CFX_ByteString CPDF_StandardSecurityHandler::GetUserPassword(
const uint8_t* owner_pass,
FX_DWORD pass_size,
int32_t key_len) {
CFX_ByteString okey = m_pEncryptDict->GetString(FX_BSTRC("O"));
uint8_t passcode[32];
FX_DWORD i;
for (i = 0; i < 32; i++) {
passcode[i] = i < pass_size ? owner_pass[i] : defpasscode[i - pass_size];
}
uint8_t digest[16];
CRYPT_MD5Generate(passcode, 32, digest);
if (m_Revision >= 3) {
for (int i = 0; i < 50; i++) {
CRYPT_MD5Generate(digest, 16, digest);
}
}
uint8_t enckey[32];
FXSYS_memset(enckey, 0, sizeof(enckey));
FX_DWORD copy_len = key_len;
if (copy_len > sizeof(digest)) {
copy_len = sizeof(digest);
}
FXSYS_memcpy(enckey, digest, copy_len);
int okeylen = okey.GetLength();
if (okeylen > 32) {
okeylen = 32;
}
uint8_t okeybuf[64];
FXSYS_memset(okeybuf, 0, sizeof(okeybuf));
FXSYS_memcpy(okeybuf, okey.c_str(), okeylen);
if (m_Revision == 2) {
CRYPT_ArcFourCryptBlock(okeybuf, okeylen, enckey, key_len);
} else {
for (int i = 19; i >= 0; i--) {
uint8_t tempkey[32];
FXSYS_memset(tempkey, 0, sizeof(tempkey));
for (int j = 0; j < m_KeyLen; j++) {
tempkey[j] = enckey[j] ^ i;
}
CRYPT_ArcFourCryptBlock(okeybuf, okeylen, tempkey, key_len);
}
}
int len = 32;
while (len && defpasscode[len - 1] == okeybuf[len - 1]) {
len--;
}
return CFX_ByteString(okeybuf, len);
}
void CPDF_StandardCryptoHandler::CryptBlock(FX_BOOL bEncrypt, FX_DWORD objnum, FX_DWORD gennum, FX_LPCBYTE src_buf, FX_DWORD src_size,
FX_LPBYTE dest_buf, FX_DWORD& dest_size)
{
if (m_Cipher == FXCIPHER_NONE) {
FXSYS_memcpy32(dest_buf, src_buf, src_size);
return;
}
FX_BYTE realkey[16];
int realkeylen = 16;
if (m_Cipher != FXCIPHER_AES || m_KeyLen != 32) {
FX_BYTE key1[32];
FXSYS_memcpy32(key1, m_EncryptKey, m_KeyLen);
key1[m_KeyLen + 0] = (FX_BYTE)objnum;
key1[m_KeyLen + 1] = (FX_BYTE)(objnum >> 8);
key1[m_KeyLen + 2] = (FX_BYTE)(objnum >> 16);
key1[m_KeyLen + 3] = (FX_BYTE)gennum;
key1[m_KeyLen + 4] = (FX_BYTE)(gennum >> 8);
FXSYS_memcpy32(key1 + m_KeyLen, &objnum, 3);
FXSYS_memcpy32(key1 + m_KeyLen + 3, &gennum, 2);
if (m_Cipher == FXCIPHER_AES) {
FXSYS_memcpy32(key1 + m_KeyLen + 5, "sAlT", 4);
}
CRYPT_MD5Generate(key1, m_Cipher == FXCIPHER_AES ? m_KeyLen + 9 : m_KeyLen + 5, realkey);
realkeylen = m_KeyLen + 5;
if (realkeylen > 16) {
realkeylen = 16;
}
}
void CPDF_CryptoHandler::CryptBlock(bool bEncrypt,
uint32_t objnum,
uint32_t gennum,
const uint8_t* src_buf,
uint32_t src_size,
uint8_t* dest_buf,
uint32_t& dest_size) {
if (m_Cipher == FXCIPHER_NONE) {
FXSYS_memcpy(dest_buf, src_buf, src_size);
return;
}
uint8_t realkey[16];
int realkeylen = 16;
if (m_Cipher != FXCIPHER_AES || m_KeyLen != 32) {
uint8_t key1[32];
PopulateKey(objnum, gennum, key1);
if (m_Cipher == FXCIPHER_AES) {
FXSYS_memcpy(key1 + m_KeyLen + 5, "sAlT", 4);
}
CRYPT_MD5Generate(
key1, m_Cipher == FXCIPHER_AES ? m_KeyLen + 9 : m_KeyLen + 5, realkey);
realkeylen = m_KeyLen + 5;
if (realkeylen > 16) {
realkeylen = 16;
}
}
if (m_Cipher == FXCIPHER_AES) {
CRYPT_AESSetKey(m_pAESContext, 16, m_KeyLen == 32 ? m_EncryptKey : realkey,
m_KeyLen, bEncrypt);
if (bEncrypt) {
uint8_t iv[16];
for (int i = 0; i < 16; i++) {
iv[i] = (uint8_t)rand();
}
CRYPT_AESSetIV(m_pAESContext, iv);
FXSYS_memcpy(dest_buf, iv, 16);
int nblocks = src_size / 16;
CRYPT_AESEncrypt(m_pAESContext, dest_buf + 16, src_buf, nblocks * 16);
uint8_t padding[16];
FXSYS_memcpy(padding, src_buf + nblocks * 16, src_size % 16);
FXSYS_memset(padding + src_size % 16, 16 - src_size % 16,
16 - src_size % 16);
CRYPT_AESEncrypt(m_pAESContext, dest_buf + nblocks * 16 + 16, padding,
16);
dest_size = 32 + nblocks * 16;
} else {
CRYPT_AESSetIV(m_pAESContext, src_buf);
CRYPT_AESDecrypt(m_pAESContext, dest_buf, src_buf + 16, src_size - 16);
dest_size = src_size - 16;
dest_size -= dest_buf[dest_size - 1];
}
} else {
ASSERT(dest_size == src_size);
if (dest_buf != src_buf) {
FXSYS_memcpy(dest_buf, src_buf, src_size);
}
CRYPT_ArcFourCryptBlock(dest_buf, dest_size, realkey, realkeylen);
}
}
void* CPDF_CryptoHandler::CryptStart(uint32_t objnum,
uint32_t gennum,
bool bEncrypt) {
if (m_Cipher == FXCIPHER_NONE) {
return this;
}
if (m_Cipher == FXCIPHER_AES && m_KeyLen == 32) {
AESCryptContext* pContext = FX_Alloc(AESCryptContext, 1);
pContext->m_bIV = true;
pContext->m_BlockOffset = 0;
CRYPT_AESSetKey(pContext->m_Context, 16, m_EncryptKey, 32, bEncrypt);
if (bEncrypt) {
for (int i = 0; i < 16; i++) {
pContext->m_Block[i] = (uint8_t)rand();
}
CRYPT_AESSetIV(pContext->m_Context, pContext->m_Block);
}
return pContext;
}
uint8_t key1[48];
PopulateKey(objnum, gennum, key1);
if (m_Cipher == FXCIPHER_AES) {
FXSYS_memcpy(key1 + m_KeyLen + 5, "sAlT", 4);
}
uint8_t realkey[16];
CRYPT_MD5Generate(
key1, m_Cipher == FXCIPHER_AES ? m_KeyLen + 9 : m_KeyLen + 5, realkey);
int realkeylen = m_KeyLen + 5;
if (realkeylen > 16) {
realkeylen = 16;
}
if (m_Cipher == FXCIPHER_AES) {
AESCryptContext* pContext = FX_Alloc(AESCryptContext, 1);
pContext->m_bIV = true;
pContext->m_BlockOffset = 0;
CRYPT_AESSetKey(pContext->m_Context, 16, realkey, 16, bEncrypt);
if (bEncrypt) {
for (int i = 0; i < 16; i++) {
pContext->m_Block[i] = (uint8_t)rand();
}
CRYPT_AESSetIV(pContext->m_Context, pContext->m_Block);
}
return pContext;
}
CRYPT_rc4_context* pContext = FX_Alloc(CRYPT_rc4_context, 1);
CRYPT_ArcFourSetup(pContext, realkey, realkeylen);
return pContext;
}
void CalcEncryptKey(CPDF_Dictionary* pEncrypt,
const uint8_t* password,
FX_DWORD pass_size,
uint8_t* key,
int keylen,
FX_BOOL bIgnoreMeta,
CPDF_Array* pIdArray) {
int revision = pEncrypt->GetInteger(FX_BSTRC("R"));
uint8_t passcode[32];
for (FX_DWORD i = 0; i < 32; i++) {
passcode[i] = i < pass_size ? password[i] : defpasscode[i - pass_size];
}
uint8_t md5[100];
CRYPT_MD5Start(md5);
CRYPT_MD5Update(md5, passcode, 32);
CFX_ByteString okey = pEncrypt->GetString(FX_BSTRC("O"));
CRYPT_MD5Update(md5, (uint8_t*)okey.c_str(), okey.GetLength());
FX_DWORD perm = pEncrypt->GetInteger(FX_BSTRC("P"));
CRYPT_MD5Update(md5, (uint8_t*)&perm, 4);
if (pIdArray) {
CFX_ByteString id = pIdArray->GetString(0);
CRYPT_MD5Update(md5, (uint8_t*)id.c_str(), id.GetLength());
}
if (!bIgnoreMeta && revision >= 3 &&
!pEncrypt->GetInteger(FX_BSTRC("EncryptMetadata"), 1)) {
FX_DWORD tag = (FX_DWORD)-1;
CRYPT_MD5Update(md5, (uint8_t*)&tag, 4);
}
uint8_t digest[16];
CRYPT_MD5Finish(md5, digest);
FX_DWORD copy_len = keylen;
if (copy_len > sizeof(digest)) {
copy_len = sizeof(digest);
}
if (revision >= 3) {
for (int i = 0; i < 50; i++) {
CRYPT_MD5Generate(digest, copy_len, digest);
}
}
FXSYS_memset(key, 0, keylen);
FXSYS_memcpy(key, digest, copy_len);
}
void CPDF_SecurityHandler::OnCreate(CPDF_Dictionary* pEncryptDict,
CPDF_Array* pIdArray,
const uint8_t* user_pass,
uint32_t user_size,
const uint8_t* owner_pass,
uint32_t owner_size,
FX_BOOL bDefault,
uint32_t type) {
int cipher = 0, key_len = 0;
if (!LoadDict(pEncryptDict, type, cipher, key_len)) {
return;
}
if (bDefault && (!owner_pass || owner_size == 0)) {
owner_pass = user_pass;
owner_size = user_size;
}
if (m_Revision >= 5) {
int t = (int)time(nullptr);
uint8_t sha[128];
CRYPT_SHA256Start(sha);
CRYPT_SHA256Update(sha, (uint8_t*)&t, sizeof t);
CRYPT_SHA256Update(sha, m_EncryptKey, 32);
CRYPT_SHA256Update(sha, (uint8_t*)"there", 5);
CRYPT_SHA256Finish(sha, m_EncryptKey);
AES256_SetPassword(pEncryptDict, user_pass, user_size, FALSE, m_EncryptKey);
if (bDefault) {
AES256_SetPassword(pEncryptDict, owner_pass, owner_size, TRUE,
m_EncryptKey);
AES256_SetPerms(pEncryptDict, m_Permissions,
pEncryptDict->GetBooleanBy("EncryptMetadata", true),
m_EncryptKey);
}
return;
}
if (bDefault) {
uint8_t passcode[32];
for (uint32_t i = 0; i < 32; i++) {
passcode[i] =
i < owner_size ? owner_pass[i] : defpasscode[i - owner_size];
}
uint8_t digest[16];
CRYPT_MD5Generate(passcode, 32, digest);
if (m_Revision >= 3) {
for (uint32_t i = 0; i < 50; i++)
CRYPT_MD5Generate(digest, 16, digest);
}
uint8_t enckey[32];
FXSYS_memcpy(enckey, digest, key_len);
for (uint32_t i = 0; i < 32; i++) {
passcode[i] = i < user_size ? user_pass[i] : defpasscode[i - user_size];
}
CRYPT_ArcFourCryptBlock(passcode, 32, enckey, key_len);
uint8_t tempkey[32];
if (m_Revision >= 3) {
for (uint8_t i = 1; i <= 19; i++) {
for (int j = 0; j < key_len; j++)
tempkey[j] = enckey[j] ^ i;
CRYPT_ArcFourCryptBlock(passcode, 32, tempkey, key_len);
}
}
pEncryptDict->SetAtString("O", CFX_ByteString(passcode, 32));
}
CalcEncryptKey(m_pEncryptDict, (uint8_t*)user_pass, user_size, m_EncryptKey,
key_len, FALSE, pIdArray);
if (m_Revision < 3) {
uint8_t tempbuf[32];
FXSYS_memcpy(tempbuf, defpasscode, 32);
CRYPT_ArcFourCryptBlock(tempbuf, 32, m_EncryptKey, key_len);
pEncryptDict->SetAtString("U", CFX_ByteString(tempbuf, 32));
} else {
uint8_t md5[100];
CRYPT_MD5Start(md5);
CRYPT_MD5Update(md5, defpasscode, 32);
if (pIdArray) {
CFX_ByteString id = pIdArray->GetStringAt(0);
CRYPT_MD5Update(md5, (uint8_t*)id.c_str(), id.GetLength());
}
uint8_t digest[32];
CRYPT_MD5Finish(md5, digest);
CRYPT_ArcFourCryptBlock(digest, 16, m_EncryptKey, key_len);
uint8_t tempkey[32];
for (uint8_t i = 1; i <= 19; i++) {
for (int j = 0; j < key_len; j++) {
tempkey[j] = m_EncryptKey[j] ^ i;
}
CRYPT_ArcFourCryptBlock(digest, 16, tempkey, key_len);
}
CRYPT_MD5Generate(digest, 16, digest + 16);
pEncryptDict->SetAtString("U", CFX_ByteString(digest, 32));
}
}
void CPDF_StandardSecurityHandler::OnCreate(CPDF_Dictionary* pEncryptDict, CPDF_Array* pIdArray,
FX_LPCBYTE user_pass, FX_DWORD user_size,
FX_LPCBYTE owner_pass, FX_DWORD owner_size, FX_BOOL bDefault, FX_DWORD type)
{
int cipher = 0, key_len = 0;
if (!LoadDict(pEncryptDict, type, cipher, key_len)) {
return;
}
if (bDefault && (owner_pass == NULL || owner_size == 0)) {
owner_pass = user_pass;
owner_size = user_size;
}
if (m_Revision >= 5) {
int t = (int)time(NULL);
FX_BYTE sha[128];
CRYPT_SHA256Start(sha);
CRYPT_SHA256Update(sha, (FX_BYTE*)&t, sizeof t);
CRYPT_SHA256Update(sha, m_EncryptKey, 32);
CRYPT_SHA256Update(sha, (FX_BYTE*)"there", 5);
CRYPT_SHA256Finish(sha, m_EncryptKey);
AES256_SetPassword(pEncryptDict, user_pass, user_size, FALSE, m_EncryptKey);
if (bDefault) {
AES256_SetPassword(pEncryptDict, owner_pass, owner_size, TRUE, m_EncryptKey);
AES256_SetPerms(pEncryptDict, m_Permissions, pEncryptDict->GetBoolean(FX_BSTRC("EncryptMetadata"), TRUE), m_EncryptKey);
}
return;
}
if (bDefault) {
FX_BYTE passcode[32];
FX_DWORD i;
for (i = 0; i < 32; i ++) {
passcode[i] = i < owner_size ? owner_pass[i] : defpasscode[i - owner_size];
}
FX_BYTE digest[16];
CRYPT_MD5Generate(passcode, 32, digest);
if (m_Revision >= 3) {
for (int i = 0; i < 50; i ++) {
CRYPT_MD5Generate(digest, 16, digest);
}
}
FX_BYTE enckey[32];
FXSYS_memcpy32(enckey, digest, key_len);
for (i = 0; i < 32; i ++) {
passcode[i] = i < user_size ? user_pass[i] : defpasscode[i - user_size];
}
CRYPT_ArcFourCryptBlock(passcode, 32, enckey, key_len);
FX_BYTE tempkey[32];
if (m_Revision >= 3) {
for (i = 1; i <= 19; i ++) {
for (int j = 0; j < key_len; j ++) {
tempkey[j] = enckey[j] ^ (FX_BYTE)i;
}
CRYPT_ArcFourCryptBlock(passcode, 32, tempkey, key_len);
}
}
pEncryptDict->SetAtString(FX_BSTRC("O"), CFX_ByteString(passcode, 32));
}
CalcEncryptKey(m_pEncryptDict, (FX_LPBYTE)user_pass, user_size, m_EncryptKey, key_len, FALSE, pIdArray);
if (m_Revision < 3) {
FX_BYTE tempbuf[32];
FXSYS_memcpy32(tempbuf, defpasscode, 32);
CRYPT_ArcFourCryptBlock(tempbuf, 32, m_EncryptKey, key_len);
pEncryptDict->SetAtString(FX_BSTRC("U"), CFX_ByteString(tempbuf, 32));
} else {
FX_BYTE md5[100];
CRYPT_MD5Start(md5);
CRYPT_MD5Update(md5, defpasscode, 32);
if (pIdArray) {
CFX_ByteString id = pIdArray->GetString(0);
CRYPT_MD5Update(md5, (FX_LPBYTE)(FX_LPCSTR)id, id.GetLength());
}
FX_BYTE digest[32];
CRYPT_MD5Finish(md5, digest);
CRYPT_ArcFourCryptBlock(digest, 16, m_EncryptKey, key_len);
FX_BYTE tempkey[32];
for (int i = 1; i <= 19; i ++) {
for (int j = 0; j < key_len; j ++) {
tempkey[j] = m_EncryptKey[j] ^ (FX_BYTE)i;
}
CRYPT_ArcFourCryptBlock(digest, 16, tempkey, key_len);
}
CRYPT_MD5Generate(digest, 16, digest + 16);
pEncryptDict->SetAtString(FX_BSTRC("U"), CFX_ByteString(digest, 32));
}
}
