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.
15 #include "blob.h" /* TODO: better include for bswap_32 compat */
17 #include <sys/types.h>
25 #if __BYTE_ORDER == __LITTLE_ENDIAN
26 #define SWAP_LE32(x) (x)
28 #define SWAP_LE32(x) bswap_32(x)
31 /* Initialize structure containing state of computation.
32 * (RFC 1321, 3.3: Step 3)
34 void md5_begin(md5_ctx_t
*ctx
)
45 /* These are the four functions used in the four steps of the MD5 algorithm
46 * and defined in the RFC 1321. The first function is a little bit optimized
47 * (as found in Colin Plumbs public domain implementation).
48 * #define FF(b, c, d) ((b & c) | (~b & d))
50 # define FF(b, c, d) (d ^ (b & (c ^ d)))
51 # define FG(b, c, d) FF (d, b, c)
52 # define FH(b, c, d) (b ^ c ^ d)
53 # define FI(b, c, d) (c ^ (b | ~d))
55 /* Hash a single block, 64 bytes long and 4-byte aligned. */
56 static void md5_hash_block(const void *buffer
, md5_ctx_t
*ctx
)
58 uint32_t correct_words
[16];
59 const uint32_t *words
= buffer
;
61 static const uint32_t C_array
[] = {
63 0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,
64 0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
65 0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
66 0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
68 0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,
69 0xd62f105d, 0x2441453, 0xd8a1e681, 0xe7d3fbc8,
70 0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
71 0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
73 0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,
74 0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
75 0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x4881d05,
76 0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
78 0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039,
79 0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
80 0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
81 0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391
84 static const char P_array
[] = {
85 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, /* 1 */
86 1, 6, 11, 0, 5, 10, 15, 4, 9, 14, 3, 8, 13, 2, 7, 12, /* 2 */
87 5, 8, 11, 14, 1, 4, 7, 10, 13, 0, 3, 6, 9, 12, 15, 2, /* 3 */
88 0, 7, 14, 5, 12, 3, 10, 1, 8, 15, 6, 13, 4, 11, 2, 9 /* 4 */
91 static const char S_array
[] = {
103 uint32_t *cwp
= correct_words
;
105 # define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s)))
113 for (i
= 0; i
< 16; i
++) {
114 cwp
[i
] = SWAP_LE32(words
[i
]);
121 for (i
= 0; i
< 16; i
++) {
122 temp
= A
+ FF(B
, C
, D
) + cwp
[(int) (*pp
++)] + *pc
++;
123 CYCLIC(temp
, ps
[i
& 3]);
132 for (i
= 0; i
< 16; i
++) {
133 temp
= A
+ FG(B
, C
, D
) + cwp
[(int) (*pp
++)] + *pc
++;
134 CYCLIC(temp
, ps
[i
& 3]);
142 for (i
= 0; i
< 16; i
++) {
143 temp
= A
+ FH(B
, C
, D
) + cwp
[(int) (*pp
++)] + *pc
++;
144 CYCLIC(temp
, ps
[i
& 3]);
152 for (i
= 0; i
< 16; i
++) {
153 temp
= A
+ FI(B
, C
, D
) + cwp
[(int) (*pp
++)] + *pc
++;
154 CYCLIC(temp
, ps
[i
& 3]);
169 /* Feed data through a temporary buffer to call md5_hash_aligned_block()
170 * with chunks of data that are 4-byte aligned and a multiple of 64 bytes.
171 * This function's internal buffer remembers previous data until it has 64
172 * bytes worth to pass on. Call md5_end() to flush this buffer. */
174 void md5_hash(const void *buffer
, size_t len
, md5_ctx_t
*ctx
)
176 char *buf
= (char *)buffer
;
178 /* RFC 1321 specifies the possible length of the file up to 2^64 bits,
179 * Here we only track the number of bytes. */
183 // Process all input.
186 unsigned i
= 64 - ctx
->buflen
;
188 // Copy data into aligned buffer.
192 memcpy(ctx
->buffer
+ ctx
->buflen
, buf
, i
);
197 // When buffer fills up, process it.
199 if (ctx
->buflen
== 64) {
200 md5_hash_block(ctx
->buffer
, ctx
);
206 /* Process the remaining bytes in the buffer and put result from CTX
207 * in first 16 bytes following RESBUF. The result is always in little
208 * endian byte order, so that a byte-wise output yields to the wanted
209 * ASCII representation of the message digest.
211 * IMPORTANT: On some systems it is required that RESBUF is correctly
212 * aligned for a 32 bits value.
214 void md5_end(void *resbuf
, md5_ctx_t
*ctx
)
216 char *buf
= ctx
->buffer
;
219 /* Pad data to block size. */
221 buf
[ctx
->buflen
++] = 0x80;
222 memset(buf
+ ctx
->buflen
, 0, 128 - ctx
->buflen
);
224 /* Put the 64-bit file length in *bits* at the end of the buffer. */
226 if (ctx
->buflen
> 56)
229 for (i
= 0; i
< 8; i
++)
230 buf
[56 + i
] = ctx
->total
>> (i
*8);
232 /* Process last bytes. */
233 if (buf
!= ctx
->buffer
)
234 md5_hash_block(ctx
->buffer
, ctx
);
235 md5_hash_block(buf
, ctx
);
237 /* Put result from CTX in first 16 bytes following RESBUF. The result is
238 * always in little endian byte order, so that a byte-wise output yields
239 * to the wanted ASCII representation of the message digest.
241 * IMPORTANT: On some systems it is required that RESBUF is correctly
242 * aligned for a 32 bits value.
244 ((uint32_t *) resbuf
)[0] = SWAP_LE32(ctx
->A
);
245 ((uint32_t *) resbuf
)[1] = SWAP_LE32(ctx
->B
);
246 ((uint32_t *) resbuf
)[2] = SWAP_LE32(ctx
->C
);
247 ((uint32_t *) resbuf
)[3] = SWAP_LE32(ctx
->D
);
250 int md5sum(char *file
, uint32_t *md5
)
257 memset(md5
, 0, sizeof(*md5
) * 4);
259 fd
= open(file
, O_RDONLY
);
265 len
= read(fd
, buf
, sizeof(buf
));
276 md5_hash(buf
, len
, &ctx
);