ngx_md5.c revision e18a033b
1
2/*
3 * An internal implementation, based on Alexander Peslyak's
4 * public domain implementation:
5 * http://openwall.info/wiki/people/solar/software/public-domain-source-code/md5
6 */
7
8
9#include <ngx_config.h>
10#include <ngx_core.h>
11#include <ngx_md5.h>
12
13
14static const u_char *ngx_md5_body(ngx_md5_t *ctx, const u_char *data,
15    size_t size);
16
17
18void
19ngx_md5_init(ngx_md5_t *ctx)
20{
21    ctx->a = 0x67452301;
22    ctx->b = 0xefcdab89;
23    ctx->c = 0x98badcfe;
24    ctx->d = 0x10325476;
25
26    ctx->bytes = 0;
27}
28
29
30void
31ngx_md5_update(ngx_md5_t *ctx, const void *data, size_t size)
32{
33    size_t  used, free;
34
35    used = (size_t) (ctx->bytes & 0x3f);
36    ctx->bytes += size;
37
38    if (used) {
39        free = 64 - used;
40
41        if (size < free) {
42            ngx_memcpy(&ctx->buffer[used], data, size);
43            return;
44        }
45
46        ngx_memcpy(&ctx->buffer[used], data, free);
47        data = (u_char *) data + free;
48        size -= free;
49        (void) ngx_md5_body(ctx, ctx->buffer, 64);
50    }
51
52    if (size >= 64) {
53        data = ngx_md5_body(ctx, data, size & ~(size_t) 0x3f);
54        size &= 0x3f;
55    }
56
57    ngx_memcpy(ctx->buffer, data, size);
58}
59
60
61void
62ngx_md5_final(u_char result[16], ngx_md5_t *ctx)
63{
64    size_t  used, free;
65
66    used = (size_t) (ctx->bytes & 0x3f);
67
68    ctx->buffer[used++] = 0x80;
69
70    free = 64 - used;
71
72    if (free < 8) {
73        ngx_memzero(&ctx->buffer[used], free);
74        (void) ngx_md5_body(ctx, ctx->buffer, 64);
75        used = 0;
76        free = 64;
77    }
78
79    ngx_memzero(&ctx->buffer[used], free - 8);
80
81    ctx->bytes <<= 3;
82    ctx->buffer[56] = (u_char) ctx->bytes;
83    ctx->buffer[57] = (u_char) (ctx->bytes >> 8);
84    ctx->buffer[58] = (u_char) (ctx->bytes >> 16);
85    ctx->buffer[59] = (u_char) (ctx->bytes >> 24);
86    ctx->buffer[60] = (u_char) (ctx->bytes >> 32);
87    ctx->buffer[61] = (u_char) (ctx->bytes >> 40);
88    ctx->buffer[62] = (u_char) (ctx->bytes >> 48);
89    ctx->buffer[63] = (u_char) (ctx->bytes >> 56);
90
91    (void) ngx_md5_body(ctx, ctx->buffer, 64);
92
93    result[0] = (u_char) ctx->a;
94    result[1] = (u_char) (ctx->a >> 8);
95    result[2] = (u_char) (ctx->a >> 16);
96    result[3] = (u_char) (ctx->a >> 24);
97    result[4] = (u_char) ctx->b;
98    result[5] = (u_char) (ctx->b >> 8);
99    result[6] = (u_char) (ctx->b >> 16);
100    result[7] = (u_char) (ctx->b >> 24);
101    result[8] = (u_char) ctx->c;
102    result[9] = (u_char) (ctx->c >> 8);
103    result[10] = (u_char) (ctx->c >> 16);
104    result[11] = (u_char) (ctx->c >> 24);
105    result[12] = (u_char) ctx->d;
106    result[13] = (u_char) (ctx->d >> 8);
107    result[14] = (u_char) (ctx->d >> 16);
108    result[15] = (u_char) (ctx->d >> 24);
109
110    ngx_memzero(ctx, sizeof(*ctx));
111}
112
113
114/*
115 * The basic MD5 functions.
116 *
117 * F and G are optimized compared to their RFC 1321 definitions for
118 * architectures that lack an AND-NOT instruction, just like in
119 * Colin Plumb's implementation.
120 */
121
122#define F(x, y, z)  ((z) ^ ((x) & ((y) ^ (z))))
123#define G(x, y, z)  ((y) ^ ((z) & ((x) ^ (y))))
124#define H(x, y, z)  ((x) ^ (y) ^ (z))
125#define I(x, y, z)  ((y) ^ ((x) | ~(z)))
126
127/*
128 * The MD5 transformation for all four rounds.
129 */
130
131#define STEP(f, a, b, c, d, x, t, s)                                          \
132    (a) += f((b), (c), (d)) + (x) + (t);                                      \
133    (a) = (((a) << (s)) | (((a) & 0xffffffff) >> (32 - (s))));                \
134    (a) += (b)
135
136/*
137 * SET() reads 4 input bytes in little-endian byte order and stores them
138 * in a properly aligned word in host byte order.
139 *
140 * The check for little-endian architectures that tolerate unaligned
141 * memory accesses is just an optimization.  Nothing will break if it
142 * does not work.
143 */
144
145#if (NGX_HAVE_LITTLE_ENDIAN && NGX_HAVE_NONALIGNED)
146
147#define SET(n)      (*(uint32_t *) &p[n * 4])
148#define GET(n)      (*(uint32_t *) &p[n * 4])
149
150#else
151
152#define SET(n)                                                                \
153    (block[n] =                                                               \
154    (uint32_t) p[n * 4] |                                                     \
155    ((uint32_t) p[n * 4 + 1] << 8) |                                          \
156    ((uint32_t) p[n * 4 + 2] << 16) |                                         \
157    ((uint32_t) p[n * 4 + 3] << 24))
158
159#define GET(n)      block[n]
160
161#endif
162
163
164/*
165 * This processes one or more 64-byte data blocks, but does not update
166 * the bit counters.  There are no alignment requirements.
167 */
168
169static const u_char *
170ngx_md5_body(ngx_md5_t *ctx, const u_char *data, size_t size)
171{
172    uint32_t       a, b, c, d;
173    uint32_t       saved_a, saved_b, saved_c, saved_d;
174    const u_char  *p;
175#if !(NGX_HAVE_LITTLE_ENDIAN && NGX_HAVE_NONALIGNED)
176    uint32_t       block[16];
177#endif
178
179    p = data;
180
181    a = ctx->a;
182    b = ctx->b;
183    c = ctx->c;
184    d = ctx->d;
185
186    do {
187        saved_a = a;
188        saved_b = b;
189        saved_c = c;
190        saved_d = d;
191
192        /* Round 1 */
193
194        STEP(F, a, b, c, d, SET(0),  0xd76aa478, 7);
195        STEP(F, d, a, b, c, SET(1),  0xe8c7b756, 12);
196        STEP(F, c, d, a, b, SET(2),  0x242070db, 17);
197        STEP(F, b, c, d, a, SET(3),  0xc1bdceee, 22);
198        STEP(F, a, b, c, d, SET(4),  0xf57c0faf, 7);
199        STEP(F, d, a, b, c, SET(5),  0x4787c62a, 12);
200        STEP(F, c, d, a, b, SET(6),  0xa8304613, 17);
201        STEP(F, b, c, d, a, SET(7),  0xfd469501, 22);
202        STEP(F, a, b, c, d, SET(8),  0x698098d8, 7);
203        STEP(F, d, a, b, c, SET(9),  0x8b44f7af, 12);
204        STEP(F, c, d, a, b, SET(10), 0xffff5bb1, 17);
205        STEP(F, b, c, d, a, SET(11), 0x895cd7be, 22);
206        STEP(F, a, b, c, d, SET(12), 0x6b901122, 7);
207        STEP(F, d, a, b, c, SET(13), 0xfd987193, 12);
208        STEP(F, c, d, a, b, SET(14), 0xa679438e, 17);
209        STEP(F, b, c, d, a, SET(15), 0x49b40821, 22);
210
211        /* Round 2 */
212
213        STEP(G, a, b, c, d, GET(1),  0xf61e2562, 5);
214        STEP(G, d, a, b, c, GET(6),  0xc040b340, 9);
215        STEP(G, c, d, a, b, GET(11), 0x265e5a51, 14);
216        STEP(G, b, c, d, a, GET(0),  0xe9b6c7aa, 20);
217        STEP(G, a, b, c, d, GET(5),  0xd62f105d, 5);
218        STEP(G, d, a, b, c, GET(10), 0x02441453, 9);
219        STEP(G, c, d, a, b, GET(15), 0xd8a1e681, 14);
220        STEP(G, b, c, d, a, GET(4),  0xe7d3fbc8, 20);
221        STEP(G, a, b, c, d, GET(9),  0x21e1cde6, 5);
222        STEP(G, d, a, b, c, GET(14), 0xc33707d6, 9);
223        STEP(G, c, d, a, b, GET(3),  0xf4d50d87, 14);
224        STEP(G, b, c, d, a, GET(8),  0x455a14ed, 20);
225        STEP(G, a, b, c, d, GET(13), 0xa9e3e905, 5);
226        STEP(G, d, a, b, c, GET(2),  0xfcefa3f8, 9);
227        STEP(G, c, d, a, b, GET(7),  0x676f02d9, 14);
228        STEP(G, b, c, d, a, GET(12), 0x8d2a4c8a, 20);
229
230        /* Round 3 */
231
232        STEP(H, a, b, c, d, GET(5),  0xfffa3942, 4);
233        STEP(H, d, a, b, c, GET(8),  0x8771f681, 11);
234        STEP(H, c, d, a, b, GET(11), 0x6d9d6122, 16);
235        STEP(H, b, c, d, a, GET(14), 0xfde5380c, 23);
236        STEP(H, a, b, c, d, GET(1),  0xa4beea44, 4);
237        STEP(H, d, a, b, c, GET(4),  0x4bdecfa9, 11);
238        STEP(H, c, d, a, b, GET(7),  0xf6bb4b60, 16);
239        STEP(H, b, c, d, a, GET(10), 0xbebfbc70, 23);
240        STEP(H, a, b, c, d, GET(13), 0x289b7ec6, 4);
241        STEP(H, d, a, b, c, GET(0),  0xeaa127fa, 11);
242        STEP(H, c, d, a, b, GET(3),  0xd4ef3085, 16);
243        STEP(H, b, c, d, a, GET(6),  0x04881d05, 23);
244        STEP(H, a, b, c, d, GET(9),  0xd9d4d039, 4);
245        STEP(H, d, a, b, c, GET(12), 0xe6db99e5, 11);
246        STEP(H, c, d, a, b, GET(15), 0x1fa27cf8, 16);
247        STEP(H, b, c, d, a, GET(2),  0xc4ac5665, 23);
248
249        /* Round 4 */
250
251        STEP(I, a, b, c, d, GET(0),  0xf4292244, 6);
252        STEP(I, d, a, b, c, GET(7),  0x432aff97, 10);
253        STEP(I, c, d, a, b, GET(14), 0xab9423a7, 15);
254        STEP(I, b, c, d, a, GET(5),  0xfc93a039, 21);
255        STEP(I, a, b, c, d, GET(12), 0x655b59c3, 6);
256        STEP(I, d, a, b, c, GET(3),  0x8f0ccc92, 10);
257        STEP(I, c, d, a, b, GET(10), 0xffeff47d, 15);
258        STEP(I, b, c, d, a, GET(1),  0x85845dd1, 21);
259        STEP(I, a, b, c, d, GET(8),  0x6fa87e4f, 6);
260        STEP(I, d, a, b, c, GET(15), 0xfe2ce6e0, 10);
261        STEP(I, c, d, a, b, GET(6),  0xa3014314, 15);
262        STEP(I, b, c, d, a, GET(13), 0x4e0811a1, 21);
263        STEP(I, a, b, c, d, GET(4),  0xf7537e82, 6);
264        STEP(I, d, a, b, c, GET(11), 0xbd3af235, 10);
265        STEP(I, c, d, a, b, GET(2),  0x2ad7d2bb, 15);
266        STEP(I, b, c, d, a, GET(9),  0xeb86d391, 21);
267
268        a += saved_a;
269        b += saved_b;
270        c += saved_c;
271        d += saved_d;
272
273        p += 64;
274
275    } while (size -= 64);
276
277    ctx->a = a;
278    ctx->b = b;
279    ctx->c = c;
280    ctx->d = d;
281
282    return p;
283}
284