
 	    else
 	    {
@@ -1818,7 +1819,7 @@ QPDFWriter::unparseObject(QPDFObjectHandle object, int level,
 	writeString("\nstream\n");
 	pushEncryptionFilter();
 	writeBuffer(stream_data);
-	char last_char = this->m->pipeline->getLastChar();
+	unsigned char last_char = this->m->pipeline->getLastChar();
 	popPipelineStack();
         if (this->m->newline_before_endstream ||
@@ -1861,7 +1862,7 @@ QPDFWriter::unparseObject(QPDFObjectHandle object, int level,
 		char* tmp = QUtil::copy_string(val);
 		size_t vlen = val.length();
 		RC4 rc4(QUtil::unsigned_char_pointer(this->m->cur_data_key),
-			this->m->cur_data_key.length());
+			QIntC::to_int(this->m->cur_data_key.length()));
 		rc4.process(QUtil::unsigned_char_pointer(tmp), vlen);
 		val = QPDF_String(std::string(tmp, vlen)).unparse();
 		delete [] tmp;
@@ -1883,14 +1884,14 @@ void
 QPDFWriter::writeObjectStreamOffsets(std::vector<qpdf_offset_t>& offsets,
 				     int first_obj)
 {
-    for (unsigned int i = 0; i < offsets.size(); ++i)
+    for (size_t i = 0; i < offsets.size(); ++i)
     {
 	if (i != 0)
 	{
 	    writeStringQDF("\n");
 	    writeStringNoQDF(" ");
 	}
-	writeString(QUtil::int_to_string(i + first_obj));
+	writeString(QUtil::uint_to_string(i + QIntC::to_size(first_obj)));
 	writeString(" ");
 	writeString(QUtil::int_to_string(offsets.at(i)));
     }
@@ -2015,13 +2016,13 @@ QPDFWriter::writeObjectStream(QPDFObjectHandle object)
     writeStringQDF("\n ");
     size_t length = stream_buffer->getSize();
     adjustAESStreamLength(length);
-    writeString(" /Length " + QUtil::int_to_string(length));
+    writeString(" /Length " + QUtil::uint_to_string(length));
     writeStringQDF("\n ");
     if (compressed)
     {
 	writeString(" /Filter /FlateDecode");
     }
-    writeString(" /N " + QUtil::int_to_string(offsets.size()));
+    writeString(" /N " + QUtil::uint_to_string(offsets.size()));
     writeStringQDF("\n ");
     writeString(" /First " + QUtil::int_to_string(first));
     if (! object.isNull())
@@ -2120,7 +2121,7 @@ QPDFWriter::writeObject(QPDFObjectHandle object, int object_stream_index)
 	    }
 	}
 	openObject(new_id + 1);
-	writeString(QUtil::int_to_string(this->m->cur_stream_length));
+	writeString(QUtil::uint_to_string(this->m->cur_stream_length));
 	closeObject(new_id + 1);
     }
 }
@@ -2308,12 +2309,12 @@ QPDFWriter::generateObjectStreams()
     std::vector<QPDFObjGen> const& eligible =
         QPDF::Writer::getCompressibleObjGens(this->m->pdf);
-    unsigned int n_object_streams = (eligible.size() + 99) / 100;
+    size_t n_object_streams = (eligible.size() + 99U) / 100U;
     if (n_object_streams == 0)
     {
         return;
     }
-    unsigned int n_per = eligible.size() / n_object_streams;
+    size_t n_per = eligible.size() / n_object_streams;
     if (n_per * n_object_streams < eligible.size())
     {
 	++n_per;
@@ -2640,7 +2641,7 @@ QPDFWriter::doWriteSetup()
 	this->m->object_stream_to_objects[stream].insert(obj);
 	this->m->max_ostream_index =
 	    std::max(this->m->max_ostream_index,
-		     static_cast<int>(
+		     QIntC::to_int(
                          this->m->object_stream_to_objects[stream].size()) - 1);
     }
@@ -2672,7 +2673,7 @@ QPDFWriter::write()
     // files, we write two passes. events_expected is an
     // approximation, but it's good enough for progress reporting,
     // which is mostly a guess anyway.
-    this->m->events_expected = (
+    this->m->events_expected = QIntC::to_int(
         this->m->pdf.getObjectCount() * (this->m->linearized ? 3 : 2));
     prepareFileForWrite();
@@ -2785,7 +2786,7 @@ QPDFWriter::writeHintStream(int hint_id)
     }
     writeString(" /Length ");
     adjustAESStreamLength(hlen);
-    writeString(QUtil::int_to_string(hlen));
+    writeString(QUtil::uint_to_string(hlen));
     writeString(" >>\nstream\n");
     if (this->m->encrypted)
@@ -2794,7 +2795,7 @@ QPDFWriter::writeHintStream(int hint_id)
     }
     pushEncryptionFilter();
     writeBuffer(hint_buffer);
-    char last_char = this->m->pipeline->getLastChar();
+    unsigned char last_char = this->m->pipeline->getLastChar();
     popPipelineStack();
     if (last_char != '\n')
@@ -2872,11 +2873,11 @@ QPDFWriter::writeXRefStream(int xref_id, int max_id, qpdf_offset_t max_offset,
     qpdf_offset_t space_before_zero = xref_offset - 1;
     // field 1 contains offsets and object stream identifiers
-    int f1_size = std::max(bytesNeeded(max_offset + hint_length),
-			   bytesNeeded(max_id));
+    unsigned int f1_size = std::max(bytesNeeded(max_offset + hint_length),
+                                    bytesNeeded(max_id));
     // field 2 contains object stream indices
-    int f2_size = bytesNeeded(this->m->max_ostream_index);
+    unsigned int f2_size = bytesNeeded(this->m->max_ostream_index);
     unsigned int esize = 1 + f1_size + f2_size;
@@ -2925,15 +2926,15 @@ QPDFWriter::writeXRefStream(int xref_id, int max_id, qpdf_offset_t max_offset,
 		    offset += hint_length;
 		}
 		writeBinary(1, 1);
-		writeBinary(offset, f1_size);
+		writeBinary(QIntC::to_ulonglong(offset), f1_size);
 		writeBinary(0, f2_size);
 	    }
 	    break;
 	  case 2:
 	    writeBinary(2, 1);
-	    writeBinary(e.getObjStreamNumber(), f1_size);
-	    writeBinary(e.getObjStreamIndex(), f2_size);
+	    writeBinary(QIntC::to_ulonglong(e.getObjStreamNumber()), f1_size);
+	    writeBinary(QIntC::to_ulonglong(e.getObjStreamIndex()), f2_size);
 	    break;
 	  default:
@@ -2949,7 +2950,7 @@ QPDFWriter::writeXRefStream(int xref_id, int max_id, qpdf_offset_t max_offset,
     writeStringQDF("\n ");
     writeString(" /Type /XRef");
     writeStringQDF("\n ");
-    writeString(" /Length " + QUtil::int_to_string(xref_data->getSize()));
+    writeString(" /Length " + QUtil::uint_to_string(xref_data->getSize()));
     if (compressed)
     {
 	writeStringQDF("\n ");
@@ -2977,7 +2978,7 @@ QPDFWriter::writeXRefStream(int xref_id, int max_id, qpdf_offset_t max_offset,
 }
 int
-QPDFWriter::calculateXrefStreamPadding(int xref_bytes)
+QPDFWriter::calculateXrefStreamPadding(qpdf_offset_t xref_bytes)
 {
     // This routine is called right after a linearization first pass
     // xref stream has been written without compression.  Calculate
@@ -2987,7 +2988,7 @@ QPDFWriter::calculateXrefStreamPadding(int xref_bytes)
     // input by 6 bytes plus 5 bytes per 16K, and then we'll add 10
     // extra bytes for number length increases.
-    return 16 + (5 * ((xref_bytes + 16383) / 16384));
+    return QIntC::to_int(16 + (5 * ((xref_bytes + 16383) / 16384)));
 }
 void
@@ -3062,7 +3063,8 @@ QPDFWriter::writeLinearized()
     //
     // Second half objects
-    int second_half_uncompressed = part7.size() + part8.size() + part9.size();
+    int second_half_uncompressed =
+        QIntC::to_int(part7.size() + part8.size() + part9.size());
     int second_half_first_obj = 1;
     int after_second_half = 1 + second_half_uncompressed;
     this->m->next_objid = after_second_half;
@@ -3093,7 +3095,7 @@ QPDFWriter::writeLinearized()
 	first_half_xref = this->m->next_objid++;
     }
     int part4_first_obj = this->m->next_objid;
-    this->m->next_objid += part4.size();
+    this->m->next_objid += QIntC::to_int(part4.size());
     int after_part4 = this->m->next_objid;
     if (this->m->encrypted)
     {
@@ -3101,7 +3103,7 @@ QPDFWriter::writeLinearized()
     }
     int hint_id = this->m->next_objid++;
     int part6_first_obj = this->m->next_objid;
-    this->m->next_objid += part6.size();
+    this->m->next_objid += QIntC::to_int(part6.size());
     int after_part6 = this->m->next_objid;
     // Assign numbers to all compressed objects in the first half
     std::vector<QPDFObjectHandle>* vecs1[] = {&part4, &part6};
@@ -3188,7 +3190,7 @@ QPDFWriter::writeLinearized()
                 this->m->pdf.getAllPages();
 	    int first_page_object =
                 this->m->obj_renumber[pages.at(0).getObjGen()];
-	    int npages = pages.size();
+	    int npages = QIntC::to_int(pages.size());
 	    writeString(" /Linearized 1 /L ");
 	    writeString(QUtil::int_to_string(file_size + hint_length));
@@ -3211,7 +3213,7 @@ QPDFWriter::writeLinearized()
 	writeString(" >>");
 	closeObject(lindict_id);
 	static int const pad = 200;
-	int spaces = (pos - this->m->pipeline->getCount() + pad);
+	int spaces = QIntC::to_int(pos - this->m->pipeline->getCount() + pad);
 	assert(spaces >= 0);
 	writePad(spaces);
 	writeString("\n");
@@ -3263,7 +3265,7 @@ QPDFWriter::writeLinearized()
 	    {
 		// Pad so that the next object starts at the same
 		// place as in pass 1.
-		writePad(first_xref_end - endpos);
+		writePad(QIntC::to_int(first_xref_end - endpos));
 		if (this->m->pipeline->getCount() != first_xref_end)
                 {
@@ -3346,7 +3348,8 @@ QPDFWriter::writeLinearized()
 	    {
 		// Make the file size the same.
 		qpdf_offset_t pos = this->m->pipeline->getCount();
-		writePad(second_xref_end + hint_length - 1 - pos);
+		writePad(
+                    QIntC::to_int(second_xref_end + hint_length - 1 - pos));
 		writeString("\n");
 		// If this assertion fails, maybe we didn't have
@@ -3396,7 +3399,7 @@ QPDFWriter::writeLinearized()
 	    activatePipelineStack();
 	    writeHintStream(hint_id);
 	    popPipelineStack(&hint_buffer);
-	    hint_length = hint_buffer->getSize();
+	    hint_length = QIntC::to_offset(hint_buffer->getSize());
 	    // Restore hint offset
 	    this->m->xref[hint_id] = QPDFXRefEntry(1, hint_offset, 0);
 #include <qpdf/QPDFXRefEntry.hh>
 #include <qpdf/QPDFExc.hh>
 #include <qpdf/QUtil.hh>
+#include <qpdf/QIntC.hh>
 QPDFXRefEntry::QPDFXRefEntry() :
     type(0),
@@ -46,7 +47,7 @@ QPDFXRefEntry::getObjStreamNumber() const
 	throw std::logic_error(
 	    "getObjStreamNumber called for xref entry of type != 2");
     }
-    return this->field1;
+    return QIntC::to_int(this->field1);
 }
 int
 #include <qpdf/QPDF_Array.hh>
 #include <qpdf/QUtil.hh>
+#include <qpdf/QIntC.hh>
 #include <stdexcept>
 QPDF_Array::QPDF_Array(std::vector<QPDFObjectHandle> const& items) :
@@ -68,18 +69,20 @@ QPDF_Array::setDescription(QPDF* qpdf, std::string const&amp; description)
 int
 QPDF_Array::getNItems() const
 {
-    return this->items.size();
+    // This should really return a size_t, but changing it would break
+    // a lot of code.
+    return QIntC::to_int(this->items.size());
 }
 QPDFObjectHandle
 QPDF_Array::getItem(int n) const
 {
-    if ((n < 0) || (n >= static_cast<int>(this->items.size())))
+    if ((n < 0) || (n >= QIntC::to_int(this->items.size())))
     {
 	throw std::logic_error(
 	    "INTERNAL ERROR: bounds error accessing QPDF_Array element");
     }
-    return this->items.at(n);
+    return this->items.at(QIntC::to_size(n));
 }
 std::vector<QPDFObjectHandle> const&
@@ -93,7 +96,7 @@ QPDF_Array::setItem(int n, QPDFObjectHandle const&amp; oh)
 {
     // Call getItem for bounds checking
     (void) getItem(n);
-    this->items.at(n) = oh;
+    this->items.at(QIntC::to_size(n)) = oh;
 }
 void
@@ -106,7 +109,7 @@ void
 QPDF_Array::insertItem(int at, QPDFObjectHandle const& item)
 {
     // As special case, also allow insert beyond the end
-    if ((at < 0) || (at > static_cast<int>(this->items.size())))
+    if ((at < 0) || (at > QIntC::to_int(this->items.size())))
     {
 	throw std::logic_error(
 	    "INTERNAL ERROR: bounds error accessing QPDF_Array element");
@@ -18,6 +18,7 @@
 #include <qpdf/QPDF.hh>
 #include <qpdf/QPDFExc.hh>
 #include <qpdf/Pl_QPDFTokenizer.hh>
+#include <qpdf/QIntC.hh>
 #include <stdexcept>
@@ -199,7 +200,7 @@ QPDF_Stream::understandDecodeParams(
             QPDFObjectHandle predictor_obj = decode_obj.getKey(key);
             if (predictor_obj.isInteger())
             {
-                predictor = predictor_obj.getIntValue();
+                predictor = predictor_obj.getIntValueAsInt();
                 if (! ((predictor == 1) || (predictor == 2) ||
                        ((predictor >= 10) && (predictor <= 15))))
                 {
@@ -216,7 +217,7 @@ QPDF_Stream::understandDecodeParams(
             QPDFObjectHandle earlychange_obj = decode_obj.getKey(key);
             if (earlychange_obj.isInteger())
             {
-                int earlychange = earlychange_obj.getIntValue();
+                int earlychange = earlychange_obj.getIntValueAsInt();
                 early_code_change = (earlychange == 1);
                 if (! ((earlychange == 0) || (earlychange == 1)))
                 {
@@ -235,7 +236,7 @@ QPDF_Stream::understandDecodeParams(
             QPDFObjectHandle param_obj = decode_obj.getKey(key);
             if (param_obj.isInteger())
             {
-                int val = param_obj.getIntValue();
+                int val = param_obj.getIntValueAsInt();
                 if (key == "/Columns")
                 {
                     columns = val;
@@ -550,7 +551,9 @@ QPDF_Stream::pipeStreamData(Pipeline* pipeline,
                     QTC::TC("qpdf", "QPDF_Stream PNG filter");
                     pipeline = new Pl_PNGFilter(
                         "png decode", pipeline, Pl_PNGFilter::a_decode,
-                        columns, colors, bits_per_component);
+                        QIntC::to_uint(columns),
+                        QIntC::to_uint(colors),
+                        QIntC::to_uint(bits_per_component));
                     to_delete.push_back(pipeline);
                 }
                 else if (predictor == 2)
@@ -558,7 +561,9 @@ QPDF_Stream::pipeStreamData(Pipeline* pipeline,
                     QTC::TC("qpdf", "QPDF_Stream TIFF predictor");
                     pipeline = new Pl_TIFFPredictor(
                         "tiff decode", pipeline, Pl_TIFFPredictor::a_decode,
-                        columns, colors, bits_per_component);
+                        QIntC::to_uint(columns),
+                        QIntC::to_uint(colors),
+                        QIntC::to_uint(bits_per_component));
                     to_delete.push_back(pipeline);
                 }
             }
@@ -744,7 +749,8 @@ QPDF_Stream::replaceFilterData(QPDFObjectHandle const&amp; filter,
     else
     {
         this->stream_dict.replaceKey(
-            "/Length", QPDFObjectHandle::newInteger(length));
+            "/Length", QPDFObjectHandle::newInteger(
+                QIntC::to_longlong(length)));
     }
 }
@@ -756,7 +762,7 @@ QPDF_Stream::replaceDict(QPDFObjectHandle new_dict)
     QPDFObjectHandle length_obj = new_dict.getKey("/Length");
     if (length_obj.isInteger())
     {
-        this->length = length_obj.getIntValue();
+        this->length = QIntC::to_size(length_obj.getUIntValue());
     }
     else
     {
@@ -9,13 +9,14 @@
 #include <string.h>
 // See above about ctype.
-static bool is_ascii_printable(unsigned char ch)
+static bool is_ascii_printable(char ch)
 {
     return ((ch >= 32) && (ch <= 126));
 }
-static bool is_iso_latin1_printable(unsigned char ch)
+static bool is_iso_latin1_printable(char ch)
 {
-    return (((ch >= 32) && (ch <= 126)) || (ch >= 160));
+    return (((ch >= 32) && (ch <= 126)) ||
+            (static_cast<unsigned char>(ch) >= 160));
 }
 QPDF_String::QPDF_String(std::string const& val) :
@@ -130,9 +130,9 @@ QPDF::EncryptionData::setV5EncryptionParameters(
 static void
 pad_or_truncate_password_V4(std::string const& password, char k1[key_bytes])
 {
-    int password_bytes = std::min(static_cast<size_t>(key_bytes),
-                                  password.length());
-    int pad_bytes = key_bytes - password_bytes;
+    size_t password_bytes = std::min(QIntC::to_size(key_bytes),
+                                     password.length());
+    size_t pad_bytes = key_bytes - password_bytes;
     memcpy(k1, password.c_str(), password_bytes);
     memcpy(k1 + password_bytes, padding_string, pad_bytes);
 }
@@ -154,9 +154,10 @@ QPDF::trim_user_password(std::string&amp; user_password)
     char const* p2 = 0;
     while ((p2 = strchr(p1, '\x28')) != 0)
     {
-	if (memcmp(p2, padding_string, len - (p2 - cstr)) == 0)
+        size_t idx = toS(p2 - cstr);
+	if (memcmp(p2, padding_string, len - idx) == 0)
 	{
-	    user_password = user_password.substr(0, p2 - cstr);
+	    user_password = user_password.substr(0, idx);
 	    return;
 	}
         else
@@ -183,7 +184,8 @@ truncate_password_V5(std::string const&amp; password)
 }
 static void
-iterate_md5_digest(MD5& md5, MD5::Digest& digest, int iterations, int key_len)
+iterate_md5_digest(MD5& md5, MD5::Digest& digest,
+                   int iterations, int key_len)
 {
     md5.digest(digest);
@@ -191,26 +193,26 @@ iterate_md5_digest(MD5&amp; md5, MD5::Digest&amp; digest, int iterations, int key_len)
     {
 	MD5 m;
 	m.encodeDataIncrementally(reinterpret_cast<char*>(digest),
-                                  key_len);
+                                  QIntC::to_size(key_len));
 	m.digest(digest);
     }
 }
 static void
-iterate_rc4(unsigned char* data, int data_len,
+iterate_rc4(unsigned char* data, size_t data_len,
 	    unsigned char* okey, int key_len,
 	    int iterations, bool reverse)
 {
-    unsigned char* key = new unsigned char[key_len];
+    unsigned char* key = new unsigned char[QIntC::to_size(key_len)];
     for (int i = 0; i < iterations; ++i)
     {
 	int const xor_value = (reverse ? iterations - 1 - i : i);
 	for (int j = 0; j < key_len; ++j)
 	{
-	    key[j] = okey[j] ^ xor_value;
+	    key[j] = static_cast<unsigned char>(okey[j] ^ xor_value);
 	}
-	RC4 rc4(key, key_len);
+	RC4 rc4(key, QIntC::to_int(key_len));
 	rc4.process(data, data_len);
     }
     delete [] key;
@@ -228,7 +230,7 @@ process_with_aes(std::string const&amp; key,
     Pl_Buffer buffer("buffer");
     Pl_AES_PDF aes("aes", &buffer, encrypt,
                    QUtil::unsigned_char_pointer(key),
-                   key.length());
+                   QIntC::to_uint(key.length()));
     if (iv)
     {
         aes.setIV(iv, iv_length);
@@ -328,7 +330,7 @@ hash_V5(std::string const&amp; password,
             {
                 unsigned int ch = static_cast<unsigned char>(*(E.rbegin()));
-                if (ch <= static_cast<unsigned int>(round_number - 32))
+                if (ch <= QIntC::to_uint(round_number - 32))
                 {
                     done = true;
                 }
@@ -341,7 +343,7 @@ hash_V5(std::string const&amp; password,
 }
 static
-void pad_short_parameter(std::string& param, unsigned int max_len)
+void pad_short_parameter(std::string& param, size_t max_len)
 {
     if (param.length() < max_len)
     {
@@ -367,11 +369,11 @@ QPDF::compute_data_key(std::string const&amp; encryption_key,
     }
     // Append low three bytes of object ID and low two bytes of generation
-    result += static_cast<char>(objid & 0xff);
-    result += static_cast<char>((objid >> 8) & 0xff);
-    result += static_cast<char>((objid >> 16) & 0xff);
-    result += static_cast<char>(generation & 0xff);
-    result += static_cast<char>((generation >> 8) & 0xff);
+    result.append(1, static_cast<char>(objid & 0xff));
+    result.append(1, static_cast<char>((objid >> 8) & 0xff));
+    result.append(1, static_cast<char>((objid >> 16) & 0xff));
+    result.append(1, static_cast<char>(generation & 0xff));
+    result.append(1, static_cast<char>((generation >> 8) & 0xff));
     if (use_aes)
     {
 	result += "sAlT";
@@ -382,7 +384,7 @@ QPDF::compute_data_key(std::string const&amp; encryption_key,
     MD5::Digest digest;
     md5.digest(digest);
     return std::string(reinterpret_cast<char*>(digest),
-		       std::min(result.length(), static_cast<size_t>(16)));
+		       std::min(result.length(), toS(16)));
 }
 std::string
@@ -437,10 +439,9 @@ QPDF::compute_encryption_key_from_password(
 	md5.encodeDataIncrementally(bytes, 4);
     }
     MD5::Digest digest;
-    int key_len = std::min(static_cast<int>(sizeof(digest)),
-                           data.getLengthBytes());
+    int key_len = std::min(QIntC::to_int(sizeof(digest)), data.getLengthBytes());
     iterate_md5_digest(md5, digest, ((data.getR() >= 3) ? 50 : 0), key_len);
-    return std::string(reinterpret_cast<char*>(digest), key_len);
+    return std::string(reinterpret_cast<char*>(digest), QIntC::to_size(key_len));
 }
 static void
@@ -463,7 +464,7 @@ compute_O_rc4_key(std::string const&amp; user_password,
     md5.encodeDataIncrementally(
 	pad_or_truncate_password_V4(password).c_str(), key_bytes);
     MD5::Digest digest;
-    int key_len = std::min(static_cast<int>(sizeof(digest)),
+    int key_len = std::min(QIntC::to_int(sizeof(digest)),
                            data.getLengthBytes());
     iterate_md5_digest(md5, digest, ((data.getR() >= 3) ? 50 : 0), key_len);
     memcpy(key, digest, OU_key_bytes_V4);
@@ -482,7 +483,7 @@ compute_O_value(std::string const&amp; user_password,
     char upass[key_bytes];
     pad_or_truncate_password_V4(user_password, upass);
     std::string k1(reinterpret_cast<char*>(O_key), OU_key_bytes_V4);
-    pad_short_parameter(k1, data.getLengthBytes());
+    pad_short_parameter(k1, QIntC::to_size(data.getLengthBytes()));
     iterate_rc4(QUtil::unsigned_char_pointer(upass), key_bytes,
 		O_key, data.getLengthBytes(),
                 (data.getR() >= 3) ? 20 : 1, false);
@@ -499,7 +500,7 @@ compute_U_value_R2(std::string const&amp; user_password,
     std::string k1 = QPDF::compute_encryption_key(user_password, data);
     char udata[key_bytes];
     pad_or_truncate_password_V4("", udata);
-    pad_short_parameter(k1, data.getLengthBytes());
+    pad_short_parameter(k1, QIntC::to_size(data.getLengthBytes()));
     iterate_rc4(QUtil::unsigned_char_pointer(udata), key_bytes,
 		QUtil::unsigned_char_pointer(k1),
                 data.getLengthBytes(), 1, false);
@@ -521,7 +522,7 @@ compute_U_value_R3(std::string const&amp; user_password,
                                 data.getId1().length());
     MD5::Digest digest;
     md5.digest(digest);
-    pad_short_parameter(k1, data.getLengthBytes());
+    pad_short_parameter(k1, QIntC::to_size(data.getLengthBytes()));
     iterate_rc4(digest, sizeof(MD5::Digest),
 		QUtil::unsigned_char_pointer(k1),
                 data.getLengthBytes(), 20, false);
@@ -555,8 +556,8 @@ check_user_password_V4(std::string const&amp; user_password,
     // Algorithm 3.6 from the PDF 1.7 Reference Manual
     std::string u_value = compute_U_value(user_password, data);
-    int to_compare = ((data.getR() >= 3) ? sizeof(MD5::Digest)
-                      : key_bytes);
+    size_t to_compare = ((data.getR() >= 3) ? sizeof(MD5::Digest)
+                         : key_bytes);
     return (memcmp(data.getU().c_str(), u_value.c_str(), to_compare) == 0);
 }
@@ -598,7 +599,7 @@ check_owner_password_V4(std::string&amp; user_password,
     unsigned char O_data[key_bytes];
     memcpy(O_data, QUtil::unsigned_char_pointer(data.getO()), key_bytes);
     std::string k1(reinterpret_cast<char*>(key), OU_key_bytes_V4);
-    pad_short_parameter(k1, data.getLengthBytes());
+    pad_short_parameter(k1, QIntC::to_size(data.getLengthBytes()));
     iterate_rc4(O_data, key_bytes, QUtil::unsigned_char_pointer(k1),
                 data.getLengthBytes(),
                 (data.getR() >= 3) ? 20 : 1, true);
@@ -694,7 +695,8 @@ compute_Perms_value_V5_clear(std::string const&amp; encryption_key,
                              unsigned char k[16])
 {
     // From algorithm 3.10 from the PDF 1.7 extension level 3
-    unsigned long long extended_perms = 0xffffffff00000000LL | data.getP();
+    unsigned long long extended_perms =
+        0xffffffff00000000LL | static_cast<unsigned long long>(data.getP());
     for (int i = 0; i < 8; ++i)
     {
         k[i] = static_cast<unsigned char>(extended_perms & 0xff);
@@ -868,11 +870,11 @@ QPDF::initializeEncryption()
 		      "or the wrong type");
     }
-    int V = encryption_dict.getKey("/V").getIntValue();
-    int R = encryption_dict.getKey("/R").getIntValue();
+    int V = encryption_dict.getKey("/V").getIntValueAsInt();
+    int R = encryption_dict.getKey("/R").getIntValueAsInt();
     std::string O = encryption_dict.getKey("/O").getStringValue();
     std::string U = encryption_dict.getKey("/U").getStringValue();
-    unsigned int P = encryption_dict.getKey("/P").getIntValue();
+    int P = encryption_dict.getKey("/P").getIntValueAsInt();
     // If supporting new encryption R/V values, remember to update
     // error message inside this if statement.
@@ -935,7 +937,7 @@ QPDF::initializeEncryption()
     int Length = 40;
     if (encryption_dict.getKey("/Length").isInteger())
     {
-	Length = encryption_dict.getKey("/Length").getIntValue();
+	Length = encryption_dict.getKey("/Length").getIntValueAsInt();
         if (R < 3)
         {
             // Force Length to 40 regardless of what the file says.
@@ -1013,7 +1015,8 @@ QPDF::initializeEncryption()
 	}
     }
-    EncryptionData data(V, R, Length / 8, P, O, U, OE, UE, Perms,
+    EncryptionData data(V, R, Length / 8,
+                        P, O, U, OE, UE, Perms,
                         id1, this->m->encp->encrypt_metadata);
     if (this->m->provided_password_is_hex_key)
     {
@@ -1154,11 +1157,11 @@ QPDF::decryptString(std::string&amp; str, int objid, int generation)
 	else
 	{
 	    QTC::TC("qpdf", "QPDF_encryption rc4 decode string");
-	    unsigned int vlen = str.length();
+	    size_t vlen = str.length();
 	    // Using PointerHolder guarantees that tmp will
 	    // be freed even if rc4.process throws an exception.
 	    PointerHolder<char> tmp(true, QUtil::copy_string(str));
-	    RC4 rc4(QUtil::unsigned_char_pointer(key), key.length());
+	    RC4 rc4(QUtil::unsigned_char_pointer(key), toI(key.length()));
 	    rc4.process(QUtil::unsigned_char_pointer(tmp.getPointer()), vlen);
 	    str = std::string(tmp.getPointer(), vlen);
 	}
@@ -1313,7 +1316,7 @@ QPDF::decryptStream(PointerHolder&lt;EncryptionParameters&gt; encp,
 	QTC::TC("qpdf", "QPDF_encryption rc4 decode stream");
 	pipeline = new Pl_RC4("RC4 stream decryption", pipeline,
 			      QUtil::unsigned_char_pointer(key),
-                              key.length());
+                              toI(key.length()));
     }
     heap.push_back(pipeline);
 }
@@ -1404,9 +1407,9 @@ QPDF::isEncrypted(int&amp; R, int&amp; P, int&amp; V,
 	QPDFObjectHandle Pkey = encrypt.getKey("/P");
 	QPDFObjectHandle Rkey = encrypt.getKey("/R");
         QPDFObjectHandle Vkey = encrypt.getKey("/V");
-	P = Pkey.getIntValue();
-	R = Rkey.getIntValue();
-        V = Vkey.getIntValue();
+	P = Pkey.getIntValueAsInt();
+	R = Rkey.getIntValueAsInt();
+        V = Vkey.getIntValueAsInt();
         stream_method = this->m->encp->cf_stream;
         string_method = this->m->encp->cf_string;
         file_method = this->m->encp->cf_file;
@@ -26,15 +26,15 @@ load_vector_int(BitStream&amp; bit_stream, int nitems, std::vector&lt;T&gt;&amp; vec,
     // nitems times, read bits_wanted from the given bit stream,
     // storing results in the ith vector entry.
-    for (int i = 0; i < nitems; ++i)
+    for (size_t i = 0; i < QIntC::to_size(nitems); ++i)
     {
         if (append)
         {
             vec.push_back(T());
         }
-	vec.at(i).*field = bit_stream.getBits(bits_wanted);
+	vec.at(i).*field = bit_stream.getBitsInt(QIntC::to_size(bits_wanted));
     }
-    if (static_cast<int>(vec.size()) != nitems)
+    if (QIntC::to_int(vec.size()) != nitems)
     {
         throw std::logic_error("vector has wrong size in load_vector_int");
     }
@@ -51,11 +51,12 @@ load_vector_vector(BitStream&amp; bit_stream,
 {
     // nitems1 times, read nitems2 (from the ith element of vec1) items
     // into the vec2 vector field of the ith item of vec1.
-    for (int i1 = 0; i1 < nitems1; ++i1)
+    for (size_t i1 = 0; i1 < QIntC::to_size(nitems1); ++i1)
     {
 	for (int i2 = 0; i2 < vec1.at(i1).*nitems2; ++i2)
 	{
-	    (vec1.at(i1).*vec2).push_back(bit_stream.getBits(bits_wanted));
+	    (vec1.at(i1).*vec2).push_back(
+                bit_stream.getBitsInt(QIntC::to_size(bits_wanted)));
 	}
     }
     bit_stream.skipToNextByte();
@@ -131,7 +132,7 @@ QPDF::isLinearized()
             (t4.getType() == QPDFTokenizer::tt_dict_open))
         {
 	    lindict_obj =
-                static_cast<int>(QUtil::string_to_ll(t1.getValue().c_str()));
+                QIntC::to_int(QUtil::string_to_ll(t1.getValue().c_str()));
 	}
     }
@@ -149,7 +150,7 @@ QPDF::isLinearized()
     QPDFObjectHandle linkey = candidate.getKey("/Linearized");
     if (! (linkey.isNumber() &&
-           (static_cast<int>(floor(linkey.getNumericValue())) == 1)))
+           (QIntC::to_int(floor(linkey.getNumericValue())) == 1)))
     {
 	return false;
     }
@@ -213,7 +214,7 @@ QPDF::readLinearizationData()
     }
     // Hint table array: offset length [ offset length ]
-    unsigned int n_H_items = H.getArrayNItems();
+    size_t n_H_items = toS(H.getArrayNItems());
     if (! ((n_H_items == 2) || (n_H_items == 4)))
     {
 	throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(),
@@ -223,12 +224,12 @@ QPDF::readLinearizationData()
     }
     std::vector<int> H_items;
-    for (unsigned int i = 0; i < n_H_items; ++i)
+    for (size_t i = 0; i < n_H_items; ++i)
     {
-	QPDFObjectHandle oh(H.getArrayItem(i));
+	QPDFObjectHandle oh(H.getArrayItem(toI(i)));
 	if (oh.isInteger())
 	{
-	    H_items.push_back(oh.getIntValue());
+	    H_items.push_back(oh.getIntValueAsInt());
 	}
 	else
 	{
@@ -258,7 +259,7 @@ QPDF::readLinearizationData()
     if (P.isInteger())
     {
 	QTC::TC("qpdf", "QPDF P present in lindict");
-	first_page = P.getIntValue();
+	first_page = P.getIntValueAsInt();
     }
     else
     {
@@ -279,9 +280,9 @@ QPDF::readLinearizationData()
     }
     // file_size initialized by isLinearized()
-    this->m->linp.first_page_object = O.getIntValue();
+    this->m->linp.first_page_object = O.getIntValueAsInt();
     this->m->linp.first_page_end = E.getIntValue();
-    this->m->linp.npages = N.getIntValue();
+    this->m->linp.npages = N.getIntValueAsInt();
     this->m->linp.xref_zero_offset = T.getIntValue();
     this->m->linp.first_page = first_page;
     this->m->linp.H_offset = H0_offset;
@@ -290,10 +291,10 @@ QPDF::readLinearizationData()
     // Read hint streams
     Pl_Buffer pb("hint buffer");
-    QPDFObjectHandle H0 = readHintStream(pb, H0_offset, H0_length);
+    QPDFObjectHandle H0 = readHintStream(pb, H0_offset, toS(H0_length));
     if (H1_offset)
     {
-	(void) readHintStream(pb, H1_offset, H1_length);
+	(void) readHintStream(pb, H1_offset, toS(H1_length));
     }
     // PDF 1.4 hint tables that we ignore:
@@ -313,31 +314,31 @@ QPDF::readLinearizationData()
     PointerHolder<Buffer> hbp = pb.getBuffer();
     Buffer* hb = hbp.getPointer();
     unsigned char const* h_buf = hb->getBuffer();
-    int h_size = hb->getSize();
+    size_t h_size = hb->getSize();
     readHPageOffset(BitStream(h_buf, h_size));
-    int HSi = HS.getIntValue();
-    if ((HSi < 0) || (HSi >= h_size))
+    int HSi = HS.getIntValueAsInt();
+    if ((HSi < 0) || (toS(HSi) >= h_size))
     {
         throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(),
                       "linearization hint table",
                       this->m->file->getLastOffset(),
                       "/S (shared object) offset is out of bounds");
     }
-    readHSharedObject(BitStream(h_buf + HSi, h_size - HSi));
+    readHSharedObject(BitStream(h_buf + HSi, h_size - toS(HSi)));
     if (HO.isInteger())
     {
-	int HOi = HO.getIntValue();
-        if ((HOi < 0) || (HOi >= h_size))
+	int HOi = HO.getIntValueAsInt();
+        if ((HOi < 0) || (toS(HOi) >= h_size))
         {
             throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(),
                           "linearization hint table",
                           this->m->file->getLastOffset(),
                           "/O (outline) offset is out of bounds");
         }
-	readHGeneric(BitStream(h_buf + HOi, h_size - HOi),
+	readHGeneric(BitStream(h_buf + HOi, h_size - toS(HOi)),
 		     this->m->outline_hints);
     }
 }
@@ -381,7 +382,7 @@ QPDF::readHintStream(Pipeline&amp; pl, qpdf_offset_t offset, size_t length)
     {
 	QTC::TC("qpdf", "QPDF hint table length direct");
     }
-    qpdf_offset_t computed_end = offset + length;
+    qpdf_offset_t computed_end = offset + toO(length);
     if ((computed_end < min_end_offset) ||
 	(computed_end > max_end_offset))
     {
@@ -405,23 +406,23 @@ QPDF::readHPageOffset(BitStream h)
     HPageOffset& t = this->m->page_offset_hints;
-    t.min_nobjects = h.getBits(32);		  	    // 1
-    t.first_page_offset = h.getBits(32);		    // 2
-    t.nbits_delta_nobjects = h.getBits(16);		    // 3
-    t.min_page_length = h.getBits(32);			    // 4
-    t.nbits_delta_page_length = h.getBits(16);		    // 5
-    t.min_content_offset = h.getBits(32);		    // 6
-    t.nbits_delta_content_offset = h.getBits(16);	    // 7
-    t.min_content_length = h.getBits(32);		    // 8
-    t.nbits_delta_content_length = h.getBits(16);	    // 9
-    t.nbits_nshared_objects = h.getBits(16);		    // 10
-    t.nbits_shared_identifier = h.getBits(16);		    // 11
-    t.nbits_shared_numerator = h.getBits(16);		    // 12
-    t.shared_denominator = h.getBits(16);		    // 13
+    t.min_nobjects = h.getBitsInt(32);                      // 1
+    t.first_page_offset = h.getBitsInt(32);                 // 2
+    t.nbits_delta_nobjects = h.getBitsInt(16);              // 3
+    t.min_page_length = h.getBitsInt(32);                   // 4
+    t.nbits_delta_page_length = h.getBitsInt(16);           // 5
+    t.min_content_offset = h.getBitsInt(32);                // 6
+    t.nbits_delta_content_offset = h.getBitsInt(16);        // 7
+    t.min_content_length = h.getBitsInt(32);                // 8
+    t.nbits_delta_content_length = h.getBitsInt(16);        // 9
+    t.nbits_nshared_objects = h.getBitsInt(16);             // 10
+    t.nbits_shared_identifier = h.getBitsInt(16);           // 11
+    t.nbits_shared_numerator = h.getBitsInt(16);            // 12
+    t.shared_denominator = h.getBitsInt(16);                // 13
     std::vector<HPageOffsetEntry>& entries = t.entries;
     entries.clear();
-    unsigned int nitems = this->m->linp.npages;
+    int nitems = this->m->linp.npages;
     load_vector_int(h, nitems, entries,
 		    t.nbits_delta_nobjects,
 		    &HPageOffsetEntry::delta_nobjects);
@@ -452,13 +453,13 @@ QPDF::readHSharedObject(BitStream h)
 {
     HSharedObject& t = this->m->shared_object_hints;
-    t.first_shared_obj = h.getBits(32);			    // 1
-    t.first_shared_offset = h.getBits(32);		    // 2
-    t.nshared_first_page = h.getBits(32);		    // 3
-    t.nshared_total = h.getBits(32);			    // 4
-    t.nbits_nobjects = h.getBits(16);			    // 5
-    t.min_group_length = h.getBits(32);			    // 6
-    t.nbits_delta_group_length = h.getBits(16);		    // 7
+    t.first_shared_obj = h.getBitsInt(32);                  // 1
+    t.first_shared_offset = h.getBitsInt(32);               // 2
+    t.nshared_first_page = h.getBitsInt(32);                // 3
+    t.nshared_total = h.getBitsInt(32);                     // 4
+    t.nbits_nobjects = h.getBitsInt(16);                    // 5
+    t.min_group_length = h.getBitsInt(32);                  // 6
+    t.nbits_delta_group_length = h.getBitsInt(16);          // 7
     QTC::TC("qpdf", "QPDF lin nshared_total > nshared_first_page",
 	    (t.nshared_total > t.nshared_first_page) ? 1 : 0);
@@ -471,7 +472,7 @@ QPDF::readHSharedObject(BitStream h)
 		    &HSharedObjectEntry::delta_group_length);
     load_vector_int(h, nitems, entries,
 		    1, &HSharedObjectEntry::signature_present);
-    for (int i = 0; i < nitems; ++i)
+    for (size_t i = 0; i < toS(nitems); ++i)
     {
 	if (entries.at(i).signature_present)
 	{
@@ -492,10 +493,10 @@ QPDF::readHSharedObject(BitStream h)
 void
 QPDF::readHGeneric(BitStream h, HGeneric& t)
 {
-    t.first_object = h.getBits(32);			    // 1
-    t.first_object_offset = h.getBits(32);		    // 2
-    t.nobjects = h.getBits(32);				    // 3
-    t.group_length = h.getBits(32);			    // 4
+    t.first_object = h.getBitsInt(32);                      // 1
+    t.first_object_offset = h.getBitsInt(32);               // 2
+    t.nobjects = h.getBitsInt(32);                          // 3
+    t.group_length = h.getBitsInt(32);                      // 4
 }
 bool
@@ -522,21 +523,21 @@ QPDF::checkLinearizationInternal()
     }
     // N: number of pages
-    int npages = pages.size();
+    int npages = toI(pages.size());
     if (p.npages != npages)
     {
 	// Not tested in the test suite
 	errors.push_back("page count (/N) mismatch");
     }
-    for (int i = 0; i < npages; ++i)
+    for (size_t i = 0; i < toS(npages); ++i)
     {
 	QPDFObjectHandle const& page = pages.at(i);
 	QPDFObjGen og(page.getObjGen());
 	if (this->m->xref_table[og].getType() == 2)
 	{
 	    errors.push_back("page dictionary for page " +
-			     QUtil::int_to_string(i) + " is compressed");
+			     QUtil::uint_to_string(i) + " is compressed");
 	}
     }
@@ -756,8 +757,8 @@ QPDF::lengthNextN(int first_object, int n,
                 stopOnError("found unknown object while"
                             " calculating length for linearization data");
             }
-	    length += this->m->obj_cache[og].end_after_space -
-		getLinearizationOffset(og);
+	    length += toI(this->m->obj_cache[og].end_after_space -
+                          getLinearizationOffset(og));
 	}
     }
     return length;
@@ -786,8 +787,8 @@ QPDF::checkHPageOffset(std::list&lt;std::string&gt;&amp; errors,
     // under a page's /Resources dictionary in with shared objects
     // even when they are private.
-    unsigned int npages = pages.size();
-    int table_offset = adjusted_offset(
+    int npages = toI(pages.size());
+    qpdf_offset_t table_offset = adjusted_offset(
 	this->m->page_offset_hints.first_page_offset);
     QPDFObjGen first_page_og(pages.at(0).getObjGen());
     if (this->m->xref_table.count(first_page_og) == 0)
@@ -800,9 +801,9 @@ QPDF::checkHPageOffset(std::list&lt;std::string&gt;&amp; errors,
 	warnings.push_back("first page object offset mismatch");
     }
-    for (unsigned int pageno = 0; pageno < npages; ++pageno)
+    for (int pageno = 0; pageno < npages; ++pageno)
     {
-	QPDFObjGen page_og(pages.at(pageno).getObjGen());
+	QPDFObjGen page_og(pages.at(toS(pageno)).getObjGen());
 	int first_object = page_og.getObj();
 	if (this->m->xref_table.count(page_og) == 0)
         {
@@ -810,8 +811,10 @@ QPDF::checkHPageOffset(std::list&lt;std::string&gt;&amp; errors,
         }
 	offset = getLinearizationOffset(page_og);
-	HPageOffsetEntry& he = this->m->page_offset_hints.entries.at(pageno);
-	CHPageOffsetEntry& ce = this->m->c_page_offset_data.entries.at(pageno);
+	HPageOffsetEntry& he =
+            this->m->page_offset_hints.entries.at(toS(pageno));
+	CHPageOffsetEntry& ce =
+            this->m->c_page_offset_data.entries.at(toS(pageno));
 	int h_nobjects = he.delta_nobjects +
 	    this->m->page_offset_hints.min_nobjects;
 	if (h_nobjects != ce.nobjects)
@@ -827,8 +830,8 @@ QPDF::checkHPageOffset(std::list&lt;std::string&gt;&amp; errors,
 	// Use value for number of objects in hint table rather than
 	// computed value if there is a discrepancy.
 	int length = lengthNextN(first_object, h_nobjects, errors);
-	int h_length = he.delta_page_length +
-	    this->m->page_offset_hints.min_page_length;
+	int h_length = toI(he.delta_page_length +
+                           this->m->page_offset_hints.min_page_length);
 	if (length != h_length)
 	{
 	    // This condition almost certainly indicates a bad hint
@@ -854,7 +857,7 @@ QPDF::checkHPageOffset(std::list&lt;std::string&gt;&amp; errors,
 	    warnings.push_back("page 0 has shared identifier entries");
 	}
-	for (int i = 0; i < he.nshared_objects; ++i)
+	for (size_t i = 0; i < toS(he.nshared_objects); ++i)
 	{
 	    int idx = he.shared_identifiers.at(i);
 	    if (shared_idx_to_obj.count(idx) == 0)
@@ -866,7 +869,7 @@ QPDF::checkHPageOffset(std::list&lt;std::string&gt;&amp; errors,
 	    hint_shared.insert(shared_idx_to_obj[idx]);
 	}
-	for (int i = 0; i < ce.nshared_objects; ++i)
+	for (size_t i = 0; i < toS(ce.nshared_objects); ++i)
 	{
 	    int idx = ce.shared_identifiers.at(i);
 	    if (idx >= this->m->c_shared_object_data.nshared_total)
@@ -874,7 +877,7 @@ QPDF::checkHPageOffset(std::list&lt;std::string&gt;&amp; errors,
                 throw std::logic_error(
                     "index out of bounds for shared object hint table");
             }
-	    int obj = this->m->c_shared_object_data.entries.at(idx).object;
+	    int obj = this->m->c_shared_object_data.entries.at(toS(idx)).object;
 	    computed_shared.insert(obj);
 	}
@@ -975,8 +978,9 @@ QPDF::checkHSharedObject(std::list&lt;std::string&gt;&amp; errors,
                 {
                     stopOnError("unknown object in shared object hint table");
                 }
-		int offset = getLinearizationOffset(og);
-		int h_offset = adjusted_offset(so.first_shared_offset);
+		qpdf_offset_t offset = getLinearizationOffset(og);
+		qpdf_offset_t h_offset =
+                    adjusted_offset(so.first_shared_offset);
 		if (offset != h_offset)
 		{
 		    errors.push_back(
@@ -987,7 +991,7 @@ QPDF::checkHSharedObject(std::list&lt;std::string&gt;&amp; errors,
 	    }
 	    idx_to_obj[i] = cur_object;
-	    HSharedObjectEntry& se = so.entries.at(i);
+	    HSharedObjectEntry& se = so.entries.at(toS(i));
 	    int nobjects = se.nobjects_minus_one + 1;
 	    int length = lengthNextN(cur_object, nobjects, errors);
 	    int h_length = so.min_group_length + se.delta_group_length;
@@ -1041,10 +1045,10 @@ QPDF::checkHOutlines(std::list&lt;std::string&gt;&amp; warnings)
             {
                 stopOnError("unknown object in outlines hint table");
             }
-	    int offset = getLinearizationOffset(og);
+	    qpdf_offset_t offset = getLinearizationOffset(og);
 	    ObjUser ou(ObjUser::ou_root_key, "/Outlines");
-	    int length = maxEnd(ou) - offset;
-	    int table_offset =
+	    int length = toI(maxEnd(ou) - offset);
+	    qpdf_offset_t table_offset =
 		adjusted_offset(this->m->outline_hints.first_object_offset);
 	    if (offset != table_offset)
 	    {
@@ -1124,8 +1128,8 @@ QPDF::dumpLinearizationDataInternal()
     }
 }
-int
-QPDF::adjusted_offset(int offset)
+qpdf_offset_t
+QPDF::adjusted_offset(qpdf_offset_t offset)
 {
     // All offsets >= H_offset have to be increased by H_length
     // since all hint table location values disregard the hint table
@@ -1170,7 +1174,7 @@ QPDF::dumpHPageOffset()
 	<< "shared_denominator: " << t.shared_denominator
 	<< std::endl;
-    for (int i1 = 0; i1 < this->m->linp.npages; ++i1)
+    for (size_t i1 = 0; i1 < toS(this->m->linp.npages); ++i1)
     {
 	HPageOffsetEntry& pe = t.entries.at(i1);
 	*this->m->out_stream
@@ -1185,7 +1189,7 @@ QPDF::dumpHPageOffset()
 	    << "  content_length: "
 	    << pe.delta_content_length + t.min_content_length << std::endl
 	    << "  nshared_objects: " << pe.nshared_objects << std::endl;
-	for (int i2 = 0; i2 < pe.nshared_objects; ++i2)
+	for (size_t i2 = 0; i2 < toS(pe.nshared_objects); ++i2)
 	{
 	    *this->m->out_stream << "    identifier " << i2 << ": "
                                  << pe.shared_identifiers.at(i2) << std::endl;
@@ -1215,7 +1219,7 @@ QPDF::dumpHSharedObject()
 	<< "nbits_delta_group_length: " << t.nbits_delta_group_length
 	<< std::endl;
-    for (int i = 0; i < t.nshared_total; ++i)
+    for (size_t i = 0; i < toS(t.nshared_total); ++i)
     {
 	HSharedObjectEntry& se = t.entries.at(i);
 	*this->m->out_stream
@@ -1516,7 +1520,7 @@ QPDF::calculateLinearizationData(std::map&lt;int, int&gt; const&amp; object_stream_data)
 	    pages.push_back(getUncompressedObject(*iter, object_stream_data));
 	}
     }
-    unsigned int npages = pages.size();
+    int npages = toI(pages.size());
     // We will be initializing some values of the computed hint
     // tables.  Specifically, we can initialize any items that deal
@@ -1531,7 +1535,7 @@ QPDF::calculateLinearizationData(std::map&lt;int, int&gt; const&amp; object_stream_data)
     // reasonable size.
     this->m->c_linp.npages = npages;
     this->m->c_page_offset_data.entries =
-        std::vector<CHPageOffsetEntry>(npages);
+        std::vector<CHPageOffsetEntry>(toS(npages));
     // Part 4: open document objects.  We don't care about the order.
@@ -1594,12 +1598,13 @@ QPDF::calculateLinearizationData(std::map&lt;int, int&gt; const&amp; object_stream_data)
     // in garbage values for all the shared object identifiers on the
     // first page.
-    this->m->c_page_offset_data.entries.at(0).nobjects = this->m->part6.size();
+    this->m->c_page_offset_data.entries.at(0).nobjects =
+        toI(this->m->part6.size());
     // Part 7: other pages' private objects
     // For each page in order:
-    for (unsigned int i = 1; i < npages; ++i)
+    for (size_t i = 1; i < toS(npages); ++i)
     {
 	// Place this page's page object
@@ -1609,7 +1614,7 @@ QPDF::calculateLinearizationData(std::map&lt;int, int&gt; const&amp; object_stream_data)
 	    throw std::logic_error(
 		"INTERNAL ERROR: "
 		"QPDF::calculateLinearizationData: page object for page " +
-		QUtil::int_to_string(i) + " not in lc_other_page_private");
+		QUtil::uint_to_string(i) + " not in lc_other_page_private");
 	}
 	lc_other_page_private.erase(page_og);
 	this->m->part7.push_back(pages.at(i));
@@ -1619,7 +1624,7 @@ QPDF::calculateLinearizationData(std::map&lt;int, int&gt; const&amp; object_stream_data)
 	this->m->c_page_offset_data.entries.at(i).nobjects = 1;
-	ObjUser ou(ObjUser::ou_page, i);
+	ObjUser ou(ObjUser::ou_page, toI(i));
 	if (this->m->obj_user_to_objects.count(ou) == 0)
         {
             stopOnError("found unreferenced page while"
@@ -1687,7 +1692,7 @@ QPDF::calculateLinearizationData(std::map&lt;int, int&gt; const&amp; object_stream_data)
     // Place private thumbnail images in page order.  Slightly more
     // information would be required if we were going to bother with
     // thumbnail hint tables.
-    for (unsigned int i = 0; i < npages; ++i)
+    for (size_t i = 0; i < toS(npages); ++i)
     {
 	QPDFObjectHandle thumb = pages.at(i).getKey("/Thumb");
 	thumb = getUncompressedObject(thumb, object_stream_data);
@@ -1710,7 +1715,8 @@ QPDF::calculateLinearizationData(std::map&lt;int, int&gt; const&amp; object_stream_data)
 		// lc_thumbnail_private.
 	    }
 	    std::set<QPDFObjGen>& ogs =
-		this->m->obj_user_to_objects[ObjUser(ObjUser::ou_thumb, i)];
+		this->m->obj_user_to_objects[
+                    ObjUser(ObjUser::ou_thumb, toI(i))];
 	    for (std::set<QPDFObjGen>::iterator iter = ogs.begin();
 		 iter != ogs.end(); ++iter)
 	    {
@@ -1753,18 +1759,18 @@ QPDF::calculateLinearizationData(std::map&lt;int, int&gt; const&amp; object_stream_data)
     // Make sure we got everything exactly once.
-    unsigned int num_placed =
+    size_t num_placed =
         this->m->part4.size() + this->m->part6.size() + this->m->part7.size() +
         this->m->part8.size() + this->m->part9.size();
-    unsigned int num_wanted = this->m->object_to_obj_users.size();
+    size_t num_wanted = this->m->object_to_obj_users.size();
     if (num_placed != num_wanted)
     {
 	throw std::logic_error(
 	    "INTERNAL ERROR: QPDF::calculateLinearizationData: wrong "
 	    "number of objects placed (num_placed = " +
-	    QUtil::int_to_string(num_placed) +
+	    QUtil::uint_to_string(num_placed) +
 	    "; number of objects: " +
-	    QUtil::int_to_string(num_wanted));
+	    QUtil::uint_to_string(num_wanted));
     }
     // Calculate shared object hint table information including
@@ -1780,10 +1786,11 @@ QPDF::calculateLinearizationData(std::map&lt;int, int&gt; const&amp; object_stream_data)
     // can map from object number only without regards to generation.
     std::map<int, int> obj_to_index;
-    this->m->c_shared_object_data.nshared_first_page = this->m->part6.size();
+    this->m->c_shared_object_data.nshared_first_page =
+        toI(this->m->part6.size());
     this->m->c_shared_object_data.nshared_total =
 	this->m->c_shared_object_data.nshared_first_page +
-        this->m->part8.size();
+        toI(this->m->part8.size());
     std::vector<CHSharedObjectEntry>& shared =
 	this->m->c_shared_object_data.entries;
@@ -1792,7 +1799,7 @@ QPDF::calculateLinearizationData(std::map&lt;int, int&gt; const&amp; object_stream_data)
     {
 	QPDFObjectHandle& oh = *iter;
 	int obj = oh.getObjectID();
-	obj_to_index[obj] = shared.size();
+	obj_to_index[obj] = toI(shared.size());
 	shared.push_back(CHSharedObjectEntry(obj));
     }
     QTC::TC("qpdf", "QPDF lin part 8 empty", this->m->part8.empty() ? 1 : 0);
@@ -1806,7 +1813,7 @@ QPDF::calculateLinearizationData(std::map&lt;int, int&gt; const&amp; object_stream_data)
 	{
 	    QPDFObjectHandle& oh = *iter;
 	    int obj = oh.getObjectID();
-	    obj_to_index[obj] = shared.size();
+	    obj_to_index[obj] = toI(shared.size());
 	    shared.push_back(CHSharedObjectEntry(obj));
 	}
     }
@@ -1820,10 +1827,10 @@ QPDF::calculateLinearizationData(std::map&lt;int, int&gt; const&amp; object_stream_data)
     // Now compute the list of shared objects for each page after the
     // first page.
-    for (unsigned int i = 1; i < npages; ++i)
+    for (size_t i = 1; i < toS(npages); ++i)
     {
 	CHPageOffsetEntry& pe = this->m->c_page_offset_data.entries.at(i);
-	ObjUser ou(ObjUser::ou_page, i);
+	ObjUser ou(ObjUser::ou_page, toI(i));
 	if (this->m->obj_user_to_objects.count(ou) == 0)
         {
             stopOnError("found unreferenced page while"
@@ -1921,7 +1928,7 @@ QPDF::outputLengthNextN(
             stopOnError("found item with unknown length"
                         " while writing linearization data");
         }
-	length += (*(lengths.find(first + i))).second;
+	length += toI((*(lengths.find(first + toI(i)))).second);
     }
     return length;
 }
@@ -1938,7 +1945,7 @@ QPDF::calculateHPageOffset(
     // values.
     std::vector<QPDFObjectHandle> const& pages = getAllPages();
-    unsigned int npages = pages.size();
+    size_t npages = pages.size();
     CHPageOffset& cph = this->m->c_page_offset_data;
     std::vector<CHPageOffsetEntry>& cphe = cph.entries;
@@ -2001,7 +2008,7 @@ QPDF::calculateHPageOffset(
     ph.nbits_delta_content_length = ph.nbits_delta_page_length;
     ph.min_content_length = ph.min_page_length;
-    for (unsigned int i = 0; i < npages; ++i)
+    for (size_t i = 0; i < npages; ++i)
     {
 	// Adjust delta entries
 	if ((phe.at(i).delta_nobjects < min_nobjects) ||
@@ -2014,7 +2021,7 @@ QPDF::calculateHPageOffset(
 	phe.at(i).delta_page_length -= min_length;
 	phe.at(i).delta_content_length = phe.at(i).delta_page_length;
-	for (int j = 0; j < cphe.at(i).nshared_objects; ++j)
+	for (size_t j = 0; j < toS(cphe.at(i).nshared_objects); ++j)
 	{
 	    phe.at(i).shared_identifiers.push_back(
 		cphe.at(i).shared_identifiers.at(j));
@@ -2039,7 +2046,7 @@ QPDF::calculateHSharedObject(
 	csoe.at(0).object, 1, lengths, obj_renumber);
     int max_length = min_length;
-    for (int i = 0; i < cso.nshared_total; ++i)
+    for (size_t i = 0; i < toS(cso.nshared_total); ++i)
     {
 	// Assign absolute numbers to deltas; adjust later
 	int length = outputLengthNextN(
@@ -2066,7 +2073,7 @@ QPDF::calculateHSharedObject(
     so.min_group_length = min_length;
     so.nbits_delta_group_length = nbits(max_length - min_length);
-    for (int i = 0; i < cso.nshared_total; ++i)
+    for (size_t i = 0; i < toS(cso.nshared_total); ++i)
     {
 	// Adjust deltas
 	if (soe.at(i).delta_group_length < min_length)
@@ -2110,9 +2117,10 @@ write_vector_int(BitWriter&amp; w, int nitems, std::vector&lt;T&gt;&amp; vec,
     // nitems times, write bits bits from the given field of the ith
     // vector to the given bit writer.
-    for (int i = 0; i < nitems; ++i)
+    for (size_t i = 0; i < QIntC::to_size(nitems); ++i)
     {
-	w.writeBits(vec.at(i).*field, bits);
+	w.writeBits(QIntC::to_ulonglong(vec.at(i).*field),
+                    QIntC::to_size(bits));
     }
     // The PDF spec says that each hint table starts at a byte
     // boundary.  Each "row" actually must start on a byte boundary.
@@ -2127,11 +2135,12 @@ write_vector_vector(BitWriter&amp; w,
 {
     // nitems1 times, write nitems2 (from the ith element of vec1) items
     // from the vec2 vector field of the ith item of vec1.
-    for (int i1 = 0; i1 < nitems1; ++i1)
+    for (size_t i1 = 0; i1 < QIntC::to_size(nitems1); ++i1)
     {
-	for (int i2 = 0; i2 < vec1.at(i1).*nitems2; ++i2)
+	for (size_t i2 = 0; i2 < QIntC::to_size(vec1.at(i1).*nitems2); ++i2)
 	{
-	    w.writeBits((vec1.at(i1).*vec2).at(i2), bits);
+	    w.writeBits(QIntC::to_ulonglong((vec1.at(i1).*vec2).at(i2)),
+                        QIntC::to_size(bits));
 	}
     }
     w.flush();
@@ -2143,21 +2152,21 @@ QPDF::writeHPageOffset(BitWriter&amp; w)
 {
     HPageOffset& t = this->m->page_offset_hints;
-    w.writeBits(t.min_nobjects, 32);			    // 1
-    w.writeBits(t.first_page_offset, 32);		    // 2
-    w.writeBits(t.nbits_delta_nobjects, 16);		    // 3
-    w.writeBits(t.min_page_length, 32);			    // 4
-    w.writeBits(t.nbits_delta_page_length, 16);		    // 5
-    w.writeBits(t.min_content_offset, 32);		    // 6
-    w.writeBits(t.nbits_delta_content_offset, 16);	    // 7
-    w.writeBits(t.min_content_length, 32);		    // 8
-    w.writeBits(t.nbits_delta_content_length, 16);	    // 9
-    w.writeBits(t.nbits_nshared_objects, 16);		    // 10
-    w.writeBits(t.nbits_shared_identifier, 16);		    // 11
-    w.writeBits(t.nbits_shared_numerator, 16);		    // 12
-    w.writeBits(t.shared_denominator, 16);		    // 13
-
-    unsigned int nitems = getAllPages().size();
+    w.writeBitsInt(t.min_nobjects, 32);                     // 1
+    w.writeBitsInt(toI(t.first_page_offset), 32);           // 2
+    w.writeBitsInt(t.nbits_delta_nobjects, 16);             // 3
+    w.writeBitsInt(t.min_page_length, 32);                  // 4
+    w.writeBitsInt(t.nbits_delta_page_length, 16);          // 5
+    w.writeBitsInt(t.min_content_offset, 32);               // 6
+    w.writeBitsInt(t.nbits_delta_content_offset, 16);       // 7
+    w.writeBitsInt(t.min_content_length, 32);               // 8
+    w.writeBitsInt(t.nbits_delta_content_length, 16);       // 9
+    w.writeBitsInt(t.nbits_nshared_objects, 16);            // 10
+    w.writeBitsInt(t.nbits_shared_identifier, 16);          // 11
+    w.writeBitsInt(t.nbits_shared_numerator, 16);           // 12
+    w.writeBitsInt(t.shared_denominator, 16);               // 13
+
+    int nitems = toI(getAllPages().size());
     std::vector<HPageOffsetEntry>& entries = t.entries;
     write_vector_int(w, nitems, entries,
@@ -2190,13 +2199,13 @@ QPDF::writeHSharedObject(BitWriter&amp; w)
 {
     HSharedObject& t = this->m->shared_object_hints;
-    w.writeBits(t.first_shared_obj, 32);		    // 1
-    w.writeBits(t.first_shared_offset, 32);		    // 2
-    w.writeBits(t.nshared_first_page, 32);		    // 3
-    w.writeBits(t.nshared_total, 32);			    // 4
-    w.writeBits(t.nbits_nobjects, 16);			    // 5
-    w.writeBits(t.min_group_length, 32);		    // 6
-    w.writeBits(t.nbits_delta_group_length, 16);	    // 7
+    w.writeBitsInt(t.first_shared_obj, 32);                 // 1
+    w.writeBitsInt(toI(t.first_shared_offset), 32);         // 2
+    w.writeBitsInt(t.nshared_first_page, 32);               // 3
+    w.writeBitsInt(t.nshared_total, 32);                    // 4
+    w.writeBitsInt(t.nbits_nobjects, 16);                   // 5
+    w.writeBitsInt(t.min_group_length, 32);                 // 6
+    w.writeBitsInt(t.nbits_delta_group_length, 16);         // 7
     QTC::TC("qpdf", "QPDF lin write nshared_total > nshared_first_page",
 	    (t.nshared_total > t.nshared_first_page) ? 1 : 0);
@@ -2209,7 +2218,7 @@ QPDF::writeHSharedObject(BitWriter&amp; w)
 		     &HSharedObjectEntry::delta_group_length);
     write_vector_int(w, nitems, entries,
 		     1, &HSharedObjectEntry::signature_present);
-    for (int i = 0; i < nitems; ++i)
+    for (size_t i = 0; i < toS(nitems); ++i)
     {
 	// If signature were present, we'd have to write a 128-bit hash.
 	if (entries.at(i).signature_present != 0)
@@ -2226,10 +2235,10 @@ QPDF::writeHSharedObject(BitWriter&amp; w)
 void
 QPDF::writeHGeneric(BitWriter& w, HGeneric& t)
 {
-    w.writeBits(t.first_object, 32);			    // 1
-    w.writeBits(t.first_object_offset, 32);		    // 2
-    w.writeBits(t.nobjects, 32);			    // 3
-    w.writeBits(t.group_length, 32);			    // 4
+    w.writeBitsInt(t.first_object, 32);                     // 1
+    w.writeBitsInt(toI(t.first_object_offset), 32);         // 2
+    w.writeBitsInt(t.nobjects, 32);                         // 3
+    w.writeBitsInt(t.group_length, 32);                     // 4
 }
 void
@@ -2252,12 +2261,12 @@ QPDF::generateHintStream(std::map&lt;int, QPDFXRefEntry&gt; const&amp; xref,
     BitWriter w(&c);
     writeHPageOffset(w);
-    S = c.getCount();
+    S = toI(c.getCount());
     writeHSharedObject(w);
     O = 0;
     if (this->m->outline_hints.nobjects > 0)
     {
-	O = c.getCount();
+	O = toI(c.getCount());
 	writeHGeneric(w, this->m->outline_hints);
     }
     c.finish();
@@ -87,11 +87,11 @@ QPDF::optimize(std::map&lt;int, int&gt; const&amp; object_stream_data,
     pushInheritedAttributesToPage(allow_changes, false);
     // Traverse pages
-    int n = this->m->all_pages.size();
+    int n = toI(this->m->all_pages.size());
     for (int pageno = 0; pageno < n; ++pageno)
     {
         updateObjectMaps(ObjUser(ObjUser::ou_page, pageno),
-                         this->m->all_pages.at(pageno));
+                         this->m->all_pages.at(toS(pageno)));
     }
     // Traverse document-level items
@@ -154,17 +154,17 @@ QPDF::flattenPagesTree()
     QPDFObjectHandle pages = getRoot().getKey("/Pages");
-    int const len = this->m->all_pages.size();
-    for (int pos = 0; pos < len; ++pos)
+    size_t const len = this->m->all_pages.size();
+    for (size_t pos = 0; pos < len; ++pos)
     {
         // populate pageobj_to_pages_pos and fix parent pointer
-        insertPageobjToPage(this->m->all_pages.at(pos), pos, true);
+        insertPageobjToPage(this->m->all_pages.at(pos), toI(pos), true);
         this->m->all_pages.at(pos).replaceKey("/Parent", pages);
     }
     pages.replaceKey("/Kids", QPDFObjectHandle::newArray(this->m->all_pages));
     // /Count has not changed
-    if (pages.getKey("/Count").getIntValue() != len)
+    if (pages.getKey("/Count").getUIntValue() != len)
     {
         throw std::logic_error("/Count is wrong after flattening pages tree");
     }
@@ -222,26 +222,25 @@ QPDF::insertPage(QPDFObjectHandle newpage, int pos)
     QTC::TC("qpdf", "QPDF insert page",
             (pos == 0) ? 0 :                      // insert at beginning
-            (pos == static_cast<int>(this->m->all_pages.size())) ? 1 : // at end
+            (pos == QIntC::to_int(this->m->all_pages.size())) ? 1 : // at end
             2);                                   // insert in middle
     QPDFObjectHandle pages = getRoot().getKey("/Pages");
     QPDFObjectHandle kids = pages.getKey("/Kids");
-    assert ((pos >= 0) &&
-            (static_cast<size_t>(pos) <= this->m->all_pages.size()));
+    assert ((pos >= 0) && (QIntC::to_size(pos) <= this->m->all_pages.size()));
     newpage.replaceKey("/Parent", pages);
     kids.insertItem(pos, newpage);
     int npages = kids.getArrayNItems();
     pages.replaceKey("/Count", QPDFObjectHandle::newInteger(npages));
     this->m->all_pages.insert(this->m->all_pages.begin() + pos, newpage);
-    assert(this->m->all_pages.size() == static_cast<size_t>(npages));
+    assert(this->m->all_pages.size() == QIntC::to_size(npages));
     for (int i = pos + 1; i < npages; ++i)
     {
-        insertPageobjToPage(this->m->all_pages.at(i), i, false);
+        insertPageobjToPage(this->m->all_pages.at(toS(i)), i, false);
     }
     insertPageobjToPage(newpage, pos, true);
-    assert(this->m->pageobj_to_pages_pos.size() == static_cast<size_t>(npages));
+    assert(this->m->pageobj_to_pages_pos.size() == QIntC::to_size(npages));
 }
 void
@@ -250,8 +249,7 @@ QPDF::removePage(QPDFObjectHandle page)
     int pos = findPage(page); // also ensures flat /Pages
     QTC::TC("qpdf", "QPDF remove page",
             (pos == 0) ? 0 :                            // remove at beginning
-            (pos == static_cast<int>(
-                this->m->all_pages.size() - 1)) ? 1 :   // end
+            (pos == QIntC::to_int(this->m->all_pages.size() - 1)) ? 1 : // end
             2);                                         // remove in middle
     QPDFObjectHandle pages = getRoot().getKey("/Pages");
@@ -261,12 +259,12 @@ QPDF::removePage(QPDFObjectHandle page)
     int npages = kids.getArrayNItems();
     pages.replaceKey("/Count", QPDFObjectHandle::newInteger(npages));
     this->m->all_pages.erase(this->m->all_pages.begin() + pos);
-    assert(this->m->all_pages.size() == static_cast<size_t>(npages));
+    assert(this->m->all_pages.size() == QIntC::to_size(npages));
     this->m->pageobj_to_pages_pos.erase(page.getObjGen());
-    assert(this->m->pageobj_to_pages_pos.size() == static_cast<size_t>(npages));
+    assert(this->m->pageobj_to_pages_pos.size() == QIntC::to_size(npages));
     for (int i = pos; i < npages; ++i)
     {
-        insertPageobjToPage(this->m->all_pages.at(i), i, false);
+        insertPageobjToPage(this->m->all_pages.at(toS(i)), i, false);
     }
 }
@@ -291,8 +289,9 @@ QPDF::addPage(QPDFObjectHandle newpage, bool first)
     }
     else
     {
-        insertPage(newpage,
-                   getRoot().getKey("/Pages").getKey("/Count").getIntValue());
+        insertPage(
+            newpage,
+            getRoot().getKey("/Pages").getKey("/Count").getIntValueAsInt());
     }
 }
@@ -251,15 +251,15 @@ int_to_string_base_internal(T num, int base, int length)
     std::ostringstream buf;
     buf << std::setbase(base) << std::nouppercase << num;
     std::string result;
-    if ((length > 0) &&
-        (buf.str().length() < QIntC::to_size(length)))
+    int str_length = QIntC::to_int(buf.str().length());
+    if ((length > 0) && (str_length < length))
     {
-	result.append(length - buf.str().length(), '0');
+	result.append(QIntC::to_size(length - str_length), '0');
     }
     result += buf.str();
-    if ((length < 0) && (buf.str().length() < QIntC::to_size(-length)))
+    if ((length < 0) && (str_length < -length))
     {
-	result.append(-length - buf.str().length(), ' ');
+	result.append(QIntC::to_size(-length - str_length), ' ');
     }
     return result;
 }
@@ -273,7 +273,7 @@ QUtil::int_to_string(long long num, int length)
 std::string
 QUtil::uint_to_string(unsigned long long num, int length)
 {
-    return int_to_string_base(num, 10, length);
+    return uint_to_string_base(num, 10, length);
 }
 std::string
@@ -420,7 +420,7 @@ QUtil::safe_fopen(char const* filename, char const* mode)
     wmode[strlen(mode)] = 0;
     for (size_t i = 0; i < strlen(mode); ++i)
     {
-        wmode[i] = mode[i];
+        wmode[i] = static_cast<wchar_t>(mode[i]);
     }
 #ifdef _MSC_VER
@@ -465,9 +465,7 @@ QUtil::seek(FILE* stream, qpdf_offset_t offset, int whence)
 # if defined _MSC_VER || defined __BORLANDC__
     return _fseeki64(stream, offset, whence);
 # else
-    return fseek(stream,
-                 QIntC::IntConverter<qpdf_offset_t, long>(offset),
-                 whence);
+    return fseek(stream, QIntC::to_long(offset), whence);
 # endif
 #endif
 }
@@ -572,17 +570,15 @@ QUtil::hex_decode(std::string const&amp; input)
         bool skip = false;
         if ((*p >= 'A') && (*p <= 'F'))
         {
-            ch -= 'A';
-            ch += 10;
+            ch = QIntC::to_char(ch - 'A' + 10);
         }
         else if ((*p >= 'a') && (*p <= 'f'))
         {
-            ch -= 'a';
-            ch += 10;
+            ch = QIntC::to_char(ch - 'a' + 10);
         }
         else if ((*p >= '0') && (*p <= '9'))
         {
-            ch -= '0';
+            ch = QIntC::to_char(ch - '0');
         }
         else
         {
@@ -592,12 +588,12 @@ QUtil::hex_decode(std::string const&amp; input)
         {
             if (pos == 0)
             {
-                result.push_back(ch << 4);
+                result.push_back(static_cast<char>(ch << 4));
                 pos = 1;
             }
             else
             {
-                result[result.length()-1] += ch;
+                result[result.length()-1] |= ch;
                 pos = 0;
             }
         }
@@ -717,7 +713,7 @@ QUtil::get_current_time()
     uinow.LowPart = filenow.dwLowDateTime;
     uinow.HighPart = filenow.dwHighDateTime;
     ULONGLONG now = uinow.QuadPart;
-    return ((now / 10000000LL) - 11644473600LL);
+    return static_cast<time_t>((now / 10000000ULL) - 11644473600ULL);
 #else
     return time(0);
 #endif
@@ -762,7 +758,7 @@ QUtil::toUTF8(unsigned long uval)
 	    *cur_byte = static_cast<unsigned char>(0x80 + (uval & 0x3f));
 	    uval >>= 6;
 	    // Maximum that will fit in high byte now shrinks by one bit
-	    maxval >>= 1;
+	    maxval = static_cast<unsigned char>(maxval >> 1);
 	    // Slide to the left one byte
 	    if (cur_byte <= bytes)
 	    {
@@ -773,7 +769,7 @@ QUtil::toUTF8(unsigned long uval)
 	// If maxval is k bits long, the high (7 - k) bits of the
 	// resulting byte must be high.
 	*cur_byte = static_cast<unsigned char>(
-            (0xff - (1 + (maxval << 1))) + uval);
+            QIntC::to_ulong(0xff - (1 + (maxval << 1))) + uval);
 	result += reinterpret_cast<char*>(cur_byte);
     }
@@ -792,20 +788,22 @@ QUtil::toUTF16(unsigned long uval)
     else if (uval <= 0xffff)
     {
         char out[2];
-        out[0] = (uval & 0xff00) >> 8;
-        out[1] = (uval & 0xff);
+        out[0] = static_cast<char>((uval & 0xff00) >> 8);
+        out[1] = static_cast<char>(uval & 0xff);
         result = std::string(out, 2);
     }
     else if (uval <= 0x10ffff)
     {
         char out[4];
         uval -= 0x10000;
-        unsigned short high = ((uval & 0xffc00) >> 10) + 0xd800;
-        unsigned short low = (uval & 0x3ff) + 0xdc00;
-        out[0] = (high & 0xff00) >> 8;
-        out[1] = (high & 0xff);
-        out[2] = (low & 0xff00) >> 8;
-        out[3] = (low & 0xff);
+        unsigned short high =
+            static_cast<unsigned short>(((uval & 0xffc00) >> 10) + 0xd800);
+        unsigned short low =
+            static_cast<unsigned short>((uval & 0x3ff) + 0xdc00);
+        out[0] = static_cast<char>((high & 0xff00) >> 8);
+        out[1] = static_cast<char>(high & 0xff);
+        out[2] = static_cast<char>((low & 0xff00) >> 8);
+        out[3] = static_cast<char>(low & 0xff);
         result = std::string(out, 4);
     }
     else
@@ -1172,7 +1170,8 @@ QUtil::parse_numrange(char const* range, int max)
         if (p)
         {
             message = "error at * in numeric range " +
-                std::string(range, p - range) + "*" + p + ": " + e.what();
+                std::string(range, QIntC::to_size(p - range)) +
+                "*" + p + ": " + e.what();
         }
         else
         {
@@ -1764,7 +1763,7 @@ unsigned long get_next_utf8_codepoint(
     while (ch & bit_check)
     {
         ++bytes_needed;
-        to_clear |= bit_check;
+        to_clear = static_cast<unsigned char>(to_clear | bit_check);
         bit_check >>= 1;
     }
     if (((bytes_needed > 5) || (bytes_needed < 1)) ||
@@ -1774,11 +1773,11 @@ unsigned long get_next_utf8_codepoint(
         return 0xfffd;
     }
-    unsigned long codepoint = (ch & ~to_clear);
+    unsigned long codepoint = static_cast<unsigned long>(ch & ~to_clear);
     while (bytes_needed > 0)
     {
         --bytes_needed;
-        ch = utf8_val.at(++pos);
+        ch = static_cast<unsigned char>(utf8_val.at(++pos));
         if ((ch & 0xc0) != 0x80)
         {
             --pos;
@@ -1823,7 +1822,7 @@ transcode_utf8(std::string const&amp; utf8_val, std::string&amp; result,
             char ch = static_cast<char>(codepoint);
             if (encoding == e_utf16)
             {
-                result += QUtil::toUTF16(ch);
+                result += QUtil::toUTF16(QIntC::to_ulong(ch));
             }
             else
             {
@@ -1837,7 +1836,7 @@ transcode_utf8(std::string const&amp; utf8_val, std::string&amp; result,
         else if ((codepoint > 160) && (codepoint < 256) &&
                  ((encoding == e_winansi) || (encoding == e_pdfdoc)))
         {
-            result.append(1, static_cast<unsigned char>(codepoint & 0xff));
+            result.append(1, static_cast<char>(codepoint & 0xff));
         }
         else
         {
@@ -1859,7 +1858,7 @@ transcode_utf8(std::string const&amp; utf8_val, std::string&amp; result,
                 okay = false;
                 ch = static_cast<unsigned char>(unknown);
             }
-            result.append(1, ch);
+            result.append(1, static_cast<char>(ch));
         }
     }
     return okay;
@@ -1956,7 +1955,7 @@ QUtil::utf16_to_utf8(std::string const&amp; val)
     }
     // If the string has an odd number of bytes, the last byte is
     // ignored.
-    for (unsigned int i = start; i < len; i += 2)
+    for (size_t i = start; i < len; i += 2)
     {
         // Convert from UTF16-BE.  If we get a malformed
         // codepoint, this code will generate incorrect output
@@ -1965,11 +1964,12 @@ QUtil::utf16_to_utf8(std::string const&amp; val)
         // discarded, and a low codepoint not preceded by a high
         // codepoint will just get its low 10 bits output.
         unsigned short bits =
-            (static_cast<unsigned char>(val.at(i)) << 8) +
-            static_cast<unsigned char>(val.at(i+1));
+            QIntC::to_ushort(
+                (static_cast<unsigned char>(val.at(i)) << 8) +
+                static_cast<unsigned char>(val.at(i+1)));
         if ((bits & 0xFC00) == 0xD800)
         {
-            codepoint = 0x10000 + ((bits & 0x3FF) << 10);
+            codepoint = 0x10000U + ((bits & 0x3FFU) << 10U);
             continue;
         }
         else if ((bits & 0xFC00) == 0xDC00)
 #include <qpdf/RC4.hh>
+#include <qpdf/QIntC.hh>
 #include <string.h>
@@ -15,12 +16,13 @@ RC4::RC4(unsigned char const* key_data, int key_len)
 {
     if (key_len == -1)
     {
-	key_len = strlen(reinterpret_cast<char const*>(key_data));
+	key_len = QIntC::to_int(
+            strlen(reinterpret_cast<char const*>(key_data)));
     }
     for (int i = 0; i < 256; ++i)
     {
-        key.state[i] = i;
+        key.state[i] = static_cast<unsigned char>(i);
     }
     key.x = 0;
     key.y = 0;
@@ -36,7 +38,7 @@ RC4::RC4(unsigned char const* key_data, int key_len)
 }
 void
-RC4::process(unsigned char *in_data, int len, unsigned char* out_data)
+RC4::process(unsigned char *in_data, size_t len, unsigned char* out_data)
 {
     if (out_data == 0)
     {
@@ -44,10 +46,10 @@ RC4::process(unsigned char *in_data, int len, unsigned char* out_data)
 	out_data = in_data;
     }
-    for (int i = 0; i < len; ++i)
+    for (size_t i = 0; i < len; ++i)
     {
-	key.x = (key.x + 1) % 256;
-	key.y = (key.state[key.x] + key.y) % 256;
+	key.x = static_cast<unsigned char>((key.x + 1) % 256);
+	key.y = static_cast<unsigned char>((key.state[key.x] + key.y) % 256);
 	swap_byte(key.state[key.x], key.state[key.y]);
 	int xor_index = (key.state[key.x] + key.state[key.y]) % 256;
 	out_data[i] = in_data[i] ^ key.state[xor_index];
@@ -53,6 +53,7 @@ class WindowsCryptProvider
 #           pragma GCC diagnostic push
 #           pragma GCC diagnostic ignored "-Wold-style-cast"
 #           pragma GCC diagnostic ignored "-Wsign-compare"
+#           pragma GCC diagnostic ignored "-Wsign-conversion"
 #endif
             if (GetLastError() == NTE_BAD_KEYSET)
 #if ((defined(__GNUC__) && ((__GNUC__ * 100) + __GNUC_MINOR__) >= 406) || \
@@ -94,7 +95,8 @@ SecureRandomDataProvider::provideRandomData(unsigned char* data, size_t len)
     // Optimization: make the WindowsCryptProvider static as long as
     // it can be done in a thread-safe fashion.
     WindowsCryptProvider c;
-    if (! CryptGenRandom(c.crypt_prov, len, reinterpret_cast<BYTE*>(data)))
+    if (! CryptGenRandom(c.crypt_prov, static_cast<DWORD>(len),
+                         reinterpret_cast<BYTE*>(data)))
     {
         throw std::runtime_error("unable to generate secure random data");
     }
@@ -112,7 +114,7 @@ SecureRandomDataProvider::provideRandomData(unsigned char* data, size_t len)
     {
         throw std::runtime_error(
             "unable to read " +
-            QUtil::int_to_string(len) +
+            QUtil::uint_to_string(len) +
             " bytes from " + std::string(RANDOM_DEVICE));
     }
@@ -16,8 +16,8 @@
 #ifdef BITS_READ
 static unsigned long long
-read_bits(unsigned char const*& p, unsigned int& bit_offset,
-	  unsigned int& bits_available, unsigned int bits_wanted)
+read_bits(unsigned char const*& p, size_t& bit_offset,
+	  size_t& bits_available, size_t bits_wanted)
 {
     // View p as a stream of bits:
@@ -46,11 +46,12 @@ read_bits(unsigned char const*&amp; p, unsigned int&amp; bit_offset,
     {
 	// Grab bits from the first byte clearing anything before
 	// bit_offset.
-	unsigned char byte = *p & ((1 << (bit_offset + 1)) - 1);
+	unsigned char byte = static_cast<unsigned char>(
+            *p & ((1U << (bit_offset + 1U)) - 1U));
 	// There are bit_offset + 1 bits available in the first byte.
-	unsigned int to_copy = std::min(bits_wanted, bit_offset + 1);
-	unsigned int leftover = (bit_offset + 1) - to_copy;
+	size_t to_copy = std::min(bits_wanted, bit_offset + 1);
+	size_t leftover = (bit_offset + 1) - to_copy;
 #ifdef BITS_TESTING
 	QTC::TC("libtests", "bits bit_offset",
@@ -61,7 +62,7 @@ read_bits(unsigned char const*&amp; p, unsigned int&amp; bit_offset,
 #endif
 	// Right shift so that all the bits we want are right justified.
-	byte >>= leftover;
+	byte = static_cast<unsigned char>(byte >> leftover);
 	// Copy the bits into result
 	result <<= to_copy;
@@ -94,8 +95,8 @@ read_bits(unsigned char const*&amp; p, unsigned int&amp; bit_offset,
 #ifdef BITS_WRITE
 static void
-write_bits(unsigned char& ch, unsigned int& bit_offset,
-	   unsigned long long val, unsigned int bits, Pipeline* pipeline)
+write_bits(unsigned char& ch, size_t& bit_offset,
+	   unsigned long long val, size_t bits, Pipeline* pipeline)
 {
     if (bits > 32)
     {
@@ -111,11 +112,11 @@ write_bits(unsigned char&amp; ch, unsigned int&amp; bit_offset,
 #endif
     while (bits > 0)
     {
-	int bits_to_write = std::min(bits, bit_offset + 1);
-	unsigned char newval =
-	    (val >> (bits - bits_to_write)) & ((1 << bits_to_write) - 1);
-	int bits_left_in_ch = bit_offset + 1 - bits_to_write;
-	newval <<= bits_left_in_ch;
+	size_t bits_to_write = std::min(bits, bit_offset + 1);
+	unsigned char newval = static_cast<unsigned char>(
+	    (val >> (bits - bits_to_write)) & ((1U << bits_to_write) - 1));
+	size_t bits_left_in_ch = bit_offset + 1 - bits_to_write;
+	newval = static_cast<unsigned char>(newval << bits_left_in_ch);
 	ch |= newval;
 	if (bits_left_in_ch == 0)
 	{
@@ -5,6 +5,7 @@
 #include <qpdf/QTC.hh>
 #include <qpdf/QPDFExc.hh>
 #include <qpdf/Pl_Discard.hh>
+#include <qpdf/QIntC.hh>
 #include <list>
 #include <string>
@@ -63,7 +64,7 @@ static void call_read(qpdf_data qpdf)
 static void call_read_memory(qpdf_data qpdf)
 {
     qpdf->qpdf->processMemoryFile(qpdf->filename, qpdf->buffer,
-				  qpdf->size, qpdf->password);
+				  QIntC::to_size(qpdf->size), qpdf->password);
 }
 // must set qpdf->filename
@@ -234,7 +235,7 @@ unsigned long long qpdf_get_error_file_position(qpdf_data qpdf, qpdf_error e)
     {
 	return 0;
     }
-    return e->exc->getFilePosition();
+    return QIntC::to_ulonglong(e->exc->getFilePosition());
 }
 char const* qpdf_get_error_message_detail(qpdf_data qpdf, qpdf_error e)
@@ -4,28 +4,33 @@
 #define BITSTREAM_HH
 #include <qpdf/DLL.h>
+#include <stddef.h>
 class BitStream
 {
   public:
     QPDF_DLL
-    BitStream(unsigned char const* p, int nbytes);
+    BitStream(unsigned char const* p, size_t nbytes);
     QPDF_DLL
     void reset();
     QPDF_DLL
-    unsigned long long getBits(int nbits);
+    unsigned long long getBits(size_t nbits);
     QPDF_DLL
-    long long getBitsSigned(int nbits);
+    long long getBitsSigned(size_t nbits);
+    // Only call getBitsInt when requesting a number of bits that will
+    // definitely fit in an int.
+    QPDF_DLL
+    int getBitsInt(size_t nbits);
     QPDF_DLL
     void skipToNextByte();
   private:
     unsigned char const* start;
-    int nbytes;
+    size_t nbytes;
     unsigned char const* p;
-    unsigned int bit_offset;
-    unsigned int bits_available;
+    size_t bit_offset;
+    size_t bits_available;
 };
 #endif // BITSTREAM_HH
@@ -4,6 +4,7 @@
 #define BITWRITER_HH
 #include <qpdf/DLL.h>
+#include <stddef.h>
 class Pipeline;
@@ -15,9 +16,11 @@ class BitWriter
     QPDF_DLL
     BitWriter(Pipeline* pl);
     QPDF_DLL
-    void writeBits(unsigned long long val, unsigned int bits);
+    void writeBits(unsigned long long val, size_t bits);
     QPDF_DLL
-    void writeBitsSigned(long long val, unsigned int bits);
+    void writeBitsSigned(long long val, size_t bits);
+    QPDF_DLL
+    void writeBitsInt(int val, size_t bits);
     // Force any partial byte to be written to the pipeline.
     QPDF_DLL
     void flush();
@@ -25,7 +28,7 @@ class BitWriter
   private:
     Pipeline* pl;
     unsigned char ch;
-    unsigned int bit_offset;
+    size_t bit_offset;
 };
 #endif // BITWRITER_HH
@@ -3,6 +3,7 @@
 #include <qpdf/DLL.h>
 #include <qpdf/qpdf-config.h>
+#include <qpdf/Types.h>
 #ifdef HAVE_INTTYPES_H
 # include <inttypes.h>
 #endif
@@ -25,9 +26,9 @@ class MD5
     QPDF_DLL
     void encodeString(char const* input_string);
-    // encodes file and finalizes
+    // encodes file and finalizes; offset < 0 reads whole file
     QPDF_DLL
-    void encodeFile(char const* filename, int up_to_size = -1);
+    void encodeFile(char const* filename, qpdf_offset_t up_to_offset = -1);
     // appends string to current md5 object
     QPDF_DLL
@@ -35,7 +36,7 @@ class MD5
     // appends arbitrary data to current md5 object
     QPDF_DLL
-    void encodeDataIncrementally(char const* input_data, int len);
+    void encodeDataIncrementally(char const* input_data, size_t len);
     // computes a raw digest
     QPDF_DLL
@@ -52,16 +53,17 @@ class MD5
     // Convenience functions
     QPDF_DLL
-    static std::string getDataChecksum(char const* buf, int len);
+    static std::string getDataChecksum(char const* buf, size_t len);
     QPDF_DLL
     static std::string getFileChecksum(char const* filename,
-				       int up_to_size = -1);
+				       qpdf_offset_t up_to_offset = -1);
     QPDF_DLL
     static bool checkDataChecksum(char const* const checksum,
-				  char const* buf, int len);
+				  char const* buf, size_t len);
     QPDF_DLL
     static bool checkFileChecksum(char const* const checksum,
-				  char const* filename, int up_to_size = -1);
+				  char const* filename,
+                                  qpdf_offset_t up_to_offset = -1);
   private:
     // POINTER defines a generic pointer type
@@ -74,12 +76,12 @@ class MD5
     typedef uint32_t UINT4;
     void init();
-    void update(unsigned char *, unsigned int);
+    void update(unsigned char *, size_t);
     void final();
     static void transform(UINT4 [4], unsigned char [64]);
-    static void encode(unsigned char *, UINT4 *, unsigned int);
-    static void decode(UINT4 *, unsigned char *, unsigned int);
+    static void encode(unsigned char *, UINT4 *, size_t);
+    static void decode(UINT4 *, unsigned char *, size_t);
     UINT4 state[4];		// state (ABCD)
     UINT4 count[2];		// number of bits, modulo 2^64 (lsb first)
@@ -16,7 +16,8 @@ class Pl_AES_PDF: public Pipeline
     QPDF_DLL
     // key should be a pointer to key_bytes bytes of data
     Pl_AES_PDF(char const* identifier, Pipeline* next,
-	       bool encrypt, unsigned char const* key, unsigned int key_bytes);
+	       bool encrypt, unsigned char const* key,
+               size_t key_bytes);
     QPDF_DLL
     virtual ~Pl_AES_PDF();
@@ -18,7 +18,7 @@ class Pl_ASCII85Decoder: public Pipeline
   private:
     void flush();
-    char inbuf[5];
+    unsigned char inbuf[5];
     size_t pos;
     size_t eod;
 };
@@ -21,23 +21,23 @@ class Pl_LZWDecoder: public Pipeline
   private:
     void sendNextCode();
-    void handleCode(int code);
-    unsigned char getFirstChar(int code);
+    void handleCode(unsigned int code);
+    unsigned char getFirstChar(unsigned int code);
     void addToTable(unsigned char next);
     // members used for converting bits to codes
     unsigned char buf[3];
-    int code_size;
-    int next;
-    int byte_pos;
-    int bit_pos;		// left to right: 01234567
-    int bits_available;
+    unsigned int code_size;
+    unsigned int next;
+    unsigned int byte_pos;
+    unsigned int bit_pos;       // left to right: 01234567
+    unsigned int bits_available;
     // members used for handle LZW decompression
     bool code_change_delta;
     bool eod;
     std::vector<Buffer> table;
-    int last_code;
+    unsigned int last_code;
 };
 #endif // PL_LZWDECODER_HH
@@ -8,7 +8,7 @@
 class Pl_RC4: public Pipeline
 {
   public:
-    static int const def_bufsize = 65536;
+    static size_t const def_bufsize = 65536;
     // key_len of -1 means treat key_data as a null-terminated string
     QPDF_DLL
 #ifndef RC4_HH
 #define RC4_HH
+#include <stddef.h>
+
 class RC4
 {
   public:
@@ -8,7 +10,8 @@ class RC4
     RC4(unsigned char const* key_data, int key_len = -1);
     // out_data = 0 means to encrypt/decrypt in place
-    void process(unsigned char* in_data, int len, unsigned char* out_data = 0);
+    void process(unsigned char* in_data, size_t len,
+                 unsigned char* out_data = 0);
   private:
     class RC4Key
@@ -8,14 +8,15 @@
 #ifdef HAVE_STDINT_H
 # include <stdint.h>
 #endif
+#include <stddef.h>
-int rijndaelSetupEncrypt(uint32_t *rk, const unsigned char *key,
-  int keybits);
-int rijndaelSetupDecrypt(uint32_t *rk, const unsigned char *key,
-  int keybits);
-void rijndaelEncrypt(const uint32_t *rk, int nrounds,
+unsigned int rijndaelSetupEncrypt(uint32_t *rk, const unsigned char *key,
+  size_t keybits);
+unsigned int rijndaelSetupDecrypt(uint32_t *rk, const unsigned char *key,
+  size_t keybits);
+void rijndaelEncrypt(const uint32_t *rk, unsigned int nrounds,
   const unsigned char plaintext[16], unsigned char ciphertext[16]);
-void rijndaelDecrypt(const uint32_t *rk, int nrounds,
+void rijndaelDecrypt(const uint32_t *rk, unsigned int nrounds,
   const unsigned char ciphertext[16], unsigned char plaintext[16]);
 #define KEYLENGTH(keybits) ((keybits)/8)
@@ -710,7 +710,7 @@ static const u32 rcon[] =
  *
  * @return the number of rounds for the given cipher key size.
  */
-int rijndaelSetupEncrypt(u32 *rk, const u8 *key, int keybits)
+unsigned int rijndaelSetupEncrypt(u32 *rk, const u8 *key, size_t keybits)
 {
   int i = 0;
   u32 temp;
@@ -799,9 +799,9 @@ int rijndaelSetupEncrypt(u32 *rk, const u8 *key, int keybits)
  *
  * @return the number of rounds for the given cipher key size.
  */
-int rijndaelSetupDecrypt(u32 *rk, const u8 *key, int keybits)
+unsigned int rijndaelSetupDecrypt(u32 *rk, const u8 *key, size_t keybits)
 {
-  int nrounds, i, j;
+  unsigned int nrounds, i, j;
   u32 temp;
   /* expand the cipher key: */
@@ -842,7 +842,8 @@ int rijndaelSetupDecrypt(u32 *rk, const u8 *key, int keybits)
   return nrounds;
 }
-void rijndaelEncrypt(const u32 *rk, int nrounds, const u8 plaintext[16],
+void rijndaelEncrypt(const u32 *rk, unsigned int nrounds,
+                     const u8 plaintext[16],
   u8 ciphertext[16])
 {
   u32 s0, s1, s2, s3, t0, t1, t2, t3;
@@ -1024,7 +1025,8 @@ void rijndaelEncrypt(const u32 *rk, int nrounds, const u8 plaintext[16],
   PUTU32(ciphertext + 12, s3);
 }
-void rijndaelDecrypt(const u32 *rk, int nrounds, const u8 ciphertext[16],
+void rijndaelDecrypt(const u32 *rk, unsigned int nrounds,
+                     const u8 ciphertext[16],
   u8 plaintext[16])
 {
   u32 s0, s1, s2, s3, t0, t1, t2, t3;
@@ -145,7 +145,7 @@ SPH_XCAT(sph_, HASH)(void *cc, const void *data, size_t len)
 		clen = SPH_BLEN - current;
 		if (clen > len)
-			clen = len;
+			clen = (unsigned)len;
 		memcpy(sc->buf + current, data, clen);
 		data = (const unsigned char *)data + clen;
 		current += clen;
@@ -257,7 +257,7 @@ SPH_XCAT(HASH, _addbits_and_close)(void *cc,
 	{
 		unsigned z;
-		z = 0x80 >> n;
+		z = 0x80U >> n;
 		sc->buf[current ++] = ((ub & -z) | z) & 0xFF;
 	}
 #endif
@@ -1337,8 +1337,8 @@ sph_bswap64(sph_u64 x)
 static SPH_INLINE void
 sph_enc16be(void *dst, unsigned val)
 {
-	((unsigned char *)dst)[0] = (val >> 8);
-	((unsigned char *)dst)[1] = val;
+	((unsigned char *)dst)[0] = (unsigned char)(val >> 8);
+	((unsigned char *)dst)[1] = (unsigned char)val;
 }
 static SPH_INLINE unsigned
@@ -1351,8 +1351,8 @@ sph_dec16be(const void *src)
 static SPH_INLINE void
 sph_enc16le(void *dst, unsigned val)
 {
-	((unsigned char *)dst)[0] = val;
-	((unsigned char *)dst)[1] = val >> 8;
+	((unsigned char *)dst)[0] = (unsigned char)val;
+	((unsigned char *)dst)[1] = (unsigned char)(val >> 8);
 }
 static SPH_INLINE unsigned
 #include <qpdf/Pl_AES_PDF.hh>
 #include <qpdf/Pl_StdioFile.hh>
 #include <qpdf/QUtil.hh>
+#include <qpdf/QIntC.hh>
 #include <stdio.h>
 #include <string.h>
@@ -87,7 +88,7 @@ int main(int argc, char* argv[])
         usage();
     }
-    unsigned int hexkeylen = strlen(hexkey);
+    unsigned int hexkeylen = QIntC::to_uint(strlen(hexkey));
     unsigned int keylen = hexkeylen / 2;
     FILE* infile = QUtil::safe_fopen(infilename, "rb");
 #include <qpdf/BitStream.hh>
 #include <qpdf/BitWriter.hh>
 #include <qpdf/Pl_Buffer.hh>
+#include <qpdf/QUtil.hh>
+#include <qpdf/QIntC.hh>
 #include <iostream>
 #include <stdio.h>
 #include <stdlib.h>
@@ -12,8 +14,8 @@
 #include "../libqpdf/bits.icc"
 static void
-print_values(int byte_offset, unsigned int bit_offset,
-	     unsigned int bits_available)
+print_values(long long byte_offset, size_t bit_offset,
+	     size_t bits_available)
 {
     std::cout << "byte offset = " << byte_offset << ", "
 	      << "bit offset = " << bit_offset << ", "
@@ -22,11 +24,11 @@ print_values(int byte_offset, unsigned int bit_offset,
 static void
 test_read_bits(unsigned char const* buf,
-	       unsigned char const*& p, unsigned int& bit_offset,
-	       unsigned int& bits_available, int bits_wanted)
+	       unsigned char const*& p, size_t& bit_offset,
+	       size_t& bits_available, size_t bits_wanted)
 {
     unsigned long result =
-	read_bits(p, bit_offset, bits_available, bits_wanted);
+	QIntC::to_ulong(read_bits(p, bit_offset, bits_available, bits_wanted));
     std::cout << "bits read: " << bits_wanted << ", result = " << result
 	      << std::endl;
@@ -34,12 +36,12 @@ test_read_bits(unsigned char const* buf,
 }
 static void
-test_write_bits(unsigned char& ch, unsigned int& bit_offset, unsigned long val,
-		int bits, Pl_Buffer* bp)
+test_write_bits(unsigned char& ch, size_t& bit_offset, unsigned long val,
+		size_t bits, Pl_Buffer* bp)
 {
     write_bits(ch, bit_offset, val, bits, bp);
-    printf("ch = %02x, bit_offset = %d\n",
-           static_cast<unsigned int>(ch), bit_offset);
+    std::cout << "ch = " << QUtil::uint_to_string_base(ch, 16, 2)
+              << ", bit_offset = " << bit_offset << std::endl;
 }
 static void
@@ -51,10 +53,10 @@ print_buffer(Pl_Buffer* bp)
     size_t l = b->getSize();
     for (unsigned long i = 0; i < l; ++i)
     {
-	printf("%02x%s", static_cast<unsigned int>(p[i]),
-	       (i == l - 1) ? "\n" : " ");
+        std::cout << QUtil::uint_to_string_base(p[i], 16, 2)
+                  << ((i == l - 1) ? "\n" : " ");
     }
-    printf("\n");
+    std::cout << std::endl;
     delete b;
 }
@@ -71,8 +73,8 @@ test()
     };
     unsigned char const* p = buf;
-    unsigned int bit_offset = 7;
-    unsigned int bits_available = 64;
+    size_t bit_offset = 7;
+    size_t bits_available = 64;
     // 11110:101 0:001010:1 01100101: 01111001
     // 0:00:1:0010 10001001 01110101 01001:011
@@ -163,7 +165,7 @@ test()
     bw.writeBits(30UL, 5);
     bw.flush();
     bw.flush();
-    bw.writeBits(0xABUL, 8);
+    bw.writeBitsInt(0xAB, 8);
     bw.flush();
     print_buffer(bp);
     bw.writeBitsSigned(-1, 3);  // 111
@@ -42,8 +42,8 @@ int main(int argc, char* argv[])
     char* infilename = argv[1];
     char* outfilename = argv[2];
-    int width = QUtil::string_to_int(argv[3]);
-    int height = QUtil::string_to_int(argv[4]);
+    JDIMENSION width = QUtil::string_to_uint(argv[3]);
+    JDIMENSION height = QUtil::string_to_uint(argv[4]);
     char* colorspace = argv[5];
     J_COLOR_SPACE cs =
         ((strcmp(colorspace, "rgb") == 0) ? JCS_RGB :
@@ -2,6 +2,7 @@
 #include <qpdf/Pl_TIFFPredictor.hh>
 #include <qpdf/Pl_StdioFile.hh>
 #include <qpdf/QUtil.hh>
+#include <qpdf/QIntC.hh>
 #include <iostream>
 #include <errno.h>
@@ -11,7 +12,7 @@
 void run(char const* filename, char const* filter,
          bool encode, unsigned int columns,
-         int bits_per_sample, int samples_per_pixel)
+         unsigned int bits_per_sample, unsigned int samples_per_pixel)
 {
     FILE* in = QUtil::safe_fopen(filename, "rb");
     FILE* o1 = QUtil::safe_fopen("out", "wb");
@@ -89,7 +90,9 @@ int main(int argc, char* argv[])
     try
     {
 	run(filename, filter, encode,
-            columns, bits_per_sample, samples_per_pixel);
+            QIntC::to_uint(columns),
+            QIntC::to_uint(bits_per_sample),
+            QIntC::to_uint(samples_per_pixel));
     }
     catch (std::exception& e)
     {
@@ -48,10 +48,10 @@ int main()
     try_convert(true,  QIntC::to_uint<uint64_t>, ul2);
     try_convert(true,  QIntC::to_offset<uint32_t>, u1);
     try_convert(true,  QIntC::to_offset<int32_t>, i1);
-    try_convert(false, QIntC::to_size<int32_t>, i1);
+    try_convert(false, QIntC::to_ulonglong<int32_t>, i1);
     try_convert(true,  QIntC::to_char<int32_t>, i2);
     try_convert(true,  QIntC::to_uchar<int32_t>, i2);
-    try_convert(false,  QIntC::to_uchar<char>, c1);
+    try_convert(false, QIntC::to_uchar<char>, c1);
     return 0;
 }
@@ -7,7 +7,7 @@ QIntC::to_int&lt;uint64_t&gt;(ul2): 12345 12345 PASSED
 QIntC::to_uint<uint64_t>(ul2): 12345 12345 PASSED
 QIntC::to_offset<uint32_t>(u1): 3141592653 3141592653 PASSED
 QIntC::to_offset<int32_t>(i1): -1153374643 -1153374643 PASSED
-QIntC::to_size<int32_t>(i1): integer out of range converting -1153374643 from a 4-byte signed type to a 8-byte unsigned type PASSED
+QIntC::to_ulonglong<int32_t>(i1): integer out of range converting -1153374643 from a 4-byte signed type to a 8-byte unsigned type PASSED
 QIntC::to_char<int32_t>(i2): 81 Q PASSED
 QIntC::to_uchar<int32_t>(i2): 81 Q PASSED
 QIntC::to_uchar<char>(c1): integer out of range converting ÷ from a 1-byte signed type to a 1-byte unsigned type PASSED
@@ -12,6 +12,7 @@
 16059
 37273
 3ebb
+5000093552
 one
 7
 compare okay
@@ -93,7 +93,8 @@ void string_conversion_test()
               << QUtil::double_to_string(.000123456, 5) << std::endl
               << QUtil::int_to_string_base(16059, 10) << std::endl
               << QUtil::int_to_string_base(16059, 8) << std::endl
-              << QUtil::int_to_string_base(16059, 16) << std::endl;
+              << QUtil::int_to_string_base(16059, 16) << std::endl
+              << QUtil::int_to_string_base(5000093552LL, 10) << std::endl;
     std::string embedded_null = "one";
     embedded_null += '\0';
 #include <qpdf/Pl_RC4.hh>
 #include <qpdf/Pl_StdioFile.hh>
 #include <qpdf/QUtil.hh>
+#include <qpdf/QIntC.hh>
 #include <stdio.h>
 #include <string.h>
@@ -18,7 +19,7 @@ int main(int argc, char* argv[])
     char* hexkey = argv[1];
     char* infilename = argv[2];
     char* outfilename = argv[3];
-    unsigned int hexkeylen = strlen(hexkey);
+    unsigned int hexkeylen = QIntC::to_uint(strlen(hexkey));
     unsigned int keylen = hexkeylen / 2;
     unsigned char* key = new unsigned char[keylen + 1];
     key[keylen] = '\0';
@@ -38,7 +39,7 @@ int main(int argc, char* argv[])
     FILE* outfile = QUtil::safe_fopen(outfilename, "wb");
     Pl_StdioFile* out = new Pl_StdioFile("stdout", outfile);
     // Use a small buffer size (64) for testing
-    Pl_RC4* rc4 = new Pl_RC4("rc4", out, key, keylen, 64);
+    Pl_RC4* rc4 = new Pl_RC4("rc4", out, key, QIntC::to_int(keylen), 64U);
     delete [] key;
     // 64 < buffer size < 512, buffer_size is not a power of 2 for testing
@@ -391,7 +391,7 @@ static void test16(char const* infile,
     qpdf_set_stream_data_mode(qpdf, qpdf_s_uncompress);
     qpdf_write(qpdf);
     f = safe_fopen(outfile, "wb");
-    buflen = qpdf_get_buffer_length(qpdf);
+    buflen = (unsigned long)(qpdf_get_buffer_length(qpdf));
     buf = qpdf_get_buffer(qpdf);
     fwrite(buf, 1, buflen, f);
     fclose(f);
@@ -24,6 +24,7 @@
 #include <qpdf/QPDFExc.hh>
 #include <qpdf/QPDFWriter.hh>
+#include <qpdf/QIntC.hh>
 static int const EXIT_ERROR = 2;
 static int const EXIT_WARNING = 3;
@@ -1809,8 +1810,7 @@ ArgParser::argKeepFilesOpen(char* parameter)
 void
 ArgParser::argKeepFilesOpenThreshold(char* parameter)
 {
-    o.keep_files_open_threshold =
-        static_cast<size_t>(QUtil::string_to_int(parameter));
+    o.keep_files_open_threshold = QUtil::string_to_uint(parameter);
 }
 void
@@ -2039,25 +2039,25 @@ ArgParser::argRemovePageLabels()
 void
 ArgParser::argOiMinWidth(char* parameter)
 {
-    o.oi_min_width = QUtil::string_to_int(parameter);
+    o.oi_min_width = QUtil::string_to_uint(parameter);
 }
 void
 ArgParser::argOiMinHeight(char* parameter)
 {
-    o.oi_min_height = QUtil::string_to_int(parameter);
+    o.oi_min_height = QUtil::string_to_uint(parameter);
 }
 void
 ArgParser::argOiMinArea(char* parameter)
 {
-    o.oi_min_area = QUtil::string_to_int(parameter);
+    o.oi_min_area = QUtil::string_to_uint(parameter);
 }
 void
 ArgParser::argIiMinBytes(char* parameter)
 {
-    o.ii_min_bytes = QUtil::string_to_int(parameter);
+    o.ii_min_bytes = QUtil::string_to_uint(parameter);
 }
 void
@@ -2318,7 +2318,7 @@ ArgParser::handleArgFileArguments()
     {
         argv[i] = new_argv.at(i).getPointer();
     }
-    argc = static_cast<int>(new_argv.size());
+    argc = QIntC::to_int(new_argv.size());
     argv[argc] = 0;
 }
@@ -2423,7 +2423,7 @@ ArgParser::handleBashArguments()
     {
         argv[i] = bash_argv.at(i).getPointer();
     }
-    argc = static_cast<int>(bash_argv.size());
+    argc = QIntC::to_int(bash_argv.size());
     argv[argc] = 0;
 }
@@ -2648,7 +2648,8 @@ QPDFPageData::QPDFPageData(std::string const&amp; filename,
     try
     {
         this->selected_pages =
-            QUtil::parse_numrange(range, this->orig_pages.size());
+            QUtil::parse_numrange(range,
+                                  QIntC::to_int(this->orig_pages.size()));
     }
     catch (std::runtime_error& e)
     {
@@ -2805,8 +2806,8 @@ ArgParser::checkCompletion()
     if (QUtil::get_env("COMP_LINE", &bash_line) &&
         QUtil::get_env("COMP_POINT", &bash_point_env))
     {
-        int p = QUtil::string_to_int(bash_point_env.c_str());
-        if ((p > 0) && (p <= static_cast<int>(bash_line.length())))
+        size_t p = QUtil::string_to_uint(bash_point_env.c_str());
+        if ((p > 0) && (p <= bash_line.length()))
         {
             // Truncate the line. We ignore everything at or after the
             // cursor for completion purposes.
@@ -2844,7 +2845,7 @@ ArgParser::checkCompletion()
         {
             // Go back to the last separator and set prev based on
             // that.
-            int p1 = p;
+            size_t p1 = p;
             while (--p1 > 0)
             {
                 char ch = bash_line.at(p1);
@@ -3342,9 +3343,9 @@ static void do_show_pages(QPDF&amp; pdf, Options&amp; o)
                     QPDFObjectHandle image = (*iter).second;
                     QPDFObjectHandle dict = image.getDict();
                     int width =
-                        dict.getKey("/Width").getIntValue();
+                        dict.getKey("/Width").getIntValueAsInt();
                     int height =
-                        dict.getKey("/Height").getIntValue();
+                        dict.getKey("/Height").getIntValueAsInt();
                     std::cout << "    " << name << ": "
                               << image.unparse()
                               << ", " << width << " x " << height
@@ -3410,7 +3411,7 @@ static void do_json_pages(QPDF&amp; pdf, Options&amp; o, JSON&amp; j)
     QPDFOutlineDocumentHelper odh(pdf);
     pdh.pushInheritedAttributesToPage();
     std::vector<QPDFPageObjectHelper> pages = pdh.getAllPages();
-    size_t pageno = 0;
+    int pageno = 0;
     for (std::vector<QPDFPageObjectHelper>::iterator iter = pages.begin();
          iter != pages.end(); ++iter, ++pageno)
     {
@@ -3503,7 +3504,8 @@ static void do_json_page_labels(QPDF&amp; pdf, Options&amp; o, JSON&amp; j)
     if (pldh.hasPageLabels())
     {
         std::vector<QPDFObjectHandle> labels;
-        pldh.getLabelsForPageRange(0, pages.size() - 1, 0, labels);
+        pldh.getLabelsForPageRange(
+            0, QIntC::to_int(pages.size()) - 1, 0, labels);
         for (std::vector<QPDFObjectHandle>::iterator iter = labels.begin();
              iter != labels.end(); ++iter)
         {
@@ -3869,10 +3871,24 @@ ImageOptimizer::makePipeline(std::string const&amp; description, Pipeline* next)
     }
     // Files have been seen in the wild whose width and height are
     // floating point, which is goofy, but we can deal with it.
-    JDIMENSION w = static_cast<JDIMENSION>(
-        w_obj.isInteger() ? w_obj.getIntValue() : w_obj.getNumericValue());
-    JDIMENSION h = static_cast<JDIMENSION>(
-        h_obj.isInteger() ? h_obj.getIntValue() : h_obj.getNumericValue());
+    JDIMENSION w = 0;
+    if (w_obj.isInteger())
+    {
+        w = w_obj.getUIntValueAsUInt();
+    }
+    else
+    {
+        w = static_cast<JDIMENSION>(w_obj.getNumericValue());
+    }
+    JDIMENSION h = 0;
+    if (h_obj.isInteger())
+    {
+        h = h_obj.getUIntValueAsUInt();
+    }
+    else
+    {
+        h = static_cast<JDIMENSION>(h_obj.getNumericValue());
+    }
     std::string colorspace = (colorspace_obj.isName() ?
                               colorspace_obj.getName() :
                               std::string());
@@ -4119,10 +4135,10 @@ static void validate_under_overlay(QPDF&amp; pdf, UnderOverlay* uo, Options&amp; o)
         return;
     }
     QPDFPageDocumentHelper main_pdh(pdf);
-    int main_npages = static_cast<int>(main_pdh.getAllPages().size());
+    int main_npages = QIntC::to_int(main_pdh.getAllPages().size());
     uo->pdf = process_file(uo->filename, uo->password, o);
     QPDFPageDocumentHelper uo_pdh(*(uo->pdf));
-    int uo_npages = static_cast<int>(uo_pdh.getAllPages().size());
+    int uo_npages = QIntC::to_int(uo_pdh.getAllPages().size());
     try
     {
         uo->to_pagenos = QUtil::parse_numrange(uo->to_nr, main_npages);
@@ -4185,7 +4201,7 @@ static void do_under_overlay_for_page(
     QPDFPageObjectHelper& dest_page,
     bool before)
 {
-    int pageno = 1 + page_idx;
+    int pageno = 1 + QIntC::to_int(page_idx);
     if (! pagenos.count(pageno))
     {
         return;
@@ -4206,7 +4222,8 @@ static void do_under_overlay_for_page(
         {
             fo[from_pageno] =
                 pdf.copyForeignObject(
-                    pages.at(from_pageno - 1).getFormXObjectForPage());
+                    pages.at(QIntC::to_size(from_pageno - 1)).
+                    getFormXObjectForPage());
         }
         // If the same page is overlaid or underlaid multiple times,
         // we'll generate multiple names for it, but that's harmless
@@ -4594,7 +4611,8 @@ static void handle_page_specs(QPDF&amp; pdf, Options&amp; o)
             int pageno = *pageno_iter - 1;
             pldh.getLabelsForPageRange(pageno, pageno, out_pageno,
                                        new_labels);
-            QPDFPageObjectHelper to_copy = page_data.orig_pages.at(pageno);
+            QPDFPageObjectHelper to_copy =
+                page_data.orig_pages.at(QIntC::to_size(pageno));
             QPDFObjGen to_copy_og = to_copy.getObjectHandle().getObjGen();
             unsigned long long from_uuid = page_data.qpdf->getUniqueId();
             if (copied_pages[from_uuid].count(to_copy_og))
@@ -4634,7 +4652,7 @@ static void handle_page_specs(QPDF&amp; pdf, Options&amp; o)
     // other places, such as the outlines dictionary.
     for (size_t pageno = 0; pageno < orig_pages.size(); ++pageno)
     {
-        if (selected_from_orig.count(pageno) == 0)
+        if (selected_from_orig.count(QIntC::to_int(pageno)) == 0)
         {
             pdf.replaceObject(
                 orig_pages.at(pageno).getObjectHandle().getObjGen(),
@@ -4647,7 +4665,7 @@ static void handle_rotations(QPDF&amp; pdf, Options&amp; o)
 {
     QPDFPageDocumentHelper dh(pdf);
     std::vector<QPDFPageObjectHelper> pages = dh.getAllPages();
-    int npages = static_cast<int>(pages.size());
+    int npages = QIntC::to_int(pages.size());
     for (std::map<std::string, RotationSpec>::iterator iter =
              o.rotations.begin();
          iter != o.rotations.end(); ++iter)
@@ -4663,7 +4681,8 @@ static void handle_rotations(QPDF&amp; pdf, Options&amp; o)
             int pageno = *i2 - 1;
             if ((pageno >= 0) && (pageno < npages))
             {
-                pages.at(pageno).rotatePage(rspec.angle, rspec.relative);
+                pages.at(QIntC::to_size(pageno)).rotatePage(
+                    rspec.angle, rspec.relative);
             }
         }
     }
@@ -4957,7 +4976,8 @@ static void write_outfile(QPDF&amp; pdf, Options&amp; o)
         if (num_spot != 0)
         {
             QTC::TC("qpdf", "qpdf split-pages %d");
-            before = std::string(o.outfilename, (num_spot - o.outfilename));
+            before = std::string(o.outfilename,
+                                 QIntC::to_size(num_spot - o.outfilename));
             after = num_spot + 2;
         }
         else if ((len >= 4) &&
@@ -4980,19 +5000,19 @@ static void write_outfile(QPDF&amp; pdf, Options&amp; o)
         }
         QPDFPageLabelDocumentHelper pldh(pdf);
         std::vector<QPDFObjectHandle> const& pages = pdf.getAllPages();
-        int pageno_len = QUtil::int_to_string(pages.size()).length();
-        unsigned int num_pages = pages.size();
-        for (unsigned int i = 0; i < num_pages; i += o.split_pages)
+        size_t pageno_len = QUtil::uint_to_string(pages.size()).length();
+        size_t num_pages = pages.size();
+        for (size_t i = 0; i < num_pages; i += QIntC::to_size(o.split_pages))
         {
-            unsigned int first = i + 1;
-            unsigned int last = i + o.split_pages;
+            size_t first = i + 1;
+            size_t last = i + QIntC::to_size(o.split_pages);
             if (last > num_pages)
             {
                 last = num_pages;
             }
             QPDF outpdf;
             outpdf.emptyPDF();
-            for (unsigned int pageno = first; pageno <= last; ++pageno)
+            for (size_t pageno = first; pageno <= last; ++pageno)
             {
                 QPDFObjectHandle page = pages.at(pageno - 1);
                 outpdf.addPage(page, false);
@@ -5000,17 +5020,22 @@ static void write_outfile(QPDF&amp; pdf, Options&amp; o)
             if (pldh.hasPageLabels())
             {
                 std::vector<QPDFObjectHandle> labels;
-                pldh.getLabelsForPageRange(first - 1, last - 1, 0, labels);
+                pldh.getLabelsForPageRange(
+                    QIntC::to_longlong(first - 1),
+                    QIntC::to_longlong(last - 1),
+                    0, labels);
                 QPDFObjectHandle page_labels =
                     QPDFObjectHandle::newDictionary();
                 page_labels.replaceKey(
                     "/Nums", QPDFObjectHandle::newArray(labels));
                 outpdf.getRoot().replaceKey("/PageLabels", page_labels);
             }
-            std::string page_range = QUtil::int_to_string(first, pageno_len);
+            std::string page_range =
+                QUtil::uint_to_string(first, QIntC::to_int(pageno_len));
             if (o.split_pages > 1)
             {
-                page_range += "-" + QUtil::int_to_string(last, pageno_len);
+                page_range += "-" +
+                    QUtil::uint_to_string(last, QIntC::to_int(pageno_len));
             }
             std::string outfile = before + page_range + after;
             QPDFWriter w(outpdf, outfile.c_str());
@@ -5117,8 +5142,10 @@ int wmain(int argc, wchar_t* argv[])
         for (size_t j = 0; j < wcslen(argv[i]); ++j)
         {
             unsigned short codepoint = static_cast<unsigned short>(argv[i][j]);
-            utf16.append(1, static_cast<unsigned char>(codepoint >> 8));
-            utf16.append(1, static_cast<unsigned char>(codepoint & 0xff));
+            utf16.append(1, static_cast<char>(
+                             QIntC::to_uchar(codepoint >> 8)));
+            utf16.append(1, static_cast<char>(
+                             QIntC::to_uchar(codepoint & 0xff)));
         }
         std::string utf8 = QUtil::utf16_to_utf8(utf16);
         utf8_argv.push_back(
@@ -5131,7 +5158,7 @@ int wmain(int argc, wchar_t* argv[])
     {
         new_argv[i] = utf8_argv.at(i).getPointer();
     }
-    argc = static_cast<int>(utf8_argv.size());
+    argc = QIntC::to_int(utf8_argv.size());
     new_argv[argc] = 0;
     return realmain(argc, new_argv);
 }
@@ -17,6 +17,7 @@
 #include <qpdf/Pl_Flate.hh>
 #include <qpdf/QPDFWriter.hh>
 #include <qpdf/QPDFSystemError.hh>
+#include <qpdf/QIntC.hh>
 #include <iostream>
 #include <sstream>
 #include <algorithm>
@@ -173,7 +174,7 @@ static void read_file_into_memory(
 {
     FILE* f = QUtil::safe_fopen(filename, "rb");
     fseek(f, 0, SEEK_END);
-    size = QUtil::tell(f);
+    size = QIntC::to_size(QUtil::tell(f));
     fseek(f, 0, SEEK_SET);
     file_buf = PointerHolder<char>(true, new char[size]);
     char* buf_p = file_buf.getPointer();
@@ -280,7 +281,7 @@ void runtest(int n, char const* filename1, char const* arg2)
         char* p = file_buf.getPointer();
         for (size_t i = 0; i < size; ++i)
         {
-            p[i] ^= 0xcc;
+            p[i] = static_cast<char>(p[i] ^ 0xcc);
         }
 	pdf.processMemoryFile((std::string(filename1) + ".pdf").c_str(),
                               p, size);
@@ -544,8 +545,8 @@ void runtest(int n, char const* filename1, char const* arg2)
 		std::string const& name = (*iter).first;
 		QPDFObjectHandle image = (*iter).second;
 		QPDFObjectHandle dict = image.getDict();
-		int width = dict.getKey("/Width").getIntValue();
-		int height = dict.getKey("/Height").getIntValue();
+		long long width = dict.getKey("/Width").getIntValue();
+		long long height = dict.getKey("/Height").getIntValue();
 		std::cout << "    " << name
 			  << ": " << width << " x " << height
 			  << std::endl;
@@ -929,7 +930,8 @@ void runtest(int n, char const* filename1, char const* arg2)
         page.replaceKey("/Parent", pages);
         pages.replaceKey(
             "/Count",
-            QPDFObjectHandle::newInteger(1 + all_pages.size()));
+            QPDFObjectHandle::newInteger(
+                1 + QIntC::to_longlong(all_pages.size())));
         kids.appendItem(page);
         assert(all_pages.size() == 10);
         pdf.updateAllPagesCache();
@@ -1096,8 +1098,8 @@ void runtest(int n, char const* filename1, char const* arg2)
         // Verify that the previously added reserved keys can be
         // dereferenced properly now
-        int i1 = res1.getArrayItem(0).getArrayItem(1).getIntValue();
-        int i2 = res2.getArrayItem(0).getArrayItem(1).getIntValue();
+        int i1 = res1.getArrayItem(0).getArrayItem(1).getIntValueAsInt();
+        int i2 = res2.getArrayItem(0).getArrayItem(1).getIntValueAsInt();
         if ((i1 == 2) && (i2 == 1))
         {
             std::cout << "circular access and lazy resolution worked" << std::endl;
@@ -1424,7 +1426,7 @@ void runtest(int n, char const* filename1, char const* arg2)
             {
                 std::string t;
                 for (size_t i = 0;
-                     i < std::min(data.size(), static_cast<size_t>(20));
+                     i < std::min(data.size(), QIntC::to_size(20));
                      ++i)
                 {
                     if ((data.at(i) >= 32) && (data.at(i) <= 126))
@@ -1436,7 +1438,7 @@ void runtest(int n, char const* filename1, char const* arg2)
                         t += ".";
                     }
                 }
-                t += " (" + QUtil::int_to_string(data.size()) + " bytes)";
+                t += " (" + QUtil::uint_to_string(data.size()) + " bytes)";
                 data = t;
             }
             std::cout << filename << ":\n" << data << "--END--\n";
@@ -1797,7 +1799,7 @@ void runtest(int n, char const* filename1, char const* arg2)
     {
         // Test page labels.
         QPDFPageLabelDocumentHelper pldh(pdf);
-        size_t npages = pdf.getRoot().getKey("/Pages").
+        long long npages = pdf.getRoot().getKey("/Pages").
             getKey("/Count").getIntValue();
         std::vector<QPDFObjectHandle> labels;
         pldh.getLabelsForPageRange(0, npages - 1, 1, labels);
@@ -2076,7 +2078,7 @@ void runtest(int n, char const* filename1, char const* arg2)
         {
             pdf.processMemoryFile("empty", "", 0);
         }
-        catch (QPDFExc& e)
+        catch (QPDFExc const&)
         {
             std::cout << "Caught QPDFExc as expected" << std::endl;
         }
@@ -2084,7 +2086,7 @@ void runtest(int n, char const* filename1, char const* arg2)
         {
             QUtil::safe_fopen("/does/not/exist", "r");
         }
-        catch (QPDFSystemError& e)
+        catch (QPDFSystemError const&)
         {
             std::cout << "Caught QPDFSystemError as expected" << std::endl;
         }
@@ -2092,7 +2094,7 @@ void runtest(int n, char const* filename1, char const* arg2)
         {
             QUtil::int_to_string_base(0, 12);
         }
-        catch (std::logic_error& e)
+        catch (std::logic_error const&)
         {
             std::cout << "Caught logic_error as expected" << std::endl;
         }
@@ -2100,7 +2102,7 @@ void runtest(int n, char const* filename1, char const* arg2)
         {
             QUtil::toUTF8(0xffffffff);
         }
-        catch (std::runtime_error& e)
+        catch (std::runtime_error const&)
         {
             std::cout << "Caught runtime_error as expected" << std::endl;
         }
@@ -2110,12 +2112,12 @@ void runtest(int n, char const* filename1, char const* arg2)
         // Test int size checks. This test will fail if int and long
         // long are the same size.
         QPDFObjectHandle t = pdf.getTrailer();
-        unsigned long long q1_l = 3L * INT_MAX;
-        long long q1 = static_cast<long long>(q1_l);
-        long long q2_l = 3L * INT_MIN;
-        long long q2 = static_cast<long long>(q2_l);
+        unsigned long long q1_l = 3ULL * QIntC::to_ulonglong(INT_MAX);
+        long long q1 = QIntC::to_longlong(q1_l);
+        long long q2_l = 3LL * QIntC::to_longlong(INT_MIN);
+        long long q2 = QIntC::to_longlong(q2_l);
         unsigned int q3_i = UINT_MAX;
-        long long q3 = static_cast<long long>(q3_i);
+        long long q3 = QIntC::to_longlong(q3_i);
         t.replaceKey("/Q1", QPDFObjectHandle::newInteger(q1));
         t.replaceKey("/Q2", QPDFObjectHandle::newInteger(q2));
         t.replaceKey("/Q3", QPDFObjectHandle::newInteger(q3));
@@ -9,6 +9,7 @@
 #include <qpdf/QPDFWriter.hh>
 #include <qpdf/QPDFObjectHandle.hh>
 #include <qpdf/QUtil.hh>
+#include <qpdf/QIntC.hh>
 #include <iostream>
 #include <string.h>
 #include <stdlib.h>
@@ -36,37 +37,39 @@
 static char const* whoami = 0;
 // Height should be a multiple of 10
-static int const nstripes = 10;
-static int const stripesize_large = 500;
-static int const stripesize_small = 5;
-static int const npages = 200;
+static size_t const nstripes = 10;
+static size_t const stripesize_large = 500;
+static size_t const stripesize_small = 5;
+static size_t const npages = 200;
 // initialized in main
-int stripesize = 0;
-int width = 0;
-int height = 0;
+size_t stripesize = 0;
+size_t width = 0;
+size_t height = 0;
 static unsigned char* buf = 0;
-static inline unsigned char get_pixel_color(int n, size_t row)
+static inline unsigned char get_pixel_color(size_t n, size_t row)
 {
-    return (n & (1 << (nstripes - 1 - row))) ? '\xc0' : '\x40';
+    return ((n & (1LLU << (nstripes - 1LLU - row)))
+            ? static_cast<unsigned char>('\xc0')
+            : static_cast<unsigned char>('\x40'));
 }
 class ImageChecker: public Pipeline
 {
   public:
-    ImageChecker(int n);
+    ImageChecker(size_t n);
     virtual ~ImageChecker();
     virtual void write(unsigned char* data, size_t len);
     virtual void finish();
   private:
-    int n;
+    size_t n;
     size_t offset;
     bool okay;
 };
-ImageChecker::ImageChecker(int n) :
+ImageChecker::ImageChecker(size_t n) :
     Pipeline("image checker", 0),
     n(n),
     offset(0),
@@ -106,16 +109,16 @@ ImageChecker::finish()
 class ImageProvider: public QPDFObjectHandle::StreamDataProvider
 {
   public:
-    ImageProvider(int n);
+    ImageProvider(size_t n);
     virtual ~ImageProvider();
     virtual void provideStreamData(int objid, int generation,
 				   Pipeline* pipeline);
   private:
-    int n;
+    size_t n;
 };
-ImageProvider::ImageProvider(int n) :
+ImageProvider::ImageProvider(size_t n) :
     n(n)
 {
 }
@@ -133,7 +136,7 @@ ImageProvider::provideStreamData(int objid, int generation,
         buf = new unsigned char[width * stripesize];
     }
     std::cout << "page " << n << " of " << npages << std::endl;
-    for (int y = 0; y < nstripes; ++y)
+    for (size_t y = 0; y < nstripes; ++y)
     {
         unsigned char color = get_pixel_color(n, y);
         memset(buf, color, width * stripesize);
@@ -156,16 +159,16 @@ static void set_parameters(bool large)
     width = height;
 }
-std::string generate_page_contents(int pageno)
+std::string generate_page_contents(size_t pageno)
 {
     std::string contents =
-        "BT /F1 24 Tf 72 720 Td (page " +  QUtil::int_to_string(pageno) +
+        "BT /F1 24 Tf 72 720 Td (page " +  QUtil::uint_to_string(pageno) +
         ") Tj ET\n"
         "q 468 0 0 468 72 72 cm /Im1 Do Q\n";
     return contents;
 }
-static QPDFObjectHandle create_page_contents(QPDF& pdf, int pageno)
+static QPDFObjectHandle create_page_contents(QPDF& pdf, size_t pageno)
 {
     return QPDFObjectHandle::newStream(&pdf, generate_page_contents(pageno));
 }
@@ -175,9 +178,9 @@ QPDFObjectHandle newName(std::string const&amp; name)
     return QPDFObjectHandle::newName(name);
 }
-QPDFObjectHandle newInteger(int val)
+QPDFObjectHandle newInteger(size_t val)
 {
-    return QPDFObjectHandle::newInteger(val);
+    return QPDFObjectHandle::newInteger(QIntC::to_longlong(val));
 }
 static void create_pdf(char const* filename)
@@ -210,7 +213,7 @@ static void create_pdf(char const* filename)
     mediabox.appendItem(newInteger(792));
     QPDFPageDocumentHelper dh(pdf);
-    for (int pageno = 1; pageno <= npages; ++pageno)
+    for (size_t pageno = 1; pageno <= npages; ++pageno)
     {
         QPDFObjectHandle image = QPDFObjectHandle::newStream(&pdf);
         QPDFObjectHandle image_dict = image.getDict();
@@ -253,7 +256,7 @@ static void create_pdf(char const* filename)
     w.write();
 }
-static void check_page_contents(int pageno, QPDFObjectHandle page)
+static void check_page_contents(size_t pageno, QPDFObjectHandle page)
 {
     PointerHolder<Buffer> buf =
         page.getKey("/Contents").getStreamData();
@@ -270,7 +273,7 @@ static void check_page_contents(int pageno, QPDFObjectHandle page)
     }
 }
-static void check_image(int pageno, QPDFObjectHandle page)
+static void check_image(size_t pageno, QPDFObjectHandle page)
 {
     QPDFObjectHandle image =
         page.getKey("/Resources").getKey("/XObject").getKey("/Im1");
@@ -283,10 +286,10 @@ static void check_pdf(char const* filename)
     QPDF pdf;
     pdf.processFile(filename);
     std::vector<QPDFObjectHandle> const& pages = pdf.getAllPages();
-    assert(pages.size() == static_cast<size_t>(npages));
-    for (int i = 0; i < npages; ++i)
+    assert(pages.size() == QIntC::to_size(npages));
+    for (size_t i = 0; i < npages; ++i)
     {
-        int pageno = i + 1;
+        size_t pageno = i + 1;
         std::cout << "page " << pageno << " of " << npages << std::endl;
         check_page_contents(pageno, pages.at(i));
         check_image(pageno, pages.at(i));
@@ -6,6 +6,7 @@
 #include <qpdf/BufferInputSource.hh>
 #include <qpdf/QPDF.hh>
 #include <qpdf/Pl_Buffer.hh>
+#include <qpdf/QIntC.hh>
 #include <stdlib.h>
 #include <stdio.h>
 #include <string.h>
@@ -46,7 +47,7 @@ Finder::check()
     QPDFTokenizer::Token t = tokenizer.readToken(is, "finder", true);
     qpdf_offset_t offset = this->is->tell();
     bool result = (t == QPDFTokenizer::Token(QPDFTokenizer::tt_word, str));
-    this->is->seek(offset - this->str.length(), SEEK_SET);
+    this->is->seek(offset - QIntC::to_offset(this->str.length()), SEEK_SET);
     return result;
 }
@@ -286,7 +287,7 @@ int main(int argc, char* argv[])
                 {
                     usage();
                 }
-                max_len = QUtil::string_to_int(argv[i]);
+                max_len = QUtil::string_to_uint(argv[i]);
             }
             else if (strcmp(argv[i], "-no-ignorable") == 0)
             {