text: //========================================================================
  //
  // Decrypt.cc
  //
  // Copyright 1996-2003 Glyph & Cog, LLC
  //
  //========================================================================
  
  #include <aconf.h>
  
  #ifdef USE_GCC_PRAGMAS
  #pragma implementation
  #endif
  
  #include <string.h>
  #include "gmem.h"
  #include "gmempp.h"
  #include "Decrypt.h"
  
  static void aes256KeyExpansion(DecryptAES256State *s,
  			       Guchar *objKey, int objKeyLen);
  static void aes256DecryptBlock(DecryptAES256State *s, Guchar *in, GBool last);
  static void sha256(Guchar *msg, int msgLen, Guchar *hash);
  static void sha384(Guchar *msg, int msgLen, Guchar *hash);
  static void sha512(Guchar *msg, int msgLen, Guchar *hash);
  
  static Guchar passwordPad[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
  };
  
  //------------------------------------------------------------------------
  // Decrypt
  //------------------------------------------------------------------------
  
  GBool Decrypt::makeFileKey(int encVersion, int encRevision, int keyLength,
  			   GString *ownerKey, GString *userKey,
  			   GString *ownerEnc, GString *userEnc,
  			   int permissions, GString *fileID,
  			   GString *ownerPassword, GString *userPassword,
  			   Guchar *fileKey, GBool encryptMetadata,
  			   GBool *ownerPasswordOk) {
    DecryptAES256State state;
    Guchar test[127 + 56], test2[32];
    GString *userPassword2;
    const char *userPW;
    Guchar fState[256];
    Guchar tmpKey[16];
    Guchar fx, fy;
    int len, i, j;
  
    *ownerPasswordOk = gFalse;
  
    if (encRevision == 5 || encRevision == 6) {
  
      // check the owner password
      if (ownerPassword) {
        //~ this is supposed to convert the password to UTF-8 using "SASLprep"
        len = ownerPassword->getLength();
        if (len > 127) {
  	len = 127;
        }
        memcpy(test, ownerPassword->getCString(), len);
        memcpy(test + len, ownerKey->getCString() + 32, 8);
        memcpy(test + len + 8, userKey->getCString(), 48);
        sha256(test, len + 56, test);
        if (encRevision == 6) {
  	r6Hash(test, 32, ownerPassword->getCString(), len,
  	       userKey->getCString());
        }
        if (!memcmp(test, ownerKey->getCString(), 32)) {
  
  	// compute the file key from the owner password
  	memcpy(test, ownerPassword->getCString(), len);
  	memcpy(test + len, ownerKey->getCString() + 40, 8);
  	memcpy(test + len + 8, userKey->getCString(), 48);
  	sha256(test, len + 56, test);
  	if (encRevision == 6) {
  	  r6Hash(test, 32, ownerPassword->getCString(), len,
  		 userKey->getCString());
  	}
  	aes256KeyExpansion(&state, test, 32);
  	for (i = 0; i < 16; ++i) {
  	  state.cbc[i] = 0;
  	}
  	aes256DecryptBlock(&state, (Guchar *)ownerEnc->getCString(), gFalse);
  	memcpy(fileKey, state.buf, 16);
  	aes256DecryptBlock(&state, (Guchar *)ownerEnc->getCString() + 16,
  			   gFalse);
  	memcpy(fileKey + 16, state.buf, 16);
  
  	*ownerPasswordOk = gTrue;
  	return gTrue;
        }
      }
  
      // check the user password
      if (userPassword) {
        //~ this is supposed to convert the password to UTF-8 using "SASLprep"
        userPW = userPassword->getCString();
        len = userPassword->getLength();
        if (len > 127) {
  	len = 127;
        }
      } else {
        userPW = "";
        len = 0;
      }
      memcpy(test, userPW, len);
      memcpy(test + len, userKey->getCString() + 32, 8);
      sha256(test, len + 8, test);
      if (encRevision == 6) {
        r6Hash(test, 32, userPW, len, NULL);
      }
      if (!memcmp(test, userKey->getCString(), 32)) {
  
        // compute the file key from the user password
        memcpy(test, userPW, len);
        memcpy(test + len, userKey->getCString() + 40, 8);
        sha256(test, len + 8, test);
        if (encRevision == 6) {
  	r6Hash(test, 32, userPW, len, NULL);
        }
        aes256KeyExpansion(&state, test, 32);
        for (i = 0; i < 16; ++i) {
  	state.cbc[i] = 0;
        }
        aes256DecryptBlock(&state, (Guchar *)userEnc->getCString(), gFalse);
        memcpy(fileKey, state.buf, 16);
        aes256DecryptBlock(&state, (Guchar *)userEnc->getCString() + 16,
  			 gFalse);
        memcpy(fileKey + 16, state.buf, 16);
  
        return gTrue; 
      }
  
      return gFalse;
  
    } else {
  
      // try using the supplied owner password to generate the user password
      if (ownerPassword) {
        len = ownerPassword->getLength();
        if (len < 32) {
  	memcpy(test, ownerPassword->getCString(), len);
  	memcpy(test + len, passwordPad, 32 - len);
        } else {
  	memcpy(test, ownerPassword->getCString(), 32);
        }
        md5(test, 32, test);
        if (encRevision == 3) {
  	for (i = 0; i < 50; ++i) {
  	  md5(test, keyLength, test);
  	}
        }
        if (encRevision == 2) {
  	rc4InitKey(test, keyLength, fState);
  	fx = fy = 0;
  	for (i = 0; i < 32; ++i) {
  	  test2[i] = rc4DecryptByte(fState, &fx, &fy, ownerKey->getChar(i));
  	}
        } else {
  	memcpy(test2, ownerKey->getCString(), 32);
  	for (i = 19; i >= 0; --i) {
  	  for (j = 0; j < keyLength; ++j) {
  	    tmpKey[j] = test[j] ^ i;
  	  }
  	  rc4InitKey(tmpKey, keyLength, fState);
  	  fx = fy = 0;
  	  for (j = 0; j < 32; ++j) {
  	    test2[j] = rc4DecryptByte(fState, &fx, &fy, test2[j]);
  	  }
  	}
        }
        userPassword2 = new GString((char *)test2, 32);
        if (makeFileKey2(encVersion, encRevision, keyLength, ownerKey, userKey,
  		       permissions, fileID, userPassword2, fileKey,
  		       encryptMetadata)) {
  	*ownerPasswordOk = gTrue;
  	delete userPassword2;
  	return gTrue;
        }
        delete userPassword2;
      }
  
      // try using the supplied user password
      return makeFileKey2(encVersion, encRevision, keyLength, ownerKey, userKey,
  			permissions, fileID, userPassword, fileKey,
  			encryptMetadata);
    }
  }
  
  void Decrypt::r6Hash(Guchar *key, int keyLen, const char *pwd, int pwdLen,
  		     char *userKey) {
    Guchar key1[64*(127+64+48)];
    DecryptAESState state128;
    int n, i, j, k;
  
    i = 0;
    while (1) {
      memcpy(key1, pwd, pwdLen);
      memcpy(key1 + pwdLen, key, keyLen);
      n = pwdLen + keyLen;
      if (userKey) {
        memcpy(key1 + pwdLen + keyLen, userKey, 48);
        n += 48;
      }
      for (j = 1; j < 64; ++j) {
        memcpy(key1 + j * n, key1, n);
      }
      n *= 64;
      aesKeyExpansion(&state128, key, 16, gFalse);
      for (j = 0; j < 16; ++j) {
        state128.cbc[j] = key[16+j];
      }
      for (j = 0; j < n; j += 16) {
        aesEncryptBlock(&state128, key1 + j);
        memcpy(key1 + j, state128.buf, 16);
      }
      k = 0;
      for (j = 0; j < 16; ++j) {
        k += key1[j] % 3;
      }
      k %= 3;
      switch (k) {
      case 0:
        sha256(key1, n, key);
        keyLen = 32;
        break;
      case 1:
        sha384(key1, n, key);
        keyLen = 48;
        break;
      case 2:
        sha512(key1, n, key);
        keyLen = 64;
        break;
      }
      // from the spec, it appears that i should be incremented after
      // the test, but that doesn't match what Adobe does
      ++i;
      if (i >= 64 && key1[n - 1] <= i - 32) {
        break;
      }
    }
  }
  
  GBool Decrypt::makeFileKey2(int encVersion, int encRevision, int keyLength,
  			    GString *ownerKey, GString *userKey,
  			    int permissions, GString *fileID,
  			    GString *userPassword, Guchar *fileKey,
  			    GBool encryptMetadata) {
    Guchar *buf;
    Guchar test[32];
    Guchar fState[256];
    Guchar tmpKey[16];
    Guchar fx, fy;
    int len, i, j;
    GBool ok;
  
    // generate file key
    buf = (Guchar *)gmalloc(72 + fileID->getLength());
    if (userPassword) {
      len = userPassword->getLength();
      if (len < 32) {
        memcpy(buf, userPassword->getCString(), len);
        memcpy(buf + len, passwordPad, 32 - len);
      } else {
        memcpy(buf, userPassword->getCString(), 32);
      }
    } else {
      memcpy(buf, passwordPad, 32);
    }
    memcpy(buf + 32, ownerKey->getCString(), 32);
    buf[64] = permissions & 0xff;
    buf[65] = (permissions >> 8) & 0xff;
    buf[66] = (permissions >> 16) & 0xff;
    buf[67] = (permissions >> 24) & 0xff;
    memcpy(buf + 68, fileID->getCString(), fileID->getLength());
    len = 68 + fileID->getLength();
    if (!encryptMetadata) {
      buf[len++] = 0xff;
      buf[len++] = 0xff;
      buf[len++] = 0xff;
      buf[len++] = 0xff;
    }
    md5(buf, len, fileKey);
    if (encRevision == 3) {
      for (i = 0; i < 50; ++i) {
        md5(fileKey, keyLength, fileKey);
      }
    }
  
    // test user password
    if (encRevision == 2) {
      rc4InitKey(fileKey, keyLength, fState);
      fx = fy = 0;
      for (i = 0; i < 32; ++i) {
        test[i] = rc4DecryptByte(fState, &fx, &fy, userKey->getChar(i));
      }
      ok = memcmp(test, passwordPad, 32) == 0;
    } else if (encRevision == 3) {
      memcpy(test, userKey->getCString(), 32);
      for (i = 19; i >= 0; --i) {
        for (j = 0; j < keyLength; ++j) {
  	tmpKey[j] = fileKey[j] ^ i;
        }
        rc4InitKey(tmpKey, keyLength, fState);
        fx = fy = 0;
        for (j = 0; j < 32; ++j) {
  	test[j] = rc4DecryptByte(fState, &fx, &fy, test[j]);
        }
      }
      memcpy(buf, passwordPad, 32);
      memcpy(buf + 32, fileID->getCString(), fileID->getLength());
      md5(buf, 32 + fileID->getLength(), buf);
      ok = memcmp(test, buf, 16) == 0;
    } else {
      ok = gFalse;
    }
  
    gfree(buf);
    return ok;
  }
  
  //------------------------------------------------------------------------
  // DecryptStream
  //------------------------------------------------------------------------
  
  DecryptStream::DecryptStream(Stream *strA, Guchar *fileKeyA,
  			     CryptAlgorithm algoA, int keyLengthA,
  			     int objNumA, int objGenA):
    FilterStream(strA)
  {
    int i;
  
    memcpy(fileKey, fileKeyA, keyLengthA);
    algo = algoA;
    keyLength = keyLengthA;
    objNum = objNumA;
    objGen = objGenA;
  
    // construct object key
    for (i = 0; i < keyLength; ++i) {
      objKey[i] = fileKey[i];
    }
    switch (algo) {
    case cryptRC4:
      objKey[keyLength] = objNum & 0xff;
      objKey[keyLength + 1] = (objNum >> 8) & 0xff;
      objKey[keyLength + 2] = (objNum >> 16) & 0xff;
      objKey[keyLength + 3] = objGen & 0xff;
      objKey[keyLength + 4] = (objGen >> 8) & 0xff;
      md5(objKey, keyLength + 5, objKey);
      if ((objKeyLength = keyLength + 5) > 16) {
        objKeyLength = 16;
      }
      break;
    case cryptAES:
      objKey[keyLength] = objNum & 0xff;
      objKey[keyLength + 1] = (objNum >> 8) & 0xff;
      objKey[keyLength + 2] = (objNum >> 16) & 0xff;
      objKey[keyLength + 3] = objGen & 0xff;
      objKey[keyLength + 4] = (objGen >> 8) & 0xff;
      objKey[keyLength + 5] = 0x73; // 's'
      objKey[keyLength + 6] = 0x41; // 'A'
      objKey[keyLength + 7] = 0x6c; // 'l'
      objKey[keyLength + 8] = 0x54; // 'T'
      md5(objKey, keyLength + 9, objKey);
      if ((objKeyLength = keyLength + 5) > 16) {
        objKeyLength = 16;
      }
      break;
    case cryptAES256:
      objKeyLength = keyLength;
      break;
    }
  }
  
  DecryptStream::~DecryptStream() {
    delete str;
  }
  
  Stream *DecryptStream::copy() {
    return new DecryptStream(str->copy(), fileKey, algo, keyLength,
  			   objNum, objGen);
  }
  
  void DecryptStream::reset() {
    str->reset();
    switch (algo) {
    case cryptRC4:
      state.rc4.x = state.rc4.y = 0;
      rc4InitKey(objKey, objKeyLength, state.rc4.state);
      state.rc4.buf = EOF;
      break;
    case cryptAES:
      aesKeyExpansion(&state.aes, objKey, objKeyLength, gTrue);
      str->getBlock((char *)state.aes.cbc, 16);
      state.aes.bufIdx = 16;
      break;
    case cryptAES256:
      aes256KeyExpansion(&state.aes256, objKey, objKeyLength);
      str->getBlock((char *)state.aes256.cbc, 16);
      state.aes256.bufIdx = 16;
      break;
    }
  }
  
  int DecryptStream::getChar() {
    Guchar in[16];
    int c;
  
    c = EOF; // make gcc happy
    switch (algo) {
    case cryptRC4:
      if (state.rc4.buf == EOF) {
        c = str->getChar();
        if (c != EOF) {
  	state.rc4.buf = rc4DecryptByte(state.rc4.state, &state.rc4.x,
  				       &state.rc4.y, (Guchar)c);
        }
      }
      c = state.rc4.buf;
      state.rc4.buf = EOF;
      break;
    case cryptAES:
      if (state.aes.bufIdx == 16) {
        if (str->getBlock((char *)in, 16) != 16) {
  	return EOF;
        }
        aesDecryptBlock(&state.aes, in, str->lookChar() == EOF);
      }
      if (state.aes.bufIdx == 16) {
        c = EOF;
      } else {
        c = state.aes.buf[state.aes.bufIdx++];
      }
      break;
    case cryptAES256:
      if (state.aes256.bufIdx == 16) {
        if (str->getBlock((char *)in, 16) != 16) {
  	return EOF;
        }
        aes256DecryptBlock(&state.aes256, in, str->lookChar() == EOF);
      }
      if (state.aes256.bufIdx == 16) {
        c = EOF;
      } else {
        c = state.aes256.buf[state.aes256.bufIdx++];
      }
      break;
    }
    return c;
  }
  
  int DecryptStream::lookChar() {
    Guchar in[16];
    int c;
  
    c = EOF; // make gcc happy
    switch (algo) {
    case cryptRC4:
      if (state.rc4.buf == EOF) {
        c = str->getChar();
        if (c != EOF) {
  	state.rc4.buf = rc4DecryptByte(state.rc4.state, &state.rc4.x,
  				       &state.rc4.y, (Guchar)c);
        }
      }
      c = state.rc4.buf;
      break;
    case cryptAES:
      if (state.aes.bufIdx == 16) {
        if (str->getBlock((char *)in, 16) != 16) {
  	return EOF;
        }
        aesDecryptBlock(&state.aes, in, str->lookChar() == EOF);
      }
      if (state.aes.bufIdx == 16) {
        c = EOF;
      } else {
        c = state.aes.buf[state.aes.bufIdx];
      }
      break;
    case cryptAES256:
      if (state.aes256.bufIdx == 16) {
        if (str->getBlock((char *)in, 16) != 16) {
  	return EOF;
        }
        aes256DecryptBlock(&state.aes256, in, str->lookChar() == EOF);
      }
      if (state.aes256.bufIdx == 16) {
        c = EOF;
      } else {
        c = state.aes256.buf[state.aes256.bufIdx];
      }
      break;
    }
    return c;
  }
  
  GBool DecryptStream::isBinary(GBool last) {
    return str->isBinary(last);
  }
  
  //------------------------------------------------------------------------
  // RC4-compatible decryption
  //------------------------------------------------------------------------
  
  void rc4InitKey(Guchar *key, int keyLen, Guchar *state) {
    Guchar index1, index2;
    Guchar t;
    int i;
  
    for (i = 0; i < 256; ++i)
      state[i] = i;
    index1 = index2 = 0;
    for (i = 0; i < 256; ++i) {
      index2 = (key[index1] + state[i] + index2) % 256;
      t = state[i];
      state[i] = state[index2];
      state[index2] = t;
      index1 = (index1 + 1) % keyLen;
    }
  }
  
  Guchar rc4DecryptByte(Guchar *state, Guchar *x, Guchar *y, Guchar c) {
    Guchar x1, y1, tx, ty;
  
    x1 = *x = (*x + 1) % 256;
    y1 = *y = (state[*x] + *y) % 256;
    tx = state[x1];
    ty = state[y1];
    state[x1] = ty;
    state[y1] = tx;
    return c ^ state[(tx + ty) % 256];
  }
  
  //------------------------------------------------------------------------
  // AES decryption
  //------------------------------------------------------------------------
  
  static Guchar sbox[256] = {
    0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76,
    0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0,
    0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15,
    0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75,
    0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84,
    0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf,
    0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8,
    0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2,
    0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73,
    0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb,
    0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79,
    0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08,
    0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a,
    0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e,
    0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf,
    0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16
  };
  
  static Guchar invSbox[256] = {
    0x52, 0x09, 0x6a, 0xd5, 0x30, 0x36, 0xa5, 0x38, 0xbf, 0x40, 0xa3, 0x9e, 0x81, 0xf3, 0xd7, 0xfb,
    0x7c, 0xe3, 0x39, 0x82, 0x9b, 0x2f, 0xff, 0x87, 0x34, 0x8e, 0x43, 0x44, 0xc4, 0xde, 0xe9, 0xcb,
    0x54, 0x7b, 0x94, 0x32, 0xa6, 0xc2, 0x23, 0x3d, 0xee, 0x4c, 0x95, 0x0b, 0x42, 0xfa, 0xc3, 0x4e,
    0x08, 0x2e, 0xa1, 0x66, 0x28, 0xd9, 0x24, 0xb2, 0x76, 0x5b, 0xa2, 0x49, 0x6d, 0x8b, 0xd1, 0x25,
    0x72, 0xf8, 0xf6, 0x64, 0x86, 0x68, 0x98, 0x16, 0xd4, 0xa4, 0x5c, 0xcc, 0x5d, 0x65, 0xb6, 0x92,
    0x6c, 0x70, 0x48, 0x50, 0xfd, 0xed, 0xb9, 0xda, 0x5e, 0x15, 0x46, 0x57, 0xa7, 0x8d, 0x9d, 0x84,
    0x90, 0xd8, 0xab, 0x00, 0x8c, 0xbc, 0xd3, 0x0a, 0xf7, 0xe4, 0x58, 0x05, 0xb8, 0xb3, 0x45, 0x06,
    0xd0, 0x2c, 0x1e, 0x8f, 0xca, 0x3f, 0x0f, 0x02, 0xc1, 0xaf, 0xbd, 0x03, 0x01, 0x13, 0x8a, 0x6b,
    0x3a, 0x91, 0x11, 0x41, 0x4f, 0x67, 0xdc, 0xea, 0x97, 0xf2, 0xcf, 0xce, 0xf0, 0xb4, 0xe6, 0x73,
    0x96, 0xac, 0x74, 0x22, 0xe7, 0xad, 0x35, 0x85, 0xe2, 0xf9, 0x37, 0xe8, 0x1c, 0x75, 0xdf, 0x6e,
    0x47, 0xf1, 0x1a, 0x71, 0x1d, 0x29, 0xc5, 0x89, 0x6f, 0xb7, 0x62, 0x0e, 0xaa, 0x18, 0xbe, 0x1b,
    0xfc, 0x56, 0x3e, 0x4b, 0xc6, 0xd2, 0x79, 0x20, 0x9a, 0xdb, 0xc0, 0xfe, 0x78, 0xcd, 0x5a, 0xf4,
    0x1f, 0xdd, 0xa8, 0x33, 0x88, 0x07, 0xc7, 0x31, 0xb1, 0x12, 0x10, 0x59, 0x27, 0x80, 0xec, 0x5f,
    0x60, 0x51, 0x7f, 0xa9, 0x19, 0xb5, 0x4a, 0x0d, 0x2d, 0xe5, 0x7a, 0x9f, 0x93, 0xc9, 0x9c, 0xef,
    0xa0, 0xe0, 0x3b, 0x4d, 0xae, 0x2a, 0xf5, 0xb0, 0xc8, 0xeb, 0xbb, 0x3c, 0x83, 0x53, 0x99, 0x61,
    0x17, 0x2b, 0x04, 0x7e, 0xba, 0x77, 0xd6, 0x26, 0xe1, 0x69, 0x14, 0x63, 0x55, 0x21, 0x0c, 0x7d
  };
  
  static Guint rcon[11] = {
    0x00000000, // unused
    0x01000000,
    0x02000000,
    0x04000000,
    0x08000000,
    0x10000000,
    0x20000000,
    0x40000000,
    0x80000000,
    0x1b000000,
    0x36000000
  };
  
  static inline Guint subWord(Guint x) {
    return (sbox[x >> 24] << 24)
           | (sbox[(x >> 16) & 0xff] << 16)
           | (sbox[(x >> 8) & 0xff] << 8)
           | sbox[x & 0xff];
  }
  
  static inline Guint rotWord(Guint x) {
    return ((x << 8) & 0xffffffff) | (x >> 24);
  }
  
  static inline void subBytes(Guchar *state) {
    int i;
  
    for (i = 0; i < 16; ++i) {
      state[i] = sbox[state[i]];
    }
  }
  
  static inline void invSubBytes(Guchar *state) {
    int i;
  
    for (i = 0; i < 16; ++i) {
      state[i] = invSbox[state[i]];
    }
  }
  
  static inline void shiftRows(Guchar *state) {
    Guchar t;
  
    t = state[4];
    state[4] = state[5];
    state[5] = state[6];
    state[6] = state[7];
    state[7] = t;
  
    t = state[8];
    state[8] = state[10];
    state[10] = t;
    t = state[9];
    state[9] = state[11];
    state[11] = t;
  
    t = state[15];
    state[15] = state[14];
    state[14] = state[13];
    state[13] = state[12];
    state[12] = t;
  }
  
  static inline void invShiftRows(Guchar *state) {
    Guchar t;
  
    t = state[7];
    state[7] = state[6];
    state[6] = state[5];
    state[5] = state[4];
    state[4] = t;
  
    t = state[8];
    state[8] = state[10];
    state[10] = t;
    t = state[9];
    state[9] = state[11];
    state[11] = t;
  
    t = state[12];
    state[12] = state[13];
    state[13] = state[14];
    state[14] = state[15];
    state[15] = t;
  }
  
  // {02} \cdot s
  static inline Guchar mul02(Guchar s) {
    Guchar s2;
  
    s2 = (s & 0x80) ? ((s << 1) ^ 0x1b) : (s << 1);
    return s2;
  }
  
  // {03} \cdot s
  static inline Guchar mul03(Guchar s) {
    Guchar s2;
  
    s2 = (s & 0x80) ? ((s << 1) ^ 0x1b) : (s << 1);
    return s ^ s2;
  }
  
  // {09} \cdot s
  static inline Guchar mul09(Guchar s) {
    Guchar s2, s4, s8;
  
    s2 = (s & 0x80) ? ((s << 1) ^ 0x1b) : (s << 1);
    s4 = (s2 & 0x80) ? ((s2 << 1) ^ 0x1b) : (s2 << 1);
    s8 = (s4 & 0x80) ? ((s4 << 1) ^ 0x1b) : (s4 << 1);
    return s ^ s8;
  }
  
  // {0b} \cdot s
  static inline Guchar mul0b(Guchar s) {
    Guchar s2, s4, s8;
  
    s2 = (s & 0x80) ? ((s << 1) ^ 0x1b) : (s << 1);
    s4 = (s2 & 0x80) ? ((s2 << 1) ^ 0x1b) : (s2 << 1);
    s8 = (s4 & 0x80) ? ((s4 << 1) ^ 0x1b) : (s4 << 1);
    return s ^ s2 ^ s8;
  }
  
  // {0d} \cdot s
  static inline Guchar mul0d(Guchar s) {
    Guchar s2, s4, s8;
  
    s2 = (s & 0x80) ? ((s << 1) ^ 0x1b) : (s << 1);
    s4 = (s2 & 0x80) ? ((s2 << 1) ^ 0x1b) : (s2 << 1);
    s8 = (s4 & 0x80) ? ((s4 << 1) ^ 0x1b) : (s4 << 1);
    return s ^ s4 ^ s8;
  }
  
  // {0e} \cdot s
  static inline Guchar mul0e(Guchar s) {
    Guchar s2, s4, s8;
  
    s2 = (s & 0x80) ? ((s << 1) ^ 0x1b) : (s << 1);
    s4 = (s2 & 0x80) ? ((s2 << 1) ^ 0x1b) : (s2 << 1);
    s8 = (s4 & 0x80) ? ((s4 << 1) ^ 0x1b) : (s4 << 1);
    return s2 ^ s4 ^ s8;
  }
  
  static inline void mixColumns(Guchar *state) {
    int c;
    Guchar s0, s1, s2, s3;
  
    for (c = 0; c < 4; ++c) {
      s0 = state[c];
      s1 = state[4+c];
      s2 = state[8+c];
      s3 = state[12+c];
      state[c] =    mul02(s0) ^ mul03(s1) ^       s2  ^       s3;
      state[4+c] =        s0  ^ mul02(s1) ^ mul03(s2) ^       s3;
      state[8+c] =        s0  ^       s1  ^ mul02(s2) ^ mul03(s3);
      state[12+c] = mul03(s0) ^       s1  ^       s2  ^ mul02(s3);
    }
  }
  
  static inline void invMixColumns(Guchar *state) {
    int c;
    Guchar s0, s1, s2, s3;
  
    for (c = 0; c < 4; ++c) {
      s0 = state[c];
      s1 = state[4+c];
      s2 = state[8+c];
      s3 = state[12+c];
      state[c] =    mul0e(s0) ^ mul0b(s1) ^ mul0d(s2) ^ mul09(s3);
      state[4+c] =  mul09(s0) ^ mul0e(s1) ^ mul0b(s2) ^ mul0d(s3);
      state[8+c] =  mul0d(s0) ^ mul09(s1) ^ mul0e(s2) ^ mul0b(s3);
      state[12+c] = mul0b(s0) ^ mul0d(s1) ^ mul09(s2) ^ mul0e(s3);
    }
  }
  
  static inline void invMixColumnsW(Guint *w) {
    int c;
    Guchar s0, s1, s2, s3;
  
    for (c = 0; c < 4; ++c) {
      s0 = w[c] >> 24;
      s1 = w[c] >> 16;
      s2 = w[c] >> 8;
      s3 = w[c];
      w[c] = ((mul0e(s0) ^ mul0b(s1) ^ mul0d(s2) ^ mul09(s3)) << 24)
             | ((mul09(s0) ^ mul0e(s1) ^ mul0b(s2) ^ mul0d(s3)) << 16)
             | ((mul0d(s0) ^ mul09(s1) ^ mul0e(s2) ^ mul0b(s3)) << 8)
             | (mul0b(s0) ^ mul0d(s1) ^ mul09(s2) ^ mul0e(s3));
    }
  }
  
  static inline void addRoundKey(Guchar *state, Guint *w) {
    int c;
  
    for (c = 0; c < 4; ++c) {
      state[c] ^= w[c] >> 24;
      state[4+c] ^= w[c] >> 16;
      state[8+c] ^= w[c] >> 8;
      state[12+c] ^= w[c];
    }
  }
  
  void aesKeyExpansion(DecryptAESState *s,
  		     Guchar *objKey, int objKeyLen,
  		     GBool decrypt) {
    Guint temp;
    int i, round;
  
    //~ this assumes objKeyLen == 16
  
    for (i = 0; i < 4; ++i) {
      s->w[i] = (objKey[4*i] << 24) + (objKey[4*i+1] << 16) +
                (objKey[4*i+2] << 8) + objKey[4*i+3];
    }
    for (i = 4; i < 44; ++i) {
      temp = s->w[i-1];
      if (!(i & 3)) {
        temp = subWord(rotWord(temp)) ^ rcon[i/4];
      }
      s->w[i] = s->w[i-4] ^ temp;
    }
    if (decrypt) {
      for (round = 1; round <= 9; ++round) {
        invMixColumnsW(&s->w[round * 4]);
      }
    }
  }
  
  void aesEncryptBlock(DecryptAESState *s, Guchar *in) {
    int c, round;
  
    // initial state + CBC
    for (c = 0; c < 4; ++c) {
      s->state[c] = in[4*c] ^ s->cbc[4*c];
      s->state[4+c] = in[4*c+1] ^ s->cbc[4*c+1];
      s->state[8+c] = in[4*c+2] ^ s->cbc[4*c+2];
      s->state[12+c] = in[4*c+3] ^ s->cbc[4*c+3];
    }
  
    // round 0
    addRoundKey(s->state, &s->w[0]);
  
    // rounds 1 .. 9
    for (round = 1; round <= 9; ++round) {
      subBytes(s->state);
      shiftRows(s->state);
      mixColumns(s->state);
      addRoundKey(s->state, &s->w[round * 4]);
    }
  
    // round 10
    subBytes(s->state);
    shiftRows(s->state);
    addRoundKey(s->state, &s->w[10 * 4]);
  
    // output + save for next CBC
    for (c = 0; c < 4; ++c) {
      s->buf[4*c] = s->cbc[4*c] = s->state[c];
      s->buf[4*c+1] = s->cbc[4*c+1] = s->state[4+c];
      s->buf[4*c+2] = s->cbc[4*c+2] = s->state[8+c];
      s->buf[4*c+3] = s->cbc[4*c+3] = s->state[12+c];
    }
  }
  
  void aesDecryptBlock(DecryptAESState *s, Guchar *in, GBool last) {
    int c, round, n, i;
  
    // initial state
    for (c = 0; c < 4; ++c) {
      s->state[c] = in[4*c];
      s->state[4+c] = in[4*c+1];
      s->state[8+c] = in[4*c+2];
      s->state[12+c] = in[4*c+3];
    }
  
    // round 0
    addRoundKey(s->state, &s->w[10 * 4]);
  
    // rounds 1-9
    for (round = 9; round >= 1; --round) {
      invSubBytes(s->state);
      invShiftRows(s->state);
      invMixColumns(s->state);
      addRoundKey(s->state, &s->w[round * 4]);
    }
  
    // round 10
    invSubBytes(s->state);
    invShiftRows(s->state);
    addRoundKey(s->state, &s->w[0]);
  
    // CBC
    for (c = 0; c < 4; ++c) {
      s->buf[4*c] = s->state[c] ^ s->cbc[4*c];
      s->buf[4*c+1] = s->state[4+c] ^ s->cbc[4*c+1];
      s->buf[4*c+2] = s->state[8+c] ^ s->cbc[4*c+2];
      s->buf[4*c+3] = s->state[12+c] ^ s->cbc[4*c+3];
    }
  
    // save the input block for the next CBC
    for (i = 0; i < 16; ++i) {
      s->cbc[i] = in[i];
    }
  
    // remove padding
    s->bufIdx = 0;
    if (last) {
      n = s->buf[15];
      if (n < 1 || n > 16) { // this should never happen
        n = 16;
      }
      for (i = 15; i >= n; --i) {
        s->buf[i] = s->buf[i-n];
      }
      s->bufIdx = n;
    }
  }
  
  //------------------------------------------------------------------------
  // AES-256 decryption
  //------------------------------------------------------------------------
  
  static void aes256KeyExpansion(DecryptAES256State *s,
  			       Guchar *objKey, int objKeyLen) {
    Guint temp;
    int i, round;
  
    //~ this assumes objKeyLen == 32
  
    for (i = 0; i < 8; ++i) {
      s->w[i] = (objKey[4*i] << 24) + (objKey[4*i+1] << 16) +
                (objKey[4*i+2] << 8) + objKey[4*i+3];
    }
    for (i = 8; i < 60; ++i) {
      temp = s->w[i-1];
      if ((i & 7) == 0) {
        temp = subWord(rotWord(temp)) ^ rcon[i/8];
      } else if ((i & 7) == 4) {
        temp = subWord(temp);
      }
      s->w[i] = s->w[i-8] ^ temp;
    }
    for (round = 1; round <= 13; ++round) {
      invMixColumnsW(&s->w[round * 4]);
    }
  }
  
  static void aes256DecryptBlock(DecryptAES256State *s, Guchar *in, GBool last) {
    int c, round, n, i;
  
    // initial state
    for (c = 0; c < 4; ++c) {
      s->state[c] = in[4*c];
      s->state[4+c] = in[4*c+1];
      s->state[8+c] = in[4*c+2];
      s->state[12+c] = in[4*c+3];
    }
  
    // round 0
    addRoundKey(s->state, &s->w[14 * 4]);
  
    // rounds 13-1
    for (round = 13; round >= 1; --round) {
      invSubBytes(s->state);
      invShiftRows(s->state);
      invMixColumns(s->state);
      addRoundKey(s->state, &s->w[round * 4]);
    }
  
    // round 14
    invSubBytes(s->state);
    invShiftRows(s->state);
    addRoundKey(s->state, &s->w[0]);
  
    // CBC
    for (c = 0; c < 4; ++c) {
      s->buf[4*c] = s->state[c] ^ s->cbc[4*c];
      s->buf[4*c+1] = s->state[4+c] ^ s->cbc[4*c+1];
      s->buf[4*c+2] = s->state[8+c] ^ s->cbc[4*c+2];
      s->buf[4*c+3] = s->state[12+c] ^ s->cbc[4*c+3];
    }
  
    // save the input block for the next CBC
    for (i = 0; i < 16; ++i) {
      s->cbc[i] = in[i];
    }
  
    // remove padding
    s->bufIdx = 0;
    if (last) {
      n = s->buf[15];
      if (n < 1 || n > 16) { // this should never happen
        n = 16;
      }
      for (i = 15; i >= n; --i) {
        s->buf[i] = s->buf[i-n];
      }
      s->bufIdx = n;
    }
  }
  
  //------------------------------------------------------------------------
  // MD5 #message digest
  //------------------------------------------------------------------------
  
  // this works around a bug in older Sun compilers
  static inline Gulong rotateLeft(Gulong x, int r) {
    x &= 0xffffffff;
    return ((x << r) | (x >> (32 - r))) & 0xffffffff;
  }
  
  static inline Gulong md5Round1(Gulong a, Gulong b, Gulong c, Gulong d,
  			       Gulong Xk,  Gulong s, Gulong Ti) {
    return b + rotateLeft((a + ((b & c) | (~b & d)) + Xk + Ti), s);
  }
  
  static inline Gulong md5Round2(Gulong a, Gulong b, Gulong c, Gulong d,
  			       Gulong Xk,  Gulong s, Gulong Ti) {
    return b + rotateLeft((a + ((b & d) | (c & ~d)) + Xk + Ti), s);
  }
  
  static inline Gulong md5Round3(Gulong a, Gulong b, Gulong c, Gulong d,
  			       Gulong Xk,  Gulong s, Gulong Ti) {
    return b + rotateLeft((a + (b ^ c ^ d) + Xk + Ti), s);
  }
  
  static inline Gulong md5Round4(Gulong a, Gulong b, Gulong c, Gulong d,
  			       Gulong Xk,  Gulong s, Gulong Ti) {
    return b + rotateLeft((a + (c ^ (b | ~d)) + Xk + Ti), s);
  }
  
  void md5Start(MD5State *state) {
    state->a = 0x67452301;
    state->b = 0xefcdab89;
    state->c = 0x98badcfe;
    state->d = 0x10325476;
    state->bufLen = 0;
    state->msgLen = 0;
  }
  
  static void md5ProcessBlock(MD5State *state) {
    Gulong x[16];
    Gulong a, b, c, d;
    int i;
  
    for (i = 0; i < 16; ++i) {
      x[i] = state->buf[4*i] | (state->buf[4*i+1] << 8) |
             (state->buf[4*i+2] << 16) | (state->buf[4*i+3] << 24);
    }
  
    a = state->a;
    b = state->b;
    c = state->c;
    d = state->d;
  
    // round 1
    a = md5Round1(a, b, c, d, x[0],   7, 0xd76aa478);
    d = md5Round1(d, a, b, c, x[1],  12, 0xe8c7b756);
    c = md5Round1(c, d, a, b, x[2],  17, 0x242070db);
    b = md5Round1(b, c, d, a, x[3],  22, 0xc1bdceee);
    a = md5Round1(a, b, c, d, x[4],   7, 0xf57c0faf);
    d = md5Round1(d, a, b, c, x[5],  12, 0x4787c62a);
    c = md5Round1(c, d, a, b, x[6],  17, 0xa8304613);
    b = md5Round1(b, c, d, a, x[7],  22, 0xfd469501);
    a = md5Round1(a, b, c, d, x[8],   7, 0x698098d8);
    d = md5Round1(d, a, b, c, x[9],  12, 0x8b44f7af);
    c = md5Round1(c, d, a, b, x[10], 17, 0xffff5bb1);
    b = md5Round1(b, c, d, a, x[11], 22, 0x895cd7be);
    a = md5Round1(a, b, c, d, x[12],  7, 0x6b901122);
    d = md5Round1(d, a, b, c, x[13], 12, 0xfd987193);
    c = md5Round1(c, d, a, b, x[14], 17, 0xa679438e);
    b = md5Round1(b, c, d, a, x[15], 22, 0x49b40821);
  
    // round 2
    a = md5Round2(a, b, c, d, x[1],   5, 0xf61e2562);
    d = md5Round2(d, a, b, c, x[6],   9, 0xc040b340);
    c = md5Round2(c, d, a, b, x[11], 14, 0x265e5a51);
    b = md5Round2(b, c, d, a, x[0],  20, 0xe9b6c7aa);
    a = md5Round2(a, b, c, d, x[5],   5, 0xd62f105d);
    d = md5Round2(d, a, b, c, x[10],  9, 0x02441453);
    c = md5Round2(c, d, a, b, x[15], 14, 0xd8a1e681);
    b = md5Round2(b, c, d, a, x[4],  20, 0xe7d3fbc8);
    a = md5Round2(a, b, c, d, x[9],   5, 0x21e1cde6);
    d = md5Round2(d, a, b, c, x[14],  9, 0xc33707d6);
    c = md5Round2(c, d, a, b, x[3],  14, 0xf4d50d87);
    b = md5Round2(b, c, d, a, x[8],  20, 0x455a14ed);
    a = md5Round2(a, b, c, d, x[13],  5, 0xa9e3e905);
    d = md5Round2(d, a, b, c, x[2],   9, 0xfcefa3f8);
    c = md5Round2(c, d, a, b, x[7],  14, 0x676f02d9);
    b = md5Round2(b, c, d, a, x[12], 20, 0x8d2a4c8a);
  
    // round 3
    a = md5Round3(a, b, c, d, x[5],   4, 0xfffa3942);
    d = md5Round3(d, a, b, c, x[8],  11, 0x8771f681);
    c = md5Round3(c, d, a, b, x[11], 16, 0x6d9d6122);
    b = md5Round3(b, c, d, a, x[14], 23, 0xfde5380c);
    a = md5Round3(a, b, c, d, x[1],   4, 0xa4beea44);
    d = md5Round3(d, a, b, c, x[4],  11, 0x4bdecfa9);
    c = md5Round3(c, d, a, b, x[7],  16, 0xf6bb4b60);
    b = md5Round3(b, c, d, a, x[10], 23, 0xbebfbc70);
    a = md5Round3(a, b, c, d, x[13],  4, 0x289b7ec6);
    d = md5Round3(d, a, b, c, x[0],  11, 0xeaa127fa);
    c = md5Round3(c, d, a, b, x[3],  16, 0xd4ef3085);
    b = md5Round3(b, c, d, a, x[6],  23, 0x04881d05);
    a = md5Round3(a, b, c, d, x[9],   4, 0xd9d4d039);
    d = md5Round3(d, a, b, c, x[12], 11, 0xe6db99e5);
    c = md5Round3(c, d, a, b, x[15], 16, 0x1fa27cf8);
    b = md5Round3(b, c, d, a, x[2],  23, 0xc4ac5665);
  
    // round 4
    a = md5Round4(a, b, c, d, x[0],   6, 0xf4292244);
    d = md5Round4(d, a, b, c, x[7],  10, 0x432aff97);
    c = md5Round4(c, d, a, b, x[14], 15, 0xab9423a7);
    b = md5Round4(b, c, d, a, x[5],  21, 0xfc93a039);
    a = md5Round4(a, b, c, d, x[12],  6, 0x655b59c3);
    d = md5Round4(d, a, b, c, x[3],  10, 0x8f0ccc92);
    c = md5Round4(c, d, a, b, x[10], 15, 0xffeff47d);
    b = md5Round4(b, c, d, a, x[1],  21, 0x85845dd1);
    a = md5Round4(a, b, c, d, x[8],   6, 0x6fa87e4f);
    d = md5Round4(d, a, b, c, x[15], 10, 0xfe2ce6e0);
    c = md5Round4(c, d, a, b, x[6],  15, 0xa3014314);
    b = md5Round4(b, c, d, a, x[13], 21, 0x4e0811a1);
    a = md5Round4(a, b, c, d, x[4],   6, 0xf7537e82);
    d = md5Round4(d, a, b, c, x[11], 10, 0xbd3af235);
    c = md5Round4(c, d, a, b, x[2],  15, 0x2ad7d2bb);
    b = md5Round4(b, c, d, a, x[9],  21, 0xeb86d391);
  
    // increment a, b, c, d
    state->a += a;
    state->b += b;
    state->c += c;
    state->d += d;
  
    state->bufLen = 0;
  }
  
  void md5Append(MD5State *state, Guchar *data, int dataLen) {
    Guchar *p;
    int remain, k;
  
    p = data;
    remain = dataLen;
    while (state->bufLen + remain >= 64) {
      k = 64 - state->bufLen;
      memcpy(state->buf + state->bufLen, p, k);
      state->bufLen = 64;
      md5ProcessBlock(state);
      p += k;
      remain -= k;
    }
    if (remain > 0) {
      memcpy(state->buf + state->bufLen, p, remain);
      state->bufLen += remain;
    }
    state->msgLen += dataLen;
  }
  
  void md5Finish(MD5State *state) {
    // padding and length
    state->buf[state->bufLen++] = 0x80;
    if (state->bufLen > 56) {
      while (state->bufLen < 64) {
        state->buf[state->bufLen++] = 0x00;
      }
      md5ProcessBlock(state);
    }      
    while (state->bufLen < 56) {
      state->buf[state->bufLen++] = 0x00;
    }
    state->buf[56] = (Guchar)(state->msgLen << 3);
    state->buf[57] = (Guchar)(state->msgLen >> 5);
    state->buf[58] = (Guchar)(state->msgLen >> 13);
    state->buf[59] = (Guchar)(state->msgLen >> 21);
    state->buf[60] = (Guchar)(state->msgLen >> 29);
    state->buf[61] = (Guchar)0;
    state->buf[62] = (Guchar)0;
    state->buf[63] = (Guchar)0;
    state->bufLen = 64;
    md5ProcessBlock(state);
  
    // break digest into bytes
    state->digest[0] = (Guchar)state->a;
    state->digest[1] = (Guchar)(state->a >> 8);
    state->digest[2] = (Guchar)(state->a >> 16);
    state->digest[3] = (Guchar)(state->a >> 24);
    state->digest[4] = (Guchar)state->b;
    state->digest[5] = (Guchar)(state->b >> 8);
    state->digest[6] = (Guchar)(state->b >> 16);
    state->digest[7] = (Guchar)(state->b >> 24);
    state->digest[8] = (Guchar)state->c;
    state->digest[9] = (Guchar)(state->c >> 8);
    state->digest[10] = (Guchar)(state->c >> 16);
    state->digest[11] = (Guchar)(state->c >> 24);
    state->digest[12] = (Guchar)state->d;
    state->digest[13] = (Guchar)(state->d >> 8);
    state->digest[14] = (Guchar)(state->d >> 16);
    state->digest[15] = (Guchar)(state->d >> 24);
  }
  
  void md5(Guchar *msg, int msgLen, Guchar *digest) {
    MD5State state;
    int i;
  
    if (msgLen < 0) {
      return;
    }
    md5Start(&state);
    md5Append(&state, msg, msgLen);
    md5Finish(&state);
    for (i = 0; i < 16; ++i) {
      digest[i] = state.digest[i];
    }
  }
  
  //------------------------------------------------------------------------
  // SHA-256 hash
  //------------------------------------------------------------------------
  
  static Guint sha256K[64] = {
    0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
    0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
    0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
    0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
    0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
    0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
    0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
    0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
    0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
    0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
    0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
    0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
    0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
    0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
    0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
    0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
  };
  
  static inline Guint rotr(Guint x, Guint n) {
    return (x >> n) | (x << (32 - n));
  }
  
  static inline Guint sha256Ch(Guint x, Guint y, Guint z) {
    return (x & y) ^ (~x & z);
  }
  
  static inline Guint sha256Maj(Guint x, Guint y, Guint z) {
    return (x & y) ^ (x & z) ^ (y & z);
  }
  
  static inline Guint sha256Sigma0(Guint x) {
    return rotr(x, 2) ^ rotr(x, 13) ^ rotr(x, 22);
  }
  
  static inline Guint sha256Sigma1(Guint x) {
    return rotr(x, 6) ^ rotr(x, 11) ^ rotr(x, 25);
  }
  
  static inline Guint sha256sigma0(Guint x) {
    return rotr(x, 7) ^ rotr(x, 18) ^ (x >> 3);
  }
  
  static inline Guint sha256sigma1(Guint x) {
    return rotr(x, 17) ^ rotr(x, 19) ^ (x >> 10);
  }
  
  static void sha256HashBlock(Guchar *blk, Guint *H) {
    Guint W[64];
    Guint a, b, c, d, e, f, g, h;
    Guint T1, T2;
    Guint t;
  
    // 1. prepare the #message schedule
    for (t = 0; t < 16; ++t) {
      W[t] = (blk[t*4] << 24) |
             (blk[t*4 + 1] << 16) |
             (blk[t*4 + 2] << 8) |
             blk[t*4 + 3];
    }
    for (t = 16; t < 64; ++t) {
      W[t] = sha256sigma1(W[t-2]) + W[t-7] + sha256sigma0(W[t-15]) + W[t-16];
    }
  
    // 2. initialize the eight working variables
    a = H[0];
    b = H[1];
    c = H[2];
    d = H[3];
    e = H[4];
    f = H[5];
    g = H[6];
    h = H[7];
  
    // 3.
    for (t = 0; t < 64; ++t) {
      T1 = h + sha256Sigma1(e) + sha256Ch(e,f,g) + sha256K[t] + W[t];
      T2 = sha256Sigma0(a) + sha256Maj(a,b,c);
      h = g;
      g = f;
      f = e;
      e = d + T1;
      d = c;
      c = b;
      b = a;
      a = T1 + T2;
    }
  
    // 4. compute the intermediate hash value
    H[0] += a;
    H[1] += b;
    H[2] += c;
    H[3] += d;
    H[4] += e;
    H[5] += f;
    H[6] += g;
    H[7] += h;
  }
  
  static void sha256(Guchar *msg, int msgLen, Guchar *hash) {
    Guchar blk[64];
    Guint H[8];
    int blkLen, i;
  
    H[0] = 0x6a09e667;
    H[1] = 0xbb67ae85;
    H[2] = 0x3c6ef372;
    H[3] = 0xa54ff53a;
    H[4] = 0x510e527f;
    H[5] = 0x9b05688c;
    H[6] = 0x1f83d9ab;
    H[7] = 0x5be0cd19;
  
    blkLen = 0;
    for (i = 0; i + 64 <= msgLen; i += 64) {
      sha256HashBlock(msg + i, H);
    }
    blkLen = msgLen - i;
    if (blkLen > 0) {
      memcpy(blk, msg + i, blkLen);
    }
  
    // pad the #message
    blk[blkLen++] = 0x80;
    if (blkLen > 56) {
      while (blkLen < 64) {
        blk[blkLen++] = 0;
      }
      sha256HashBlock(blk, H);
      blkLen = 0;
    }
    while (blkLen < 56) {
      blk[blkLen++] = 0;
    }
    blk[56] = 0;
    blk[57] = 0;
    blk[58] = 0;
    blk[59] = 0;
    blk[60] = (Guchar)(msgLen >> 21);
    blk[61] = (Guchar)(msgLen >> 13);
    blk[62] = (Guchar)(msgLen >> 5);
    blk[63] = (Guchar)(msgLen << 3);
    sha256HashBlock(blk, H);
  
    // copy the output into the buffer (convert words to bytes)
    for (i = 0; i < 8; ++i) {
      hash[i*4]     = (Guchar)(H[i] >> 24);
      hash[i*4 + 1] = (Guchar)(H[i] >> 16);
      hash[i*4 + 2] = (Guchar)(H[i] >> 8);
      hash[i*4 + 3] = (Guchar)H[i];
    }
  }
  
  //------------------------------------------------------------------------
  // SHA-384 and SHA-512 hashes
  //------------------------------------------------------------------------
  
  typedef unsigned long long SHA512Uint64;
  
  static SHA512Uint64 sha512K[80] = {
    0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL,
    0xb5c0fbcfec4d3b2fULL, 0xe9b5dba58189dbbcULL,
    0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL,
    0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL,
    0xd807aa98a3030242ULL, 0x12835b0145706fbeULL,
    0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL,
    0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL,
    0x9bdc06a725c71235ULL, 0xc19bf174cf692694ULL,
    0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL,
    0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL,
    0x2de92c6f592b0275ULL, 0x4a7484aa6ea6e483ULL,
    0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL,
    0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL,
    0xb00327c898fb213fULL, 0xbf597fc7beef0ee4ULL,
    0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL,
    0x06ca6351e003826fULL, 0x142929670a0e6e70ULL,
    0x27b70a8546d22ffcULL, 0x2e1b21385c26c926ULL,
    0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL,
    0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL,
    0x81c2c92e47edaee6ULL, 0x92722c851482353bULL,
    0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL,
    0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL,
    0xd192e819d6ef5218ULL, 0xd69906245565a910ULL,
    0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL,
    0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL,
    0x2748774cdf8eeb99ULL, 0x34b0bcb5e19b48a8ULL,
    0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL,
    0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL,
    0x748f82ee5defb2fcULL, 0x78a5636f43172f60ULL,
    0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL,
    0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL,
    0xbef9a3f7b2c67915ULL, 0xc67178f2e372532bULL,
    0xca273eceea26619cULL, 0xd186b8c721c0c207ULL,
    0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL,
    0x06f067aa72176fbaULL, 0x0a637dc5a2c898a6ULL,
    0x113f9804bef90daeULL, 0x1b710b35131c471bULL,
    0x28db77f523047d84ULL, 0x32caab7b40c72493ULL,
    0x3c9ebe0a15c9bebcULL, 0x431d67c49c100d4cULL,
    0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL,
    0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL
  };
  
  static inline SHA512Uint64 rotr64(SHA512Uint64 x, Guint n) {
    return (x >> n) | (x << (64 - n));
  }
  
  static inline SHA512Uint64 sha512Ch(SHA512Uint64 x, SHA512Uint64 y,
  				    SHA512Uint64 z) {
    return (x & y) ^ (~x & z);
  }
  
  static inline SHA512Uint64 sha512Maj(SHA512Uint64 x, SHA512Uint64 y,
  				     SHA512Uint64 z) {
    return (x & y) ^ (x & z) ^ (y & z);
  }
  
  static inline SHA512Uint64 sha512Sigma0(SHA512Uint64 x) {
    return rotr64(x, 28) ^ rotr64(x, 34) ^ rotr64(x, 39);
  }
  
  static inline SHA512Uint64 sha512Sigma1(SHA512Uint64 x) {
    return rotr64(x, 14) ^ rotr64(x, 18) ^ rotr64(x, 41);
  }
  
  static inline SHA512Uint64 sha512sigma0(SHA512Uint64 x) {
    return rotr64(x, 1) ^ rotr64(x, 8) ^ (x >> 7);
  }
  
  static inline SHA512Uint64 sha512sigma1(SHA512Uint64 x) {
    return rotr64(x, 19) ^ rotr64(x, 61) ^ (x >> 6);
  }
  
  static void sha512HashBlock(Guchar *blk, SHA512Uint64 *H) {
    SHA512Uint64 W[80];
    SHA512Uint64 a, b, c, d, e, f, g, h;
    SHA512Uint64 T1, T2;
    Guint t;
  
    // 1. prepare the #message schedule
    for (t = 0; t < 16; ++t) {
      W[t] = ((SHA512Uint64)blk[t*8] << 56) |
             ((SHA512Uint64)blk[t*8 + 1] << 48) |
             ((SHA512Uint64)blk[t*8 + 2] << 40) |
             ((SHA512Uint64)blk[t*8 + 3] << 32) |
             ((SHA512Uint64)blk[t*8 + 4] << 24) |
             ((SHA512Uint64)blk[t*8 + 5] << 16) |
             ((SHA512Uint64)blk[t*8 + 6] << 8) |
             (SHA512Uint64)blk[t*8 + 7];
    }
    for (t = 16; t < 80; ++t) {
      W[t] = sha512sigma1(W[t-2]) + W[t-7] + sha512sigma0(W[t-15]) + W[t-16];
    }
  
    // 2. initialize the eight working variables
    a = H[0];
    b = H[1];
    c = H[2];
    d = H[3];
    e = H[4];
    f = H[5];
    g = H[6];
    h = H[7];
  
    // 3.
    for (t = 0; t < 80; ++t) {
      T1 = h + sha512Sigma1(e) + sha512Ch(e,f,g) + sha512K[t] + W[t];
      T2 = sha512Sigma0(a) + sha512Maj(a,b,c);
      h = g;
      g = f;
      f = e;
      e = d + T1;
      d = c;
      c = b;
      b = a;
      a = T1 + T2;
    }
  
    // 4. compute the intermediate hash value
    H[0] += a;
    H[1] += b;
    H[2] += c;
    H[3] += d;
    H[4] += e;
    H[5] += f;
    H[6] += g;
    H[7] += h;
  }
  
  static void sha512(Guchar *msg, int msgLen, Guchar *hash) {
    Guchar blk[128];
    SHA512Uint64 H[8];
    int blkLen, i;
  
    H[0] = 0x6a09e667f3bcc908LL;
    H[1] = 0xbb67ae8584caa73bLL;
    H[2] = 0x3c6ef372fe94f82bLL;
    H[3] = 0xa54ff53a5f1d36f1LL;
    H[4] = 0x510e527fade682d1LL;
    H[5] = 0x9b05688c2b3e6c1fLL;
    H[6] = 0x1f83d9abfb41bd6bLL;
    H[7] = 0x5be0cd19137e2179LL;
  
    blkLen = 0;
    for (i = 0; i + 128 <= msgLen; i += 128) {
      sha512HashBlock(msg + i, H);
    }
    blkLen = msgLen - i;
    if (blkLen > 0) {
      memcpy(blk, msg + i, blkLen);
    }
  
    // pad the #message
    blk[blkLen++] = 0x80;
    if (blkLen > 112) {
      while (blkLen < 128) {
        blk[blkLen++] = 0;
      }
      sha512HashBlock(blk, H);
      blkLen = 0;
    }
    while (blkLen < 112) {
      blk[blkLen++] = 0;
    }
    blk[112] = 0;
    blk[113] = 0;
    blk[114] = 0;
    blk[115] = 0;
    blk[116] = 0;
    blk[117] = 0;
    blk[118] = 0;
    blk[119] = 0;
    blk[120] = 0;
    blk[121] = 0;
    blk[122] = 0;
    blk[123] = 0;
    blk[124] = (Guchar)(msgLen >> 21);
    blk[125] = (Guchar)(msgLen >> 13);
    blk[126] = (Guchar)(msgLen >> 5);
    blk[127] = (Guchar)(msgLen << 3);
    sha512HashBlock(blk, H);
  
    // copy the output into the buffer (convert words to bytes)
    for (i = 0; i < 8; ++i) {
      hash[i*8]     = (Guchar)(H[i] >> 56);
      hash[i*8 + 1] = (Guchar)(H[i] >> 48);
      hash[i*8 + 2] = (Guchar)(H[i] >> 40);
      hash[i*8 + 3] = (Guchar)(H[i] >> 32);
      hash[i*8 + 4] = (Guchar)(H[i] >> 24);
      hash[i*8 + 5] = (Guchar)(H[i] >> 16);
      hash[i*8 + 6] = (Guchar)(H[i] >> 8);
      hash[i*8 + 7] = (Guchar)H[i];
    }
  }
  
  static void sha384(Guchar *msg, int msgLen, Guchar *hash) {
    Guchar blk[128];
    SHA512Uint64 H[8];
    int blkLen, i;
  
    H[0] = 0xcbbb9d5dc1059ed8LL;
    H[1] = 0x629a292a367cd507LL;
    H[2] = 0x9159015a3070dd17LL;
    H[3] = 0x152fecd8f70e5939LL;
    H[4] = 0x67332667ffc00b31LL;
    H[5] = 0x8eb44a8768581511LL;
    H[6] = 0xdb0c2e0d64f98fa7LL;
    H[7] = 0x47b5481dbefa4fa4LL;
  
    blkLen = 0;
    for (i = 0; i + 128 <= msgLen; i += 128) {
      sha512HashBlock(msg + i, H);
    }
    blkLen = msgLen - i;
    if (blkLen > 0) {
      memcpy(blk, msg + i, blkLen);
    }
  
    // pad the #message
    blk[blkLen++] = 0x80;
    if (blkLen > 112) {
      while (blkLen < 128) {
        blk[blkLen++] = 0;
      }
      sha512HashBlock(blk, H);
      blkLen = 0;
    }
    while (blkLen < 112) {
      blk[blkLen++] = 0;
    }
    blk[112] = 0;
    blk[113] = 0;
    blk[114] = 0;
    blk[115] = 0;
    blk[116] = 0;
    blk[117] = 0;
    blk[118] = 0;
    blk[119] = 0;
    blk[120] = 0;
    blk[121] = 0;
    blk[122] = 0;
    blk[123] = 0;
    blk[124] = (Guchar)(msgLen >> 21);
    blk[125] = (Guchar)(msgLen >> 13);
    blk[126] = (Guchar)(msgLen >> 5);
    blk[127] = (Guchar)(msgLen << 3);
    sha512HashBlock(blk, H);
  
    // copy the output into the buffer (convert words to bytes)
    for (i = 0; i < 6; ++i) {
      hash[i*8]     = (Guchar)(H[i] >> 56);
      hash[i*8 + 1] = (Guchar)(H[i] >> 48);
      hash[i*8 + 2] = (Guchar)(H[i] >> 40);
      hash[i*8 + 3] = (Guchar)(H[i] >> 32);
      hash[i*8 + 4] = (Guchar)(H[i] >> 24);
      hash[i*8 + 5] = (Guchar)(H[i] >> 16);
      hash[i*8 + 6] = (Guchar)(H[i] >> 8);
      hash[i*8 + 7] = (Guchar)H[i];
    }
  }
  