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/cvs/ermyth/src/md5.C
Revision: 1.6
Committed: Sat Sep 22 14:27:30 2007 UTC (16 years, 8 months ago) by pippijn
Content type: text/plain
Branch: MAIN
CVS Tags: HEAD
Changes since 1.5: +1 -1 lines
State: FILE REMOVED
Log Message:
split up ermyth into ermyth-modules, libermyth (currently just ermyth-util) and ermyth-core

File Contents

# User Rev Content
1 pippijn 1.4 /**
2     * md5.C: Message Digest 5 algorithm implementation
3 pippijn 1.2 *
4 pippijn 1.5 * Copyright © 2007 Pippijn van Steenhoven / The Ermyth Team
5     * Rights to this code are as documented in COPYING.
6 pippijn 1.2 */
7 pippijn 1.4
8 pippijn 1.6 static char const rcsid[] = "$Id: md5.C,v 1.5 2007-09-16 18:54:45 pippijn Exp $";
9 pippijn 1.4
10 pippijn 1.1 #include <memory> /* for memcpy() */
11    
12     #include <svsconfig.h>
13     #include "md5.h"
14    
15     #ifndef HIGHFIRST
16     #define byteReverse(buf, len) /* Nothing */
17     #else
18     void
19     byteReverse (unsigned char *buf, unsigned longs)
20     {
21 pippijn 1.2 register uint32_t t;
22 pippijn 1.1 do
23     {
24     t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 | ((unsigned) buf[1] << 8 | buf[0]);
25     *(uint32_t *) buf = t;
26     buf += 4;
27     }
28     while (--longs);
29     }
30     #endif
31    
32     /**
33     * Start MD5 accumulation. Set bit count to 0 and buffer to mysterious
34     * initialization constants.
35     */
36     void
37     MD5Init (MD5Context *ctx)
38     {
39     ctx->buf[0] = 0x67452301;
40     ctx->buf[1] = 0xefcdab89;
41     ctx->buf[2] = 0x98badcfe;
42     ctx->buf[3] = 0x10325476;
43    
44     ctx->bits[0] = 0;
45     ctx->bits[1] = 0;
46     }
47    
48     /**
49     * Update context to reflect the concatenation of another buffer full
50     * of bytes.
51     */
52     void
53     MD5Update (MD5Context *ctx, unsigned char const *buf, unsigned len)
54     {
55 pippijn 1.2 register uint32_t t;
56 pippijn 1.1
57     /* Update bitcount */
58    
59     t = ctx->bits[0];
60     if ((ctx->bits[0] = t + ((uint32_t) len << 3)) < t)
61     ctx->bits[1]++; /* Carry from low to high */
62     ctx->bits[1] += len >> 29;
63    
64     t = (t >> 3) & 0x3f; /* Bytes already in shsInfo->data */
65    
66     /* Handle any leading odd-sized chunks */
67    
68     if (t)
69     {
70     unsigned char *p = (unsigned char *) ctx->in + t;
71    
72     t = 64 - t;
73     if (len < t)
74     {
75     std::memcpy (p, buf, len);
76     return;
77     }
78     std::memcpy (p, buf, t);
79     byteReverse (ctx->in, 16);
80     MD5Transform (ctx->buf, (uint32_t *) ctx->in);
81     buf += t;
82     len -= t;
83     }
84     /* Process data in 64-byte chunks */
85    
86     while (len >= 64)
87     {
88     std::memcpy (ctx->in, buf, 64);
89     byteReverse (ctx->in, 16);
90     MD5Transform (ctx->buf, (uint32_t *) ctx->in);
91     buf += 64;
92     len -= 64;
93     }
94    
95     /* Handle any remaining bytes of data. */
96    
97     std::memcpy (ctx->in, buf, len);
98     }
99    
100     /**
101     * Final wrapup - pad to 64-byte boundary with the bit pattern
102     * 1 0* (64-bit count of bits processed, MSB-first)
103     */
104     void
105     MD5Final (unsigned char digest[16], MD5Context *ctx)
106     {
107 pippijn 1.2 register unsigned count;
108 pippijn 1.1 unsigned char *p;
109    
110     /* Compute number of bytes mod 64 */
111     count = (ctx->bits[0] >> 3) & 0x3F;
112    
113     /* Set the first char of padding to 0x80. This is safe since there is
114     always at least one byte free */
115     p = ctx->in + count;
116     *p++ = 0x80;
117    
118     /* Bytes of padding needed to make 64 bytes */
119     count = 64 - 1 - count;
120    
121     /* Pad out to 56 mod 64 */
122     if (count < 8)
123     {
124     /* Two lots of padding: Pad the first block to 64 bytes */
125     memset (p, 0, count);
126     byteReverse (ctx->in, 16);
127     MD5Transform (ctx->buf, (uint32_t *) ctx->in);
128    
129     /* Now fill the next block with 56 bytes */
130     memset (ctx->in, 0, 56);
131     }
132     else
133     {
134     /* Pad block to 56 bytes */
135     memset (p, 0, count - 8);
136     }
137     byteReverse (ctx->in, 14);
138    
139     /* Append length in bits and transform */
140     ((uint32_t *) ctx->in)[14] = ctx->bits[0];
141     ((uint32_t *) ctx->in)[15] = ctx->bits[1];
142    
143     MD5Transform (ctx->buf, (uint32_t *) ctx->in);
144     byteReverse ((unsigned char *) ctx->buf, 4);
145     std::memcpy (digest, ctx->buf, 16);
146     memset (ctx, 0, sizeof (ctx)); /* In case it's sensitive */
147     }
148    
149    
150     /* The four core functions - F1 is optimized somewhat */
151    
152     /* #define F1(x, y, z) (x & y | ~x & z) */
153     inline uint32_t F1 (uint32_t x, uint32_t y, uint32_t z) { return z ^ (x & (y ^ z)); }
154     inline uint32_t F2 (uint32_t x, uint32_t y, uint32_t z) { return F1(z, x, y); }
155     inline uint32_t F3 (uint32_t x, uint32_t y, uint32_t z) { return (x ^ y ^ z); }
156     inline uint32_t F4 (uint32_t x, uint32_t y, uint32_t z) { return (y ^ (x | ~z)); }
157    
158     /* This is the central step in the MD5 algorithm. */
159     inline void
160     MD5STEP (uint32_t (*f)(uint32_t, uint32_t, uint32_t), uint32_t &w, uint32_t &x, uint32_t &y, uint32_t &z, unsigned data, int s)
161     {
162     w += f (x, y, z) + data;
163     w = w << s | w >> (32 - s);
164     w += x;
165     }
166    
167     /**
168     * The core of the MD5 algorithm, this alters an existing MD5 hash to
169     * reflect the addition of 16 longwords of new data. MD5Update blocks
170     * the data and converts bytes into longwords for this routine.
171     */
172     void
173     MD5Transform (uint32_t buf[4], uint32_t in[16])
174     {
175 pippijn 1.2 uint32_t a, b, c, d;
176 pippijn 1.1
177     a = buf[0];
178     b = buf[1];
179     c = buf[2];
180     d = buf[3];
181    
182     MD5STEP (&F1, a, b, c, d, in[0] + 0xd76aa478, 7);
183     MD5STEP (&F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
184     MD5STEP (&F1, c, d, a, b, in[2] + 0x242070db, 17);
185     MD5STEP (&F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
186     MD5STEP (&F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
187     MD5STEP (&F1, d, a, b, c, in[5] + 0x4787c62a, 12);
188     MD5STEP (&F1, c, d, a, b, in[6] + 0xa8304613, 17);
189     MD5STEP (&F1, b, c, d, a, in[7] + 0xfd469501, 22);
190     MD5STEP (&F1, a, b, c, d, in[8] + 0x698098d8, 7);
191     MD5STEP (&F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
192     MD5STEP (&F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
193     MD5STEP (&F1, b, c, d, a, in[11] + 0x895cd7be, 22);
194     MD5STEP (&F1, a, b, c, d, in[12] + 0x6b901122, 7);
195     MD5STEP (&F1, d, a, b, c, in[13] + 0xfd987193, 12);
196     MD5STEP (&F1, c, d, a, b, in[14] + 0xa679438e, 17);
197     MD5STEP (&F1, b, c, d, a, in[15] + 0x49b40821, 22);
198    
199     MD5STEP (&F2, a, b, c, d, in[1] + 0xf61e2562, 5);
200     MD5STEP (&F2, d, a, b, c, in[6] + 0xc040b340, 9);
201     MD5STEP (&F2, c, d, a, b, in[11] + 0x265e5a51, 14);
202     MD5STEP (&F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
203     MD5STEP (&F2, a, b, c, d, in[5] + 0xd62f105d, 5);
204     MD5STEP (&F2, d, a, b, c, in[10] + 0x02441453, 9);
205     MD5STEP (&F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
206     MD5STEP (&F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
207     MD5STEP (&F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
208     MD5STEP (&F2, d, a, b, c, in[14] + 0xc33707d6, 9);
209     MD5STEP (&F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
210     MD5STEP (&F2, b, c, d, a, in[8] + 0x455a14ed, 20);
211     MD5STEP (&F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
212     MD5STEP (&F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
213     MD5STEP (&F2, c, d, a, b, in[7] + 0x676f02d9, 14);
214     MD5STEP (&F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
215    
216     MD5STEP (&F3, a, b, c, d, in[5] + 0xfffa3942, 4);
217     MD5STEP (&F3, d, a, b, c, in[8] + 0x8771f681, 11);
218     MD5STEP (&F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
219     MD5STEP (&F3, b, c, d, a, in[14] + 0xfde5380c, 23);
220     MD5STEP (&F3, a, b, c, d, in[1] + 0xa4beea44, 4);
221     MD5STEP (&F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
222     MD5STEP (&F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
223     MD5STEP (&F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
224     MD5STEP (&F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
225     MD5STEP (&F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
226     MD5STEP (&F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
227     MD5STEP (&F3, b, c, d, a, in[6] + 0x04881d05, 23);
228     MD5STEP (&F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
229     MD5STEP (&F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
230     MD5STEP (&F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
231     MD5STEP (&F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
232    
233     MD5STEP (&F4, a, b, c, d, in[0] + 0xf4292244, 6);
234     MD5STEP (&F4, d, a, b, c, in[7] + 0x432aff97, 10);
235     MD5STEP (&F4, c, d, a, b, in[14] + 0xab9423a7, 15);
236     MD5STEP (&F4, b, c, d, a, in[5] + 0xfc93a039, 21);
237     MD5STEP (&F4, a, b, c, d, in[12] + 0x655b59c3, 6);
238     MD5STEP (&F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
239     MD5STEP (&F4, c, d, a, b, in[10] + 0xffeff47d, 15);
240     MD5STEP (&F4, b, c, d, a, in[1] + 0x85845dd1, 21);
241     MD5STEP (&F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
242     MD5STEP (&F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
243     MD5STEP (&F4, c, d, a, b, in[6] + 0xa3014314, 15);
244     MD5STEP (&F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
245     MD5STEP (&F4, a, b, c, d, in[4] + 0xf7537e82, 6);
246     MD5STEP (&F4, d, a, b, c, in[11] + 0xbd3af235, 10);
247     MD5STEP (&F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
248     MD5STEP (&F4, b, c, d, a, in[9] + 0xeb86d391, 21);
249    
250     buf[0] += a;
251     buf[1] += b;
252     buf[2] += c;
253     buf[3] += d;
254     }