xref: /openbsd-src/gnu/usr.bin/cvs/lib/md5.c (revision 1e72d8d26fae84dfb4bcd4cecabd10b989ec3f29)
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 
18 #include "config.h"
19 
20 #if HAVE_STRING_H || STDC_HEADERS
21 #include <string.h>	/* for memcpy() */
22 #endif
23 
24 /* Add prototype support.  */
25 #ifndef PROTO
26 #if defined (USE_PROTOTYPES) ? USE_PROTOTYPES : defined (__STDC__)
27 #define PROTO(ARGS) ARGS
28 #else
29 #define PROTO(ARGS) ()
30 #endif
31 #endif
32 
33 #include "md5.h"
34 
35 void byteReverse PROTO ((unsigned char *buf, unsigned longs));
36 
37 #ifndef ASM_MD5
38 /*
39  * Note: this code is harmless on little-endian machines.
40  */
41 void byteReverse (buf, longs)
42      unsigned char *buf;
43      unsigned longs;
44 {
45 	uint32 t;
46 	do {
47 		t = (uint32)((unsigned)buf[3]<<8 | buf[2]) << 16 |
48 		            ((unsigned)buf[1]<<8 | buf[0]);
49 		*(uint32 *)buf = t;
50 		buf += 4;
51 	} while (--longs);
52 }
53 #endif
54 
55 /*
56  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
57  * initialization constants.
58  */
59 void
60 MD5Init(ctx)
61      struct MD5Context *ctx;
62 {
63 	ctx->buf[0] = 0x67452301;
64 	ctx->buf[1] = 0xefcdab89;
65 	ctx->buf[2] = 0x98badcfe;
66 	ctx->buf[3] = 0x10325476;
67 
68 	ctx->bits[0] = 0;
69 	ctx->bits[1] = 0;
70 }
71 
72 /*
73  * Update context to reflect the concatenation of another buffer full
74  * of bytes.
75  */
76 void
77 MD5Update(ctx, buf, len)
78      struct MD5Context *ctx;
79      unsigned char const *buf;
80      unsigned len;
81 {
82 	uint32 t;
83 
84 	/* Update bitcount */
85 
86 	t = ctx->bits[0];
87 	if ((ctx->bits[0] = t + ((uint32)len << 3)) < t)
88 		ctx->bits[1]++;	/* Carry from low to high */
89 	ctx->bits[1] += len >> 29;
90 
91 	t = (t >> 3) & 0x3f;	/* Bytes already in shsInfo->data */
92 
93 	/* Handle any leading odd-sized chunks */
94 
95 	if ( t ) {
96 		unsigned char *p = (unsigned char *)ctx->in + t;
97 
98 		t = 64-t;
99 		if (len < t) {
100 			memcpy(p, buf, len);
101 			return;
102 		}
103 		memcpy(p, buf, t);
104 		byteReverse(ctx->in, 16);
105 		MD5Transform(ctx->buf, (uint32 *)ctx->in);
106 		buf += t;
107 		len -= t;
108 	}
109 
110 	/* Process data in 64-byte chunks */
111 
112 	while (len >= 64) {
113 		memcpy(ctx->in, buf, 64);
114 		byteReverse(ctx->in, 16);
115 		MD5Transform(ctx->buf, (uint32 *)ctx->in);
116 		buf += 64;
117 		len -= 64;
118 	}
119 
120 	/* Handle any remaining bytes of data. */
121 
122 	memcpy(ctx->in, buf, len);
123 }
124 
125 /*
126  * Final wrapup - pad to 64-byte boundary with the bit pattern
127  * 1 0* (64-bit count of bits processed, MSB-first)
128  */
129 void
130 MD5Final(digest, ctx)
131      unsigned char digest[16];
132      struct MD5Context *ctx;
133 {
134 	unsigned count;
135 	unsigned char *p;
136 
137 	/* Compute number of bytes mod 64 */
138 	count = (ctx->bits[0] >> 3) & 0x3F;
139 
140 	/* Set the first char of padding to 0x80.  This is safe since there is
141 	   always at least one byte free */
142 	p = ctx->in + count;
143 	*p++ = 0x80;
144 
145 	/* Bytes of padding needed to make 64 bytes */
146 	count = 64 - 1 - count;
147 
148 	/* Pad out to 56 mod 64 */
149 	if (count < 8) {
150 		/* Two lots of padding:  Pad the first block to 64 bytes */
151 		memset(p, 0, count);
152 		byteReverse(ctx->in, 16);
153 		MD5Transform(ctx->buf, (uint32 *)ctx->in);
154 
155 		/* Now fill the next block with 56 bytes */
156 		memset(ctx->in, 0, 56);
157 	} else {
158 		/* Pad block to 56 bytes */
159 		memset(p, 0, count-8);
160 	}
161 	byteReverse(ctx->in, 14);
162 
163 	/* Append length in bits and transform */
164 	((uint32 *)ctx->in)[ 14 ] = ctx->bits[0];
165 	((uint32 *)ctx->in)[ 15 ] = ctx->bits[1];
166 
167 	MD5Transform(ctx->buf, (uint32 *)ctx->in);
168 	byteReverse((unsigned char *)ctx->buf, 4);
169 	memcpy(digest, ctx->buf, 16);
170 	memset(ctx, 0, sizeof(ctx));	/* In case it's sensitive */
171 }
172 
173 #ifndef ASM_MD5
174 
175 /* The four core functions - F1 is optimized somewhat */
176 
177 /* #define F1(x, y, z) (x & y | ~x & z) */
178 #define F1(x, y, z) (z ^ (x & (y ^ z)))
179 #define F2(x, y, z) F1(z, x, y)
180 #define F3(x, y, z) (x ^ y ^ z)
181 #define F4(x, y, z) (y ^ (x | ~z))
182 
183 /* This is the central step in the MD5 algorithm. */
184 #define MD5STEP(f, w, x, y, z, data, s) \
185 	( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
186 
187 /*
188  * The core of the MD5 algorithm, this alters an existing MD5 hash to
189  * reflect the addition of 16 longwords of new data.  MD5Update blocks
190  * the data and converts bytes into longwords for this routine.
191  */
192 void
193 MD5Transform(buf, in)
194      uint32 buf[4];
195      uint32 const in[16];
196 {
197 	register uint32 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 #endif
278