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 <sys/types.h> /* for stupid systems */
24
25 #include <string.h> /* for memcpy() */
26
27 #include "md5_utils.h"
28
29 void
byteSwap(UWORD32 * buf,unsigned words)30 byteSwap(UWORD32 *buf, unsigned words)
31 {
32 md5byte *p;
33
34 /* Only swap bytes for big endian machines */
35 int i = 1;
36
37 if (*(char *)&i == 1)
38 return;
39
40 p = (md5byte *)buf;
41
42 do
43 {
44 *buf++ = (UWORD32)((unsigned)p[3] << 8 | p[2]) << 16 |
45 ((unsigned)p[1] << 8 | p[0]);
46 p += 4;
47 }
48 while (--words);
49 }
50
51 /*
52 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
53 * initialization constants.
54 */
55 void
MD5Init(struct MD5Context * ctx)56 MD5Init(struct MD5Context *ctx)
57 {
58 ctx->buf[0] = 0x67452301;
59 ctx->buf[1] = 0xefcdab89;
60 ctx->buf[2] = 0x98badcfe;
61 ctx->buf[3] = 0x10325476;
62
63 ctx->bytes[0] = 0;
64 ctx->bytes[1] = 0;
65 }
66
67 /*
68 * Update context to reflect the concatenation of another buffer full
69 * of bytes.
70 */
71 void
MD5Update(struct MD5Context * ctx,md5byte const * buf,unsigned len)72 MD5Update(struct MD5Context *ctx, md5byte const *buf, unsigned len)
73 {
74 UWORD32 t;
75
76 /* Update byte count */
77
78 t = ctx->bytes[0];
79
80 if ((ctx->bytes[0] = t + len) < t)
81 ctx->bytes[1]++; /* Carry from low to high */
82
83 t = 64 - (t & 0x3f); /* Space available in ctx->in (at least 1) */
84
85 if (t > len)
86 {
87 memcpy((md5byte *)ctx->in + 64 - t, buf, len);
88 return;
89 }
90
91 /* First chunk is an odd size */
92 memcpy((md5byte *)ctx->in + 64 - t, buf, t);
93 byteSwap(ctx->in, 16);
94 MD5Transform(ctx->buf, ctx->in);
95 buf += t;
96 len -= t;
97
98 /* Process data in 64-byte chunks */
99 while (len >= 64)
100 {
101 memcpy(ctx->in, buf, 64);
102 byteSwap(ctx->in, 16);
103 MD5Transform(ctx->buf, ctx->in);
104 buf += 64;
105 len -= 64;
106 }
107
108 /* Handle any remaining bytes of data. */
109 memcpy(ctx->in, buf, len);
110 }
111
112 /*
113 * Final wrapup - pad to 64-byte boundary with the bit pattern
114 * 1 0* (64-bit count of bits processed, MSB-first)
115 */
116 void
MD5Final(md5byte digest[16],struct MD5Context * ctx)117 MD5Final(md5byte digest[16], struct MD5Context *ctx)
118 {
119 int count = ctx->bytes[0] & 0x3f; /* Number of bytes in ctx->in */
120 md5byte *p = (md5byte *)ctx->in + count;
121
122 /* Set the first char of padding to 0x80. There is always room. */
123 *p++ = 0x80;
124
125 /* Bytes of padding needed to make 56 bytes (-8..55) */
126 count = 56 - 1 - count;
127
128 if (count < 0) /* Padding forces an extra block */
129 {
130 memset(p, 0, count + 8);
131 byteSwap(ctx->in, 16);
132 MD5Transform(ctx->buf, ctx->in);
133 p = (md5byte *)ctx->in;
134 count = 56;
135 }
136
137 memset(p, 0, count);
138 byteSwap(ctx->in, 14);
139
140 /* Append length in bits and transform */
141 ctx->in[14] = ctx->bytes[0] << 3;
142 ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
143 MD5Transform(ctx->buf, ctx->in);
144
145 byteSwap(ctx->buf, 4);
146 memcpy(digest, ctx->buf, 16);
147 memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */
148 }
149
150 #ifndef ASM_MD5
151
152 /* The four core functions - F1 is optimized somewhat */
153
154 /* #define F1(x, y, z) (x & y | ~x & z) */
155 #define F1(x, y, z) (z ^ (x & (y ^ z)))
156 #define F2(x, y, z) F1(z, x, y)
157 #define F3(x, y, z) (x ^ y ^ z)
158 #define F4(x, y, z) (y ^ (x | ~z))
159
160 /* This is the central step in the MD5 algorithm. */
161 #define MD5STEP(f,w,x,y,z,in,s) \
162 (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
163
164 /*
165 * The core of the MD5 algorithm, this alters an existing MD5 hash to
166 * reflect the addition of 16 longwords of new data. MD5Update blocks
167 * the data and converts bytes into longwords for this routine.
168 */
169 void
MD5Transform(UWORD32 buf[4],UWORD32 const in[16])170 MD5Transform(UWORD32 buf[4], UWORD32 const in[16])
171 {
172 register UWORD32 a, b, c, d;
173
174 a = buf[0];
175 b = buf[1];
176 c = buf[2];
177 d = buf[3];
178
179 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
180 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
181 MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
182 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
183 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
184 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
185 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
186 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
187 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
188 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
189 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
190 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
191 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
192 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
193 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
194 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
195
196 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
197 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
198 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
199 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
200 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
201 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
202 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
203 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
204 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
205 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
206 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
207 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
208 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
209 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
210 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
211 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
212
213 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
214 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
215 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
216 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
217 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
218 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
219 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
220 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
221 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
222 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
223 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
224 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
225 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
226 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
227 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
228 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
229
230 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
231 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
232 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
233 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
234 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
235 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
236 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
237 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
238 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
239 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
240 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
241 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
242 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
243 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
244 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
245 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
246
247 buf[0] += a;
248 buf[1] += b;
249 buf[2] += c;
250 buf[3] += d;
251 }
252
253 #endif
254