diff options
Diffstat (limited to 'libqpdf/QPDF_encryption.cc')
| -rw-r--r-- | libqpdf/QPDF_encryption.cc | 154 |
1 files changed, 83 insertions, 71 deletions
diff --git a/libqpdf/QPDF_encryption.cc b/libqpdf/QPDF_encryption.cc index 54d7ad03..c0778b6a 100644 --- a/libqpdf/QPDF_encryption.cc +++ b/libqpdf/QPDF_encryption.cc @@ -437,11 +437,10 @@ QPDF::compute_encryption_key_from_password( md5.encodeDataIncrementally(bytes, 4); } MD5::Digest digest; - iterate_md5_digest(md5, digest, ((data.getR() >= 3) ? 50 : 0), - data.getLengthBytes()); - return std::string(reinterpret_cast<char*>(digest), - std::min(static_cast<int>(sizeof(digest)), - data.getLengthBytes())); + int key_len = std::min(static_cast<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); } static void @@ -464,8 +463,9 @@ compute_O_rc4_key(std::string const& user_password, md5.encodeDataIncrementally( pad_or_truncate_password_V4(password).c_str(), key_bytes); MD5::Digest digest; - iterate_md5_digest(md5, digest, ((data.getR() >= 3) ? 50 : 0), - data.getLengthBytes()); + int key_len = std::min(static_cast<int>(sizeof(digest)), + data.getLengthBytes()); + iterate_md5_digest(md5, digest, ((data.getR() >= 3) ? 50 : 0), key_len); memcpy(key, digest, OU_key_bytes_V4); } @@ -764,14 +764,15 @@ QPDF::recover_encryption_key_with_password( } QPDF::encryption_method_e -QPDF::interpretCF(QPDFObjectHandle cf) +QPDF::interpretCF( + PointerHolder<EncryptionParameters> encp, QPDFObjectHandle cf) { if (cf.isName()) { std::string filter = cf.getName(); - if (this->m->crypt_filters.count(filter) != 0) + if (encp->crypt_filters.count(filter) != 0) { - return this->m->crypt_filters[filter]; + return encp->crypt_filters[filter]; } else if (filter == "/Identity") { @@ -792,11 +793,11 @@ QPDF::interpretCF(QPDFObjectHandle cf) void QPDF::initializeEncryption() { - if (this->m->encryption_initialized) + if (this->m->encp->encryption_initialized) { return; } - this->m->encryption_initialized = true; + this->m->encp->encryption_initialized = true; // After we initialize encryption parameters, we must used stored // key information and never look at /Encrypt again. Otherwise, @@ -811,7 +812,7 @@ QPDF::initializeEncryption() // Go ahead and set this->m->encrypted here. That way, isEncrypted // will return true even if there were errors reading the // encryption dictionary. - this->m->encrypted = true; + this->m->encp->encrypted = true; std::string id1; QPDFObjectHandle id_obj = this->m->trailer.getKey("/ID"); @@ -885,8 +886,8 @@ QPDF::initializeEncryption() QUtil::int_to_string(V) + " (max 5)"); } - this->m->encryption_V = V; - this->m->encryption_R = R; + this->m->encp->encryption_V = V; + this->m->encp->encryption_R = R; // OE, UE, and Perms are only present if V >= 5. std::string OE; @@ -949,10 +950,10 @@ QPDF::initializeEncryption() } } - this->m->encrypt_metadata = true; + this->m->encp->encrypt_metadata = true; if ((V >= 4) && (encryption_dict.getKey("/EncryptMetadata").isBool())) { - this->m->encrypt_metadata = + this->m->encp->encrypt_metadata = encryption_dict.getKey("/EncryptMetadata").getBoolValue(); } @@ -993,40 +994,41 @@ QPDF::initializeEncryption() method = e_unknown; } } - this->m->crypt_filters[filter] = method; + this->m->encp->crypt_filters[filter] = method; } } QPDFObjectHandle StmF = encryption_dict.getKey("/StmF"); QPDFObjectHandle StrF = encryption_dict.getKey("/StrF"); QPDFObjectHandle EFF = encryption_dict.getKey("/EFF"); - this->m->cf_stream = interpretCF(StmF); - this->m->cf_string = interpretCF(StrF); + this->m->encp->cf_stream = interpretCF(this->m->encp, StmF); + this->m->encp->cf_string = interpretCF(this->m->encp, StrF); if (EFF.isName()) { - this->m->cf_file = interpretCF(EFF); + this->m->encp->cf_file = interpretCF(this->m->encp, EFF); } else { - this->m->cf_file = this->m->cf_stream; + this->m->encp->cf_file = this->m->encp->cf_stream; } } EncryptionData data(V, R, Length / 8, P, O, U, OE, UE, Perms, - id1, this->m->encrypt_metadata); + id1, this->m->encp->encrypt_metadata); if (this->m->provided_password_is_hex_key) { // ignore passwords in file } else if (check_owner_password( - this->m->user_password, this->m->provided_password, data)) + this->m->encp->user_password, + this->m->encp->provided_password, data)) { // password supplied was owner password; user_password has // been initialized for V < 5 } - else if (check_user_password(this->m->provided_password, data)) + else if (check_user_password(this->m->encp->provided_password, data)) { - this->m->user_password = this->m->provided_password; + this->m->encp->user_password = this->m->encp->provided_password; } else { @@ -1036,15 +1038,16 @@ QPDF::initializeEncryption() if (this->m->provided_password_is_hex_key) { - this->m->encryption_key = QUtil::hex_decode(this->m->provided_password); + this->m->encp->encryption_key = + QUtil::hex_decode(this->m->encp->provided_password); } else if (V < 5) { // For V < 5, the user password is encrypted with the owner // password, and the user password is always used for // computing the encryption key. - this->m->encryption_key = compute_encryption_key( - this->m->user_password, data); + this->m->encp->encryption_key = compute_encryption_key( + this->m->encp->user_password, data); } else { @@ -1052,8 +1055,8 @@ QPDF::initializeEncryption() // compute the encryption key, and neither password can be // used to recover the other. bool perms_valid; - this->m->encryption_key = recover_encryption_key_with_password( - this->m->provided_password, data, perms_valid); + this->m->encp->encryption_key = recover_encryption_key_with_password( + this->m->encp->provided_password, data, perms_valid); if (! perms_valid) { warn(QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), @@ -1066,26 +1069,28 @@ QPDF::initializeEncryption() } std::string -QPDF::getKeyForObject(int objid, int generation, bool use_aes) +QPDF::getKeyForObject( + PointerHolder<EncryptionParameters> encp, + int objid, int generation, bool use_aes) { - if (! this->m->encrypted) + if (! encp->encrypted) { throw std::logic_error( "request for encryption key in non-encrypted PDF"); } - if (! ((objid == this->m->cached_key_objid) && - (generation == this->m->cached_key_generation))) + if (! ((objid == encp->cached_key_objid) && + (generation == encp->cached_key_generation))) { - this->m->cached_object_encryption_key = - compute_data_key(this->m->encryption_key, objid, generation, - use_aes, this->m->encryption_V, - this->m->encryption_R); - this->m->cached_key_objid = objid; - this->m->cached_key_generation = generation; + encp->cached_object_encryption_key = + compute_data_key(encp->encryption_key, objid, generation, + use_aes, encp->encryption_V, + encp->encryption_R); + encp->cached_key_objid = objid; + encp->cached_key_generation = generation; } - return this->m->cached_object_encryption_key; + return encp->cached_object_encryption_key; } void @@ -1096,9 +1101,9 @@ QPDF::decryptString(std::string& str, int objid, int generation) return; } bool use_aes = false; - if (this->m->encryption_V >= 4) + if (this->m->encp->encryption_V >= 4) { - switch (this->m->cf_string) + switch (this->m->encp->cf_string) { case e_none: return; @@ -1123,12 +1128,14 @@ QPDF::decryptString(std::string& str, int objid, int generation) " strings may be decrypted improperly")); // To avoid repeated warnings, reset cf_string. Assume // we'd want to use AES if V == 4. - this->m->cf_string = e_aes; + this->m->encp->cf_string = e_aes; + use_aes = true; break; } } - std::string key = getKeyForObject(objid, generation, use_aes); + std::string key = getKeyForObject( + this->m->encp, objid, generation, use_aes); try { if (use_aes) @@ -1172,8 +1179,12 @@ QPDF::decryptString(std::string& str, int objid, int generation) } void -QPDF::decryptStream(Pipeline*& pipeline, int objid, int generation, +QPDF::decryptStream(PointerHolder<EncryptionParameters> encp, + PointerHolder<InputSource> file, + QPDF& qpdf_for_warning, Pipeline*& pipeline, + int objid, int generation, QPDFObjectHandle& stream_dict, + bool is_attachment_stream, std::vector<PointerHolder<Pipeline> >& heap) { std::string type; @@ -1187,7 +1198,7 @@ QPDF::decryptStream(Pipeline*& pipeline, int objid, int generation, return; } bool use_aes = false; - if (this->m->encryption_V >= 4) + if (encp->encryption_V >= 4) { encryption_method_e method = e_unknown; std::string method_source = "/StmF from /Encrypt dictionary"; @@ -1203,7 +1214,7 @@ QPDF::decryptStream(Pipeline*& pipeline, int objid, int generation, "/CryptFilterDecodeParms")) { QTC::TC("qpdf", "QPDF_encryption stream crypt filter"); - method = interpretCF(decode_parms.getKey("/Name")); + method = interpretCF(encp, decode_parms.getKey("/Name")); method_source = "stream's Crypt decode parameters"; } } @@ -1226,7 +1237,7 @@ QPDF::decryptStream(Pipeline*& pipeline, int objid, int generation, { QTC::TC("qpdf", "QPDF_encrypt crypt array"); method = interpretCF( - crypt_params.getKey("/Name")); + encp, crypt_params.getKey("/Name")); method_source = "stream's Crypt " "decode parameters (array)"; } @@ -1238,21 +1249,21 @@ QPDF::decryptStream(Pipeline*& pipeline, int objid, int generation, if (method == e_unknown) { - if ((! this->m->encrypt_metadata) && (type == "/Metadata")) + if ((! encp->encrypt_metadata) && (type == "/Metadata")) { QTC::TC("qpdf", "QPDF_encryption cleartext metadata"); method = e_none; } else { - if (this->m->attachment_streams.count( - QPDFObjGen(objid, generation)) > 0) + if (is_attachment_stream) { - method = this->m->cf_file; + QTC::TC("qpdf", "QPDF_encryption attachment stream"); + method = encp->cf_file; } else { - method = this->m->cf_stream; + method = encp->cf_stream; } } } @@ -1276,19 +1287,20 @@ QPDF::decryptStream(Pipeline*& pipeline, int objid, int generation, default: // filter local to this stream. - warn(QPDFExc(qpdf_e_damaged_pdf, this->m->file->getName(), - this->m->last_object_description, - this->m->file->getLastOffset(), - "unknown encryption filter for streams" - " (check " + method_source + ");" - " streams may be decrypted improperly")); + qpdf_for_warning.warn( + QPDFExc(qpdf_e_damaged_pdf, file->getName(), + "", file->getLastOffset(), + "unknown encryption filter for streams" + " (check " + method_source + ");" + " streams may be decrypted improperly")); // To avoid repeated warnings, reset cf_stream. Assume // we'd want to use AES if V == 4. - this->m->cf_stream = e_aes; + encp->cf_stream = e_aes; + use_aes = true; break; } } - std::string key = getKeyForObject(objid, generation, use_aes); + std::string key = getKeyForObject(encp, objid, generation, use_aes); if (use_aes) { QTC::TC("qpdf", "QPDF_encryption aes decode stream"); @@ -1348,13 +1360,13 @@ QPDF::compute_encryption_parameters_V5( std::string const& QPDF::getPaddedUserPassword() const { - return this->m->user_password; + return this->m->encp->user_password; } std::string QPDF::getTrimmedUserPassword() const { - std::string result = this->m->user_password; + std::string result = this->m->encp->user_password; trim_user_password(result); return result; } @@ -1362,13 +1374,13 @@ QPDF::getTrimmedUserPassword() const std::string QPDF::getEncryptionKey() const { - return this->m->encryption_key; + return this->m->encp->encryption_key; } bool QPDF::isEncrypted() const { - return this->m->encrypted; + return this->m->encp->encrypted; } bool @@ -1385,7 +1397,7 @@ QPDF::isEncrypted(int& R, int& P, int& V, encryption_method_e& string_method, encryption_method_e& file_method) { - if (this->m->encrypted) + if (this->m->encp->encrypted) { QPDFObjectHandle trailer = getTrailer(); QPDFObjectHandle encrypt = trailer.getKey("/Encrypt"); @@ -1395,9 +1407,9 @@ QPDF::isEncrypted(int& R, int& P, int& V, P = Pkey.getIntValue(); R = Rkey.getIntValue(); V = Vkey.getIntValue(); - stream_method = this->m->cf_stream; - string_method = this->m->cf_stream; - file_method = this->m->cf_file; + stream_method = this->m->encp->cf_stream; + string_method = this->m->encp->cf_string; + file_method = this->m->encp->cf_file; return true; } else |