1 /* $OpenBSD: md5.c,v 1.12 2020/10/13 04:42:28 guenther 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 <sys/types.h>
21 #include <string.h>
22 #include <md5.h>
23
24 #define PUT_64BIT_LE(cp, value) do { \
25 (cp)[7] = (value) >> 56; \
26 (cp)[6] = (value) >> 48; \
27 (cp)[5] = (value) >> 40; \
28 (cp)[4] = (value) >> 32; \
29 (cp)[3] = (value) >> 24; \
30 (cp)[2] = (value) >> 16; \
31 (cp)[1] = (value) >> 8; \
32 (cp)[0] = (value); } while (0)
33
34 #define PUT_32BIT_LE(cp, value) do { \
35 (cp)[3] = (value) >> 24; \
36 (cp)[2] = (value) >> 16; \
37 (cp)[1] = (value) >> 8; \
38 (cp)[0] = (value); } while (0)
39
40 static const u_int8_t PADDING[MD5_BLOCK_LENGTH] = {
41 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
42 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
43 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
44 };
45
46 /*
47 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
48 * initialization constants.
49 */
50 void
MD5Init(MD5_CTX * ctx)51 MD5Init(MD5_CTX *ctx)
52 {
53 ctx->count = 0;
54 ctx->state[0] = 0x67452301;
55 ctx->state[1] = 0xefcdab89;
56 ctx->state[2] = 0x98badcfe;
57 ctx->state[3] = 0x10325476;
58 }
59 DEF_WEAK(MD5Init);
60
61 /*
62 * Update context to reflect the concatenation of another buffer full
63 * of bytes.
64 */
65 void
MD5Update(MD5_CTX * ctx,const unsigned char * input,size_t len)66 MD5Update(MD5_CTX *ctx, const unsigned char *input, size_t len)
67 {
68 size_t have, need;
69
70 /* Check how many bytes we already have and how many more we need. */
71 have = (size_t)((ctx->count >> 3) & (MD5_BLOCK_LENGTH - 1));
72 need = MD5_BLOCK_LENGTH - have;
73
74 /* Update bitcount */
75 ctx->count += (u_int64_t)len << 3;
76
77 if (len >= need) {
78 if (have != 0) {
79 memcpy(ctx->buffer + have, input, need);
80 MD5Transform(ctx->state, ctx->buffer);
81 input += need;
82 len -= need;
83 have = 0;
84 }
85
86 /* Process data in MD5_BLOCK_LENGTH-byte chunks. */
87 while (len >= MD5_BLOCK_LENGTH) {
88 MD5Transform(ctx->state, input);
89 input += MD5_BLOCK_LENGTH;
90 len -= MD5_BLOCK_LENGTH;
91 }
92 }
93
94 /* Handle any remaining bytes of data. */
95 if (len != 0)
96 memcpy(ctx->buffer + have, input, len);
97 }
98 DEF_WEAK(MD5Update);
99
100 /*
101 * Pad pad to 64-byte boundary with the bit pattern
102 * 1 0* (64-bit count of bits processed, MSB-first)
103 */
104 void
MD5Pad(MD5_CTX * ctx)105 MD5Pad(MD5_CTX *ctx)
106 {
107 u_int8_t count[8];
108 size_t padlen;
109
110 /* Convert count to 8 bytes in little endian order. */
111 PUT_64BIT_LE(count, ctx->count);
112
113 /* Pad out to 56 mod 64. */
114 padlen = MD5_BLOCK_LENGTH -
115 ((ctx->count >> 3) & (MD5_BLOCK_LENGTH - 1));
116 if (padlen < 1 + 8)
117 padlen += MD5_BLOCK_LENGTH;
118 MD5Update(ctx, PADDING, padlen - 8); /* padlen - 8 <= 64 */
119 MD5Update(ctx, count, 8);
120 }
121 DEF_WEAK(MD5Pad);
122
123 /*
124 * Final wrapup--call MD5Pad, fill in digest and zero out ctx.
125 */
126 void
MD5Final(unsigned char digest[MD5_DIGEST_LENGTH],MD5_CTX * ctx)127 MD5Final(unsigned char digest[MD5_DIGEST_LENGTH], MD5_CTX *ctx)
128 {
129 int i;
130
131 MD5Pad(ctx);
132 for (i = 0; i < 4; i++)
133 PUT_32BIT_LE(digest + i * 4, ctx->state[i]);
134 explicit_bzero(ctx, sizeof(*ctx));
135 }
136 DEF_WEAK(MD5Final);
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 DEF_WEAK(MD5Transform);
252