OpenSystemsDevelopment / qpdf

Commit 4635a59e65c859b5aac7b08f5780c6f0a679b948

Authored by m-holger
1 parent 11266b14

Remove redundant `compute_U_UE_value_V5`, `compute_O_OE_value_V5`, and `compute_… 

…Perms_value_V5` methods; inline their logic into `setV5EncryptionParameters` to simplify encryption data processing.
Inline Side-by-side
Showing 2 changed files with 14 additions and 53 deletions
include/qpdf/QPDF.hh
  View file @4635a59
... ... @@ -532,21 +532,9 @@ class QPDF
532 532  
533 533 std::string hash_V5(
534 534 std::string const& password, std::string const& salt, std::string const& udata) const;
535   - std::string compute_Perms_value_V5(std::string const& encryption_key) const;
536 535 std::string
537 536 compute_O_value(std::string const& user_password, std::string const& owner_password) const;
538 537 std::string compute_U_value(std::string const& user_password) const;
539   - void compute_O_OE_value_V5(
540   - std::string const& owner_password,
541   - std::string const& encryption_key,
542   - std::string const& U,
543   - std::string& O,
544   - std::string& OE) const;
545   - void compute_U_UE_value_V5(
546   - std::string const& user_password,
547   - std::string const& encryption_key,
548   - std::string& U,
549   - std::string& UE) const;
550 538 std::string compute_encryption_key_from_password(std::string const& password) const;
551 539 std::string recover_encryption_key_with_password(std::string const& password) const;
552 540 bool check_owner_password_V4(
... ...
libqpdf/QPDF_encryption.cc
  View file @4635a59
... ... @@ -612,37 +612,6 @@ QPDF::EncryptionData::recover_encryption_key_with_password(std::string const& pa
612 612 return recover_encryption_key_with_password(password, disregard);
613 613 }
614 614  
615   -void
616   -QPDF::EncryptionData::compute_U_UE_value_V5(
617   - std::string const& user_password,
618   - std::string const& encryption_key,
619   - std::string& out_U,
620   - std::string& out_UE) const
621   -{
622   - // Algorithm 3.8 from the PDF 1.7 extension level 3
623   - auto validation_salt = util::random_string(8);
624   - auto key_salt = util::random_string(8);
625   - out_U = hash_V5(user_password, validation_salt, "").append(validation_salt).append(key_salt);
626   - auto intermediate_key = hash_V5(user_password, key_salt, "");
627   - out_UE = process_with_aes(intermediate_key, true, encryption_key);
628   -}
629   -
630   -void
631   -QPDF::EncryptionData::compute_O_OE_value_V5(
632   - std::string const& owner_password,
633   - std::string const& encryption_key,
634   - std::string const& in_U,
635   - std::string& out_O,
636   - std::string& out_OE) const
637   -{
638   - // Algorithm 3.9 from the PDF 1.7 extension level 3
639   - auto validation_salt = util::random_string(8);
640   - auto key_salt = util::random_string(8);
641   - out_O = hash_V5(owner_password, validation_salt, in_U) + validation_salt + key_salt;
642   - std::string intermediate_key = hash_V5(owner_password, key_salt, in_U);
643   - out_OE = process_with_aes(intermediate_key, true, encryption_key);
644   -}
645   -
646 615 std::string
647 616 QPDF::EncryptionData::compute_Perms_value_V5_clear() const
648 617 {
... ... @@ -661,13 +630,6 @@ QPDF::EncryptionData::compute_Perms_value_V5_clear() const
661 630 }
662 631  
663 632 std::string
664   -QPDF::EncryptionData::compute_Perms_value_V5(std::string const& encryption_key) const
665   -{
666   - // Algorithm 3.10 from the PDF 1.7 extension level 3
667   - return process_with_aes(encryption_key, true, compute_Perms_value_V5_clear());
668   -}
669   -
670   -std::string
671 633 QPDF::EncryptionData::recover_encryption_key_with_password(
672 634 std::string const& password, bool& perms_valid) const
673 635 {
... ... @@ -1207,9 +1169,20 @@ QPDF::EncryptionData::compute_encryption_parameters_V5(
1207 1169 std::string& out_Perms)
1208 1170 {
1209 1171 out_encryption_key = util::random_string(key_bytes);
1210   - compute_U_UE_value_V5(user_password, out_encryption_key, out_U, out_UE);
1211   - compute_O_OE_value_V5(owner_password, out_encryption_key, out_U, out_O, out_OE);
1212   - out_Perms = compute_Perms_value_V5(out_encryption_key);
  1172 + // Algorithm 8 from the PDF 2.0
  1173 + auto validation_salt = util::random_string(8);
  1174 + auto key_salt = util::random_string(8);
  1175 + out_U = hash_V5(user_password, validation_salt, "").append(validation_salt).append(key_salt);
  1176 + auto intermediate_key = hash_V5(user_password, key_salt, "");
  1177 + out_UE = process_with_aes(intermediate_key, true, out_encryption_key);
  1178 + // Algorithm 9 from the PDF 2.0
  1179 + validation_salt = util::random_string(8);
  1180 + key_salt = util::random_string(8);
  1181 + out_O = hash_V5(owner_password, validation_salt, out_U) + validation_salt + key_salt;
  1182 + intermediate_key = hash_V5(owner_password, key_salt, out_U);
  1183 + out_OE = process_with_aes(intermediate_key, true, out_encryption_key);
  1184 + // Algorithm 10 from the PDF 2.0
  1185 + out_Perms = process_with_aes(out_encryption_key, true, compute_Perms_value_V5_clear());
1213 1186 setV5EncryptionParameters(out_O, out_OE, out_U, out_UE, out_Perms);
1214 1187 }
1215 1188  
... ...