jshn: drop json_select warnings when called from json_get_values()
[project/libubox.git] / md5.c
1 /*
2 * md5.c - Compute MD5 checksum of strings according to the
3 * definition of MD5 in RFC 1321 from April 1992.
4 *
5 * Written by Ulrich Drepper <drepper@gnu.ai.mit.edu>, 1995.
6 *
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
11 *
12 * Licensed under the GPL v2 or later, see the file LICENSE in this tarball.
13 */
14
15 #include "blob.h" /* TODO: better include for bswap_32 compat */
16
17 #include <sys/types.h>
18 #include <sys/stat.h>
19
20 #include <fcntl.h>
21 #include <unistd.h>
22
23 #include "md5.h"
24
25 #if __BYTE_ORDER == __LITTLE_ENDIAN
26 #define SWAP_LE32(x) (x)
27 #else
28 #define SWAP_LE32(x) bswap_32(x)
29 #endif
30
31 /* Initialize structure containing state of computation.
32 * (RFC 1321, 3.3: Step 3)
33 */
34 void md5_begin(md5_ctx_t *ctx)
35 {
36 ctx->A = 0x67452301;
37 ctx->B = 0xefcdab89;
38 ctx->C = 0x98badcfe;
39 ctx->D = 0x10325476;
40
41 ctx->total = 0;
42 ctx->buflen = 0;
43 }
44
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))
49 */
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))
54
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)
57 {
58 uint32_t correct_words[16];
59 const uint32_t *words = buffer;
60
61 static const uint32_t C_array[] = {
62 /* round 1 */
63 0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,
64 0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
65 0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
66 0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
67 /* round 2 */
68 0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,
69 0xd62f105d, 0x2441453, 0xd8a1e681, 0xe7d3fbc8,
70 0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
71 0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
72 /* round 3 */
73 0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,
74 0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
75 0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x4881d05,
76 0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
77 /* round 4 */
78 0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039,
79 0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
80 0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
81 0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391
82 };
83
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 */
89 };
90
91 static const char S_array[] = {
92 7, 12, 17, 22,
93 5, 9, 14, 20,
94 4, 11, 16, 23,
95 6, 10, 15, 21
96 };
97
98 uint32_t A = ctx->A;
99 uint32_t B = ctx->B;
100 uint32_t C = ctx->C;
101 uint32_t D = ctx->D;
102
103 uint32_t *cwp = correct_words;
104
105 # define CYCLIC(w, s) (w = (w << s) | (w >> (32 - s)))
106
107 const uint32_t *pc;
108 const char *pp;
109 const char *ps;
110 int i;
111 uint32_t temp;
112
113 for (i = 0; i < 16; i++) {
114 cwp[i] = SWAP_LE32(words[i]);
115 }
116 words += 16;
117
118 pc = C_array;
119 pp = P_array;
120 ps = S_array;
121
122 for (i = 0; i < 16; i++) {
123 temp = A + FF(B, C, D) + cwp[(int) (*pp++)] + *pc++;
124 CYCLIC(temp, ps[i & 3]);
125 temp += B;
126 A = D;
127 D = C;
128 C = B;
129 B = temp;
130 }
131
132 ps += 4;
133 for (i = 0; i < 16; i++) {
134 temp = A + FG(B, C, D) + cwp[(int) (*pp++)] + *pc++;
135 CYCLIC(temp, ps[i & 3]);
136 temp += B;
137 A = D;
138 D = C;
139 C = B;
140 B = temp;
141 }
142 ps += 4;
143 for (i = 0; i < 16; i++) {
144 temp = A + FH(B, C, D) + cwp[(int) (*pp++)] + *pc++;
145 CYCLIC(temp, ps[i & 3]);
146 temp += B;
147 A = D;
148 D = C;
149 C = B;
150 B = temp;
151 }
152 ps += 4;
153 for (i = 0; i < 16; i++) {
154 temp = A + FI(B, C, D) + cwp[(int) (*pp++)] + *pc++;
155 CYCLIC(temp, ps[i & 3]);
156 temp += B;
157 A = D;
158 D = C;
159 C = B;
160 B = temp;
161 }
162
163
164 ctx->A += A;
165 ctx->B += B;
166 ctx->C += C;
167 ctx->D += D;
168 }
169
170 /* Feed data through a temporary buffer to call md5_hash_aligned_block()
171 * with chunks of data that are 4-byte aligned and a multiple of 64 bytes.
172 * This function's internal buffer remembers previous data until it has 64
173 * bytes worth to pass on. Call md5_end() to flush this buffer. */
174
175 void md5_hash(const void *buffer, size_t len, md5_ctx_t *ctx)
176 {
177 char *buf = (char *)buffer;
178
179 /* RFC 1321 specifies the possible length of the file up to 2^64 bits,
180 * Here we only track the number of bytes. */
181
182 ctx->total += len;
183
184 // Process all input.
185
186 while (len) {
187 unsigned i = 64 - ctx->buflen;
188
189 // Copy data into aligned buffer.
190
191 if (i > len)
192 i = len;
193 memcpy(ctx->buffer + ctx->buflen, buf, i);
194 len -= i;
195 ctx->buflen += i;
196 buf += i;
197
198 // When buffer fills up, process it.
199
200 if (ctx->buflen == 64) {
201 md5_hash_block(ctx->buffer, ctx);
202 ctx->buflen = 0;
203 }
204 }
205 }
206
207 /* Process the remaining bytes in the buffer and put result from CTX
208 * in first 16 bytes following RESBUF. The result is always in little
209 * endian byte order, so that a byte-wise output yields to the wanted
210 * ASCII representation of the message digest.
211 *
212 * IMPORTANT: On some systems it is required that RESBUF is correctly
213 * aligned for a 32 bits value.
214 */
215 void md5_end(void *resbuf, md5_ctx_t *ctx)
216 {
217 char *buf = ctx->buffer;
218 int i;
219
220 /* Pad data to block size. */
221
222 buf[ctx->buflen++] = 0x80;
223 memset(buf + ctx->buflen, 0, 128 - ctx->buflen);
224
225 /* Put the 64-bit file length in *bits* at the end of the buffer. */
226 ctx->total <<= 3;
227 if (ctx->buflen > 56)
228 buf += 64;
229
230 for (i = 0; i < 8; i++)
231 buf[56 + i] = ctx->total >> (i*8);
232
233 /* Process last bytes. */
234 if (buf != ctx->buffer)
235 md5_hash_block(ctx->buffer, ctx);
236 md5_hash_block(buf, ctx);
237
238 /* Put result from CTX in first 16 bytes following RESBUF. The result is
239 * always in little endian byte order, so that a byte-wise output yields
240 * to the wanted ASCII representation of the message digest.
241 *
242 * IMPORTANT: On some systems it is required that RESBUF is correctly
243 * aligned for a 32 bits value.
244 */
245 ((uint32_t *) resbuf)[0] = SWAP_LE32(ctx->A);
246 ((uint32_t *) resbuf)[1] = SWAP_LE32(ctx->B);
247 ((uint32_t *) resbuf)[2] = SWAP_LE32(ctx->C);
248 ((uint32_t *) resbuf)[3] = SWAP_LE32(ctx->D);
249 }
250
251 int md5sum(char *file, uint32_t *md5)
252 {
253 char buf[256];
254 md5_ctx_t ctx;
255 int len, fd;
256 int ret = 0;
257
258 memset(md5, 0, sizeof(*md5) * 4);
259
260 fd = open(file, O_RDONLY);
261 if (fd < 0)
262 return -1;
263
264 md5_begin(&ctx);
265 do {
266 len = read(fd, buf, sizeof(buf));
267 if (len < 0) {
268 if (errno == EINTR)
269 continue;
270
271 ret = -1;
272 goto out;
273 }
274 if (!len)
275 break;
276
277 md5_hash(buf, len, &ctx);
278 } while(1);
279
280 md5_end(md5, &ctx);
281 out:
282 close(fd);
283
284 return ret;
285 }