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 * Changed so as no longer to depend on Colin Plumb's `usual.h' header
18 * definitions
19 * - Ian Jackson <ian@chiark.greenend.org.uk>.
20 * Still in the public domain.
21 */
22
23 #include <string.h> /* for memcpy() */
24
25 #include "md5_utils.h"
26
27 void
byteSwap(UWORD32 * buf,unsigned words)28 byteSwap(UWORD32 *buf, unsigned words) {
29 md5byte *p;
30
31 /* Only swap bytes for big endian machines */
32 int i = 1;
33
34 if (*(char *)&i == 1)
35 return;
36
37 p = (md5byte *)buf;
38
39 do {
40 *buf++ = (UWORD32)((unsigned)p[3] << 8 | p[2]) << 16 |
41 ((unsigned)p[1] << 8 | p[0]);
42 p += 4;
43 } while (--words);
44 }
45
46 /*
47 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
48 * initialization constants.
49 */
50 void
MD5Init(struct MD5Context * ctx)51 MD5Init(struct MD5Context *ctx) {
52 ctx->buf[0] = 0x67452301;
53 ctx->buf[1] = 0xefcdab89;
54 ctx->buf[2] = 0x98badcfe;
55 ctx->buf[3] = 0x10325476;
56
57 ctx->bytes[0] = 0;
58 ctx->bytes[1] = 0;
59 }
60
61 /*
62 * Update context to reflect the concatenation of another buffer full
63 * of bytes.
64 */
65 void
MD5Update(struct MD5Context * ctx,md5byte const * buf,unsigned len)66 MD5Update(struct MD5Context *ctx, md5byte const *buf, unsigned len) {
67 UWORD32 t;
68
69 /* Update byte count */
70
71 t = ctx->bytes[0];
72
73 if ((ctx->bytes[0] = t + len) < t)
74 ctx->bytes[1]++; /* Carry from low to high */
75
76 t = 64 - (t & 0x3f); /* Space available in ctx->in (at least 1) */
77
78 if (t > len) {
79 memcpy((md5byte *)ctx->in + 64 - t, buf, len);
80 return;
81 }
82
83 /* First chunk is an odd size */
84 memcpy((md5byte *)ctx->in + 64 - t, buf, t);
85 byteSwap(ctx->in, 16);
86 MD5Transform(ctx->buf, ctx->in);
87 buf += t;
88 len -= t;
89
90 /* Process data in 64-byte chunks */
91 while (len >= 64) {
92 memcpy(ctx->in, buf, 64);
93 byteSwap(ctx->in, 16);
94 MD5Transform(ctx->buf, ctx->in);
95 buf += 64;
96 len -= 64;
97 }
98
99 /* Handle any remaining bytes of data. */
100 memcpy(ctx->in, buf, len);
101 }
102
103 /*
104 * Final wrapup - pad to 64-byte boundary with the bit pattern
105 * 1 0* (64-bit count of bits processed, MSB-first)
106 */
107 void
MD5Final(md5byte digest[16],struct MD5Context * ctx)108 MD5Final(md5byte digest[16], struct MD5Context *ctx) {
109 int count = ctx->bytes[0] & 0x3f; /* Number of bytes in ctx->in */
110 md5byte *p = (md5byte *)ctx->in + count;
111
112 /* Set the first char of padding to 0x80. There is always room. */
113 *p++ = 0x80;
114
115 /* Bytes of padding needed to make 56 bytes (-8..55) */
116 count = 56 - 1 - count;
117
118 if (count < 0) { /* Padding forces an extra block */
119 memset(p, 0, count + 8);
120 byteSwap(ctx->in, 16);
121 MD5Transform(ctx->buf, ctx->in);
122 p = (md5byte *)ctx->in;
123 count = 56;
124 }
125
126 memset(p, 0, count);
127 byteSwap(ctx->in, 14);
128
129 /* Append length in bits and transform */
130 ctx->in[14] = ctx->bytes[0] << 3;
131 ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
132 MD5Transform(ctx->buf, ctx->in);
133
134 byteSwap(ctx->buf, 4);
135 memcpy(digest, ctx->buf, 16);
136 memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */
137 }
138
139 #ifndef ASM_MD5
140
141 /* The four core functions - F1 is optimized somewhat */
142
143 /* #define F1(x, y, z) (x & y | ~x & z) */
144 #define F1(x, y, z) (z ^ (x & (y ^ z)))
145 #define F2(x, y, z) F1(z, x, y)
146 #define F3(x, y, z) (x ^ y ^ z)
147 #define F4(x, y, z) (y ^ (x | ~z))
148
149 /* This is the central step in the MD5 algorithm. */
150 #define MD5STEP(f,w,x,y,z,in,s) \
151 (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
152
153 /*
154 * The core of the MD5 algorithm, this alters an existing MD5 hash to
155 * reflect the addition of 16 longwords of new data. MD5Update blocks
156 * the data and converts bytes into longwords for this routine.
157 */
158 void
MD5Transform(UWORD32 buf[4],UWORD32 const in[16])159 MD5Transform(UWORD32 buf[4], UWORD32 const in[16]) {
160 register UWORD32 a, b, c, d;
161
162 a = buf[0];
163 b = buf[1];
164 c = buf[2];
165 d = buf[3];
166
167 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
168 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
169 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
170 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
171 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
172 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
173 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
174 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
175 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
176 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
177 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
178 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
179 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
180 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
181 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
182 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
183
184 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
185 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
186 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
187 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
188 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
189 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
190 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
191 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
192 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
193 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
194 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
195 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
196 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
197 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
198 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
199 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
200
201 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
202 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
203 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
204 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
205 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
206 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
207 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
208 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
209 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
210 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
211 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
212 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
213 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
214 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
215 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
216 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
217
218 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
219 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
220 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
221 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
222 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
223 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
224 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
225 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
226 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
227 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
228 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
229 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
230 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
231 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
232 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
233 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
234
235 buf[0] += a;
236 buf[1] += b;
237 buf[2] += c;
238 buf[3] += d;
239 }
240
241 #endif
242