converted to C++ class by Frank Thilo (thilo@unix-ag.org)
for bzflag (http://www.bzflag.org)
reference implemantion of RFC 1321
Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
License to copy and use this software is granted provided that it
is identified as the "RSA Data Security, Inc. MD5 Message-Digest
Algorithm" in all material mentioning or referencing this software
License is also granted to make and use derivative works provided
that such works are identified as "derived from the RSA Data
Security, Inc. MD5 Message-Digest Algorithm" in all material
mentioning or referencing the derived work.
RSA Data Security, Inc. makes no representations concerning either
the merchantability of this software or the suitability of this
software for any particular purpose. It is provided "as is"
without express or implied warranty of any kind.
These notices must be retained in any copies of any part of this
documentation and/or software.
// Constants for MD5Transform routine.
///////////////////////////////////////////////
// F, G, H and I are basic MD5 functions.
inline uint32_t MD5::F(uint32_t x, uint32_t y, uint32_t z)
inline uint32_t MD5::G(uint32_t x, uint32_t y, uint32_t z)
inline uint32_t MD5::H(uint32_t x, uint32_t y, uint32_t z)
inline uint32_t MD5::I(uint32_t x, uint32_t y, uint32_t z)
// rotate_left rotates x left n bits.
inline uint32_t MD5::rotate_left(uint32_t x, int n)
return (x << n) | (x >> (32 - n));
// FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
// Rotation is separate from addition to prevent recomputation.
inline void MD5::FF(uint32_t &a, uint32_t b, uint32_t c, uint32_t d, uint32_t x, uint32_t s, uint32_t ac)
a = rotate_left(a + F(b, c, d) + x + ac, s) + b;
inline void MD5::GG(uint32_t &a, uint32_t b, uint32_t c, uint32_t d, uint32_t x, uint32_t s, uint32_t ac)
a = rotate_left(a + G(b, c, d) + x + ac, s) + b;
inline void MD5::HH(uint32_t &a, uint32_t b, uint32_t c, uint32_t d, uint32_t x, uint32_t s, uint32_t ac)
a = rotate_left(a + H(b, c, d) + x + ac, s) + b;
inline void MD5::II(uint32_t &a, uint32_t b, uint32_t c, uint32_t d, uint32_t x, uint32_t s, uint32_t ac)
a = rotate_left(a + I(b, c, d) + x + ac, s) + b;
//////////////////////////////////////////////
// default ctor, just initailize
//////////////////////////////
// load magic initialization constants.
//////////////////////////////
// decodes input (unsigned char) into output (uint32_t). Assumes len is a multiple of 4.
void MD5::decode(uint32_t output[], const uint8_t input[], size_type len)
for (unsigned int i = 0, j = 0; j < len; i++, j += 4)
output[i] = ((uint32_t)input[j]) | (((uint32_t)input[j + 1]) << 8) |
(((uint32_t)input[j + 2]) << 16) | (((uint32_t)input[j + 3]) << 24);
//////////////////////////////
// encodes input (uint32_t) into output (unsigned char). Assumes len is
void MD5::encode(uint8_t output[], const uint32_t input[], size_type len)
for (size_type i = 0, j = 0; j < len; i++, j += 4)
output[j] = input[i] & 0xff;
output[j + 1] = (input[i] >> 8) & 0xff;
output[j + 2] = (input[i] >> 16) & 0xff;
output[j + 3] = (input[i] >> 24) & 0xff;
//////////////////////////////
// apply MD5 algo on a block
void MD5::transform(const uint8_t block[blocksize])
uint32_t a = state[0], b = state[1], c = state[2], d = state[3], x[16];
decode(x, block, blocksize);
FF(a, b, c, d, x[0], S11, 0xd76aa478); /* 1 */
FF(d, a, b, c, x[1], S12, 0xe8c7b756); /* 2 */
FF(c, d, a, b, x[2], S13, 0x242070db); /* 3 */
FF(b, c, d, a, x[3], S14, 0xc1bdceee); /* 4 */
FF(a, b, c, d, x[4], S11, 0xf57c0faf); /* 5 */
FF(d, a, b, c, x[5], S12, 0x4787c62a); /* 6 */
FF(c, d, a, b, x[6], S13, 0xa8304613); /* 7 */
FF(b, c, d, a, x[7], S14, 0xfd469501); /* 8 */
FF(a, b, c, d, x[8], S11, 0x698098d8); /* 9 */
FF(d, a, b, c, x[9], S12, 0x8b44f7af); /* 10 */
FF(c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
FF(b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
FF(a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
FF(d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
FF(c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
FF(b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
GG(a, b, c, d, x[1], S21, 0xf61e2562); /* 17 */
GG(d, a, b, c, x[6], S22, 0xc040b340); /* 18 */
GG(c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
GG(b, c, d, a, x[0], S24, 0xe9b6c7aa); /* 20 */
GG(a, b, c, d, x[5], S21, 0xd62f105d); /* 21 */
GG(d, a, b, c, x[10], S22, 0x2441453); /* 22 */
GG(c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
GG(b, c, d, a, x[4], S24, 0xe7d3fbc8); /* 24 */
GG(a, b, c, d, x[9], S21, 0x21e1cde6); /* 25 */
GG(d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
GG(c, d, a, b, x[3], S23, 0xf4d50d87); /* 27 */
GG(b, c, d, a, x[8], S24, 0x455a14ed); /* 28 */
GG(a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
GG(d, a, b, c, x[2], S22, 0xfcefa3f8); /* 30 */
GG(c, d, a, b, x[7], S23, 0x676f02d9); /* 31 */
GG(b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
HH(a, b, c, d, x[5], S31, 0xfffa3942); /* 33 */
HH(d, a, b, c, x[8], S32, 0x8771f681); /* 34 */
HH(c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
HH(b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
HH(a, b, c, d, x[1], S31, 0xa4beea44); /* 37 */
HH(d, a, b, c, x[4], S32, 0x4bdecfa9); /* 38 */
HH(c, d, a, b, x[7], S33, 0xf6bb4b60); /* 39 */
HH(b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
HH(a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
HH(d, a, b, c, x[0], S32, 0xeaa127fa); /* 42 */
HH(c, d, a, b, x[3], S33, 0xd4ef3085); /* 43 */
HH(b, c, d, a, x[6], S34, 0x4881d05); /* 44 */
HH(a, b, c, d, x[9], S31, 0xd9d4d039); /* 45 */
HH(d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
HH(c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
HH(b, c, d, a, x[2], S34, 0xc4ac5665); /* 48 */
II(a, b, c, d, x[0], S41, 0xf4292244); /* 49 */
II(d, a, b, c, x[7], S42, 0x432aff97); /* 50 */
II(c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
II(b, c, d, a, x[5], S44, 0xfc93a039); /* 52 */
II(a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
II(d, a, b, c, x[3], S42, 0x8f0ccc92); /* 54 */
II(c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
II(b, c, d, a, x[1], S44, 0x85845dd1); /* 56 */
II(a, b, c, d, x[8], S41, 0x6fa87e4f); /* 57 */
II(d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
II(c, d, a, b, x[6], S43, 0xa3014314); /* 59 */
II(b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
II(a, b, c, d, x[4], S41, 0xf7537e82); /* 61 */
II(d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
II(c, d, a, b, x[2], S43, 0x2ad7d2bb); /* 63 */
II(b, c, d, a, x[9], S44, 0xeb86d391); /* 64 */
// Zeroize sensitive information.
//////////////////////////////
// MD5 block update operation. Continues an MD5 message-digest
// operation, processing another message block
void MD5::update(const unsigned char input[], size_type length)
// compute number of bytes mod 64
size_type index = count[0] / 8 % blocksize;
if ((count[0] += (length << 3)) < (length << 3))
count[1] += (length >> 29);
// number of bytes we need to fill in buffer
size_type firstpart = 64 - index;
// transform as many times as possible.
// fill buffer first, transform
memcpy(&buffer[index], input, firstpart);
// transform chunks of blocksize (64 bytes)
for (i = firstpart; i + blocksize <= length; i += blocksize)
// buffer remaining input
memcpy(&buffer[index], &input[i], length - i);
//////////////////////////////
MD5::digest_t MD5::digest()
static const unsigned char padding[64] = {
0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
uint8_t _buffer[blocksize];
// Backup hash state at previous block boundary
memcpy(_buffer, buffer, blocksize);
memcpy(_count, count, 8);
memcpy(_state, state, 16);
size_type index = count[0] / 8 % 64;
size_type padLen = (index < 56) ? (56 - index) : (120 - index);
// Append length (before padding)
encode(result.data, state, 16);
// revert hash state to previous hash boundary
memcpy(buffer, _buffer, blocksize);
memcpy(count, _count, 8);
memcpy(state, _state, 16);