1 /*
2 * This code implements the MD5 message-digest algorithm.
3 * The algorithm is due to Ron Rivest. This code was
4 * written by Colin Plumb in 1993, no copyright is claimed.
5 * This code is in the public domain; do with it what you wish.
6 *
7 * Equivalent code is available from RSA Data Security, Inc.
8 * This code has been tested against that, and is equivalent,
9 * except that you don't need to include two pages of legalese
10 * with every copy.
11 *
12 * To compute the message digest of a chunk of bytes, declare an
13 * MD5Context structure, pass it to MD5Init, call MD5Update as
14 * needed on buffers full of bytes, and then call MD5Final, which
15 * will fill a supplied 16-byte array with the digest.
16 *
17 * Changed 2007 by Bernhard R. Link for usage in LPRng (only
18 * type names and such stuff), still in public domain */
19
20 #include <config.h>
21
22 #ifdef HAVE_ENDIAN_H
23 #include <endian.h>
24 #endif
25 #ifdef HAVE_STRING_H
26 #include <string.h>
27 #endif
28 #ifdef HAVE_STRINGS_H
29 #include <strings.h>
30 #endif
31
32 #include "md5.h"
33
34 #ifdef __BYTE_ORDER
35 #if __BYTE_ORDER == __LITTLE_ENDIAN
36 #define LITTLE_ENDIAN_FOR_SURE 1
37 #endif
38 #else
39 #ifdef BYTE_ORDER
40 #if BYTE_ORDER == LITTLE_ENDIAN
41 #define LITTLE_ENDIAN_FOR_SURE 1
42 #endif
43 #endif
44 #endif
45
46 #ifdef LITTLE_ENDIAN_FOR_SURE
47 #define byteReverse(buf, len) /* Nothing */
48 #else
49 static void byteReverse(unsigned char *buf, unsigned longs);
50
51 /*
52 * Note: this code is harmless on little-endian machines.
53 */
byteReverse(unsigned char * buf,unsigned longs)54 static void byteReverse(unsigned char *buf, unsigned longs)
55 {
56 uint32_t t;
57 do {
58 t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
59 ((unsigned) buf[1] << 8 | buf[0]);
60 *(uint32_t *) buf = t;
61 buf += 4;
62 } while (--longs);
63 }
64 #endif
65
66 static void MD5Transform(uint32_t buf[4], uint32_t const in[16]);
67
68 /*
69 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
70 * initialization constants.
71 */
MD5Init(struct MD5Context * ctx)72 void MD5Init(struct MD5Context *ctx)
73 {
74 ctx->buf[0] = 0x67452301;
75 ctx->buf[1] = 0xefcdab89;
76 ctx->buf[2] = 0x98badcfe;
77 ctx->buf[3] = 0x10325476;
78
79 ctx->bits[0] = 0;
80 ctx->bits[1] = 0;
81 }
82
83 /*
84 * Update context to reflect the concatenation of another buffer full
85 * of bytes.
86 */
MD5Update(struct MD5Context * ctx,unsigned char const * buf,unsigned len)87 void MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
88 {
89 register uint32_t t;
90
91 /* Update bitcount */
92
93 t = ctx->bits[0];
94 if ((ctx->bits[0] = t + ((uint32_t) len << 3)) < t)
95 ctx->bits[1]++; /* Carry from low to high */
96 ctx->bits[1] += len >> 29;
97
98 t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
99
100 /* Handle any leading odd-sized chunks */
101
102 if (t) {
103 unsigned char *p = (unsigned char *) ctx->in + t;
104
105 t = 64 - t;
106 if (len < t) {
107 memcpy(p, buf, len);
108 return;
109 }
110 memcpy(p, buf, t);
111 byteReverse(ctx->in, 16);
112 MD5Transform(ctx->buf, (uint32_t *) ctx->in);
113 buf += t;
114 len -= t;
115 }
116 /* Process data in 64-byte chunks */
117
118 while (len >= 64) {
119 memcpy(ctx->in, buf, 64);
120 byteReverse(ctx->in, 16);
121 MD5Transform(ctx->buf, (uint32_t *) ctx->in);
122 buf += 64;
123 len -= 64;
124 }
125
126 /* Handle any remaining bytes of data. */
127
128 memcpy(ctx->in, buf, len);
129 }
130
131 /*
132 * Final wrapup - pad to 64-byte boundary with the bit pattern
133 * 1 0* (64-bit count of bits processed, MSB-first)
134 */
MD5Final(struct MD5Context * ctx,unsigned char * digest)135 void MD5Final(struct MD5Context *ctx, unsigned char* digest)
136 {
137 unsigned int count;
138 unsigned char *p;
139
140 /* Compute number of bytes mod 64 */
141 count = (ctx->bits[0] >> 3) & 0x3F;
142
143 /* Set the first char of padding to 0x80. This is safe since there is
144 always at least one byte free */
145 p = ctx->in + count;
146 *p++ = 0x80;
147
148 /* Bytes of padding needed to make 64 bytes */
149 count = 64 - 1 - count;
150
151 /* Pad out to 56 mod 64 */
152 if (count < 8) {
153 /* Two lots of padding: Pad the first block to 64 bytes */
154 memset(p, 0, count);
155 byteReverse(ctx->in, 16);
156 MD5Transform(ctx->buf, (uint32_t *) ctx->in);
157
158 /* Now fill the next block with 56 bytes */
159 memset(ctx->in, 0, 56);
160 } else {
161 /* Pad block to 56 bytes */
162 memset(p, 0, count - 8);
163 }
164 byteReverse(ctx->in, 14);
165
166 /* Append length in bits and transform */
167 ((uint32_t *) ctx->in)[14] = ctx->bits[0];
168 ((uint32_t *) ctx->in)[15] = ctx->bits[1];
169
170 MD5Transform(ctx->buf, (uint32_t *) ctx->in);
171 byteReverse((unsigned char *) ctx->buf, 4);
172
173 if (digest!=NULL)
174 memcpy(digest, ctx->buf, 16);
175 memset(ctx, 0, sizeof(ctx)); /* In case it's sensitive */
176 }
177
178 /* The four core functions - F1 is optimized somewhat */
179
180 /* #define F1(x, y, z) (x & y | ~x & z) */
181 #define F1(x, y, z) (z ^ (x & (y ^ z)))
182 #define F2(x, y, z) F1(z, x, y)
183 #define F3(x, y, z) (x ^ y ^ z)
184 #define F4(x, y, z) (y ^ (x | ~z))
185
186 /* This is the central step in the MD5 algorithm. */
187 #define MD5STEP(f, w, x, y, z, data, s) \
188 ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
189
190 /*
191 * The core of the MD5 algorithm, this alters an existing MD5 hash to
192 * reflect the addition of 16 longwords of new data. MD5Update blocks
193 * the data and converts bytes into longwords for this routine.
194 */
MD5Transform(uint32_t buf[4],uint32_t const in[16])195 static void MD5Transform(uint32_t buf[4], uint32_t const in[16])
196 {
197 register uint32_t a, b, c, d;
198
199 a = buf[0];
200 b = buf[1];
201 c = buf[2];
202 d = buf[3];
203
204 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
205 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
206 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
207 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
208 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
209 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
210 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
211 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
212 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
213 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
214 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
215 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
216 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
217 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
218 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
219 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
220
221 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
222 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
223 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
224 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
225 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
226 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
227 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
228 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
229 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
230 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
231 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
232 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
233 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
234 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
235 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
236 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
237
238 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
239 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
240 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
241 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
242 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
243 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
244 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
245 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
246 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
247 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
248 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
249 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
250 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
251 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
252 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
253 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
254
255 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
256 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
257 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
258 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
259 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
260 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
261 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
262 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
263 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
264 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
265 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
266 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
267 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
268 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
269 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
270 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
271
272 buf[0] += a;
273 buf[1] += b;
274 buf[2] += c;
275 buf[3] += d;
276 }
277