| // Copyright 2014 PDFium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com |
| |
| #include <time.h> |
| #include "../../../include/fpdfapi/fpdf_parser.h" |
| #include "../../../include/fdrm/fx_crypt.h" |
| const uint8_t defpasscode[32] = { |
| 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 |
| }; |
| 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_memset32(key, 0, keylen); |
| FXSYS_memcpy32(key, digest, copy_len); |
| } |
| CPDF_CryptoHandler* CPDF_StandardSecurityHandler::CreateCryptoHandler() |
| { |
| return new CPDF_StandardCryptoHandler; |
| } |
| typedef struct _PDF_CRYPTOITEM { |
| int32_t m_Cipher; |
| int32_t m_KeyLen; |
| FX_BOOL m_bChecked; |
| CPDF_StandardCryptoHandler* m_pCryptoHandler; |
| } PDF_CRYPTOITEM; |
| CPDF_StandardSecurityHandler::CPDF_StandardSecurityHandler() |
| { |
| m_Version = 0; |
| m_Revision = 0; |
| m_pParser = NULL; |
| m_pEncryptDict = NULL; |
| m_bOwner = FALSE; |
| m_Permissions = 0; |
| m_Cipher = FXCIPHER_NONE; |
| m_KeyLen = 0; |
| } |
| CPDF_StandardSecurityHandler::~CPDF_StandardSecurityHandler() |
| { |
| } |
| FX_BOOL CPDF_StandardSecurityHandler::OnInit(CPDF_Parser* pParser, CPDF_Dictionary* pEncryptDict) |
| { |
| m_pParser = pParser; |
| if (!LoadDict(pEncryptDict)) { |
| return FALSE; |
| } |
| if (m_Cipher == FXCIPHER_NONE) { |
| return TRUE; |
| } |
| return CheckSecurity(m_KeyLen); |
| } |
| FX_BOOL CPDF_StandardSecurityHandler::CheckSecurity(int32_t key_len) |
| { |
| CFX_ByteString password = m_pParser->GetPassword(); |
| if (CheckPassword(password, password.GetLength(), TRUE, m_EncryptKey, key_len)) { |
| if (password.IsEmpty()) { |
| if (!CheckPassword(password, password.GetLength(), FALSE, m_EncryptKey, key_len)) { |
| return FALSE; |
| } |
| } |
| m_bOwner = TRUE; |
| return TRUE; |
| } |
| return CheckPassword(password, password.GetLength(), FALSE, m_EncryptKey, key_len); |
| } |
| FX_DWORD CPDF_StandardSecurityHandler::GetPermissions() |
| { |
| return m_Permissions; |
| } |
| static FX_BOOL _LoadCryptInfo(CPDF_Dictionary* pEncryptDict, const CFX_ByteStringC& name, int& cipher, int& keylen) |
| { |
| int Version = pEncryptDict->GetInteger(FX_BSTRC("V")); |
| cipher = FXCIPHER_RC4; |
| keylen = 0; |
| if (Version >= 4) { |
| CPDF_Dictionary* pCryptFilters = pEncryptDict->GetDict(FX_BSTRC("CF")); |
| if (pCryptFilters == NULL) { |
| return FALSE; |
| } |
| if (name == FX_BSTRC("Identity")) { |
| cipher = FXCIPHER_NONE; |
| } else { |
| CPDF_Dictionary* pDefFilter = pCryptFilters->GetDict(name); |
| if (pDefFilter == NULL) { |
| return FALSE; |
| } |
| int nKeyBits = 0; |
| if (Version == 4) { |
| nKeyBits = pDefFilter->GetInteger(FX_BSTRC("Length"), 0); |
| if (nKeyBits == 0) { |
| nKeyBits = pEncryptDict->GetInteger(FX_BSTRC("Length"), 128); |
| } |
| } else { |
| nKeyBits = pEncryptDict->GetInteger(FX_BSTRC("Length"), 256); |
| } |
| if (nKeyBits < 40) { |
| nKeyBits *= 8; |
| } |
| keylen = nKeyBits / 8; |
| CFX_ByteString cipher_name = pDefFilter->GetString(FX_BSTRC("CFM")); |
| if (cipher_name == FX_BSTRC("AESV2") || cipher_name == FX_BSTRC("AESV3")) { |
| cipher = FXCIPHER_AES; |
| } |
| } |
| } else { |
| keylen = Version > 1 ? pEncryptDict->GetInteger(FX_BSTRC("Length"), 40) / 8 : 5; |
| } |
| if (keylen > 32 || keylen < 0) { |
| return FALSE; |
| } |
| return TRUE; |
| } |
| FX_BOOL CPDF_StandardSecurityHandler::LoadDict(CPDF_Dictionary* pEncryptDict) |
| { |
| m_pEncryptDict = pEncryptDict; |
| m_bOwner = FALSE; |
| m_Version = pEncryptDict->GetInteger(FX_BSTRC("V")); |
| m_Revision = pEncryptDict->GetInteger(FX_BSTRC("R")); |
| m_Permissions = pEncryptDict->GetInteger(FX_BSTRC("P"), -1); |
| if (m_Version < 4) { |
| return _LoadCryptInfo(pEncryptDict, CFX_ByteString(), m_Cipher, m_KeyLen); |
| } |
| CFX_ByteString stmf_name = pEncryptDict->GetString(FX_BSTRC("StmF")); |
| CFX_ByteString strf_name = pEncryptDict->GetString(FX_BSTRC("StrF")); |
| if (stmf_name != strf_name) { |
| return FALSE; |
| } |
| if (!_LoadCryptInfo(pEncryptDict, strf_name, m_Cipher, m_KeyLen)) { |
| return FALSE; |
| } |
| return TRUE; |
| } |
| FX_BOOL CPDF_StandardSecurityHandler::LoadDict(CPDF_Dictionary* pEncryptDict, FX_DWORD type, int& cipher, int& key_len) |
| { |
| m_pEncryptDict = pEncryptDict; |
| m_bOwner = FALSE; |
| m_Version = pEncryptDict->GetInteger(FX_BSTRC("V")); |
| m_Revision = pEncryptDict->GetInteger(FX_BSTRC("R")); |
| m_Permissions = pEncryptDict->GetInteger(FX_BSTRC("P"), -1); |
| CFX_ByteString strf_name, stmf_name; |
| if (m_Version >= 4) { |
| stmf_name = pEncryptDict->GetString(FX_BSTRC("StmF")); |
| strf_name = pEncryptDict->GetString(FX_BSTRC("StrF")); |
| if (stmf_name != strf_name) { |
| return FALSE; |
| } |
| } |
| if (!_LoadCryptInfo(pEncryptDict, strf_name, cipher, key_len)) { |
| return FALSE; |
| } |
| m_Cipher = cipher; |
| m_KeyLen = key_len; |
| return TRUE; |
| return TRUE; |
| } |
| FX_BOOL CPDF_StandardSecurityHandler::GetCryptInfo(int& cipher, const uint8_t*& buffer, int& keylen) |
| { |
| cipher = m_Cipher; |
| buffer = m_EncryptKey; |
| keylen = m_KeyLen; |
| return TRUE; |
| } |
| #define FX_GET_32WORD(n,b,i) \ |
| { \ |
| (n) = (FX_DWORD)(( (uint64_t) (b)[(i)] << 24 ) \ |
| | ( (uint64_t) (b)[(i) + 1] << 16 ) \ |
| | ( (uint64_t) (b)[(i) + 2] << 8 ) \ |
| | ( (uint64_t) (b)[(i) + 3] )); \ |
| } |
| int BigOrder64BitsMod3(uint8_t* data) |
| { |
| uint64_t ret = 0; |
| for (int i = 0; i < 4; ++i) { |
| FX_DWORD value; |
| FX_GET_32WORD(value, data, 4 * i); |
| ret <<= 32; |
| ret |= value; |
| ret %= 3; |
| } |
| return (int)ret; |
| } |
| void Revision6_Hash(const uint8_t* password, FX_DWORD size, const uint8_t* salt, const uint8_t* vector, uint8_t* hash) |
| { |
| int iBlockSize = 32; |
| uint8_t sha[128]; |
| CRYPT_SHA256Start(sha); |
| CRYPT_SHA256Update(sha, password, size); |
| CRYPT_SHA256Update(sha, salt, 8); |
| if (vector) { |
| CRYPT_SHA256Update(sha, vector, 48); |
| } |
| uint8_t digest[32]; |
| CRYPT_SHA256Finish(sha, digest); |
| CFX_ByteTextBuf buf; |
| uint8_t* input = digest; |
| uint8_t* key = input; |
| uint8_t* iv = input + 16; |
| uint8_t* E = buf.GetBuffer(); |
| int iBufLen = buf.GetLength(); |
| CFX_ByteTextBuf interDigest; |
| int i = 0; |
| uint8_t* aes = FX_Alloc(uint8_t, 2048); |
| while (i < 64 || i < E[iBufLen - 1] + 32) { |
| int iRoundSize = size + iBlockSize; |
| if (vector) { |
| iRoundSize += 48; |
| } |
| iBufLen = iRoundSize * 64; |
| buf.EstimateSize(iBufLen); |
| E = buf.GetBuffer(); |
| CFX_ByteTextBuf content; |
| for (int j = 0; j < 64; ++j) { |
| content.AppendBlock(password, size); |
| content.AppendBlock(input, iBlockSize); |
| if (vector) { |
| content.AppendBlock(vector, 48); |
| } |
| } |
| CRYPT_AESSetKey(aes, 16, key, 16, TRUE); |
| CRYPT_AESSetIV(aes, iv); |
| CRYPT_AESEncrypt(aes, E, content.GetBuffer(), iBufLen); |
| int iHash = 0; |
| switch (BigOrder64BitsMod3(E)) { |
| case 0: |
| iHash = 0; |
| iBlockSize = 32; |
| break; |
| case 1: |
| iHash = 1; |
| iBlockSize = 48; |
| break; |
| default: |
| iHash = 2; |
| iBlockSize = 64; |
| break; |
| } |
| interDigest.EstimateSize(iBlockSize); |
| input = interDigest.GetBuffer(); |
| if (iHash == 0) { |
| CRYPT_SHA256Generate(E, iBufLen, input); |
| } else if (iHash == 1) { |
| CRYPT_SHA384Generate(E, iBufLen, input); |
| } else if (iHash == 2) { |
| CRYPT_SHA512Generate(E, iBufLen, input); |
| } |
| key = input; |
| iv = input + 16; |
| ++i; |
| } |
| FX_Free(aes); |
| if (hash) { |
| FXSYS_memcpy32(hash, input, 32); |
| } |
| } |
| FX_BOOL CPDF_StandardSecurityHandler::AES256_CheckPassword(const uint8_t* password, FX_DWORD size, |
| FX_BOOL bOwner, uint8_t* key) |
| { |
| CFX_ByteString okey = m_pEncryptDict ? m_pEncryptDict->GetString(FX_BSTRC("O")) : CFX_ByteString(); |
| if (okey.GetLength() < 48) { |
| return FALSE; |
| } |
| CFX_ByteString ukey = m_pEncryptDict ? m_pEncryptDict->GetString(FX_BSTRC("U")) : CFX_ByteString(); |
| if (ukey.GetLength() < 48) { |
| return FALSE; |
| } |
| const uint8_t* pkey = bOwner ? (const uint8_t*)okey : (const uint8_t*)ukey; |
| uint8_t sha[128]; |
| uint8_t digest[32]; |
| if (m_Revision >= 6) { |
| Revision6_Hash(password, size, (const uint8_t*)pkey + 32, (bOwner ? (const uint8_t*)ukey : NULL), digest); |
| } else { |
| CRYPT_SHA256Start(sha); |
| CRYPT_SHA256Update(sha, password, size); |
| CRYPT_SHA256Update(sha, pkey + 32, 8); |
| if (bOwner) { |
| CRYPT_SHA256Update(sha, ukey, 48); |
| } |
| CRYPT_SHA256Finish(sha, digest); |
| } |
| if (FXSYS_memcmp32(digest, pkey, 32) != 0) { |
| return FALSE; |
| } |
| if (key == NULL) { |
| return TRUE; |
| } |
| if (m_Revision >= 6) { |
| Revision6_Hash(password, size, (const uint8_t*)pkey + 40, (bOwner ? (const uint8_t*)ukey : NULL), digest); |
| } else { |
| CRYPT_SHA256Start(sha); |
| CRYPT_SHA256Update(sha, password, size); |
| CRYPT_SHA256Update(sha, pkey + 40, 8); |
| if (bOwner) { |
| CRYPT_SHA256Update(sha, ukey, 48); |
| } |
| CRYPT_SHA256Finish(sha, digest); |
| } |
| CFX_ByteString ekey = m_pEncryptDict ? m_pEncryptDict->GetString(bOwner ? FX_BSTRC("OE") : FX_BSTRC("UE")) : CFX_ByteString(); |
| if (ekey.GetLength() < 32) { |
| return FALSE; |
| } |
| uint8_t* aes = FX_Alloc(uint8_t, 2048); |
| CRYPT_AESSetKey(aes, 16, digest, 32, FALSE); |
| uint8_t iv[16]; |
| FXSYS_memset32(iv, 0, 16); |
| CRYPT_AESSetIV(aes, iv); |
| CRYPT_AESDecrypt(aes, key, ekey, 32); |
| CRYPT_AESSetKey(aes, 16, key, 32, FALSE); |
| CRYPT_AESSetIV(aes, iv); |
| CFX_ByteString perms = m_pEncryptDict->GetString(FX_BSTRC("Perms")); |
| if (perms.IsEmpty()) { |
| return FALSE; |
| } |
| uint8_t perms_buf[16]; |
| FXSYS_memset32(perms_buf, 0, sizeof(perms_buf)); |
| FX_DWORD copy_len = sizeof(perms_buf); |
| if (copy_len > (FX_DWORD)perms.GetLength()) { |
| copy_len = perms.GetLength(); |
| } |
| FXSYS_memcpy32(perms_buf, (const uint8_t*)perms, copy_len); |
| uint8_t buf[16]; |
| CRYPT_AESDecrypt(aes, buf, perms_buf, 16); |
| FX_Free(aes); |
| if (buf[9] != 'a' || buf[10] != 'd' || buf[11] != 'b') { |
| return FALSE; |
| } |
| if (FXDWORD_GET_LSBFIRST(buf) != m_Permissions) { |
| return FALSE; |
| } |
| if ((buf[8] == 'T' && !IsMetadataEncrypted()) || (buf[8] == 'F' && IsMetadataEncrypted())) { |
| return FALSE; |
| } |
| return TRUE; |
| } |
| int CPDF_StandardSecurityHandler::CheckPassword(const uint8_t* password, FX_DWORD pass_size, FX_BOOL bOwner, uint8_t* key) |
| { |
| return CheckPassword(password, pass_size, bOwner, key, m_KeyLen); |
| } |
| int CPDF_StandardSecurityHandler::CheckPassword(const uint8_t* password, FX_DWORD size, FX_BOOL bOwner, uint8_t* key, int32_t key_len) |
| { |
| if (m_Revision >= 5) { |
| return AES256_CheckPassword(password, size, bOwner, key); |
| } |
| uint8_t keybuf[32]; |
| if (key == NULL) { |
| key = keybuf; |
| } |
| if (bOwner) { |
| return CheckOwnerPassword(password, size, key, key_len); |
| } |
| return CheckUserPassword(password, size, FALSE, key, key_len) || CheckUserPassword(password, size, TRUE, key, key_len); |
| } |
| FX_BOOL CPDF_StandardSecurityHandler::CheckUserPassword(const uint8_t* password, FX_DWORD pass_size, |
| FX_BOOL bIgnoreEncryptMeta, uint8_t* key, int32_t key_len) |
| { |
| CalcEncryptKey(m_pEncryptDict, password, pass_size, key, key_len, bIgnoreEncryptMeta, |
| m_pParser->GetIDArray()); |
| CFX_ByteString ukey = m_pEncryptDict ? m_pEncryptDict->GetString(FX_BSTRC("U")) : CFX_ByteString(); |
| if (ukey.GetLength() < 16) { |
| return FALSE; |
| } |
| uint8_t ukeybuf[32]; |
| if (m_Revision == 2) { |
| FXSYS_memcpy32(ukeybuf, defpasscode, 32); |
| CRYPT_ArcFourCryptBlock(ukeybuf, 32, key, key_len); |
| } else { |
| uint8_t test[32], tmpkey[32]; |
| FX_DWORD copy_len = sizeof(test); |
| if (copy_len > (FX_DWORD)ukey.GetLength()) { |
| copy_len = ukey.GetLength(); |
| } |
| FXSYS_memset32(test, 0, sizeof(test)); |
| FXSYS_memset32(tmpkey, 0, sizeof(tmpkey)); |
| FXSYS_memcpy32(test, ukey.c_str(), copy_len); |
| for (int i = 19; i >= 0; i --) { |
| for (int j = 0; j < key_len; j ++) { |
| tmpkey[j] = key[j] ^ i; |
| } |
| CRYPT_ArcFourCryptBlock(test, 32, tmpkey, key_len); |
| } |
| uint8_t md5[100]; |
| CRYPT_MD5Start(md5); |
| CRYPT_MD5Update(md5, defpasscode, 32); |
| CPDF_Array* pIdArray = m_pParser->GetIDArray(); |
| if (pIdArray) { |
| CFX_ByteString id = pIdArray->GetString(0); |
| CRYPT_MD5Update(md5, (uint8_t*)id.c_str(), id.GetLength()); |
| } |
| CRYPT_MD5Finish(md5, ukeybuf); |
| return FXSYS_memcmp32(test, ukeybuf, 16) == 0; |
| } |
| if (FXSYS_memcmp32((void*)ukey.c_str(), ukeybuf, 16) == 0) { |
| return TRUE; |
| } |
| return FALSE; |
| } |
| CFX_ByteString CPDF_StandardSecurityHandler::GetUserPassword(const uint8_t* owner_pass, FX_DWORD pass_size) |
| { |
| return GetUserPassword(owner_pass, pass_size, m_KeyLen); |
| } |
| 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_memset32(enckey, 0, sizeof(enckey)); |
| FX_DWORD copy_len = key_len; |
| if (copy_len > sizeof(digest)) { |
| copy_len = sizeof(digest); |
| } |
| FXSYS_memcpy32(enckey, digest, copy_len); |
| int okeylen = okey.GetLength(); |
| if (okeylen > 32) { |
| okeylen = 32; |
| } |
| uint8_t okeybuf[64]; |
| FXSYS_memset32(okeybuf, 0, sizeof(okeybuf)); |
| FXSYS_memcpy32(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_memset32(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); |
| } |
| FX_BOOL CPDF_StandardSecurityHandler::CheckOwnerPassword(const uint8_t* password, FX_DWORD pass_size, |
| uint8_t* key, int32_t key_len) |
| { |
| CFX_ByteString user_pass = GetUserPassword(password, pass_size, key_len); |
| if (CheckUserPassword(user_pass, user_pass.GetLength(), FALSE, key, key_len)) { |
| return TRUE; |
| } |
| return CheckUserPassword(user_pass, user_pass.GetLength(), TRUE, key, key_len); |
| } |
| FX_BOOL CPDF_StandardSecurityHandler::IsMetadataEncrypted() |
| { |
| return m_pEncryptDict->GetBoolean(FX_BSTRC("EncryptMetadata"), TRUE); |
| } |
| CPDF_SecurityHandler* FPDF_CreateStandardSecurityHandler() |
| { |
| return new CPDF_StandardSecurityHandler; |
| } |
| void CPDF_StandardSecurityHandler::OnCreate(CPDF_Dictionary* pEncryptDict, CPDF_Array* pIdArray, |
| const uint8_t* user_pass, FX_DWORD user_size, |
| const uint8_t* 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); |
| 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->GetBoolean(FX_BSTRC("EncryptMetadata"), TRUE), m_EncryptKey); |
| } |
| return; |
| } |
| if (bDefault) { |
| uint8_t passcode[32]; |
| FX_DWORD i; |
| for (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 (int i = 0; i < 50; i ++) { |
| CRYPT_MD5Generate(digest, 16, digest); |
| } |
| } |
| uint8_t 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); |
| uint8_t tempkey[32]; |
| if (m_Revision >= 3) { |
| for (i = 1; i <= 19; i ++) { |
| for (int j = 0; j < key_len; j ++) { |
| tempkey[j] = enckey[j] ^ (uint8_t)i; |
| } |
| CRYPT_ArcFourCryptBlock(passcode, 32, tempkey, key_len); |
| } |
| } |
| pEncryptDict->SetAtString(FX_BSTRC("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_memcpy32(tempbuf, defpasscode, 32); |
| CRYPT_ArcFourCryptBlock(tempbuf, 32, m_EncryptKey, key_len); |
| pEncryptDict->SetAtString(FX_BSTRC("U"), CFX_ByteString(tempbuf, 32)); |
| } else { |
| uint8_t md5[100]; |
| CRYPT_MD5Start(md5); |
| CRYPT_MD5Update(md5, defpasscode, 32); |
| if (pIdArray) { |
| CFX_ByteString id = pIdArray->GetString(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 (int i = 1; i <= 19; i ++) { |
| for (int j = 0; j < key_len; j ++) { |
| tempkey[j] = m_EncryptKey[j] ^ (uint8_t)i; |
| } |
| CRYPT_ArcFourCryptBlock(digest, 16, tempkey, key_len); |
| } |
| CRYPT_MD5Generate(digest, 16, digest + 16); |
| pEncryptDict->SetAtString(FX_BSTRC("U"), CFX_ByteString(digest, 32)); |
| } |
| } |
| void CPDF_StandardSecurityHandler::OnCreate(CPDF_Dictionary* pEncryptDict, CPDF_Array* pIdArray, |
| const uint8_t* user_pass, FX_DWORD user_size, |
| const uint8_t* owner_pass, FX_DWORD owner_size, FX_DWORD type) |
| { |
| OnCreate(pEncryptDict, pIdArray, user_pass, user_size, owner_pass, owner_size, TRUE, type); |
| } |
| void CPDF_StandardSecurityHandler::OnCreate(CPDF_Dictionary* pEncryptDict, CPDF_Array* pIdArray, const uint8_t* user_pass, FX_DWORD user_size, FX_DWORD type) |
| { |
| OnCreate(pEncryptDict, pIdArray, user_pass, user_size, NULL, 0, FALSE, type); |
| } |
| void CPDF_StandardSecurityHandler::AES256_SetPassword(CPDF_Dictionary* pEncryptDict, const uint8_t* password, FX_DWORD size, FX_BOOL bOwner, const uint8_t* key) |
| { |
| uint8_t sha[128]; |
| CRYPT_SHA1Start(sha); |
| CRYPT_SHA1Update(sha, key, 32); |
| CRYPT_SHA1Update(sha, (uint8_t*)"hello", 5); |
| uint8_t digest[20]; |
| CRYPT_SHA1Finish(sha, digest); |
| CFX_ByteString ukey = pEncryptDict->GetString(FX_BSTRC("U")); |
| uint8_t digest1[48]; |
| if (m_Revision >= 6) { |
| Revision6_Hash(password, size, digest, (bOwner ? (const uint8_t*)ukey : NULL), digest1); |
| } else { |
| CRYPT_SHA256Start(sha); |
| CRYPT_SHA256Update(sha, password, size); |
| CRYPT_SHA256Update(sha, digest, 8); |
| if (bOwner) { |
| CRYPT_SHA256Update(sha, ukey, ukey.GetLength()); |
| } |
| CRYPT_SHA256Finish(sha, digest1); |
| } |
| FXSYS_memcpy32(digest1 + 32, digest, 16); |
| pEncryptDict->SetAtString(bOwner ? FX_BSTRC("O") : FX_BSTRC("U"), CFX_ByteString(digest1, 48)); |
| if (m_Revision >= 6) { |
| Revision6_Hash(password, size, digest + 8, (bOwner ? (const uint8_t*)ukey : NULL), digest1); |
| } else { |
| CRYPT_SHA256Start(sha); |
| CRYPT_SHA256Update(sha, password, size); |
| CRYPT_SHA256Update(sha, digest + 8, 8); |
| if (bOwner) { |
| CRYPT_SHA256Update(sha, ukey, ukey.GetLength()); |
| } |
| CRYPT_SHA256Finish(sha, digest1); |
| } |
| uint8_t* aes = FX_Alloc(uint8_t, 2048); |
| CRYPT_AESSetKey(aes, 16, digest1, 32, TRUE); |
| uint8_t iv[16]; |
| FXSYS_memset32(iv, 0, 16); |
| CRYPT_AESSetIV(aes, iv); |
| CRYPT_AESEncrypt(aes, digest1, key, 32); |
| FX_Free(aes); |
| pEncryptDict->SetAtString(bOwner ? FX_BSTRC("OE") : FX_BSTRC("UE"), CFX_ByteString(digest1, 32)); |
| } |
| void CPDF_StandardSecurityHandler::AES256_SetPerms(CPDF_Dictionary* pEncryptDict, FX_DWORD permissions, |
| FX_BOOL bEncryptMetadata, const uint8_t* key) |
| { |
| uint8_t buf[16]; |
| buf[0] = (uint8_t)permissions; |
| buf[1] = (uint8_t)(permissions >> 8); |
| buf[2] = (uint8_t)(permissions >> 16); |
| buf[3] = (uint8_t)(permissions >> 24); |
| buf[4] = 0xff; |
| buf[5] = 0xff; |
| buf[6] = 0xff; |
| buf[7] = 0xff; |
| buf[8] = bEncryptMetadata ? 'T' : 'F'; |
| buf[9] = 'a'; |
| buf[10] = 'd'; |
| buf[11] = 'b'; |
| uint8_t* aes = FX_Alloc(uint8_t, 2048); |
| CRYPT_AESSetKey(aes, 16, key, 32, TRUE); |
| uint8_t iv[16], buf1[16]; |
| FXSYS_memset32(iv, 0, 16); |
| CRYPT_AESSetIV(aes, iv); |
| CRYPT_AESEncrypt(aes, buf1, buf, 16); |
| FX_Free(aes); |
| pEncryptDict->SetAtString(FX_BSTRC("Perms"), CFX_ByteString(buf1, 16)); |
| } |
| void CPDF_StandardCryptoHandler::CryptBlock(FX_BOOL bEncrypt, FX_DWORD objnum, FX_DWORD gennum, const uint8_t* src_buf, FX_DWORD src_size, |
| uint8_t* dest_buf, FX_DWORD& dest_size) |
| { |
| if (m_Cipher == FXCIPHER_NONE) { |
| FXSYS_memcpy32(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]; |
| FXSYS_memcpy32(key1, m_EncryptKey, m_KeyLen); |
| key1[m_KeyLen + 0] = (uint8_t)objnum; |
| key1[m_KeyLen + 1] = (uint8_t)(objnum >> 8); |
| key1[m_KeyLen + 2] = (uint8_t)(objnum >> 16); |
| key1[m_KeyLen + 3] = (uint8_t)gennum; |
| key1[m_KeyLen + 4] = (uint8_t)(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; |
| } |
| } |
| 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_memcpy32(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_memcpy32(padding, src_buf + nblocks * 16, src_size % 16); |
| FXSYS_memset8(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_memcpy32(dest_buf, src_buf, src_size); |
| } |
| CRYPT_ArcFourCryptBlock(dest_buf, dest_size, realkey, realkeylen); |
| } |
| } |
| typedef struct _AESCryptContext { |
| uint8_t m_Context[2048]; |
| FX_BOOL m_bIV; |
| uint8_t m_Block[16]; |
| FX_DWORD m_BlockOffset; |
| } AESCryptContext; |
| void* CPDF_StandardCryptoHandler::CryptStart(FX_DWORD objnum, FX_DWORD gennum, FX_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]; |
| FXSYS_memcpy32(key1, m_EncryptKey, m_KeyLen); |
| 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); |
| } |
| 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; |
| } |
| void* pContext = FX_Alloc(uint8_t, 1040); |
| CRYPT_ArcFourSetup(pContext, realkey, realkeylen); |
| return pContext; |
| } |
| FX_BOOL CPDF_StandardCryptoHandler::CryptStream(void* context, const uint8_t* src_buf, FX_DWORD src_size, CFX_BinaryBuf& dest_buf, FX_BOOL bEncrypt) |
| { |
| if (!context) { |
| return FALSE; |
| } |
| if (m_Cipher == FXCIPHER_NONE) { |
| dest_buf.AppendBlock(src_buf, src_size); |
| return TRUE; |
| } |
| if (m_Cipher == FXCIPHER_RC4) { |
| int old_size = dest_buf.GetSize(); |
| dest_buf.AppendBlock(src_buf, src_size); |
| CRYPT_ArcFourCrypt(context, dest_buf.GetBuffer() + old_size, src_size); |
| return TRUE; |
| } |
| AESCryptContext* pContext = (AESCryptContext*)context; |
| if (pContext->m_bIV && bEncrypt) { |
| dest_buf.AppendBlock(pContext->m_Block, 16); |
| pContext->m_bIV = FALSE; |
| } |
| FX_DWORD src_off = 0; |
| FX_DWORD src_left = src_size; |
| while (1) { |
| FX_DWORD copy_size = 16 - pContext->m_BlockOffset; |
| if (copy_size > src_left) { |
| copy_size = src_left; |
| } |
| FXSYS_memcpy32(pContext->m_Block + pContext->m_BlockOffset, src_buf + src_off, copy_size); |
| src_off += copy_size; |
| src_left -= copy_size; |
| pContext->m_BlockOffset += copy_size; |
| if (pContext->m_BlockOffset == 16) { |
| if (!bEncrypt && pContext->m_bIV) { |
| CRYPT_AESSetIV(pContext->m_Context, pContext->m_Block); |
| pContext->m_bIV = FALSE; |
| pContext->m_BlockOffset = 0; |
| } else if (src_off < src_size) { |
| uint8_t block_buf[16]; |
| if (bEncrypt) { |
| CRYPT_AESEncrypt(pContext->m_Context, block_buf, pContext->m_Block, 16); |
| } else { |
| CRYPT_AESDecrypt(pContext->m_Context, block_buf, pContext->m_Block, 16); |
| } |
| dest_buf.AppendBlock(block_buf, 16); |
| pContext->m_BlockOffset = 0; |
| } |
| } |
| if (!src_left) { |
| break; |
| } |
| } |
| return TRUE; |
| } |
| FX_BOOL CPDF_StandardCryptoHandler::CryptFinish(void* context, CFX_BinaryBuf& dest_buf, FX_BOOL bEncrypt) |
| { |
| if (!context) { |
| return FALSE; |
| } |
| if (m_Cipher == FXCIPHER_NONE) { |
| return TRUE; |
| } |
| if (m_Cipher == FXCIPHER_RC4) { |
| FX_Free(context); |
| return TRUE; |
| } |
| AESCryptContext* pContext = (AESCryptContext*)context; |
| if (bEncrypt) { |
| uint8_t block_buf[16]; |
| if (pContext->m_BlockOffset == 16) { |
| CRYPT_AESEncrypt(pContext->m_Context, block_buf, pContext->m_Block, 16); |
| dest_buf.AppendBlock(block_buf, 16); |
| pContext->m_BlockOffset = 0; |
| } |
| FXSYS_memset8(pContext->m_Block + pContext->m_BlockOffset, (uint8_t)(16 - pContext->m_BlockOffset), 16 - pContext->m_BlockOffset); |
| CRYPT_AESEncrypt(pContext->m_Context, block_buf, pContext->m_Block, 16); |
| dest_buf.AppendBlock(block_buf, 16); |
| } else if (pContext->m_BlockOffset == 16) { |
| uint8_t block_buf[16]; |
| CRYPT_AESDecrypt(pContext->m_Context, block_buf, pContext->m_Block, 16); |
| if (block_buf[15] <= 16) { |
| dest_buf.AppendBlock(block_buf, 16 - block_buf[15]); |
| } |
| } |
| FX_Free(pContext); |
| return TRUE; |
| } |
| void* CPDF_StandardCryptoHandler::DecryptStart(FX_DWORD objnum, FX_DWORD gennum) |
| { |
| return CryptStart(objnum, gennum, FALSE); |
| } |
| FX_DWORD CPDF_StandardCryptoHandler::DecryptGetSize(FX_DWORD src_size) |
| { |
| return m_Cipher == FXCIPHER_AES ? src_size - 16 : src_size; |
| } |
| FX_BOOL CPDF_StandardCryptoHandler::Init(CPDF_Dictionary* pEncryptDict, CPDF_SecurityHandler* pSecurityHandler) |
| { |
| const uint8_t* key; |
| if (!pSecurityHandler->GetCryptInfo(m_Cipher, key, m_KeyLen)) { |
| return FALSE; |
| } |
| if (m_KeyLen > 32 || m_KeyLen < 0) { |
| return FALSE; |
| } |
| if (m_Cipher != FXCIPHER_NONE) { |
| FXSYS_memcpy32(m_EncryptKey, key, m_KeyLen); |
| } |
| if (m_Cipher == FXCIPHER_AES) { |
| m_pAESContext = FX_Alloc(uint8_t, 2048); |
| } |
| return TRUE; |
| } |
| FX_BOOL CPDF_StandardCryptoHandler::Init(int cipher, const uint8_t* key, int keylen) |
| { |
| if (cipher == FXCIPHER_AES) { |
| switch(keylen) { |
| case 16: |
| case 24: |
| case 32: |
| break; |
| default: |
| return FALSE; |
| } |
| } else if (cipher == FXCIPHER_AES2) { |
| if (keylen != 32) { |
| return FALSE; |
| } |
| } else if (cipher == FXCIPHER_RC4) { |
| if (keylen < 5 || keylen > 16) { |
| return FALSE; |
| } |
| } else { |
| if (keylen > 32) { |
| keylen = 32; |
| } |
| } |
| m_Cipher = cipher; |
| m_KeyLen = keylen; |
| FXSYS_memcpy32(m_EncryptKey, key, keylen); |
| if (m_Cipher == FXCIPHER_AES) { |
| m_pAESContext = FX_Alloc(uint8_t, 2048); |
| } |
| return TRUE; |
| } |
| FX_BOOL CPDF_StandardCryptoHandler::DecryptStream(void* context, const uint8_t* src_buf, FX_DWORD src_size, |
| CFX_BinaryBuf& dest_buf) |
| { |
| return CryptStream(context, src_buf, src_size, dest_buf, FALSE); |
| } |
| FX_BOOL CPDF_StandardCryptoHandler::DecryptFinish(void* context, CFX_BinaryBuf& dest_buf) |
| { |
| return CryptFinish(context, dest_buf, FALSE); |
| } |
| FX_DWORD CPDF_StandardCryptoHandler::EncryptGetSize(FX_DWORD objnum, FX_DWORD version, const uint8_t* src_buf, FX_DWORD src_size) |
| { |
| if (m_Cipher == FXCIPHER_AES) { |
| return src_size + 32; |
| } |
| return src_size; |
| } |
| FX_BOOL CPDF_StandardCryptoHandler::EncryptContent(FX_DWORD objnum, FX_DWORD gennum, const uint8_t* src_buf, FX_DWORD src_size, |
| uint8_t* dest_buf, FX_DWORD& dest_size) |
| { |
| CryptBlock(TRUE, objnum, gennum, src_buf, src_size, dest_buf, dest_size); |
| return TRUE; |
| } |
| void CPDF_CryptoHandler::Decrypt(FX_DWORD objnum, FX_DWORD gennum, CFX_ByteString& str) |
| { |
| CFX_BinaryBuf dest_buf; |
| void* context = DecryptStart(objnum, gennum); |
| DecryptStream(context, (const uint8_t*)str, str.GetLength(), dest_buf); |
| DecryptFinish(context, dest_buf); |
| str = dest_buf; |
| } |
| CPDF_StandardCryptoHandler::CPDF_StandardCryptoHandler() |
| { |
| m_pAESContext = NULL; |
| m_Cipher = FXCIPHER_NONE; |
| m_KeyLen = 0; |
| } |
| CPDF_StandardCryptoHandler::~CPDF_StandardCryptoHandler() |
| { |
| if (m_pAESContext) { |
| FX_Free(m_pAESContext); |
| } |
| } |
