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-rw-r--r--libqpdf/QPDF_encryption.cc208
1 files changed, 66 insertions, 142 deletions
diff --git a/libqpdf/QPDF_encryption.cc b/libqpdf/QPDF_encryption.cc
index 78b9da20..74136060 100644
--- a/libqpdf/QPDF_encryption.cc
+++ b/libqpdf/QPDF_encryption.cc
@@ -20,9 +20,8 @@
#include <cstring>
static unsigned char const padding_string[] = {
- 0x28, 0xbf, 0x4e, 0x5e, 0x4e, 0x75, 0x8a, 0x41, 0x64, 0x00, 0x4e,
- 0x56, 0xff, 0xfa, 0x01, 0x08, 0x2e, 0x2e, 0x00, 0xb6, 0xd0, 0x68,
- 0x3e, 0x80, 0x2f, 0x0c, 0xa9, 0xfe, 0x64, 0x53, 0x69, 0x7a};
+ 0x28, 0xbf, 0x4e, 0x5e, 0x4e, 0x75, 0x8a, 0x41, 0x64, 0x00, 0x4e, 0x56, 0xff, 0xfa, 0x01, 0x08,
+ 0x2e, 0x2e, 0x00, 0xb6, 0xd0, 0x68, 0x3e, 0x80, 0x2f, 0x0c, 0xa9, 0xfe, 0x64, 0x53, 0x69, 0x7a};
static unsigned int const key_bytes = 32;
@@ -129,8 +128,7 @@ QPDF::EncryptionData::setV5EncryptionParameters(
static void
pad_or_truncate_password_V4(std::string const& password, char k1[key_bytes])
{
- size_t password_bytes =
- std::min(QIntC::to_size(key_bytes), password.length());
+ 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);
@@ -173,8 +171,7 @@ pad_or_truncate_password_V4(std::string const& password)
static std::string
truncate_password_V5(std::string const& password)
{
- return password.substr(
- 0, std::min(static_cast<size_t>(127), password.length()));
+ return password.substr(0, std::min(static_cast<size_t>(127), password.length()));
}
static void
@@ -184,8 +181,7 @@ iterate_md5_digest(MD5& md5, MD5::Digest& digest, int iterations, int key_len)
for (int i = 0; i < iterations; ++i) {
MD5 m;
- m.encodeDataIncrementally(
- reinterpret_cast<char*>(digest), QIntC::to_size(key_len));
+ m.encodeDataIncrementally(reinterpret_cast<char*>(digest), QIntC::to_size(key_len));
m.digest(digest);
}
}
@@ -223,11 +219,7 @@ process_with_aes(
{
Pl_Buffer buffer("buffer");
Pl_AES_PDF aes(
- "aes",
- &buffer,
- encrypt,
- QUtil::unsigned_char_pointer(key),
- QIntC::to_uint(key.length()));
+ "aes", &buffer, encrypt, QUtil::unsigned_char_pointer(key), QIntC::to_uint(key.length()));
if (iv) {
aes.setIV(iv, iv_length);
} else {
@@ -371,13 +363,11 @@ QPDF::compute_data_key(
md5.encodeDataIncrementally(result.c_str(), result.length());
MD5::Digest digest;
md5.digest(digest);
- return std::string(
- reinterpret_cast<char*>(digest), std::min(result.length(), toS(16)));
+ return std::string(reinterpret_cast<char*>(digest), std::min(result.length(), toS(16)));
}
std::string
-QPDF::compute_encryption_key(
- std::string const& password, EncryptionData const& data)
+QPDF::compute_encryption_key(std::string const& password, EncryptionData const& data)
{
if (data.getV() >= 5) {
// For V >= 5, the encryption key is generated and stored in
@@ -392,8 +382,7 @@ QPDF::compute_encryption_key(
}
std::string
-QPDF::compute_encryption_key_from_password(
- std::string const& password, EncryptionData const& data)
+QPDF::compute_encryption_key_from_password(std::string const& password, EncryptionData const& data)
{
// Algorithm 3.2 from the PDF 1.7 Reference Manual
@@ -405,8 +394,7 @@ QPDF::compute_encryption_key_from_password(
// presented in its final form.
MD5 md5;
- md5.encodeDataIncrementally(
- pad_or_truncate_password_V4(password).c_str(), key_bytes);
+ md5.encodeDataIncrementally(pad_or_truncate_password_V4(password).c_str(), key_bytes);
md5.encodeDataIncrementally(data.getO().c_str(), key_bytes);
char pbytes[4];
int P = data.getP();
@@ -442,11 +430,9 @@ compute_O_rc4_key(
password = user_password;
}
MD5 md5;
- md5.encodeDataIncrementally(
- pad_or_truncate_password_V4(password).c_str(), key_bytes);
+ md5.encodeDataIncrementally(pad_or_truncate_password_V4(password).c_str(), key_bytes);
MD5::Digest digest;
- int key_len =
- std::min(QIntC::to_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);
memcpy(key, digest, OU_key_bytes_V4);
}
@@ -477,8 +463,7 @@ compute_O_value(
}
static std::string
-compute_U_value_R2(
- std::string const& user_password, QPDF::EncryptionData const& data)
+compute_U_value_R2(std::string const& user_password, QPDF::EncryptionData const& data)
{
// Algorithm 3.4 from the PDF 1.7 Reference Manual
@@ -497,15 +482,13 @@ compute_U_value_R2(
}
static std::string
-compute_U_value_R3(
- std::string const& user_password, QPDF::EncryptionData const& data)
+compute_U_value_R3(std::string const& user_password, QPDF::EncryptionData const& data)
{
// Algorithm 3.5 from the PDF 1.7 Reference Manual
std::string k1 = QPDF::compute_encryption_key(user_password, data);
MD5 md5;
- md5.encodeDataIncrementally(
- pad_or_truncate_password_V4("").c_str(), key_bytes);
+ md5.encodeDataIncrementally(pad_or_truncate_password_V4("").c_str(), key_bytes);
md5.encodeDataIncrementally(data.getId1().c_str(), data.getId1().length());
MD5::Digest digest;
md5.digest(digest);
@@ -528,8 +511,7 @@ compute_U_value_R3(
}
static std::string
-compute_U_value(
- std::string const& user_password, QPDF::EncryptionData const& data)
+compute_U_value(std::string const& user_password, QPDF::EncryptionData const& data)
{
if (data.getR() >= 3) {
return compute_U_value_R3(user_password, data);
@@ -539,8 +521,7 @@ compute_U_value(
}
static bool
-check_user_password_V4(
- std::string const& user_password, QPDF::EncryptionData const& data)
+check_user_password_V4(std::string const& user_password, QPDF::EncryptionData const& data)
{
// Algorithm 3.6 from the PDF 1.7 Reference Manual
@@ -550,8 +531,7 @@ check_user_password_V4(
}
static bool
-check_user_password_V5(
- std::string const& user_password, QPDF::EncryptionData const& data)
+check_user_password_V5(std::string const& user_password, QPDF::EncryptionData const& data)
{
// Algorithm 3.11 from the PDF 1.7 extension level 3
@@ -562,8 +542,7 @@ check_user_password_V5(
}
static bool
-check_user_password(
- std::string const& user_password, QPDF::EncryptionData const& data)
+check_user_password(std::string const& user_password, QPDF::EncryptionData const& data)
{
if (data.getV() < 5) {
return check_user_password_V4(user_password, data);
@@ -574,9 +553,7 @@ check_user_password(
static bool
check_owner_password_V4(
- std::string& user_password,
- std::string const& owner_password,
- QPDF::EncryptionData const& data)
+ std::string& user_password, std::string const& owner_password, QPDF::EncryptionData const& data)
{
// Algorithm 3.7 from the PDF 1.7 Reference Manual
@@ -593,8 +570,7 @@ check_owner_password_V4(
data.getLengthBytes(),
(data.getR() >= 3) ? 20 : 1,
true);
- std::string new_user_password =
- std::string(reinterpret_cast<char*>(O_data), key_bytes);
+ std::string new_user_password = std::string(reinterpret_cast<char*>(O_data), key_bytes);
bool result = false;
if (check_user_password(new_user_password, data)) {
result = true;
@@ -604,8 +580,7 @@ check_owner_password_V4(
}
static bool
-check_owner_password_V5(
- std::string const& owner_password, QPDF::EncryptionData const& data)
+check_owner_password_V5(std::string const& owner_password, QPDF::EncryptionData const& data)
{
// Algorithm 3.12 from the PDF 1.7 extension level 3
@@ -618,9 +593,7 @@ check_owner_password_V5(
static bool
check_owner_password(
- std::string& user_password,
- std::string const& owner_password,
- QPDF::EncryptionData const& data)
+ std::string& user_password, std::string const& owner_password, QPDF::EncryptionData const& data)
{
if (data.getV() < 5) {
return check_owner_password_V4(user_password, owner_password, data);
@@ -630,8 +603,7 @@ check_owner_password(
}
std::string
-QPDF::recover_encryption_key_with_password(
- std::string const& password, EncryptionData const& data)
+QPDF::recover_encryption_key_with_password(std::string const& password, EncryptionData const& data)
{
// Disregard whether Perms is valid.
bool disregard;
@@ -648,12 +620,10 @@ compute_U_UE_value_V5(
{
// Algorithm 3.8 from the PDF 1.7 extension level 3
char k[16];
- QUtil::initializeWithRandomBytes(
- reinterpret_cast<unsigned char*>(k), sizeof(k));
+ QUtil::initializeWithRandomBytes(reinterpret_cast<unsigned char*>(k), sizeof(k));
std::string validation_salt(k, 8);
std::string key_salt(k + 8, 8);
- U = hash_V5(user_password, validation_salt, "", data) + validation_salt +
- key_salt;
+ U = hash_V5(user_password, validation_salt, "", data) + validation_salt + key_salt;
std::string intermediate_key = hash_V5(user_password, key_salt, "", data);
UE = process_with_aes(intermediate_key, true, encryption_key);
}
@@ -669,21 +639,17 @@ compute_O_OE_value_V5(
{
// Algorithm 3.9 from the PDF 1.7 extension level 3
char k[16];
- QUtil::initializeWithRandomBytes(
- reinterpret_cast<unsigned char*>(k), sizeof(k));
+ QUtil::initializeWithRandomBytes(reinterpret_cast<unsigned char*>(k), sizeof(k));
std::string validation_salt(k, 8);
std::string key_salt(k + 8, 8);
- O = hash_V5(owner_password, validation_salt, U, data) + validation_salt +
- key_salt;
+ O = hash_V5(owner_password, validation_salt, U, data) + validation_salt + key_salt;
std::string intermediate_key = hash_V5(owner_password, key_salt, U, data);
OE = process_with_aes(intermediate_key, true, encryption_key);
}
void
compute_Perms_value_V5_clear(
- std::string const& encryption_key,
- QPDF::EncryptionData const& data,
- unsigned char k[16])
+ std::string const& encryption_key, QPDF::EncryptionData const& data, unsigned char k[16])
{
// From algorithm 3.10 from the PDF 1.7 extension level 3
unsigned long long extended_perms =
@@ -700,16 +666,13 @@ compute_Perms_value_V5_clear(
}
static std::string
-compute_Perms_value_V5(
- std::string const& encryption_key, QPDF::EncryptionData const& data)
+compute_Perms_value_V5(std::string const& encryption_key, QPDF::EncryptionData const& data)
{
// Algorithm 3.10 from the PDF 1.7 extension level 3
unsigned char k[16];
compute_Perms_value_V5_clear(encryption_key, data, k);
return process_with_aes(
- encryption_key,
- true,
- std::string(reinterpret_cast<char*>(k), sizeof(k)));
+ encryption_key, true, std::string(reinterpret_cast<char*>(k), sizeof(k)));
}
std::string
@@ -737,14 +700,11 @@ QPDF::recover_encryption_key_with_password(
key_salt = data.getU().substr(40, 8);
encrypted_file_key = data.getUE().substr(0, 32);
}
- std::string intermediate_key =
- hash_V5(key_password, key_salt, user_data, data);
- std::string file_key =
- process_with_aes(intermediate_key, false, encrypted_file_key);
+ std::string intermediate_key = hash_V5(key_password, key_salt, user_data, data);
+ std::string file_key = process_with_aes(intermediate_key, false, encrypted_file_key);
// Decrypt Perms and check against expected value
- std::string perms_check =
- process_with_aes(file_key, false, data.getPerms(), 12);
+ std::string perms_check = process_with_aes(file_key, false, data.getPerms(), 12);
unsigned char k[16];
compute_Perms_value_V5_clear(file_key, data, k);
perms_valid = (memcmp(perms_check.c_str(), k, 12) == 0);
@@ -753,8 +713,7 @@ QPDF::recover_encryption_key_with_password(
}
QPDF::encryption_method_e
-QPDF::interpretCF(
- std::shared_ptr<EncryptionParameters> encp, QPDFObjectHandle cf)
+QPDF::interpretCF(std::shared_ptr<EncryptionParameters> encp, QPDFObjectHandle cf)
{
if (cf.isName()) {
std::string filter = cf.getName();
@@ -795,8 +754,7 @@ QPDF::initializeEncryption()
std::string id1;
QPDFObjectHandle id_obj = m->trailer.getKey("/ID");
- if ((id_obj.isArray() && (id_obj.getArrayNItems() == 2) &&
- id_obj.getArrayItem(0).isString())) {
+ if ((id_obj.isArray() && (id_obj.getArrayNItems() == 2) && id_obj.getArrayItem(0).isString())) {
id1 = id_obj.getArrayItem(0).getStringValue();
} else {
// Treating a missing ID as the empty string enables qpdf to
@@ -827,10 +785,8 @@ QPDF::initializeEncryption()
"file uses encryption SubFilters, which qpdf does not support");
}
- if (!(encryption_dict.getKey("/V").isInteger() &&
- encryption_dict.getKey("/R").isInteger() &&
- encryption_dict.getKey("/O").isString() &&
- encryption_dict.getKey("/U").isString() &&
+ if (!(encryption_dict.getKey("/V").isInteger() && encryption_dict.getKey("/R").isInteger() &&
+ encryption_dict.getKey("/O").isString() && encryption_dict.getKey("/U").isString() &&
encryption_dict.getKey("/P").isInteger())) {
throw damagedPDF(
"encryption dictionary",
@@ -846,16 +802,14 @@ QPDF::initializeEncryption()
// If supporting new encryption R/V values, remember to update
// error message inside this if statement.
- if (!(((R >= 2) && (R <= 6)) &&
- ((V == 1) || (V == 2) || (V == 4) || (V == 5)))) {
+ if (!(((R >= 2) && (R <= 6)) && ((V == 1) || (V == 2) || (V == 4) || (V == 5)))) {
throw QPDFExc(
qpdf_e_unsupported,
m->file->getName(),
"encryption dictionary",
m->file->getLastOffset(),
- "Unsupported /R or /V in encryption dictionary; R = " +
- std::to_string(R) + " (max 6), V = " + std::to_string(V) +
- " (max 5)");
+ "Unsupported /R or /V in encryption dictionary; R = " + std::to_string(R) +
+ " (max 6), V = " + std::to_string(V) + " (max 5)");
}
m->encp->encryption_V = V;
@@ -918,8 +872,7 @@ QPDF::initializeEncryption()
m->encp->encrypt_metadata = true;
if ((V >= 4) && (encryption_dict.getKey("/EncryptMetadata").isBool())) {
- m->encp->encrypt_metadata =
- encryption_dict.getKey("/EncryptMetadata").getBoolValue();
+ m->encp->encrypt_metadata = encryption_dict.getKey("/EncryptMetadata").getBoolValue();
}
if ((V == 4) || (V == 5)) {
@@ -975,23 +928,12 @@ QPDF::initializeEncryption()
}
}
- EncryptionData data(
- V,
- R,
- Length / 8,
- P,
- O,
- U,
- OE,
- UE,
- Perms,
- id1,
- m->encp->encrypt_metadata);
+ EncryptionData data(V, R, Length / 8, P, O, U, OE, UE, Perms, id1, m->encp->encrypt_metadata);
if (m->provided_password_is_hex_key) {
// ignore passwords in file
} else {
- m->encp->owner_password_matched = check_owner_password(
- m->encp->user_password, m->encp->provided_password, data);
+ m->encp->owner_password_matched =
+ check_owner_password(m->encp->user_password, m->encp->provided_password, data);
if (m->encp->owner_password_matched && (V < 5)) {
// password supplied was owner password; user_password has
// been initialized for V < 5
@@ -1000,8 +942,7 @@ QPDF::initializeEncryption()
QTC::TC("qpdf", "QPDF_encryption user matches owner V < 5");
}
} else {
- m->encp->user_password_matched =
- check_user_password(m->encp->provided_password, data);
+ m->encp->user_password_matched = check_user_password(m->encp->provided_password, data);
if (m->encp->user_password_matched) {
m->encp->user_password = m->encp->provided_password;
}
@@ -1009,10 +950,8 @@ QPDF::initializeEncryption()
if (m->encp->user_password_matched && m->encp->owner_password_matched) {
QTC::TC("qpdf", "QPDF_encryption same password", (V < 5) ? 0 : 1);
}
- if (!(m->encp->owner_password_matched ||
- m->encp->user_password_matched)) {
- throw QPDFExc(
- qpdf_e_password, m->file->getName(), "", 0, "invalid password");
+ if (!(m->encp->owner_password_matched || m->encp->user_password_matched)) {
+ throw QPDFExc(qpdf_e_password, m->file->getName(), "", 0, "invalid password");
}
}
@@ -1022,15 +961,14 @@ QPDF::initializeEncryption()
// For V < 5, the user password is encrypted with the owner
// password, and the user password is always used for
// computing the encryption key.
- m->encp->encryption_key =
- compute_encryption_key(m->encp->user_password, data);
+ m->encp->encryption_key = compute_encryption_key(m->encp->user_password, data);
} else {
// For V >= 5, either password can be used independently to
// compute the encryption key, and neither password can be
// used to recover the other.
bool perms_valid;
- m->encp->encryption_key = recover_encryption_key_with_password(
- m->encp->provided_password, data, perms_valid);
+ m->encp->encryption_key =
+ recover_encryption_key_with_password(m->encp->provided_password, data, perms_valid);
if (!perms_valid) {
warn(damagedPDF(
"encryption dictionary",
@@ -1042,13 +980,10 @@ QPDF::initializeEncryption()
std::string
QPDF::getKeyForObject(
- std::shared_ptr<EncryptionParameters> encp,
- QPDFObjGen const& og,
- bool use_aes)
+ std::shared_ptr<EncryptionParameters> encp, QPDFObjGen const& og, bool use_aes)
{
if (!encp->encrypted) {
- throw std::logic_error(
- "request for encryption key in non-encrypted PDF");
+ throw std::logic_error("request for encryption key in non-encrypted PDF");
}
if (og != encp->cached_key_og) {
@@ -1089,9 +1024,8 @@ QPDF::decryptString(std::string& str, QPDFObjGen const& og)
break;
default:
- warn(damagedPDF(
- "unknown encryption filter for strings (check /StrF in "
- "/Encrypt dictionary); strings may be decrypted improperly"));
+ warn(damagedPDF("unknown encryption filter for strings (check /StrF in "
+ "/Encrypt dictionary); strings may be decrypted improperly"));
// To avoid repeated warnings, reset cf_string. Assume
// we'd want to use AES if V == 4.
m->encp->cf_string = e_aes;
@@ -1114,8 +1048,7 @@ QPDF::decryptString(std::string& str, QPDFObjGen const& og)
pl.writeString(str);
pl.finish();
auto buf = bufpl.getBufferSharedPointer();
- str = std::string(
- reinterpret_cast<char*>(buf->getBuffer()), buf->getSize());
+ str = std::string(reinterpret_cast<char*>(buf->getBuffer()), buf->getSize());
} else {
QTC::TC("qpdf", "QPDF_encryption rc4 decode string");
size_t vlen = str.length();
@@ -1130,9 +1063,7 @@ QPDF::decryptString(std::string& str, QPDFObjGen const& og)
} catch (QPDFExc&) {
throw;
} catch (std::runtime_error& e) {
- throw damagedPDF(
- "error decrypting string for object " + og.unparse() + ": " +
- e.what());
+ throw damagedPDF("error decrypting string for object " + og.unparse() + ": " + e.what());
}
}
@@ -1161,10 +1092,8 @@ QPDF::decryptStream(
if (stream_dict.getKey("/Filter").isOrHasName("/Crypt")) {
if (stream_dict.getKey("/DecodeParms").isDictionary()) {
- QPDFObjectHandle decode_parms =
- stream_dict.getKey("/DecodeParms");
- if (decode_parms.isDictionaryOfType(
- "/CryptFilterDecodeParms")) {
+ QPDFObjectHandle decode_parms = stream_dict.getKey("/DecodeParms");
+ if (decode_parms.isDictionaryOfType("/CryptFilterDecodeParms")) {
QTC::TC("qpdf", "QPDF_encryption stream crypt filter");
method = interpretCF(encp, decode_parms.getKey("/Name"));
method_source = "stream's Crypt decode parameters";
@@ -1177,13 +1106,11 @@ QPDF::decryptStream(
if (filter.getArrayNItems() == decode.getArrayNItems()) {
for (int i = 0; i < filter.getArrayNItems(); ++i) {
if (filter.getArrayItem(i).isNameAndEquals("/Crypt")) {
- QPDFObjectHandle crypt_params =
- decode.getArrayItem(i);
+ QPDFObjectHandle crypt_params = decode.getArrayItem(i);
if (crypt_params.isDictionary() &&
crypt_params.getKey("/Name").isName()) {
QTC::TC("qpdf", "QPDF_encrypt crypt array");
- method = interpretCF(
- encp, crypt_params.getKey("/Name"));
+ method = interpretCF(encp, crypt_params.getKey("/Name"));
method_source = "stream's Crypt "
"decode parameters (array)";
}
@@ -1225,8 +1152,8 @@ QPDF::decryptStream(
file->getName(),
"",
file->getLastOffset(),
- "unknown encryption filter for streams (check " +
- method_source + "); streams may be decrypted improperly"));
+ "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.
encp->cf_stream = e_aes;
@@ -1270,11 +1197,9 @@ QPDF::compute_encryption_O_U(
std::string& U)
{
if (V >= 5) {
- throw std::logic_error(
- "compute_encryption_O_U called for file with V >= 5");
+ throw std::logic_error("compute_encryption_O_U called for file with V >= 5");
}
- EncryptionData data(
- V, R, key_len, P, "", "", "", "", "", id1, encrypt_metadata);
+ EncryptionData data(V, R, key_len, P, "", "", "", "", "", id1, encrypt_metadata);
data.setO(compute_O_value(user_password, owner_password, data));
O = data.getO();
data.setU(compute_U_value(user_password, data));
@@ -1298,8 +1223,7 @@ QPDF::compute_encryption_parameters_V5(
std::string& UE,
std::string& Perms)
{
- EncryptionData data(
- V, R, key_len, P, "", "", "", "", "", id1, encrypt_metadata);
+ EncryptionData data(V, R, key_len, P, "", "", "", "", "", id1, encrypt_metadata);
unsigned char k[key_bytes];
QUtil::initializeWithRandomBytes(k, key_bytes);
encryption_key = std::string(reinterpret_cast<char*>(k), key_bytes);
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-06-29 13:25:39 +0200