md5.c revision 258945
1/* 2 * Copyright (C) 2004, 2005, 2007 Internet Systems Consortium, Inc. ("ISC") 3 * Copyright (C) 2000, 2001 Internet Software Consortium. 4 * 5 * Permission to use, copy, modify, and/or distribute this software for any 6 * purpose with or without fee is hereby granted, provided that the above 7 * copyright notice and this permission notice appear in all copies. 8 * 9 * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 10 * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 11 * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 12 * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 13 * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 14 * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 15 * PERFORMANCE OF THIS SOFTWARE. 16 */ 17 18/* $Id: md5.c,v 1.14 2007/06/19 23:47:17 tbox Exp $ */ 19 20/*! \file 21 * This code implements the MD5 message-digest algorithm. 22 * The algorithm is due to Ron Rivest. This code was 23 * written by Colin Plumb in 1993, no copyright is claimed. 24 * This code is in the public domain; do with it what you wish. 25 * 26 * Equivalent code is available from RSA Data Security, Inc. 27 * This code has been tested against that, and is equivalent, 28 * except that you don't need to include two pages of legalese 29 * with every copy. 30 * 31 * To compute the message digest of a chunk of bytes, declare an 32 * MD5Context structure, pass it to MD5Init, call MD5Update as 33 * needed on buffers full of bytes, and then call MD5Final, which 34 * will fill a supplied 16-byte array with the digest. 35 */ 36 37#include "config.h" 38 39#include <isc/assertions.h> 40#include <isc/md5.h> 41#include <isc/string.h> 42#include <isc/types.h> 43#include <isc/util.h> 44 45static void 46byteSwap(isc_uint32_t *buf, unsigned words) 47{ 48 unsigned char *p = (unsigned char *)buf; 49 50 do { 51 *buf++ = (isc_uint32_t)((unsigned)p[3] << 8 | p[2]) << 16 | 52 ((unsigned)p[1] << 8 | p[0]); 53 p += 4; 54 } while (--words); 55} 56 57/*! 58 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious 59 * initialization constants. 60 */ 61void 62isc_md5_init(isc_md5_t *ctx) { 63 ctx->buf[0] = 0x67452301; 64 ctx->buf[1] = 0xefcdab89; 65 ctx->buf[2] = 0x98badcfe; 66 ctx->buf[3] = 0x10325476; 67 68 ctx->bytes[0] = 0; 69 ctx->bytes[1] = 0; 70} 71 72void 73isc_md5_invalidate(isc_md5_t *ctx) { 74 memset(ctx, 0, sizeof(isc_md5_t)); 75} 76 77/*@{*/ 78/*! The four core functions - F1 is optimized somewhat */ 79 80/* #define F1(x, y, z) (x & y | ~x & z) */ 81#define F1(x, y, z) (z ^ (x & (y ^ z))) 82#define F2(x, y, z) F1(z, x, y) 83#define F3(x, y, z) (x ^ y ^ z) 84#define F4(x, y, z) (y ^ (x | ~z)) 85/*@}*/ 86 87/*! This is the central step in the MD5 algorithm. */ 88#define MD5STEP(f,w,x,y,z,in,s) \ 89 (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x) 90 91/*! 92 * The core of the MD5 algorithm, this alters an existing MD5 hash to 93 * reflect the addition of 16 longwords of new data. MD5Update blocks 94 * the data and converts bytes into longwords for this routine. 95 */ 96static void 97transform(isc_uint32_t buf[4], isc_uint32_t const in[16]) { 98 register isc_uint32_t a, b, c, d; 99 100 a = buf[0]; 101 b = buf[1]; 102 c = buf[2]; 103 d = buf[3]; 104 105 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7); 106 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12); 107 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17); 108 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22); 109 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7); 110 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12); 111 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17); 112 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22); 113 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7); 114 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12); 115 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17); 116 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22); 117 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7); 118 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12); 119 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17); 120 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22); 121 122 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5); 123 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9); 124 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14); 125 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20); 126 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5); 127 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9); 128 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14); 129 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20); 130 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5); 131 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9); 132 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14); 133 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20); 134 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5); 135 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9); 136 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14); 137 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20); 138 139 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4); 140 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11); 141 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16); 142 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23); 143 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4); 144 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11); 145 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16); 146 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23); 147 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4); 148 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11); 149 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16); 150 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23); 151 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4); 152 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11); 153 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16); 154 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23); 155 156 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6); 157 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10); 158 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15); 159 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21); 160 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6); 161 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10); 162 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15); 163 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21); 164 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6); 165 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10); 166 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15); 167 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21); 168 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6); 169 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10); 170 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15); 171 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21); 172 173 buf[0] += a; 174 buf[1] += b; 175 buf[2] += c; 176 buf[3] += d; 177} 178 179/*! 180 * Update context to reflect the concatenation of another buffer full 181 * of bytes. 182 */ 183void 184isc_md5_update(isc_md5_t *ctx, const unsigned char *buf, unsigned int len) { 185 isc_uint32_t t; 186 187 /* Update byte count */ 188 189 t = ctx->bytes[0]; 190 if ((ctx->bytes[0] = t + len) < t) 191 ctx->bytes[1]++; /* Carry from low to high */ 192 193 t = 64 - (t & 0x3f); /* Space available in ctx->in (at least 1) */ 194 if (t > len) { 195 memcpy((unsigned char *)ctx->in + 64 - t, buf, len); 196 return; 197 } 198 /* First chunk is an odd size */ 199 memcpy((unsigned char *)ctx->in + 64 - t, buf, t); 200 byteSwap(ctx->in, 16); 201 transform(ctx->buf, ctx->in); 202 buf += t; 203 len -= t; 204 205 /* Process data in 64-byte chunks */ 206 while (len >= 64) { 207 memcpy(ctx->in, buf, 64); 208 byteSwap(ctx->in, 16); 209 transform(ctx->buf, ctx->in); 210 buf += 64; 211 len -= 64; 212 } 213 214 /* Handle any remaining bytes of data. */ 215 memcpy(ctx->in, buf, len); 216} 217 218/*! 219 * Final wrapup - pad to 64-byte boundary with the bit pattern 220 * 1 0* (64-bit count of bits processed, MSB-first) 221 */ 222void 223isc_md5_final(isc_md5_t *ctx, unsigned char *digest) { 224 int count = ctx->bytes[0] & 0x3f; /* Number of bytes in ctx->in */ 225 unsigned char *p = (unsigned char *)ctx->in + count; 226 227 /* Set the first char of padding to 0x80. There is always room. */ 228 *p++ = 0x80; 229 230 /* Bytes of padding needed to make 56 bytes (-8..55) */ 231 count = 56 - 1 - count; 232 233 if (count < 0) { /* Padding forces an extra block */ 234 memset(p, 0, count + 8); 235 byteSwap(ctx->in, 16); 236 transform(ctx->buf, ctx->in); 237 p = (unsigned char *)ctx->in; 238 count = 56; 239 } 240 memset(p, 0, count); 241 byteSwap(ctx->in, 14); 242 243 /* Append length in bits and transform */ 244 ctx->in[14] = ctx->bytes[0] << 3; 245 ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29; 246 transform(ctx->buf, ctx->in); 247 248 byteSwap(ctx->buf, 4); 249 memcpy(digest, ctx->buf, 16); 250 memset(ctx, 0, sizeof(isc_md5_t)); /* In case it's sensitive */ 251} 252