diff options
Diffstat (limited to 'libqpdf/QPDF_encryption.cc')
| -rw-r--r-- | libqpdf/QPDF_encryption.cc | 42 |
1 files changed, 29 insertions, 13 deletions
diff --git a/libqpdf/QPDF_encryption.cc b/libqpdf/QPDF_encryption.cc index b5f16e0c..b15cb29d 100644 --- a/libqpdf/QPDF_encryption.cc +++ b/libqpdf/QPDF_encryption.cc @@ -935,22 +935,38 @@ QPDF::initializeEncryption() pad_short_parameter(Perms, Perms_key_bytes_V5); } - int Length = 40; - if (encryption_dict.getKey("/Length").isInteger()) + int Length = 0; + if (V <= 1) { - Length = encryption_dict.getKey("/Length").getIntValueAsInt(); - if (R < 3) + Length = 40; + } + else if (V == 4) + { + Length = 128; + } + else if (V == 5) + { + Length = 256; + } + else + { + if (encryption_dict.getKey("/Length").isInteger()) + { + Length = encryption_dict.getKey("/Length").getIntValueAsInt(); + if ((Length % 8) || (Length < 40) || (Length > 128)) + { + Length = 0; + } + } + if (Length == 0) { - // Force Length to 40 regardless of what the file says. - Length = 40; + Length = 128; } - if ((Length % 8) || (Length < 40) || (Length > 256)) - { - throw QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), - "encryption dictionary", - this->m->file->getLastOffset(), - "invalid /Length value in encryption dictionary"); - } + } + if (Length == 0) + { + // Still no Length? Just take a guess. + Length = 128; } this->m->encp->encrypt_metadata = true; |