1 /*
2 * $Id$
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
21 #include <string.h>
22 #include "md5.h"
23
24 #include "pam_inline.h"
25
26 #ifndef HIGHFIRST
27 #define byteReverse(buf, len) /* Nothing */
28 #else
29
30 static void byteReverse(uint32 *buf, unsigned longs);
31
32 #ifndef ASM_MD5
33 /*
34 * Note: this code is harmless on little-endian machines.
35 */
36 static void byteReverse(uint32 *buf, unsigned longs)
37 {
38 uint32 t;
39 do {
40 unsigned char *p = (unsigned char *) buf;
41 t = (uint32) ((unsigned) p[3] << 8 | p[2]) << 16 |
42 ((unsigned) p[1] << 8 | p[0]);
43 *buf = t;
44 ++buf;
45 } while (--longs);
46 }
47 #endif
48 #endif
49
50 /*
51 * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
52 * initialization constants.
53 */
54 void MD5Name(MD5Init)(struct MD5Context *ctx)
55 {
56 ctx->buf.i[0] = 0x67452301U;
57 ctx->buf.i[1] = 0xefcdab89U;
58 ctx->buf.i[2] = 0x98badcfeU;
59 ctx->buf.i[3] = 0x10325476U;
60
61 ctx->bits[0] = 0;
62 ctx->bits[1] = 0;
63 }
64
65 /*
66 * Update context to reflect the concatenation of another buffer full
67 * of bytes.
68 */
69 void MD5Name(MD5Update)(struct MD5Context *ctx, unsigned const char *buf, unsigned len)
70 {
71 uint32 t;
72
73 /* Update bitcount */
74
75 t = ctx->bits[0];
76 if ((ctx->bits[0] = t + ((uint32) len << 3)) < t)
77 ctx->bits[1]++; /* Carry from low to high */
78 ctx->bits[1] += len >> 29;
79
80 t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
81
82 /* Handle any leading odd-sized chunks */
83
84 if (t) {
85 unsigned char *p = ctx->in.c + t;
86
87 t = 64 - t;
88 if (len < t) {
89 memcpy(p, buf, len);
90 return;
91 }
92 memcpy(p, buf, t);
93 byteReverse(ctx->in.i, 16);
94 MD5Name(MD5Transform)(ctx->buf.i, ctx->in.i);
95 buf += t;
96 len -= t;
97 }
98 /* Process data in 64-byte chunks */
99
100 while (len >= 64) {
101 memcpy(ctx->in.c, buf, 64);
102 byteReverse(ctx->in.i, 16);
103 MD5Name(MD5Transform)(ctx->buf.i, ctx->in.i);
104 buf += 64;
105 len -= 64;
106 }
107
108 /* Handle any remaining bytes of data. */
109
110 memcpy(ctx->in.c, buf, len);
111 }
112
113 /*
114 * Final wrapup - pad to 64-byte boundary with the bit pattern
115 * 1 0* (64-bit count of bits processed, MSB-first)
116 */
117 void MD5Name(MD5Final)(unsigned char digest[16], struct MD5Context *ctx)
118 {
119 unsigned count;
120 unsigned char *p;
121
122 /* Compute number of bytes mod 64 */
123 count = (ctx->bits[0] >> 3) & 0x3F;
124
125 /* Set the first char of padding to 0x80. This is safe since there is
126 always at least one byte free */
127 p = ctx->in.c + count;
128 *p++ = 0x80;
129
130 /* Bytes of padding needed to make 64 bytes */
131 count = 64 - 1 - count;
132
133 /* Pad out to 56 mod 64 */
134 if (count < 8) {
135 /* Two lots of padding: Pad the first block to 64 bytes */
136 memset(p, 0, count);
137 byteReverse(ctx->in.i, 16);
138 MD5Name(MD5Transform)(ctx->buf.i, ctx->in.i);
139
140 /* Now fill the next block with 56 bytes */
141 memset(ctx->in.c, 0, 56);
142 } else {
143 /* Pad block to 56 bytes */
144 memset(p, 0, count - 8);
145 }
146 byteReverse(ctx->in.i, 14);
147
148 /* Append length in bits and transform */
149 memcpy(ctx->in.i + 14, ctx->bits, 2*sizeof(uint32));
150
151 MD5Name(MD5Transform)(ctx->buf.i, ctx->in.i);
152 byteReverse(ctx->buf.i, 4);
153 memcpy(digest, ctx->buf.c, 16);
154 pam_overwrite_object(ctx); /* In case it's sensitive */
155 }
156
157 #ifndef ASM_MD5
158
159 /* The four core functions - F1 is optimized somewhat */
160
161 /* #define F1(x, y, z) (x & y | ~x & z) */
162 #define F1(x, y, z) (z ^ (x & (y ^ z)))
163 #define F2(x, y, z) F1(z, x, y)
164 #define F3(x, y, z) (x ^ y ^ z)
165 #define F4(x, y, z) (y ^ (x | ~z))
166
167 /* This is the central step in the MD5 algorithm. */
168 #define MD5STEP(f, w, x, y, z, data, s) \
169 ( w += f(x, y, z) + data, w = w<<s | w>>(32-s), w += x )
170
171 /*
172 * The core of the MD5 algorithm, this alters an existing MD5 hash to
173 * reflect the addition of 16 longwords of new data. MD5Update blocks
174 * the data and converts bytes into longwords for this routine.
175 */
176 void MD5Name(MD5Transform)(uint32 buf[4], uint32 const in[16])
177 {
178 register uint32 a, b, c, d;
179
180 a = buf[0];
181 b = buf[1];
182 c = buf[2];
183 d = buf[3];
184
185 MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478U, 7);
186 MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756U, 12);
187 MD5STEP(F1, c, d, a, b, in[2] + 0x242070dbU, 17);
188 MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceeeU, 22);
189 MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0fafU, 7);
190 MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62aU, 12);
191 MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613U, 17);
192 MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501U, 22);
193 MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8U, 7);
194 MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7afU, 12);
195 MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1U, 17);
196 MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7beU, 22);
197 MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122U, 7);
198 MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193U, 12);
199 MD5STEP(F1, c, d, a, b, in[14] + 0xa679438eU, 17);
200 MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821U, 22);
201
202 MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562U, 5);
203 MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340U, 9);
204 MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51U, 14);
205 MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aaU, 20);
206 MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105dU, 5);
207 MD5STEP(F2, d, a, b, c, in[10] + 0x02441453U, 9);
208 MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681U, 14);
209 MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8U, 20);
210 MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6U, 5);
211 MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6U, 9);
212 MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87U, 14);
213 MD5STEP(F2, b, c, d, a, in[8] + 0x455a14edU, 20);
214 MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905U, 5);
215 MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8U, 9);
216 MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9U, 14);
217 MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8aU, 20);
218
219 MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942U, 4);
220 MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681U, 11);
221 MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122U, 16);
222 MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380cU, 23);
223 MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44U, 4);
224 MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9U, 11);
225 MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60U, 16);
226 MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70U, 23);
227 MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6U, 4);
228 MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127faU, 11);
229 MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085U, 16);
230 MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05U, 23);
231 MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039U, 4);
232 MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5U, 11);
233 MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8U, 16);
234 MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665U, 23);
235
236 MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244U, 6);
237 MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97U, 10);
238 MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7U, 15);
239 MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039U, 21);
240 MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3U, 6);
241 MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92U, 10);
242 MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47dU, 15);
243 MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1U, 21);
244 MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4fU, 6);
245 MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0U, 10);
246 MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314U, 15);
247 MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1U, 21);
248 MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82U, 6);
249 MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235U, 10);
250 MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bbU, 15);
251 MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391U, 21);
252
253 buf[0] += a;
254 buf[1] += b;
255 buf[2] += c;
256 buf[3] += d;
257 }
258
259 #endif