xref: /openssh-portable/openbsd-compat/md5.c (revision 81bfbd0b)
1 /*	$OpenBSD: md5.c,v 1.9 2014/01/08 06:14:57 tedu Exp $	*/
2 
3 /*
4  * This code implements the MD5 message-digest algorithm.
5  * The algorithm is due to Ron Rivest.	This code was
6  * written by Colin Plumb in 1993, no copyright is claimed.
7  * This code is in the public domain; do with it what you wish.
8  *
9  * Equivalent code is available from RSA Data Security, Inc.
10  * This code has been tested against that, and is equivalent,
11  * except that you don't need to include two pages of legalese
12  * with every copy.
13  *
14  * To compute the message digest of a chunk of bytes, declare an
15  * MD5Context structure, pass it to MD5Init, call MD5Update as
16  * needed on buffers full of bytes, and then call MD5Final, which
17  * will fill a supplied 16-byte array with the digest.
18  */
19 
20 #include "includes.h"
21 
22 #ifndef WITH_OPENSSL
23 
24 #include <sys/types.h>
25 #include <string.h>
26 #include "md5.h"
27 
28 #define PUT_64BIT_LE(cp, value) do {					\
29 	(cp)[7] = (value) >> 56;					\
30 	(cp)[6] = (value) >> 48;					\
31 	(cp)[5] = (value) >> 40;					\
32 	(cp)[4] = (value) >> 32;					\
33 	(cp)[3] = (value) >> 24;					\
34 	(cp)[2] = (value) >> 16;					\
35 	(cp)[1] = (value) >> 8;						\
36 	(cp)[0] = (value); } while (0)
37 
38 #define PUT_32BIT_LE(cp, value) do {					\
39 	(cp)[3] = (value) >> 24;					\
40 	(cp)[2] = (value) >> 16;					\
41 	(cp)[1] = (value) >> 8;						\
42 	(cp)[0] = (value); } while (0)
43 
44 static u_int8_t PADDING[MD5_BLOCK_LENGTH] = {
45 	0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
46 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
47 	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
48 };
49 
50 /*
51  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
52  * initialization constants.
53  */
54 void
MD5Init(MD5_CTX * ctx)55 MD5Init(MD5_CTX *ctx)
56 {
57 	ctx->count = 0;
58 	ctx->state[0] = 0x67452301;
59 	ctx->state[1] = 0xefcdab89;
60 	ctx->state[2] = 0x98badcfe;
61 	ctx->state[3] = 0x10325476;
62 }
63 
64 /*
65  * Update context to reflect the concatenation of another buffer full
66  * of bytes.
67  */
68 void
MD5Update(MD5_CTX * ctx,const unsigned char * input,size_t len)69 MD5Update(MD5_CTX *ctx, const unsigned char *input, size_t len)
70 {
71 	size_t have, need;
72 
73 	/* Check how many bytes we already have and how many more we need. */
74 	have = (size_t)((ctx->count >> 3) & (MD5_BLOCK_LENGTH - 1));
75 	need = MD5_BLOCK_LENGTH - have;
76 
77 	/* Update bitcount */
78 	ctx->count += (u_int64_t)len << 3;
79 
80 	if (len >= need) {
81 		if (have != 0) {
82 			memcpy(ctx->buffer + have, input, need);
83 			MD5Transform(ctx->state, ctx->buffer);
84 			input += need;
85 			len -= need;
86 			have = 0;
87 		}
88 
89 		/* Process data in MD5_BLOCK_LENGTH-byte chunks. */
90 		while (len >= MD5_BLOCK_LENGTH) {
91 			MD5Transform(ctx->state, input);
92 			input += MD5_BLOCK_LENGTH;
93 			len -= MD5_BLOCK_LENGTH;
94 		}
95 	}
96 
97 	/* Handle any remaining bytes of data. */
98 	if (len != 0)
99 		memcpy(ctx->buffer + have, input, len);
100 }
101 
102 /*
103  * Pad pad to 64-byte boundary with the bit pattern
104  * 1 0* (64-bit count of bits processed, MSB-first)
105  */
106 void
MD5Pad(MD5_CTX * ctx)107 MD5Pad(MD5_CTX *ctx)
108 {
109 	u_int8_t count[8];
110 	size_t padlen;
111 
112 	/* Convert count to 8 bytes in little endian order. */
113 	PUT_64BIT_LE(count, ctx->count);
114 
115 	/* Pad out to 56 mod 64. */
116 	padlen = MD5_BLOCK_LENGTH -
117 	    ((ctx->count >> 3) & (MD5_BLOCK_LENGTH - 1));
118 	if (padlen < 1 + 8)
119 		padlen += MD5_BLOCK_LENGTH;
120 	MD5Update(ctx, PADDING, padlen - 8);		/* padlen - 8 <= 64 */
121 	MD5Update(ctx, count, 8);
122 }
123 
124 /*
125  * Final wrapup--call MD5Pad, fill in digest and zero out ctx.
126  */
127 void
MD5Final(unsigned char digest[MD5_DIGEST_LENGTH],MD5_CTX * ctx)128 MD5Final(unsigned char digest[MD5_DIGEST_LENGTH], MD5_CTX *ctx)
129 {
130 	int i;
131 
132 	MD5Pad(ctx);
133 	for (i = 0; i < 4; i++)
134 		PUT_32BIT_LE(digest + i * 4, ctx->state[i]);
135 	memset(ctx, 0, sizeof(*ctx));
136 }
137 
138 
139 /* The four core functions - F1 is optimized somewhat */
140 
141 /* #define F1(x, y, z) (x & y | ~x & z) */
142 #define F1(x, y, z) (z ^ (x & (y ^ z)))
143 #define F2(x, y, z) F1(z, x, y)
144 #define F3(x, y, z) (x ^ y ^ z)
145 #define F4(x, y, z) (y ^ (x | ~z))
146 
147 /* This is the central step in the MD5 algorithm. */
148 #define MD5STEP(f, w, x, y, z, data, s) \
149 	( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
150 
151 /*
152  * The core of the MD5 algorithm, this alters an existing MD5 hash to
153  * reflect the addition of 16 longwords of new data.  MD5Update blocks
154  * the data and converts bytes into longwords for this routine.
155  */
156 void
MD5Transform(u_int32_t state[4],const u_int8_t block[MD5_BLOCK_LENGTH])157 MD5Transform(u_int32_t state[4], const u_int8_t block[MD5_BLOCK_LENGTH])
158 {
159 	u_int32_t a, b, c, d, in[MD5_BLOCK_LENGTH / 4];
160 
161 #if BYTE_ORDER == LITTLE_ENDIAN
162 	memcpy(in, block, sizeof(in));
163 #else
164 	for (a = 0; a < MD5_BLOCK_LENGTH / 4; a++) {
165 		in[a] = (u_int32_t)(
166 		    (u_int32_t)(block[a * 4 + 0]) |
167 		    (u_int32_t)(block[a * 4 + 1]) <<  8 |
168 		    (u_int32_t)(block[a * 4 + 2]) << 16 |
169 		    (u_int32_t)(block[a * 4 + 3]) << 24);
170 	}
171 #endif
172 
173 	a = state[0];
174 	b = state[1];
175 	c = state[2];
176 	d = state[3];
177 
178 	MD5STEP(F1, a, b, c, d, in[ 0] + 0xd76aa478,  7);
179 	MD5STEP(F1, d, a, b, c, in[ 1] + 0xe8c7b756, 12);
180 	MD5STEP(F1, c, d, a, b, in[ 2] + 0x242070db, 17);
181 	MD5STEP(F1, b, c, d, a, in[ 3] + 0xc1bdceee, 22);
182 	MD5STEP(F1, a, b, c, d, in[ 4] + 0xf57c0faf,  7);
183 	MD5STEP(F1, d, a, b, c, in[ 5] + 0x4787c62a, 12);
184 	MD5STEP(F1, c, d, a, b, in[ 6] + 0xa8304613, 17);
185 	MD5STEP(F1, b, c, d, a, in[ 7] + 0xfd469501, 22);
186 	MD5STEP(F1, a, b, c, d, in[ 8] + 0x698098d8,  7);
187 	MD5STEP(F1, d, a, b, c, in[ 9] + 0x8b44f7af, 12);
188 	MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
189 	MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
190 	MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122,  7);
191 	MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
192 	MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
193 	MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
194 
195 	MD5STEP(F2, a, b, c, d, in[ 1] + 0xf61e2562,  5);
196 	MD5STEP(F2, d, a, b, c, in[ 6] + 0xc040b340,  9);
197 	MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
198 	MD5STEP(F2, b, c, d, a, in[ 0] + 0xe9b6c7aa, 20);
199 	MD5STEP(F2, a, b, c, d, in[ 5] + 0xd62f105d,  5);
200 	MD5STEP(F2, d, a, b, c, in[10] + 0x02441453,  9);
201 	MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
202 	MD5STEP(F2, b, c, d, a, in[ 4] + 0xe7d3fbc8, 20);
203 	MD5STEP(F2, a, b, c, d, in[ 9] + 0x21e1cde6,  5);
204 	MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6,  9);
205 	MD5STEP(F2, c, d, a, b, in[ 3] + 0xf4d50d87, 14);
206 	MD5STEP(F2, b, c, d, a, in[ 8] + 0x455a14ed, 20);
207 	MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905,  5);
208 	MD5STEP(F2, d, a, b, c, in[ 2] + 0xfcefa3f8,  9);
209 	MD5STEP(F2, c, d, a, b, in[ 7] + 0x676f02d9, 14);
210 	MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
211 
212 	MD5STEP(F3, a, b, c, d, in[ 5] + 0xfffa3942,  4);
213 	MD5STEP(F3, d, a, b, c, in[ 8] + 0x8771f681, 11);
214 	MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
215 	MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
216 	MD5STEP(F3, a, b, c, d, in[ 1] + 0xa4beea44,  4);
217 	MD5STEP(F3, d, a, b, c, in[ 4] + 0x4bdecfa9, 11);
218 	MD5STEP(F3, c, d, a, b, in[ 7] + 0xf6bb4b60, 16);
219 	MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
220 	MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6,  4);
221 	MD5STEP(F3, d, a, b, c, in[ 0] + 0xeaa127fa, 11);
222 	MD5STEP(F3, c, d, a, b, in[ 3] + 0xd4ef3085, 16);
223 	MD5STEP(F3, b, c, d, a, in[ 6] + 0x04881d05, 23);
224 	MD5STEP(F3, a, b, c, d, in[ 9] + 0xd9d4d039,  4);
225 	MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
226 	MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
227 	MD5STEP(F3, b, c, d, a, in[2 ] + 0xc4ac5665, 23);
228 
229 	MD5STEP(F4, a, b, c, d, in[ 0] + 0xf4292244,  6);
230 	MD5STEP(F4, d, a, b, c, in[7 ] + 0x432aff97, 10);
231 	MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
232 	MD5STEP(F4, b, c, d, a, in[5 ] + 0xfc93a039, 21);
233 	MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3,  6);
234 	MD5STEP(F4, d, a, b, c, in[3 ] + 0x8f0ccc92, 10);
235 	MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
236 	MD5STEP(F4, b, c, d, a, in[1 ] + 0x85845dd1, 21);
237 	MD5STEP(F4, a, b, c, d, in[8 ] + 0x6fa87e4f,  6);
238 	MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
239 	MD5STEP(F4, c, d, a, b, in[6 ] + 0xa3014314, 15);
240 	MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
241 	MD5STEP(F4, a, b, c, d, in[4 ] + 0xf7537e82,  6);
242 	MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
243 	MD5STEP(F4, c, d, a, b, in[2 ] + 0x2ad7d2bb, 15);
244 	MD5STEP(F4, b, c, d, a, in[9 ] + 0xeb86d391, 21);
245 
246 	state[0] += a;
247 	state[1] += b;
248 	state[2] += c;
249 	state[3] += d;
250 }
251 #endif /* !WITH_OPENSSL */
252