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 #include "fcint.h"
18
19 struct MD5Context {
20 FcChar32 buf[4];
21 FcChar32 bits[2];
22 unsigned char in[64];
23 };
24
25 static void MD5Init(struct MD5Context *ctx);
26 static void MD5Update(struct MD5Context *ctx, const unsigned char *buf, unsigned len);
27 static void MD5Final(unsigned char digest[16], struct MD5Context *ctx);
28 static void MD5Transform(FcChar32 buf[4], FcChar32 in[16]);
29
30 #ifndef WORDS_BIGENDIAN
31 #define byteReverse(buf, len) /* Nothing */
32 #else
33 /*
34 * Note: this code is harmless on little-endian machines.
35 */
36 void byteReverse(unsigned char *buf, unsigned longs)
37 {
38 FcChar32 t;
39 do {
40 t = (FcChar32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
41 ((unsigned) buf[1] << 8 | buf[0]);
42 *(FcChar32 *) buf = t;
43 buf += 4;
44 } while (--longs);
45 }
46 #endif
47
48 /*
49 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
50 * initialization constants.
51 */
52 static void MD5Init(struct MD5Context *ctx)
53 {
54 ctx->buf[0] = 0x67452301;
55 ctx->buf[1] = 0xefcdab89;
56 ctx->buf[2] = 0x98badcfe;
57 ctx->buf[3] = 0x10325476;
58
59 ctx->bits[0] = 0;
60 ctx->bits[1] = 0;
61 }
62
63 /*
64 * Update context to reflect the concatenation of another buffer full
65 * of bytes.
66 */
67 static void MD5Update(struct MD5Context *ctx, const unsigned char *buf, unsigned len)
68 {
69 FcChar32 t;
70
71 /* Update bitcount */
72
73 t = ctx->bits[0];
74 if ((ctx->bits[0] = t + ((FcChar32) len << 3)) < t)
75 ctx->bits[1]++; /* Carry from low to high */
76 ctx->bits[1] += len >> 29;
77
78 t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
79
80 /* Handle any leading odd-sized chunks */
81
82 if (t) {
83 unsigned char *p = (unsigned char *) ctx->in + t;
84
85 t = 64 - t;
86 if (len < t) {
87 memcpy(p, buf, len);
88 return;
89 }
90 memcpy(p, buf, t);
91 byteReverse(ctx->in, 16);
92 MD5Transform(ctx->buf, (FcChar32 *) ctx->in);
93 buf += t;
94 len -= t;
95 }
96 /* Process data in 64-byte chunks */
97
98 while (len >= 64) {
99 memcpy(ctx->in, buf, 64);
100 byteReverse(ctx->in, 16);
101 MD5Transform(ctx->buf, (FcChar32 *) ctx->in);
102 buf += 64;
103 len -= 64;
104 }
105
106 /* Handle any remaining bytes of data. */
107
108 memcpy(ctx->in, buf, len);
109 }
110
111 /*
112 * Final wrapup - pad to 64-byte boundary with the bit pattern
113 * 1 0* (64-bit count of bits processed, MSB-first)
114 */
115 static void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
116 {
117 unsigned count;
118 unsigned char *p;
119
120 /* Compute number of bytes mod 64 */
121 count = (ctx->bits[0] >> 3) & 0x3F;
122
123 /* Set the first char of padding to 0x80. This is safe since there is
124 always at least one byte free */
125 p = ctx->in + count;
126 *p++ = 0x80;
127
128 /* Bytes of padding needed to make 64 bytes */
129 count = 64 - 1 - count;
130
131 /* Pad out to 56 mod 64 */
132 if (count < 8) {
133 /* Two lots of padding: Pad the first block to 64 bytes */
134 memset(p, 0, count);
135 byteReverse(ctx->in, 16);
136 MD5Transform(ctx->buf, (FcChar32 *) ctx->in);
137
138 /* Now fill the next block with 56 bytes */
139 memset(ctx->in, 0, 56);
140 } else {
141 /* Pad block to 56 bytes */
142 memset(p, 0, count - 8);
143 }
144 byteReverse(ctx->in, 14);
145
146 /* Append length in bits and transform */
147 ((FcChar32 *) ctx->in)[14] = ctx->bits[0];
148 ((FcChar32 *) ctx->in)[15] = ctx->bits[1];
149
150 MD5Transform(ctx->buf, (FcChar32 *) ctx->in);
151 byteReverse((unsigned char *) ctx->buf, 4);
152 memcpy(digest, ctx->buf, 16);
153 memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */
154 }
155
156
157 /* The four core functions - F1 is optimized somewhat */
158
159 /* #define F1(x, y, z) (x & y | ~x & z) */
160 #define F1(x, y, z) (z ^ (x & (y ^ z)))
161 #define F2(x, y, z) F1(z, x, y)
162 #define F3(x, y, z) (x ^ y ^ z)
163 #define F4(x, y, z) (y ^ (x | ~z))
164
165 /* This is the central step in the MD5 algorithm. */
166 #define MD5STEP(f, w, x, y, z, data, s) \
167 ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
168
169 /*
170 * The core of the MD5 algorithm, this alters an existing MD5 hash to
171 * reflect the addition of 16 longwords of new data. MD5Update blocks
172 * the data and converts bytes into longwords for this routine.
173 */
174 static void MD5Transform(FcChar32 buf[4], FcChar32 in[16])
175 {
176 register FcChar32 a, b, c, d;
177
178 a = buf[0];
179 b = buf[1];
180 c = buf[2];
181 d = buf[3];
182
183 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
184 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
185 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
186 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
187 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
188 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
189 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
190 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
191 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
192 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
193 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
194 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
195 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
196 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
197 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
198 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
199
200 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
201 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
202 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
203 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
204 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
205 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
206 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
207 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
208 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
209 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
210 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
211 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
212 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
213 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
214 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
215 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
216
217 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
218 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
219 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
220 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
221 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
222 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
223 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
224 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
225 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
226 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
227 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
228 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
229 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
230 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
231 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
232 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
233
234 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
235 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
236 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
237 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
238 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
239 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
240 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
241 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
242 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
243 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
244 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
245 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
246 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
247 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
248 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
249 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
250
251 buf[0] += a;
252 buf[1] += b;
253 buf[2] += c;
254 buf[3] += d;
255 }