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 <sys/param.h>
19 #include <inttypes.h>
20
21 #include <string.h>
22
23 #include "md5.h"
24
25 #define PUT_64BIT_LE(cp, value) do { \
26 (cp)[7] = (uint8_t)((value) >> 56); \
27 (cp)[6] = (uint8_t)((value) >> 48); \
28 (cp)[5] = (uint8_t)((value) >> 40); \
29 (cp)[4] = (uint8_t)((value) >> 32); \
30 (cp)[3] = (uint8_t)((value) >> 24); \
31 (cp)[2] = (uint8_t)((value) >> 16); \
32 (cp)[1] = (uint8_t)((value) >> 8); \
33 (cp)[0] = (uint8_t)(value); } while (0)
34
35 #define PUT_32BIT_LE(cp, value) do { \
36 (cp)[3] = (uint8_t)((value) >> 24); \
37 (cp)[2] = (uint8_t)((value) >> 16); \
38 (cp)[1] = (uint8_t)((value) >> 8); \
39 (cp)[0] = (uint8_t)(value); } while (0)
40
41 static uint8_t PADDING[MD5_BLOCK_LENGTH] = {
42 0x80, 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, 0, 0, 0, 0,
44 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
45 };
46
47 /*
48 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
49 * initialization constants.
50 */
51 void
MD5Init(MD5_CTX * ctx)52 MD5Init(MD5_CTX *ctx)
53 {
54 ctx->count = 0;
55 ctx->state[0] = 0x67452301;
56 ctx->state[1] = 0xefcdab89;
57 ctx->state[2] = 0x98badcfe;
58 ctx->state[3] = 0x10325476;
59 }
60
61
62 /* The four core functions - F1 is optimized somewhat */
63
64 /* #define F1(x, y, z) (x & y | ~x & z) */
65 #define F1(x, y, z) (z ^ (x & (y ^ z)))
66 #define F2(x, y, z) F1(z, x, y)
67 #define F3(x, y, z) (x ^ y ^ z)
68 #define F4(x, y, z) (y ^ (x | ~z))
69
70 /* This is the central step in the MD5 algorithm. */
71 #define MD5STEP(f, w, x, y, z, data, s) \
72 ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
73
74 /*
75 * The core of the MD5 algorithm, this alters an existing MD5 hash to
76 * reflect the addition of 16 longwords of new data. MD5Update blocks
77 * the data and converts bytes into longwords for this routine.
78 */
79 static void
MD5Transform(uint32_t state[4],const uint8_t block[MD5_BLOCK_LENGTH])80 MD5Transform(uint32_t state[4], const uint8_t block[MD5_BLOCK_LENGTH])
81 {
82 uint32_t a, b, c, d, in[MD5_BLOCK_LENGTH / 4];
83
84 #if BYTE_ORDER == LITTLE_ENDIAN
85 memcpy(in, block, sizeof(in));
86 #else
87 for (a = 0; a < MD5_BLOCK_LENGTH / 4; a++) {
88 in[a] = (uint32_t)(
89 (uint32_t)(block[a * 4 + 0]) |
90 (uint32_t)(block[a * 4 + 1]) << 8 |
91 (uint32_t)(block[a * 4 + 2]) << 16 |
92 (uint32_t)(block[a * 4 + 3]) << 24);
93 }
94 #endif
95
96 a = state[0];
97 b = state[1];
98 c = state[2];
99 d = state[3];
100
101 MD5STEP(F1, a, b, c, d, in[ 0] + 0xd76aa478, 7);
102 MD5STEP(F1, d, a, b, c, in[ 1] + 0xe8c7b756, 12);
103 MD5STEP(F1, c, d, a, b, in[ 2] + 0x242070db, 17);
104 MD5STEP(F1, b, c, d, a, in[ 3] + 0xc1bdceee, 22);
105 MD5STEP(F1, a, b, c, d, in[ 4] + 0xf57c0faf, 7);
106 MD5STEP(F1, d, a, b, c, in[ 5] + 0x4787c62a, 12);
107 MD5STEP(F1, c, d, a, b, in[ 6] + 0xa8304613, 17);
108 MD5STEP(F1, b, c, d, a, in[ 7] + 0xfd469501, 22);
109 MD5STEP(F1, a, b, c, d, in[ 8] + 0x698098d8, 7);
110 MD5STEP(F1, d, a, b, c, in[ 9] + 0x8b44f7af, 12);
111 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
112 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
113 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
114 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
115 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
116 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
117
118 MD5STEP(F2, a, b, c, d, in[ 1] + 0xf61e2562, 5);
119 MD5STEP(F2, d, a, b, c, in[ 6] + 0xc040b340, 9);
120 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
121 MD5STEP(F2, b, c, d, a, in[ 0] + 0xe9b6c7aa, 20);
122 MD5STEP(F2, a, b, c, d, in[ 5] + 0xd62f105d, 5);
123 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
124 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
125 MD5STEP(F2, b, c, d, a, in[ 4] + 0xe7d3fbc8, 20);
126 MD5STEP(F2, a, b, c, d, in[ 9] + 0x21e1cde6, 5);
127 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
128 MD5STEP(F2, c, d, a, b, in[ 3] + 0xf4d50d87, 14);
129 MD5STEP(F2, b, c, d, a, in[ 8] + 0x455a14ed, 20);
130 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
131 MD5STEP(F2, d, a, b, c, in[ 2] + 0xfcefa3f8, 9);
132 MD5STEP(F2, c, d, a, b, in[ 7] + 0x676f02d9, 14);
133 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
134
135 MD5STEP(F3, a, b, c, d, in[ 5] + 0xfffa3942, 4);
136 MD5STEP(F3, d, a, b, c, in[ 8] + 0x8771f681, 11);
137 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
138 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
139 MD5STEP(F3, a, b, c, d, in[ 1] + 0xa4beea44, 4);
140 MD5STEP(F3, d, a, b, c, in[ 4] + 0x4bdecfa9, 11);
141 MD5STEP(F3, c, d, a, b, in[ 7] + 0xf6bb4b60, 16);
142 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
143 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
144 MD5STEP(F3, d, a, b, c, in[ 0] + 0xeaa127fa, 11);
145 MD5STEP(F3, c, d, a, b, in[ 3] + 0xd4ef3085, 16);
146 MD5STEP(F3, b, c, d, a, in[ 6] + 0x04881d05, 23);
147 MD5STEP(F3, a, b, c, d, in[ 9] + 0xd9d4d039, 4);
148 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
149 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
150 MD5STEP(F3, b, c, d, a, in[2 ] + 0xc4ac5665, 23);
151
152 MD5STEP(F4, a, b, c, d, in[ 0] + 0xf4292244, 6);
153 MD5STEP(F4, d, a, b, c, in[7 ] + 0x432aff97, 10);
154 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
155 MD5STEP(F4, b, c, d, a, in[5 ] + 0xfc93a039, 21);
156 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
157 MD5STEP(F4, d, a, b, c, in[3 ] + 0x8f0ccc92, 10);
158 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
159 MD5STEP(F4, b, c, d, a, in[1 ] + 0x85845dd1, 21);
160 MD5STEP(F4, a, b, c, d, in[8 ] + 0x6fa87e4f, 6);
161 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
162 MD5STEP(F4, c, d, a, b, in[6 ] + 0xa3014314, 15);
163 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
164 MD5STEP(F4, a, b, c, d, in[4 ] + 0xf7537e82, 6);
165 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
166 MD5STEP(F4, c, d, a, b, in[2 ] + 0x2ad7d2bb, 15);
167 MD5STEP(F4, b, c, d, a, in[9 ] + 0xeb86d391, 21);
168
169 state[0] += a;
170 state[1] += b;
171 state[2] += c;
172 state[3] += d;
173 }
174
175 /*
176 * Update context to reflect the concatenation of another buffer full
177 * of bytes.
178 */
179 void
MD5Update(MD5_CTX * ctx,const unsigned char * input,size_t len)180 MD5Update(MD5_CTX *ctx, const unsigned char *input, size_t len)
181 {
182 size_t have, need;
183
184 /* Check how many bytes we already have and how many more we need. */
185 have = (size_t)((ctx->count >> 3) & (MD5_BLOCK_LENGTH - 1));
186 need = MD5_BLOCK_LENGTH - have;
187
188 /* Update bitcount */
189 ctx->count += (uint64_t)len << 3;
190
191 if (len >= need) {
192 if (have != 0) {
193 memcpy(ctx->buffer + have, input, need);
194 MD5Transform(ctx->state, ctx->buffer);
195 input += need;
196 len -= need;
197 have = 0;
198 }
199
200 /* Process data in MD5_BLOCK_LENGTH-byte chunks. */
201 while (len >= MD5_BLOCK_LENGTH) {
202 MD5Transform(ctx->state, input);
203 input += MD5_BLOCK_LENGTH;
204 len -= MD5_BLOCK_LENGTH;
205 }
206 }
207
208 /* Handle any remaining bytes of data. */
209 if (len != 0)
210 memcpy(ctx->buffer + have, input, len);
211 }
212
213 /*
214 * Final wrapup - pad to 64-byte boundary with the bit pattern
215 * 1 0* (64-bit count of bits processed, MSB-first)
216 */
217 void
MD5Final(unsigned char digest[MD5_DIGEST_LENGTH],MD5_CTX * ctx)218 MD5Final(unsigned char digest[MD5_DIGEST_LENGTH], MD5_CTX *ctx)
219 {
220 uint8_t count[8];
221 size_t padlen;
222 int i;
223
224 /* Convert count to 8 bytes in little endian order. */
225 PUT_64BIT_LE(count, ctx->count);
226
227 /* Pad out to 56 mod 64. */
228 padlen = MD5_BLOCK_LENGTH -
229 ((ctx->count >> 3) & (MD5_BLOCK_LENGTH - 1));
230 if (padlen < 1 + 8)
231 padlen += MD5_BLOCK_LENGTH;
232 MD5Update(ctx, PADDING, padlen - 8); /* padlen - 8 <= 64 */
233 MD5Update(ctx, count, 8);
234
235 if (digest != NULL) {
236 for (i = 0; i < 4; i++)
237 PUT_32BIT_LE(digest + i * 4, ctx->state[i]);
238 }
239 memset(ctx, 0, sizeof(*ctx)); /* in case it's sensitive */
240 }
241
242
243