1 // Copyright 2014 PDFium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com 6 7 #include <time.h> 8 #include "../../../include/fpdfapi/fpdf_parser.h" 9 #include "../../../include/fdrm/fx_crypt.h" 10 const FX_BYTE defpasscode[32] = { 11 0x28, 0xbf, 0x4e, 0x5e, 0x4e, 0x75, 0x8a, 0x41, 12 0x64, 0x00, 0x4e, 0x56, 0xff, 0xfa, 0x01, 0x08, 13 0x2e, 0x2e, 0x00, 0xb6, 0xd0, 0x68, 0x3e, 0x80, 14 0x2f, 0x0c, 0xa9, 0xfe, 0x64, 0x53, 0x69, 0x7a 15 }; 16 void CalcEncryptKey(CPDF_Dictionary* pEncrypt, FX_LPCBYTE password, FX_DWORD pass_size, 17 FX_LPBYTE key, int keylen, FX_BOOL bIgnoreMeta, CPDF_Array* pIdArray) 18 { 19 int revision = pEncrypt->GetInteger(FX_BSTRC("R")); 20 FX_BYTE passcode[32]; 21 for (FX_DWORD i = 0; i < 32; i ++) { 22 passcode[i] = i < pass_size ? password[i] : defpasscode[i - pass_size]; 23 } 24 FX_BYTE md5[100]; 25 CRYPT_MD5Start(md5); 26 CRYPT_MD5Update(md5, passcode, 32); 27 CFX_ByteString okey = pEncrypt->GetString(FX_BSTRC("O")); 28 CRYPT_MD5Update(md5, (FX_LPBYTE)(FX_LPCSTR)okey, okey.GetLength()); 29 FX_DWORD perm = pEncrypt->GetInteger(FX_BSTRC("P")); 30 CRYPT_MD5Update(md5, (FX_LPBYTE)&perm, 4); 31 if (pIdArray) { 32 CFX_ByteString id = pIdArray->GetString(0); 33 CRYPT_MD5Update(md5, (FX_LPBYTE)(FX_LPCSTR)id, id.GetLength()); 34 } 35 if (!bIgnoreMeta && revision >= 3 && !pEncrypt->GetInteger(FX_BSTRC("EncryptMetadata"), 1)) { 36 FX_DWORD tag = (FX_DWORD) - 1; 37 CRYPT_MD5Update(md5, (FX_LPBYTE)&tag, 4); 38 } 39 FX_BYTE digest[16]; 40 CRYPT_MD5Finish(md5, digest); 41 FX_DWORD copy_len = keylen; 42 if (copy_len > sizeof(digest)) { 43 copy_len = sizeof(digest); 44 } 45 if (revision >= 3) { 46 for (int i = 0; i < 50; i ++) { 47 CRYPT_MD5Generate(digest, copy_len, digest); 48 } 49 } 50 FXSYS_memset32(key, 0, keylen); 51 FXSYS_memcpy32(key, digest, copy_len); 52 } 53 CPDF_CryptoHandler* CPDF_StandardSecurityHandler::CreateCryptoHandler() 54 { 55 return FX_NEW CPDF_StandardCryptoHandler; 56 } 57 typedef struct _PDF_CRYPTOITEM : public CFX_Object { 58 FX_INT32 m_Cipher; 59 FX_INT32 m_KeyLen; 60 FX_BOOL m_bChecked; 61 CPDF_StandardCryptoHandler* m_pCryptoHandler; 62 } PDF_CRYPTOITEM; 63 CPDF_StandardSecurityHandler::CPDF_StandardSecurityHandler() 64 { 65 m_Version = 0; 66 m_Revision = 0; 67 m_pParser = NULL; 68 m_pEncryptDict = NULL; 69 m_bOwner = FALSE; 70 m_Permissions = 0; 71 m_Cipher = FXCIPHER_NONE; 72 m_KeyLen = 0; 73 } 74 CPDF_StandardSecurityHandler::~CPDF_StandardSecurityHandler() 75 { 76 } 77 FX_BOOL CPDF_StandardSecurityHandler::OnInit(CPDF_Parser* pParser, CPDF_Dictionary* pEncryptDict) 78 { 79 m_pParser = pParser; 80 if (!LoadDict(pEncryptDict)) { 81 return FALSE; 82 } 83 if (m_Cipher == FXCIPHER_NONE) { 84 return TRUE; 85 } 86 return CheckSecurity(m_KeyLen); 87 } 88 FX_BOOL CPDF_StandardSecurityHandler::CheckSecurity(FX_INT32 key_len) 89 { 90 CFX_ByteString password = m_pParser->GetPassword(); 91 if (CheckPassword(password, password.GetLength(), TRUE, m_EncryptKey, key_len)) { 92 if (password.IsEmpty()) { 93 if (!CheckPassword(password, password.GetLength(), FALSE, m_EncryptKey, key_len)) { 94 return FALSE; 95 } 96 } 97 m_bOwner = TRUE; 98 return TRUE; 99 } 100 return CheckPassword(password, password.GetLength(), FALSE, m_EncryptKey, key_len); 101 } 102 FX_DWORD CPDF_StandardSecurityHandler::GetPermissions() 103 { 104 return m_Permissions; 105 } 106 static FX_BOOL _LoadCryptInfo(CPDF_Dictionary* pEncryptDict, FX_BSTR name, int& cipher, int& keylen) 107 { 108 int Version = pEncryptDict->GetInteger(FX_BSTRC("V")); 109 int Revision = pEncryptDict->GetInteger(FX_BSTRC("R")); 110 cipher = FXCIPHER_RC4; 111 keylen = 0; 112 if (Version >= 4) { 113 CPDF_Dictionary* pCryptFilters = pEncryptDict->GetDict(FX_BSTRC("CF")); 114 if (pCryptFilters == NULL) { 115 return FALSE; 116 } 117 if (name == FX_BSTRC("Identity")) { 118 cipher = FXCIPHER_NONE; 119 } else { 120 CPDF_Dictionary* pDefFilter = pCryptFilters->GetDict(name); 121 if (pDefFilter == NULL) { 122 return FALSE; 123 } 124 int nKeyBits = 0; 125 if (Version == 4) { 126 nKeyBits = pDefFilter->GetInteger(FX_BSTRC("Length"), 0); 127 if (nKeyBits == 0) { 128 nKeyBits = pEncryptDict->GetInteger(FX_BSTRC("Length"), 128); 129 } 130 } else { 131 nKeyBits = pEncryptDict->GetInteger(FX_BSTRC("Length"), 256); 132 } 133 if (nKeyBits < 40) { 134 nKeyBits *= 8; 135 } 136 keylen = nKeyBits / 8; 137 CFX_ByteString cipher_name = pDefFilter->GetString(FX_BSTRC("CFM")); 138 if (cipher_name == FX_BSTRC("AESV2") || cipher_name == FX_BSTRC("AESV3")) { 139 cipher = FXCIPHER_AES; 140 } 141 } 142 } else { 143 keylen = Version > 1 ? pEncryptDict->GetInteger(FX_BSTRC("Length"), 40) / 8 : 5; 144 } 145 if (keylen > 32 || keylen < 0) { 146 return FALSE; 147 } 148 return TRUE; 149 } 150 FX_BOOL CPDF_StandardSecurityHandler::LoadDict(CPDF_Dictionary* pEncryptDict) 151 { 152 m_pEncryptDict = pEncryptDict; 153 m_bOwner = FALSE; 154 m_Version = pEncryptDict->GetInteger(FX_BSTRC("V")); 155 m_Revision = pEncryptDict->GetInteger(FX_BSTRC("R")); 156 m_Permissions = pEncryptDict->GetInteger(FX_BSTRC("P"), -1); 157 if (m_Version < 4) { 158 return _LoadCryptInfo(pEncryptDict, CFX_ByteString(), m_Cipher, m_KeyLen); 159 } 160 CFX_ByteString stmf_name = pEncryptDict->GetString(FX_BSTRC("StmF")); 161 CFX_ByteString strf_name = pEncryptDict->GetString(FX_BSTRC("StrF")); 162 if (stmf_name != strf_name) { 163 return FALSE; 164 } 165 if (!_LoadCryptInfo(pEncryptDict, strf_name, m_Cipher, m_KeyLen)) { 166 return FALSE; 167 } 168 return TRUE; 169 } 170 FX_BOOL CPDF_StandardSecurityHandler::LoadDict(CPDF_Dictionary* pEncryptDict, FX_DWORD type, int& cipher, int& key_len) 171 { 172 m_pEncryptDict = pEncryptDict; 173 m_bOwner = FALSE; 174 m_Version = pEncryptDict->GetInteger(FX_BSTRC("V")); 175 m_Revision = pEncryptDict->GetInteger(FX_BSTRC("R")); 176 m_Permissions = pEncryptDict->GetInteger(FX_BSTRC("P"), -1); 177 CFX_ByteString strf_name, stmf_name; 178 if (m_Version >= 4) { 179 stmf_name = pEncryptDict->GetString(FX_BSTRC("StmF")); 180 strf_name = pEncryptDict->GetString(FX_BSTRC("StrF")); 181 if (stmf_name != strf_name) { 182 return FALSE; 183 } 184 } 185 if (!_LoadCryptInfo(pEncryptDict, strf_name, cipher, key_len)) { 186 return FALSE; 187 } 188 m_Cipher = cipher; 189 m_KeyLen = key_len; 190 return TRUE; 191 return TRUE; 192 } 193 FX_BOOL CPDF_StandardSecurityHandler::GetCryptInfo(int& cipher, FX_LPCBYTE& buffer, int& keylen) 194 { 195 cipher = m_Cipher; 196 buffer = m_EncryptKey; 197 keylen = m_KeyLen; 198 return TRUE; 199 } 200 #define FX_GET_32WORD(n,b,i) \ 201 { \ 202 (n) = (FX_DWORD)(( (FX_UINT64) (b)[(i)] << 24 ) \ 203 | ( (FX_UINT64) (b)[(i) + 1] << 16 ) \ 204 | ( (FX_UINT64) (b)[(i) + 2] << 8 ) \ 205 | ( (FX_UINT64) (b)[(i) + 3] )); \ 206 } 207 int BigOrder64BitsMod3(FX_LPBYTE data) 208 { 209 FX_UINT64 ret = 0; 210 for (int i = 0; i < 4; ++i) { 211 FX_DWORD value; 212 FX_GET_32WORD(value, data, 4 * i); 213 ret <<= 32; 214 ret |= value; 215 ret %= 3; 216 } 217 return (int)ret; 218 } 219 void Revision6_Hash(FX_LPCBYTE password, FX_DWORD size, FX_LPCBYTE salt, FX_LPCBYTE vector, FX_LPBYTE hash) 220 { 221 int iBlockSize = 32; 222 FX_BYTE sha[128]; 223 CRYPT_SHA256Start(sha); 224 CRYPT_SHA256Update(sha, password, size); 225 CRYPT_SHA256Update(sha, salt, 8); 226 if (vector) { 227 CRYPT_SHA256Update(sha, vector, 48); 228 } 229 FX_BYTE digest[32]; 230 CRYPT_SHA256Finish(sha, digest); 231 CFX_ByteTextBuf buf; 232 FX_LPBYTE input = digest; 233 FX_LPBYTE key = input; 234 FX_LPBYTE iv = input + 16; 235 FX_LPBYTE E = buf.GetBuffer(); 236 int iBufLen = buf.GetLength(); 237 CFX_ByteTextBuf interDigest; 238 int i = 0; 239 FX_LPBYTE aes = FX_Alloc(FX_BYTE, 2048); 240 while (i < 64 || i < E[iBufLen - 1] + 32) { 241 int iRoundSize = size + iBlockSize; 242 if (vector) { 243 iRoundSize += 48; 244 } 245 iBufLen = iRoundSize * 64; 246 buf.EstimateSize(iBufLen); 247 E = buf.GetBuffer(); 248 CFX_ByteTextBuf content; 249 for (int j = 0; j < 64; ++j) { 250 content.AppendBlock(password, size); 251 content.AppendBlock(input, iBlockSize); 252 if (vector) { 253 content.AppendBlock(vector, 48); 254 } 255 } 256 CRYPT_AESSetKey(aes, 16, key, 16, TRUE); 257 CRYPT_AESSetIV(aes, iv); 258 CRYPT_AESEncrypt(aes, E, content.GetBuffer(), iBufLen); 259 int iHash = 0; 260 switch (BigOrder64BitsMod3(E)) { 261 case 0: 262 iHash = 0; 263 iBlockSize = 32; 264 break; 265 case 1: 266 iHash = 1; 267 iBlockSize = 48; 268 break; 269 default: 270 iHash = 2; 271 iBlockSize = 64; 272 break; 273 } 274 interDigest.EstimateSize(iBlockSize); 275 input = interDigest.GetBuffer(); 276 if (iHash == 0) { 277 CRYPT_SHA256Generate(E, iBufLen, input); 278 } else if (iHash == 1) { 279 CRYPT_SHA384Generate(E, iBufLen, input); 280 } else if (iHash == 2) { 281 CRYPT_SHA512Generate(E, iBufLen, input); 282 } 283 key = input; 284 iv = input + 16; 285 ++i; 286 } 287 FX_Free(aes); 288 if (hash) { 289 FXSYS_memcpy32(hash, input, 32); 290 } 291 } 292 FX_BOOL CPDF_StandardSecurityHandler::AES256_CheckPassword(FX_LPCBYTE password, FX_DWORD size, 293 FX_BOOL bOwner, FX_LPBYTE key) 294 { 295 CFX_ByteString okey = m_pEncryptDict->GetString(FX_BSTRC("O")); 296 if (okey.GetLength() < 48) { 297 return FALSE; 298 } 299 CFX_ByteString ukey = m_pEncryptDict->GetString(FX_BSTRC("U")); 300 if (ukey.GetLength() < 48) { 301 return FALSE; 302 } 303 FX_LPCBYTE pkey = bOwner ? (FX_LPCBYTE)okey : (FX_LPCBYTE)ukey; 304 FX_BYTE sha[128]; 305 FX_BYTE digest[32]; 306 if (m_Revision >= 6) { 307 Revision6_Hash(password, size, (FX_LPCBYTE)pkey + 32, (bOwner ? (FX_LPCBYTE)ukey : NULL), digest); 308 } else { 309 CRYPT_SHA256Start(sha); 310 CRYPT_SHA256Update(sha, password, size); 311 CRYPT_SHA256Update(sha, pkey + 32, 8); 312 if (bOwner) { 313 CRYPT_SHA256Update(sha, ukey, 48); 314 } 315 CRYPT_SHA256Finish(sha, digest); 316 } 317 if (FXSYS_memcmp32(digest, pkey, 32) != 0) { 318 return FALSE; 319 } 320 if (key == NULL) { 321 return TRUE; 322 } 323 if (m_Revision >= 6) { 324 Revision6_Hash(password, size, (FX_LPCBYTE)pkey + 40, (bOwner ? (FX_LPCBYTE)ukey : NULL), digest); 325 } else { 326 CRYPT_SHA256Start(sha); 327 CRYPT_SHA256Update(sha, password, size); 328 CRYPT_SHA256Update(sha, pkey + 40, 8); 329 if (bOwner) { 330 CRYPT_SHA256Update(sha, ukey, 48); 331 } 332 CRYPT_SHA256Finish(sha, digest); 333 } 334 CFX_ByteString ekey = m_pEncryptDict->GetString(bOwner ? FX_BSTRC("OE") : FX_BSTRC("UE")); 335 if (ekey.GetLength() < 32) { 336 return FALSE; 337 } 338 FX_BYTE* aes = FX_Alloc(FX_BYTE, 2048); 339 CRYPT_AESSetKey(aes, 16, digest, 32, FALSE); 340 FX_BYTE iv[16]; 341 FXSYS_memset32(iv, 0, 16); 342 CRYPT_AESSetIV(aes, iv); 343 CRYPT_AESDecrypt(aes, key, ekey, 32); 344 CRYPT_AESSetKey(aes, 16, key, 32, FALSE); 345 CRYPT_AESSetIV(aes, iv); 346 CFX_ByteString perms = m_pEncryptDict->GetString(FX_BSTRC("Perms")); 347 if (perms.IsEmpty()) { 348 return FALSE; 349 } 350 FX_BYTE perms_buf[16]; 351 FXSYS_memset32(perms_buf, 0, sizeof(perms_buf)); 352 FX_DWORD copy_len = sizeof(perms_buf); 353 if (copy_len > (FX_DWORD)perms.GetLength()) { 354 copy_len = perms.GetLength(); 355 } 356 FXSYS_memcpy32(perms_buf, (FX_LPCBYTE)perms, copy_len); 357 FX_BYTE buf[16]; 358 CRYPT_AESDecrypt(aes, buf, perms_buf, 16); 359 FX_Free(aes); 360 if (buf[9] != 'a' || buf[10] != 'd' || buf[11] != 'b') { 361 return FALSE; 362 } 363 if (FXDWORD_GET_LSBFIRST(buf) != m_Permissions) { 364 return FALSE; 365 } 366 if ((buf[8] == 'T' && !IsMetadataEncrypted()) || (buf[8] == 'F' && IsMetadataEncrypted())) { 367 return FALSE; 368 } 369 return TRUE; 370 } 371 int CPDF_StandardSecurityHandler::CheckPassword(FX_LPCBYTE password, FX_DWORD pass_size, FX_BOOL bOwner, FX_LPBYTE key) 372 { 373 return CheckPassword(password, pass_size, bOwner, key, m_KeyLen); 374 } 375 int CPDF_StandardSecurityHandler::CheckPassword(FX_LPCBYTE password, FX_DWORD size, FX_BOOL bOwner, FX_LPBYTE key, FX_INT32 key_len) 376 { 377 if (m_Revision >= 5) { 378 return AES256_CheckPassword(password, size, bOwner, key); 379 } 380 FX_BYTE keybuf[32]; 381 if (key == NULL) { 382 key = keybuf; 383 } 384 if (bOwner) { 385 return CheckOwnerPassword(password, size, key, key_len); 386 } 387 return CheckUserPassword(password, size, FALSE, key, key_len) || CheckUserPassword(password, size, TRUE, key, key_len); 388 } 389 FX_BOOL CPDF_StandardSecurityHandler::CheckUserPassword(FX_LPCBYTE password, FX_DWORD pass_size, 390 FX_BOOL bIgnoreEncryptMeta, FX_LPBYTE key, FX_INT32 key_len) 391 { 392 CalcEncryptKey(m_pEncryptDict, password, pass_size, key, key_len, bIgnoreEncryptMeta, 393 m_pParser->GetIDArray()); 394 CFX_ByteString ukey = m_pEncryptDict->GetString(FX_BSTRC("U")); 395 if (ukey.GetLength() < 16) { 396 return FALSE; 397 } 398 FX_BYTE ukeybuf[32]; 399 if (m_Revision == 2) { 400 FXSYS_memcpy32(ukeybuf, defpasscode, 32); 401 CRYPT_ArcFourCryptBlock(ukeybuf, 32, key, key_len); 402 } else { 403 FX_BYTE test[32], tmpkey[32]; 404 FX_DWORD copy_len = sizeof(test); 405 if (copy_len > (FX_DWORD)ukey.GetLength()) { 406 copy_len = ukey.GetLength(); 407 } 408 FXSYS_memset32(test, 0, sizeof(test)); 409 FXSYS_memcpy32(test, (FX_LPCSTR)ukey, copy_len); 410 for (int i = 19; i >= 0; i --) { 411 for (int j = 0; j < key_len; j ++) { 412 tmpkey[j] = key[j] ^ i; 413 } 414 CRYPT_ArcFourCryptBlock(test, 32, tmpkey, key_len); 415 } 416 FX_BYTE md5[100]; 417 CRYPT_MD5Start(md5); 418 CRYPT_MD5Update(md5, defpasscode, 32); 419 CPDF_Array* pIdArray = m_pParser->GetIDArray(); 420 if (pIdArray) { 421 CFX_ByteString id = pIdArray->GetString(0); 422 CRYPT_MD5Update(md5, (FX_LPBYTE)(FX_LPCSTR)id, id.GetLength()); 423 } 424 CRYPT_MD5Finish(md5, ukeybuf); 425 return FXSYS_memcmp32(test, ukeybuf, 16) == 0; 426 } 427 if (FXSYS_memcmp32((FX_LPVOID)(FX_LPCSTR)ukey, ukeybuf, 16) == 0) { 428 return TRUE; 429 } 430 return FALSE; 431 } 432 CFX_ByteString CPDF_StandardSecurityHandler::GetUserPassword(FX_LPCBYTE owner_pass, FX_DWORD pass_size) 433 { 434 return GetUserPassword(owner_pass, pass_size, m_KeyLen); 435 } 436 CFX_ByteString CPDF_StandardSecurityHandler::GetUserPassword(FX_LPCBYTE owner_pass, FX_DWORD pass_size, FX_INT32 key_len) 437 { 438 CFX_ByteString okey = m_pEncryptDict->GetString(FX_BSTRC("O")); 439 FX_BYTE passcode[32]; 440 FX_DWORD i; 441 for (i = 0; i < 32; i ++) { 442 passcode[i] = i < pass_size ? owner_pass[i] : defpasscode[i - pass_size]; 443 } 444 FX_BYTE digest[16]; 445 CRYPT_MD5Generate(passcode, 32, digest); 446 if (m_Revision >= 3) { 447 for (int i = 0; i < 50; i ++) { 448 CRYPT_MD5Generate(digest, 16, digest); 449 } 450 } 451 FX_BYTE enckey[32]; 452 FXSYS_memset32(enckey, 0, sizeof(enckey)); 453 FX_DWORD copy_len = key_len; 454 if (copy_len > sizeof(digest)) { 455 copy_len = sizeof(digest); 456 } 457 FXSYS_memcpy32(enckey, digest, copy_len); 458 int okeylen = okey.GetLength(); 459 if (okeylen > 32) { 460 okeylen = 32; 461 } 462 FX_BYTE okeybuf[64]; 463 FXSYS_memcpy32(okeybuf, (FX_LPCSTR)okey, okeylen); 464 if (m_Revision == 2) { 465 CRYPT_ArcFourCryptBlock(okeybuf, okeylen, enckey, key_len); 466 } else { 467 for (int i = 19; i >= 0; i --) { 468 FX_BYTE tempkey[32]; 469 for (int j = 0; j < m_KeyLen; j ++) { 470 tempkey[j] = enckey[j] ^ i; 471 } 472 CRYPT_ArcFourCryptBlock(okeybuf, okeylen, tempkey, key_len); 473 } 474 } 475 int len = 32; 476 while (len && defpasscode[len - 1] == okeybuf[len - 1]) { 477 len --; 478 } 479 return CFX_ByteString(okeybuf, len); 480 } 481 FX_BOOL CPDF_StandardSecurityHandler::CheckOwnerPassword(FX_LPCBYTE password, FX_DWORD pass_size, 482 FX_LPBYTE key, FX_INT32 key_len) 483 { 484 CFX_ByteString user_pass = GetUserPassword(password, pass_size, key_len); 485 if (CheckUserPassword(user_pass, user_pass.GetLength(), FALSE, key, key_len)) { 486 return TRUE; 487 } 488 return CheckUserPassword(user_pass, user_pass.GetLength(), TRUE, key, key_len); 489 } 490 FX_BOOL CPDF_StandardSecurityHandler::IsMetadataEncrypted() 491 { 492 return m_pEncryptDict->GetBoolean(FX_BSTRC("EncryptMetadata"), TRUE); 493 } 494 CPDF_SecurityHandler* FPDF_CreateStandardSecurityHandler() 495 { 496 return FX_NEW CPDF_StandardSecurityHandler; 497 } 498 void CPDF_StandardSecurityHandler::OnCreate(CPDF_Dictionary* pEncryptDict, CPDF_Array* pIdArray, 499 FX_LPCBYTE user_pass, FX_DWORD user_size, 500 FX_LPCBYTE owner_pass, FX_DWORD owner_size, FX_BOOL bDefault, FX_DWORD type) 501 { 502 int cipher = 0, key_len = 0; 503 if (!LoadDict(pEncryptDict, type, cipher, key_len)) { 504 return; 505 } 506 if (bDefault && (owner_pass == NULL || owner_size == 0)) { 507 owner_pass = user_pass; 508 owner_size = user_size; 509 } 510 if (m_Revision >= 5) { 511 int t = (int)time(NULL); 512 FX_BYTE sha[128]; 513 CRYPT_SHA256Start(sha); 514 CRYPT_SHA256Update(sha, (FX_BYTE*)&t, sizeof t); 515 CRYPT_SHA256Update(sha, m_EncryptKey, 32); 516 CRYPT_SHA256Update(sha, (FX_BYTE*)"there", 5); 517 CRYPT_SHA256Finish(sha, m_EncryptKey); 518 AES256_SetPassword(pEncryptDict, user_pass, user_size, FALSE, m_EncryptKey); 519 if (bDefault) { 520 AES256_SetPassword(pEncryptDict, owner_pass, owner_size, TRUE, m_EncryptKey); 521 AES256_SetPerms(pEncryptDict, m_Permissions, pEncryptDict->GetBoolean(FX_BSTRC("EncryptMetadata"), TRUE), m_EncryptKey); 522 } 523 return; 524 } 525 if (bDefault) { 526 FX_BYTE passcode[32]; 527 FX_DWORD i; 528 for (i = 0; i < 32; i ++) { 529 passcode[i] = i < owner_size ? owner_pass[i] : defpasscode[i - owner_size]; 530 } 531 FX_BYTE digest[16]; 532 CRYPT_MD5Generate(passcode, 32, digest); 533 if (m_Revision >= 3) { 534 for (int i = 0; i < 50; i ++) { 535 CRYPT_MD5Generate(digest, 16, digest); 536 } 537 } 538 FX_BYTE enckey[32]; 539 FXSYS_memcpy32(enckey, digest, key_len); 540 for (i = 0; i < 32; i ++) { 541 passcode[i] = i < user_size ? user_pass[i] : defpasscode[i - user_size]; 542 } 543 CRYPT_ArcFourCryptBlock(passcode, 32, enckey, key_len); 544 FX_BYTE tempkey[32]; 545 if (m_Revision >= 3) { 546 for (i = 1; i <= 19; i ++) { 547 for (int j = 0; j < key_len; j ++) { 548 tempkey[j] = enckey[j] ^ (FX_BYTE)i; 549 } 550 CRYPT_ArcFourCryptBlock(passcode, 32, tempkey, key_len); 551 } 552 } 553 pEncryptDict->SetAtString(FX_BSTRC("O"), CFX_ByteString(passcode, 32)); 554 } 555 CalcEncryptKey(m_pEncryptDict, (FX_LPBYTE)user_pass, user_size, m_EncryptKey, key_len, FALSE, pIdArray); 556 if (m_Revision < 3) { 557 FX_BYTE tempbuf[32]; 558 FXSYS_memcpy32(tempbuf, defpasscode, 32); 559 CRYPT_ArcFourCryptBlock(tempbuf, 32, m_EncryptKey, key_len); 560 pEncryptDict->SetAtString(FX_BSTRC("U"), CFX_ByteString(tempbuf, 32)); 561 } else { 562 FX_BYTE md5[100]; 563 CRYPT_MD5Start(md5); 564 CRYPT_MD5Update(md5, defpasscode, 32); 565 if (pIdArray) { 566 CFX_ByteString id = pIdArray->GetString(0); 567 CRYPT_MD5Update(md5, (FX_LPBYTE)(FX_LPCSTR)id, id.GetLength()); 568 } 569 FX_BYTE digest[32]; 570 CRYPT_MD5Finish(md5, digest); 571 CRYPT_ArcFourCryptBlock(digest, 16, m_EncryptKey, key_len); 572 FX_BYTE tempkey[32]; 573 for (int i = 1; i <= 19; i ++) { 574 for (int j = 0; j < key_len; j ++) { 575 tempkey[j] = m_EncryptKey[j] ^ (FX_BYTE)i; 576 } 577 CRYPT_ArcFourCryptBlock(digest, 16, tempkey, key_len); 578 } 579 CRYPT_MD5Generate(digest, 16, digest + 16); 580 pEncryptDict->SetAtString(FX_BSTRC("U"), CFX_ByteString(digest, 32)); 581 } 582 } 583 void CPDF_StandardSecurityHandler::OnCreate(CPDF_Dictionary* pEncryptDict, CPDF_Array* pIdArray, 584 FX_LPCBYTE user_pass, FX_DWORD user_size, 585 FX_LPCBYTE owner_pass, FX_DWORD owner_size, FX_DWORD type) 586 { 587 OnCreate(pEncryptDict, pIdArray, user_pass, user_size, owner_pass, owner_size, TRUE, type); 588 } 589 void CPDF_StandardSecurityHandler::OnCreate(CPDF_Dictionary* pEncryptDict, CPDF_Array* pIdArray, FX_LPCBYTE user_pass, FX_DWORD user_size, FX_DWORD type) 590 { 591 OnCreate(pEncryptDict, pIdArray, user_pass, user_size, NULL, 0, FALSE, type); 592 } 593 void CPDF_StandardSecurityHandler::AES256_SetPassword(CPDF_Dictionary* pEncryptDict, FX_LPCBYTE password, FX_DWORD size, FX_BOOL bOwner, FX_LPCBYTE key) 594 { 595 FX_BYTE sha[128]; 596 CRYPT_SHA1Start(sha); 597 CRYPT_SHA1Update(sha, key, 32); 598 CRYPT_SHA1Update(sha, (FX_BYTE*)"hello", 5); 599 FX_BYTE digest[20]; 600 CRYPT_SHA1Finish(sha, digest); 601 CFX_ByteString ukey = pEncryptDict->GetString(FX_BSTRC("U")); 602 FX_BYTE digest1[48]; 603 if (m_Revision >= 6) { 604 Revision6_Hash(password, size, digest, (bOwner ? (FX_LPCBYTE)ukey : NULL), digest1); 605 } else { 606 CRYPT_SHA256Start(sha); 607 CRYPT_SHA256Update(sha, password, size); 608 CRYPT_SHA256Update(sha, digest, 8); 609 if (bOwner) { 610 CRYPT_SHA256Update(sha, ukey, ukey.GetLength()); 611 } 612 CRYPT_SHA256Finish(sha, digest1); 613 } 614 FXSYS_memcpy32(digest1 + 32, digest, 16); 615 pEncryptDict->SetAtString(bOwner ? FX_BSTRC("O") : FX_BSTRC("U"), CFX_ByteString(digest1, 48)); 616 if (m_Revision >= 6) { 617 Revision6_Hash(password, size, digest + 8, (bOwner ? (FX_LPCBYTE)ukey : NULL), digest1); 618 } else { 619 CRYPT_SHA256Start(sha); 620 CRYPT_SHA256Update(sha, password, size); 621 CRYPT_SHA256Update(sha, digest + 8, 8); 622 if (bOwner) { 623 CRYPT_SHA256Update(sha, ukey, ukey.GetLength()); 624 } 625 CRYPT_SHA256Finish(sha, digest1); 626 } 627 FX_BYTE* aes = FX_Alloc(FX_BYTE, 2048); 628 CRYPT_AESSetKey(aes, 16, digest1, 32, TRUE); 629 FX_BYTE iv[16]; 630 FXSYS_memset32(iv, 0, 16); 631 CRYPT_AESSetIV(aes, iv); 632 CRYPT_AESEncrypt(aes, digest1, key, 32); 633 FX_Free(aes); 634 pEncryptDict->SetAtString(bOwner ? FX_BSTRC("OE") : FX_BSTRC("UE"), CFX_ByteString(digest1, 32)); 635 } 636 void CPDF_StandardSecurityHandler::AES256_SetPerms(CPDF_Dictionary* pEncryptDict, FX_DWORD permissions, 637 FX_BOOL bEncryptMetadata, FX_LPCBYTE key) 638 { 639 FX_BYTE buf[16]; 640 buf[0] = (FX_BYTE)permissions; 641 buf[1] = (FX_BYTE)(permissions >> 8); 642 buf[2] = (FX_BYTE)(permissions >> 16); 643 buf[3] = (FX_BYTE)(permissions >> 24); 644 buf[4] = 0xff; 645 buf[5] = 0xff; 646 buf[6] = 0xff; 647 buf[7] = 0xff; 648 buf[8] = bEncryptMetadata ? 'T' : 'F'; 649 buf[9] = 'a'; 650 buf[10] = 'd'; 651 buf[11] = 'b'; 652 FX_BYTE* aes = FX_Alloc(FX_BYTE, 2048); 653 CRYPT_AESSetKey(aes, 16, key, 32, TRUE); 654 FX_BYTE iv[16], buf1[16]; 655 FXSYS_memset32(iv, 0, 16); 656 CRYPT_AESSetIV(aes, iv); 657 CRYPT_AESEncrypt(aes, buf1, buf, 16); 658 FX_Free(aes); 659 pEncryptDict->SetAtString(FX_BSTRC("Perms"), CFX_ByteString(buf1, 16)); 660 } 661 void CPDF_StandardCryptoHandler::CryptBlock(FX_BOOL bEncrypt, FX_DWORD objnum, FX_DWORD gennum, FX_LPCBYTE src_buf, FX_DWORD src_size, 662 FX_LPBYTE dest_buf, FX_DWORD& dest_size) 663 { 664 if (m_Cipher == FXCIPHER_NONE) { 665 FXSYS_memcpy32(dest_buf, src_buf, src_size); 666 return; 667 } 668 FX_BYTE realkey[16]; 669 int realkeylen = 16; 670 if (m_Cipher != FXCIPHER_AES || m_KeyLen != 32) { 671 FX_BYTE key1[32]; 672 FXSYS_memcpy32(key1, m_EncryptKey, m_KeyLen); 673 key1[m_KeyLen + 0] = (FX_BYTE)objnum; 674 key1[m_KeyLen + 1] = (FX_BYTE)(objnum >> 8); 675 key1[m_KeyLen + 2] = (FX_BYTE)(objnum >> 16); 676 key1[m_KeyLen + 3] = (FX_BYTE)gennum; 677 key1[m_KeyLen + 4] = (FX_BYTE)(gennum >> 8); 678 FXSYS_memcpy32(key1 + m_KeyLen, &objnum, 3); 679 FXSYS_memcpy32(key1 + m_KeyLen + 3, &gennum, 2); 680 if (m_Cipher == FXCIPHER_AES) { 681 FXSYS_memcpy32(key1 + m_KeyLen + 5, "sAlT", 4); 682 } 683 CRYPT_MD5Generate(key1, m_Cipher == FXCIPHER_AES ? m_KeyLen + 9 : m_KeyLen + 5, realkey); 684 realkeylen = m_KeyLen + 5; 685 if (realkeylen > 16) { 686 realkeylen = 16; 687 } 688 } 689 if (m_Cipher == FXCIPHER_AES) { 690 CRYPT_AESSetKey(m_pAESContext, 16, m_KeyLen == 32 ? m_EncryptKey : realkey, m_KeyLen, bEncrypt); 691 if (bEncrypt) { 692 FX_BYTE iv[16]; 693 for (int i = 0; i < 16; i ++) { 694 iv[i] = (FX_BYTE)rand(); 695 } 696 CRYPT_AESSetIV(m_pAESContext, iv); 697 FXSYS_memcpy32(dest_buf, iv, 16); 698 int nblocks = src_size / 16; 699 CRYPT_AESEncrypt(m_pAESContext, dest_buf + 16, src_buf, nblocks * 16); 700 FX_BYTE padding[16]; 701 FXSYS_memcpy32(padding, src_buf + nblocks * 16, src_size % 16); 702 FXSYS_memset8(padding + src_size % 16, 16 - src_size % 16, 16 - src_size % 16); 703 CRYPT_AESEncrypt(m_pAESContext, dest_buf + nblocks * 16 + 16, padding, 16); 704 dest_size = 32 + nblocks * 16; 705 } else { 706 CRYPT_AESSetIV(m_pAESContext, src_buf); 707 CRYPT_AESDecrypt(m_pAESContext, dest_buf, src_buf + 16, src_size - 16); 708 dest_size = src_size - 16; 709 dest_size -= dest_buf[dest_size - 1]; 710 } 711 } else { 712 ASSERT(dest_size == src_size); 713 if (dest_buf != src_buf) { 714 FXSYS_memcpy32(dest_buf, src_buf, src_size); 715 } 716 CRYPT_ArcFourCryptBlock(dest_buf, dest_size, realkey, realkeylen); 717 } 718 } 719 typedef struct _AESCryptContext { 720 FX_BYTE m_Context[2048]; 721 FX_BOOL m_bIV; 722 FX_BYTE m_Block[16]; 723 FX_DWORD m_BlockOffset; 724 } AESCryptContext; 725 FX_LPVOID CPDF_StandardCryptoHandler::CryptStart(FX_DWORD objnum, FX_DWORD gennum, FX_BOOL bEncrypt) 726 { 727 if (m_Cipher == FXCIPHER_NONE) { 728 return this; 729 } 730 if (m_Cipher == FXCIPHER_AES && m_KeyLen == 32) { 731 AESCryptContext* pContext = FX_Alloc(AESCryptContext, 1); 732 pContext->m_bIV = TRUE; 733 pContext->m_BlockOffset = 0; 734 CRYPT_AESSetKey(pContext->m_Context, 16, m_EncryptKey, 32, bEncrypt); 735 if (bEncrypt) { 736 for (int i = 0; i < 16; i ++) { 737 pContext->m_Block[i] = (FX_BYTE)rand(); 738 } 739 CRYPT_AESSetIV(pContext->m_Context, pContext->m_Block); 740 } 741 return pContext; 742 } 743 FX_BYTE key1[48]; 744 FXSYS_memcpy32(key1, m_EncryptKey, m_KeyLen); 745 FXSYS_memcpy32(key1 + m_KeyLen, &objnum, 3); 746 FXSYS_memcpy32(key1 + m_KeyLen + 3, &gennum, 2); 747 if (m_Cipher == FXCIPHER_AES) { 748 FXSYS_memcpy32(key1 + m_KeyLen + 5, "sAlT", 4); 749 } 750 FX_BYTE realkey[16]; 751 CRYPT_MD5Generate(key1, m_Cipher == FXCIPHER_AES ? m_KeyLen + 9 : m_KeyLen + 5, realkey); 752 int realkeylen = m_KeyLen + 5; 753 if (realkeylen > 16) { 754 realkeylen = 16; 755 } 756 if (m_Cipher == FXCIPHER_AES) { 757 AESCryptContext* pContext = FX_Alloc(AESCryptContext, 1); 758 pContext->m_bIV = TRUE; 759 pContext->m_BlockOffset = 0; 760 CRYPT_AESSetKey(pContext->m_Context, 16, realkey, 16, bEncrypt); 761 if (bEncrypt) { 762 for (int i = 0; i < 16; i ++) { 763 pContext->m_Block[i] = (FX_BYTE)rand(); 764 } 765 CRYPT_AESSetIV(pContext->m_Context, pContext->m_Block); 766 } 767 return pContext; 768 } 769 void* pContext = FX_Alloc(FX_BYTE, 1040); 770 CRYPT_ArcFourSetup(pContext, realkey, realkeylen); 771 return pContext; 772 } 773 FX_BOOL CPDF_StandardCryptoHandler::CryptStream(FX_LPVOID context, FX_LPCBYTE src_buf, FX_DWORD src_size, CFX_BinaryBuf& dest_buf, FX_BOOL bEncrypt) 774 { 775 if (!context) { 776 return FALSE; 777 } 778 if (m_Cipher == FXCIPHER_NONE) { 779 dest_buf.AppendBlock(src_buf, src_size); 780 return TRUE; 781 } 782 if (m_Cipher == FXCIPHER_RC4) { 783 int old_size = dest_buf.GetSize(); 784 dest_buf.AppendBlock(src_buf, src_size); 785 CRYPT_ArcFourCrypt(context, dest_buf.GetBuffer() + old_size, src_size); 786 return TRUE; 787 } 788 AESCryptContext* pContext = (AESCryptContext*)context; 789 if (pContext->m_bIV && bEncrypt) { 790 dest_buf.AppendBlock(pContext->m_Block, 16); 791 pContext->m_bIV = FALSE; 792 } 793 FX_DWORD src_off = 0; 794 FX_DWORD src_left = src_size; 795 while (1) { 796 FX_DWORD copy_size = 16 - pContext->m_BlockOffset; 797 if (copy_size > src_left) { 798 copy_size = src_left; 799 } 800 FXSYS_memcpy32(pContext->m_Block + pContext->m_BlockOffset, src_buf + src_off, copy_size); 801 src_off += copy_size; 802 src_left -= copy_size; 803 pContext->m_BlockOffset += copy_size; 804 if (pContext->m_BlockOffset == 16) { 805 if (!bEncrypt && pContext->m_bIV) { 806 CRYPT_AESSetIV(pContext->m_Context, pContext->m_Block); 807 pContext->m_bIV = FALSE; 808 pContext->m_BlockOffset = 0; 809 } else if (src_off < src_size) { 810 FX_BYTE block_buf[16]; 811 if (bEncrypt) { 812 CRYPT_AESEncrypt(pContext->m_Context, block_buf, pContext->m_Block, 16); 813 } else { 814 CRYPT_AESDecrypt(pContext->m_Context, block_buf, pContext->m_Block, 16); 815 } 816 dest_buf.AppendBlock(block_buf, 16); 817 pContext->m_BlockOffset = 0; 818 } 819 } 820 if (!src_left) { 821 break; 822 } 823 } 824 return TRUE; 825 } 826 FX_BOOL CPDF_StandardCryptoHandler::CryptFinish(FX_LPVOID context, CFX_BinaryBuf& dest_buf, FX_BOOL bEncrypt) 827 { 828 if (!context) { 829 return FALSE; 830 } 831 if (m_Cipher == FXCIPHER_NONE) { 832 return TRUE; 833 } 834 if (m_Cipher == FXCIPHER_RC4) { 835 FX_Free(context); 836 return TRUE; 837 } 838 AESCryptContext* pContext = (AESCryptContext*)context; 839 if (bEncrypt) { 840 FX_BYTE block_buf[16]; 841 if (pContext->m_BlockOffset == 16) { 842 CRYPT_AESEncrypt(pContext->m_Context, block_buf, pContext->m_Block, 16); 843 dest_buf.AppendBlock(block_buf, 16); 844 pContext->m_BlockOffset = 0; 845 } 846 FXSYS_memset8(pContext->m_Block + pContext->m_BlockOffset, (FX_BYTE)(16 - pContext->m_BlockOffset), 16 - pContext->m_BlockOffset); 847 CRYPT_AESEncrypt(pContext->m_Context, block_buf, pContext->m_Block, 16); 848 dest_buf.AppendBlock(block_buf, 16); 849 } else if (pContext->m_BlockOffset == 16) { 850 FX_BYTE block_buf[16]; 851 CRYPT_AESDecrypt(pContext->m_Context, block_buf, pContext->m_Block, 16); 852 if (block_buf[15] <= 16) { 853 dest_buf.AppendBlock(block_buf, 16 - block_buf[15]); 854 } 855 } 856 FX_Free(pContext); 857 return TRUE; 858 } 859 FX_LPVOID CPDF_StandardCryptoHandler::DecryptStart(FX_DWORD objnum, FX_DWORD gennum) 860 { 861 return CryptStart(objnum, gennum, FALSE); 862 } 863 FX_DWORD CPDF_StandardCryptoHandler::DecryptGetSize(FX_DWORD src_size) 864 { 865 return m_Cipher == FXCIPHER_AES ? src_size - 16 : src_size; 866 } 867 FX_BOOL CPDF_StandardCryptoHandler::Init(CPDF_Dictionary* pEncryptDict, CPDF_SecurityHandler* pSecurityHandler) 868 { 869 FX_LPCBYTE key; 870 if (!pSecurityHandler->GetCryptInfo(m_Cipher, key, m_KeyLen)) { 871 return FALSE; 872 } 873 if (m_KeyLen > 32 || m_KeyLen < 0) { 874 return FALSE; 875 } 876 if (m_Cipher != FXCIPHER_NONE) { 877 FXSYS_memcpy32(m_EncryptKey, key, m_KeyLen); 878 } 879 if (m_Cipher == FXCIPHER_AES) { 880 m_pAESContext = FX_Alloc(FX_BYTE, 2048); 881 } 882 return TRUE; 883 } 884 FX_BOOL CPDF_StandardCryptoHandler::Init(int cipher, FX_LPCBYTE key, int keylen) 885 { 886 if (cipher == FXCIPHER_AES) { 887 switch(keylen) { 888 case 16: 889 case 24: 890 case 32: 891 break; 892 default: 893 return FALSE; 894 } 895 } else if (cipher == FXCIPHER_AES2) { 896 if (keylen != 32) { 897 return FALSE; 898 } 899 } else if (cipher == FXCIPHER_RC4) { 900 if (keylen < 5 || keylen > 16) { 901 return FALSE; 902 } 903 } else { 904 if (keylen > 32) { 905 keylen = 32; 906 } 907 } 908 m_Cipher = cipher; 909 m_KeyLen = keylen; 910 FXSYS_memcpy32(m_EncryptKey, key, keylen); 911 if (m_Cipher == FXCIPHER_AES) { 912 m_pAESContext = FX_Alloc(FX_BYTE, 2048); 913 } 914 return TRUE; 915 } 916 FX_BOOL CPDF_StandardCryptoHandler::DecryptStream(FX_LPVOID context, FX_LPCBYTE src_buf, FX_DWORD src_size, 917 CFX_BinaryBuf& dest_buf) 918 { 919 return CryptStream(context, src_buf, src_size, dest_buf, FALSE); 920 } 921 FX_BOOL CPDF_StandardCryptoHandler::DecryptFinish(FX_LPVOID context, CFX_BinaryBuf& dest_buf) 922 { 923 return CryptFinish(context, dest_buf, FALSE); 924 } 925 FX_DWORD CPDF_StandardCryptoHandler::EncryptGetSize(FX_DWORD objnum, FX_DWORD version, FX_LPCBYTE src_buf, FX_DWORD src_size) 926 { 927 if (m_Cipher == FXCIPHER_AES) { 928 return src_size + 32; 929 } 930 return src_size; 931 } 932 FX_BOOL CPDF_StandardCryptoHandler::EncryptContent(FX_DWORD objnum, FX_DWORD gennum, FX_LPCBYTE src_buf, FX_DWORD src_size, 933 FX_LPBYTE dest_buf, FX_DWORD& dest_size) 934 { 935 CryptBlock(TRUE, objnum, gennum, src_buf, src_size, dest_buf, dest_size); 936 return TRUE; 937 } 938 void CPDF_CryptoHandler::Decrypt(FX_DWORD objnum, FX_DWORD gennum, CFX_ByteString& str) 939 { 940 CFX_BinaryBuf dest_buf; 941 FX_LPVOID context = DecryptStart(objnum, gennum); 942 DecryptStream(context, (FX_LPCBYTE)str, str.GetLength(), dest_buf); 943 DecryptFinish(context, dest_buf); 944 str = dest_buf; 945 } 946 CPDF_StandardCryptoHandler::CPDF_StandardCryptoHandler() 947 { 948 m_pAESContext = NULL; 949 m_Cipher = FXCIPHER_NONE; 950 m_KeyLen = 0; 951 } 952 CPDF_StandardCryptoHandler::~CPDF_StandardCryptoHandler() 953 { 954 if (m_pAESContext) { 955 FX_Free(m_pAESContext); 956 } 957 } 958
