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Diffstat (limited to 'md5.c')
| -rw-r--r-- | md5.c | 189 |
1 files changed, 189 insertions, 0 deletions
@@ -0,0 +1,189 @@ +/********************************************************************* +* Filename: md5.c +* Author: Brad Conte (brad AT bradconte.com) +* Copyright: +* Disclaimer: This code is presented "as is" without any guarantees. +* Details: Implementation of the MD5 hashing algorithm. + Algorithm specification can be found here: + * http://tools.ietf.org/html/rfc1321 + This implementation uses little endian byte order. +*********************************************************************/ + +/*************************** HEADER FILES ***************************/ +#include <stdlib.h> +#include <memory.h> +#include "md5.h" + +/****************************** MACROS ******************************/ +#define ROTLEFT(a,b) ((a << b) | (a >> (32-b))) + +#define F(x,y,z) ((x & y) | (~x & z)) +#define G(x,y,z) ((x & z) | (y & ~z)) +#define H(x,y,z) (x ^ y ^ z) +#define I(x,y,z) (y ^ (x | ~z)) + +#define FF(a,b,c,d,m,s,t) { a += F(b,c,d) + m + t; \ + a = b + ROTLEFT(a,s); } +#define GG(a,b,c,d,m,s,t) { a += G(b,c,d) + m + t; \ + a = b + ROTLEFT(a,s); } +#define HH(a,b,c,d,m,s,t) { a += H(b,c,d) + m + t; \ + a = b + ROTLEFT(a,s); } +#define II(a,b,c,d,m,s,t) { a += I(b,c,d) + m + t; \ + a = b + ROTLEFT(a,s); } + +/*********************** FUNCTION DEFINITIONS ***********************/ +void md5_transform(MD5_CTX *ctx, const BYTE data[]) +{ + WORD a, b, c, d, m[16], i, j; + + // MD5 specifies big endian byte order, but this implementation assumes a little + // endian byte order CPU. Reverse all the bytes upon input, and re-reverse them + // on output (in md5_final()). + for (i = 0, j = 0; i < 16; ++i, j += 4) + m[i] = (data[j]) + (data[j + 1] << 8) + (data[j + 2] << 16) + (data[j + 3] << 24); + + a = ctx->state[0]; + b = ctx->state[1]; + c = ctx->state[2]; + d = ctx->state[3]; + + FF(a,b,c,d,m[0], 7,0xd76aa478); + FF(d,a,b,c,m[1], 12,0xe8c7b756); + FF(c,d,a,b,m[2], 17,0x242070db); + FF(b,c,d,a,m[3], 22,0xc1bdceee); + FF(a,b,c,d,m[4], 7,0xf57c0faf); + FF(d,a,b,c,m[5], 12,0x4787c62a); + FF(c,d,a,b,m[6], 17,0xa8304613); + FF(b,c,d,a,m[7], 22,0xfd469501); + FF(a,b,c,d,m[8], 7,0x698098d8); + FF(d,a,b,c,m[9], 12,0x8b44f7af); + FF(c,d,a,b,m[10],17,0xffff5bb1); + FF(b,c,d,a,m[11],22,0x895cd7be); + FF(a,b,c,d,m[12], 7,0x6b901122); + FF(d,a,b,c,m[13],12,0xfd987193); + FF(c,d,a,b,m[14],17,0xa679438e); + FF(b,c,d,a,m[15],22,0x49b40821); + + GG(a,b,c,d,m[1], 5,0xf61e2562); + GG(d,a,b,c,m[6], 9,0xc040b340); + GG(c,d,a,b,m[11],14,0x265e5a51); + GG(b,c,d,a,m[0], 20,0xe9b6c7aa); + GG(a,b,c,d,m[5], 5,0xd62f105d); + GG(d,a,b,c,m[10], 9,0x02441453); + GG(c,d,a,b,m[15],14,0xd8a1e681); + GG(b,c,d,a,m[4], 20,0xe7d3fbc8); + GG(a,b,c,d,m[9], 5,0x21e1cde6); + GG(d,a,b,c,m[14], 9,0xc33707d6); + GG(c,d,a,b,m[3], 14,0xf4d50d87); + GG(b,c,d,a,m[8], 20,0x455a14ed); + GG(a,b,c,d,m[13], 5,0xa9e3e905); + GG(d,a,b,c,m[2], 9,0xfcefa3f8); + GG(c,d,a,b,m[7], 14,0x676f02d9); + GG(b,c,d,a,m[12],20,0x8d2a4c8a); + + HH(a,b,c,d,m[5], 4,0xfffa3942); + HH(d,a,b,c,m[8], 11,0x8771f681); + HH(c,d,a,b,m[11],16,0x6d9d6122); + HH(b,c,d,a,m[14],23,0xfde5380c); + HH(a,b,c,d,m[1], 4,0xa4beea44); + HH(d,a,b,c,m[4], 11,0x4bdecfa9); + HH(c,d,a,b,m[7], 16,0xf6bb4b60); + HH(b,c,d,a,m[10],23,0xbebfbc70); + HH(a,b,c,d,m[13], 4,0x289b7ec6); + HH(d,a,b,c,m[0], 11,0xeaa127fa); + HH(c,d,a,b,m[3], 16,0xd4ef3085); + HH(b,c,d,a,m[6], 23,0x04881d05); + HH(a,b,c,d,m[9], 4,0xd9d4d039); + HH(d,a,b,c,m[12],11,0xe6db99e5); + HH(c,d,a,b,m[15],16,0x1fa27cf8); + HH(b,c,d,a,m[2], 23,0xc4ac5665); + + II(a,b,c,d,m[0], 6,0xf4292244); + II(d,a,b,c,m[7], 10,0x432aff97); + II(c,d,a,b,m[14],15,0xab9423a7); + II(b,c,d,a,m[5], 21,0xfc93a039); + II(a,b,c,d,m[12], 6,0x655b59c3); + II(d,a,b,c,m[3], 10,0x8f0ccc92); + II(c,d,a,b,m[10],15,0xffeff47d); + II(b,c,d,a,m[1], 21,0x85845dd1); + II(a,b,c,d,m[8], 6,0x6fa87e4f); + II(d,a,b,c,m[15],10,0xfe2ce6e0); + II(c,d,a,b,m[6], 15,0xa3014314); + II(b,c,d,a,m[13],21,0x4e0811a1); + II(a,b,c,d,m[4], 6,0xf7537e82); + II(d,a,b,c,m[11],10,0xbd3af235); + II(c,d,a,b,m[2], 15,0x2ad7d2bb); + II(b,c,d,a,m[9], 21,0xeb86d391); + + ctx->state[0] += a; + ctx->state[1] += b; + ctx->state[2] += c; + ctx->state[3] += d; +} + +void md5_init(MD5_CTX *ctx) +{ + ctx->datalen = 0; + ctx->bitlen = 0; + ctx->state[0] = 0x67452301; + ctx->state[1] = 0xEFCDAB89; + ctx->state[2] = 0x98BADCFE; + ctx->state[3] = 0x10325476; +} + +void md5_update(MD5_CTX *ctx, const BYTE data[], size_t len) +{ + size_t i; + + for (i = 0; i < len; ++i) { + ctx->data[ctx->datalen] = data[i]; + ctx->datalen++; + if (ctx->datalen == 64) { + md5_transform(ctx, ctx->data); + ctx->bitlen += 512; + ctx->datalen = 0; + } + } +} + +void md5_final(MD5_CTX *ctx, BYTE hash[]) +{ + size_t i; + + i = ctx->datalen; + + // Pad whatever data is left in the buffer. + if (ctx->datalen < 56) { + ctx->data[i++] = 0x80; + while (i < 56) + ctx->data[i++] = 0x00; + } + else if (ctx->datalen >= 56) { + ctx->data[i++] = 0x80; + while (i < 64) + ctx->data[i++] = 0x00; + md5_transform(ctx, ctx->data); + memset(ctx->data, 0, 56); + } + + // Append to the padding the total message's length in bits and transform. + ctx->bitlen += ctx->datalen * 8; + ctx->data[56] = ctx->bitlen; + ctx->data[57] = ctx->bitlen >> 8; + ctx->data[58] = ctx->bitlen >> 16; + ctx->data[59] = ctx->bitlen >> 24; + ctx->data[60] = ctx->bitlen >> 32; + ctx->data[61] = ctx->bitlen >> 40; + ctx->data[62] = ctx->bitlen >> 48; + ctx->data[63] = ctx->bitlen >> 56; + md5_transform(ctx, ctx->data); + + // Since this implementation uses little endian byte ordering and MD uses big endian, + // reverse all the bytes when copying the final state to the output hash. + for (i = 0; i < 4; ++i) { + hash[i] = (ctx->state[0] >> (i * 8)) & 0x000000ff; + hash[i + 4] = (ctx->state[1] >> (i * 8)) & 0x000000ff; + hash[i + 8] = (ctx->state[2] >> (i * 8)) & 0x000000ff; + hash[i + 12] = (ctx->state[3] >> (i * 8)) & 0x000000ff; + } +} |