2 * md5.c - Compute MD5 checksum of strings according to the
3 * definition of MD5 in RFC 1321 from April 1992.
5 * Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995.
7 * Copyright (C) 1995-1999 Free Software Foundation, Inc.
8 * Copyright (C) 2001 Manuel Novoa III
9 * Copyright (C) 2003 Glenn L. McGrath
10 * Copyright (C) 2003 Erik Andersen
12 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
20 #if __BYTE_ORDER == __LITTLE_ENDIAN
21 #define SWAP_LE32(x) (x)
23 #define SWAP_LE32(x) bswap_32(x)
27 /* Initialize structure containing state of computation.
28 * (RFC 1321, 3.3: Step 3)
30 void md5_begin(md5_ctx_t *ctx)
41 /* These are the four functions used in the four steps of the MD5 algorithm
42 * and defined in the RFC 1321. The first function is a little bit optimized
43 * (as found in Colin Plumbs public domain implementation).
44 * #define FF(b, c, d) ((b & c) | (~b & d))
46 # define FF(b, c, d) (d ^ (b & (c ^ d)))
47 # define FG(b, c, d) FF (d, b, c)
48 # define FH(b, c, d) (b ^ c ^ d)
49 # define FI(b, c, d) (c ^ (b | ~d))
51 /* Hash a single block, 64 bytes long and 4-byte aligned. */
52 static void md5_hash_block(const void *buffer, md5_ctx_t *ctx)
54 uint32_t correct_words[16];
55 const uint32_t *words = buffer;
57 static const uint32_t C_array[] = {
59 0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,
60 0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
61 0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
62 0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
64 0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,
65 0xd62f105d, 0x2441453, 0xd8a1e681, 0xe7d3fbc8,
66 0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
67 0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
69 0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,
70 0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
71 0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x4881d05,
72 0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
74 0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039,
75 0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
76 0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
77 0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391
80 static const char P_array[] = {
81 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, /* 1 */
82 1, 6, 11, 0, 5, 10, 15, 4, 9, 14, 3, 8, 13, 2, 7, 12, /* 2 */
83 5, 8, 11, 14, 1, 4, 7, 10, 13, 0, 3, 6, 9, 12, 15, 2, /* 3 */
84 0, 7, 14, 5, 12, 3, 10, 1, 8, 15, 6, 13, 4, 11, 2, 9 /* 4 */
87 static const char S_array[] = {
99 uint32_t *cwp = correct_words;
101 # define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s)))
109 for (i = 0; i < 16; i++) {
110 cwp[i] = SWAP_LE32(words[i]);
118 for (i = 0; i < 16; i++) {
119 temp = A + FF(B, C, D) + cwp[(int) (*pp++)] + *pc++;
120 CYCLIC(temp, ps[i & 3]);
129 for (i = 0; i < 16; i++) {
130 temp = A + FG(B, C, D) + cwp[(int) (*pp++)] + *pc++;
131 CYCLIC(temp, ps[i & 3]);
139 for (i = 0; i < 16; i++) {
140 temp = A + FH(B, C, D) + cwp[(int) (*pp++)] + *pc++;
141 CYCLIC(temp, ps[i & 3]);
149 for (i = 0; i < 16; i++) {
150 temp = A + FI(B, C, D) + cwp[(int) (*pp++)] + *pc++;
151 CYCLIC(temp, ps[i & 3]);
166 /* Feed data through a temporary buffer to call md5_hash_aligned_block()
167 * with chunks of data that are 4-byte aligned and a multiple of 64 bytes.
168 * This function's internal buffer remembers previous data until it has 64
169 * bytes worth to pass on. Call md5_end() to flush this buffer. */
171 void md5_hash(const void *buffer, size_t len, md5_ctx_t *ctx)
173 char *buf = (char *)buffer;
175 /* RFC 1321 specifies the possible length of the file up to 2^64 bits,
176 * Here we only track the number of bytes. */
180 // Process all input.
183 unsigned i = 64 - ctx->buflen;
185 // Copy data into aligned buffer.
189 memcpy(ctx->buffer + ctx->buflen, buf, i);
194 // When buffer fills up, process it.
196 if (ctx->buflen == 64) {
197 md5_hash_block(ctx->buffer, ctx);
203 /* Process the remaining bytes in the buffer and put result from CTX
204 * in first 16 bytes following RESBUF. The result is always in little
205 * endian byte order, so that a byte-wise output yields to the wanted
206 * ASCII representation of the message digest.
208 * IMPORTANT: On some systems it is required that RESBUF is correctly
209 * aligned for a 32 bits value.
211 void md5_end(void *resbuf, md5_ctx_t *ctx)
213 char *buf = ctx->buffer;
216 /* Pad data to block size. */
218 buf[ctx->buflen++] = (char)0x80;
219 memset(buf + ctx->buflen, 0, 128 - ctx->buflen);
221 /* Put the 64-bit file length in *bits* at the end of the buffer. */
223 if (ctx->buflen > 56)
226 for (i = 0; i < 8; i++)
227 buf[56 + i] = ctx->total >> (i*8);
229 /* Process last bytes. */
230 if (buf != ctx->buffer)
231 md5_hash_block(ctx->buffer, ctx);
232 md5_hash_block(buf, ctx);
234 /* Put result from CTX in first 16 bytes following RESBUF. The result is
235 * always in little endian byte order, so that a byte-wise output yields
236 * to the wanted ASCII representation of the message digest.
238 * IMPORTANT: On some systems it is required that RESBUF is correctly
239 * aligned for a 32 bits value.
241 ((uint32_t *) resbuf)[0] = SWAP_LE32(ctx->A);
242 ((uint32_t *) resbuf)[1] = SWAP_LE32(ctx->B);
243 ((uint32_t *) resbuf)[2] = SWAP_LE32(ctx->C);
244 ((uint32_t *) resbuf)[3] = SWAP_LE32(ctx->D);