xref: /reactos/sdk/lib/cryptlib/md5.c (revision 67d5a538)
1 /*
2  * Copyright (C) 2001 Nikos Mavroyanopoulos
3  * Copyright (C) 2004 Hans Leidekker
4  *
5  * This library is free software; you can redistribute it and/or
6  * modify it under the terms of the GNU Lesser General Public
7  * License as published by the Free Software Foundation; either
8  * version 2.1 of the License, or (at your option) any later version.
9  *
10  * This library is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13  * Lesser General Public License for more details.
14  *
15  * You should have received a copy of the GNU Lesser General Public
16  * License along with this library; if not, write to the Free Software
17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
18  */
19 
20 /*
21  * This code implements the MD5 message-digest algorithm.
22  * It is based on code in the public domain written by Colin
23  * Plumb in 1993. The algorithm is due to Ron Rivest.
24  *
25  * Equivalent code is available from RSA Data Security, Inc.
26  * This code has been tested against that, and is equivalent,
27  * except that you don't need to include two pages of legalese
28  * with every copy.
29  *
30  * To compute the message digest of a chunk of bytes, declare an
31  * MD5_CTX structure, pass it to MD5Init, call MD5Update as
32  * needed on buffers full of bytes, and then call MD5Final, which
33  * will fill a supplied 16-byte array with the digest.
34  */
35 
36 #include "md5.h"
37 #include "util.h"
38 
39 static void MD5Transform( unsigned int buf[4], const unsigned int in[16] );
40 
41 /*
42  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
43  * initialization constants.
44  */
45 VOID NTAPI MD5Init( MD5_CTX *ctx )
46 {
47     ctx->buf[0] = 0x67452301;
48     ctx->buf[1] = 0xefcdab89;
49     ctx->buf[2] = 0x98badcfe;
50     ctx->buf[3] = 0x10325476;
51 
52     ctx->i[0] = ctx->i[1] = 0;
53 }
54 
55 /*
56  * Update context to reflect the concatenation of another buffer full
57  * of bytes.
58  */
59 VOID NTAPI MD5Update( MD5_CTX *ctx, const unsigned char *buf, unsigned int len )
60 {
61     register unsigned int t;
62 
63     /* Update bitcount */
64     t = ctx->i[0];
65 
66     if ((ctx->i[0] = t + (len << 3)) < t)
67         ctx->i[1]++;        /* Carry from low to high */
68 
69     ctx->i[1] += len >> 29;
70     t = (t >> 3) & 0x3f;
71 
72     /* Handle any leading odd-sized chunks */
73     if (t)
74     {
75         unsigned char *p = (unsigned char *)ctx->in + t;
76         t = 64 - t;
77 
78         if (len < t)
79         {
80             memcpy( p, buf, len );
81             return;
82         }
83 
84         memcpy( p, buf, t );
85         byteReverse( ctx->in, 16 );
86 
87         MD5Transform( ctx->buf, (unsigned int *)ctx->in );
88 
89         buf += t;
90         len -= t;
91     }
92 
93     /* Process data in 64-byte chunks */
94     while (len >= 64)
95     {
96         memcpy( ctx->in, buf, 64 );
97         byteReverse( ctx->in, 16 );
98 
99         MD5Transform( ctx->buf, (unsigned int *)ctx->in );
100 
101         buf += 64;
102         len -= 64;
103     }
104 
105     /* Handle any remaining bytes of data. */
106     memcpy( ctx->in, buf, len );
107 }
108 
109 /*
110  * Final wrapup - pad to 64-byte boundary with the bit pattern
111  * 1 0* (64-bit count of bits processed, MSB-first)
112  */
113 VOID NTAPI MD5Final( MD5_CTX *ctx )
114 {
115     unsigned int count;
116     unsigned char *p;
117 
118     /* Compute number of bytes mod 64 */
119     count = (ctx->i[0] >> 3) & 0x3F;
120 
121     /* Set the first char of padding to 0x80.  This is safe since there is
122        always at least one byte free */
123     p = ctx->in + count;
124     *p++ = 0x80;
125 
126     /* Bytes of padding needed to make 64 bytes */
127     count = 64 - 1 - count;
128 
129     /* Pad out to 56 mod 64 */
130     if (count < 8)
131     {
132         /* Two lots of padding:  Pad the first block to 64 bytes */
133         memset( p, 0, count );
134         byteReverse( ctx->in, 16 );
135         MD5Transform( ctx->buf, (unsigned int *)ctx->in );
136 
137         /* Now fill the next block with 56 bytes */
138         memset( ctx->in, 0, 56 );
139     }
140     else
141     {
142         /* Pad block to 56 bytes */
143         memset( p, 0, count - 8 );
144     }
145 
146     byteReverse( ctx->in, 14 );
147 
148     /* Append length in bits and transform */
149     ((unsigned int *)ctx->in)[14] = ctx->i[0];
150     ((unsigned int *)ctx->in)[15] = ctx->i[1];
151 
152     MD5Transform( ctx->buf, (unsigned int *)ctx->in );
153     byteReverse( (unsigned char *)ctx->buf, 4 );
154     memcpy( ctx->digest, ctx->buf, 16 );
155     memset(ctx->in, 0, sizeof(ctx->in));
156 }
157 
158 /* The four core functions - F1 is optimized somewhat */
159 
160 /* #define F1( x, y, z ) (x & y | ~x & z) */
161 #define F1( x, y, z ) (z ^ (x & (y ^ z)))
162 #define F2( x, y, z ) F1( z, x, y )
163 #define F3( x, y, z ) (x ^ y ^ z)
164 #define F4( x, y, z ) (y ^ (x | ~z))
165 
166 /* This is the central step in the MD5 algorithm. */
167 #define MD5STEP( f, w, x, y, z, data, s ) \
168         ( w += f( x, y, z ) + data,  w = w << s | w >> (32 - s),  w += x )
169 
170 /*
171  * The core of the MD5 algorithm, this alters an existing MD5 hash to
172  * reflect the addition of 16 longwords of new data.  MD5Update blocks
173  * the data and converts bytes into longwords for this routine.
174  */
175 static void MD5Transform( unsigned int buf[4], const unsigned int in[16] )
176 {
177     register unsigned int a, b, c, d;
178 
179     a = buf[0];
180     b = buf[1];
181     c = buf[2];
182     d = buf[3];
183 
184     MD5STEP( F1, a, b, c, d, in[0] + 0xd76aa478, 7 );
185     MD5STEP( F1, d, a, b, c, in[1] + 0xe8c7b756, 12 );
186     MD5STEP( F1, c, d, a, b, in[2] + 0x242070db, 17 );
187     MD5STEP( F1, b, c, d, a, in[3] + 0xc1bdceee, 22 );
188     MD5STEP( F1, a, b, c, d, in[4] + 0xf57c0faf, 7 );
189     MD5STEP( F1, d, a, b, c, in[5] + 0x4787c62a, 12 );
190     MD5STEP( F1, c, d, a, b, in[6] + 0xa8304613, 17 );
191     MD5STEP( F1, b, c, d, a, in[7] + 0xfd469501, 22 );
192     MD5STEP( F1, a, b, c, d, in[8] + 0x698098d8, 7 );
193     MD5STEP( F1, d, a, b, c, in[9] + 0x8b44f7af, 12 );
194     MD5STEP( F1, c, d, a, b, in[10] + 0xffff5bb1, 17 );
195     MD5STEP( F1, b, c, d, a, in[11] + 0x895cd7be, 22 );
196     MD5STEP( F1, a, b, c, d, in[12] + 0x6b901122, 7 );
197     MD5STEP( F1, d, a, b, c, in[13] + 0xfd987193, 12 );
198     MD5STEP( F1, c, d, a, b, in[14] + 0xa679438e, 17 );
199     MD5STEP( F1, b, c, d, a, in[15] + 0x49b40821, 22 );
200 
201     MD5STEP( F2, a, b, c, d, in[1] + 0xf61e2562, 5 );
202     MD5STEP( F2, d, a, b, c, in[6] + 0xc040b340, 9 );
203     MD5STEP( F2, c, d, a, b, in[11] + 0x265e5a51, 14 );
204     MD5STEP( F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20 );
205     MD5STEP( F2, a, b, c, d, in[5] + 0xd62f105d, 5 );
206     MD5STEP( F2, d, a, b, c, in[10] + 0x02441453, 9 );
207     MD5STEP( F2, c, d, a, b, in[15] + 0xd8a1e681, 14 );
208     MD5STEP( F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20 );
209     MD5STEP( F2, a, b, c, d, in[9] + 0x21e1cde6, 5 );
210     MD5STEP( F2, d, a, b, c, in[14] + 0xc33707d6, 9 );
211     MD5STEP( F2, c, d, a, b, in[3] + 0xf4d50d87, 14 );
212     MD5STEP( F2, b, c, d, a, in[8] + 0x455a14ed, 20 );
213     MD5STEP( F2, a, b, c, d, in[13] + 0xa9e3e905, 5 );
214     MD5STEP( F2, d, a, b, c, in[2] + 0xfcefa3f8, 9 );
215     MD5STEP( F2, c, d, a, b, in[7] + 0x676f02d9, 14 );
216     MD5STEP( F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20 );
217 
218     MD5STEP( F3, a, b, c, d, in[5] + 0xfffa3942, 4 );
219     MD5STEP( F3, d, a, b, c, in[8] + 0x8771f681, 11 );
220     MD5STEP( F3, c, d, a, b, in[11] + 0x6d9d6122, 16 );
221     MD5STEP( F3, b, c, d, a, in[14] + 0xfde5380c, 23 );
222     MD5STEP( F3, a, b, c, d, in[1] + 0xa4beea44, 4 );
223     MD5STEP( F3, d, a, b, c, in[4] + 0x4bdecfa9, 11 );
224     MD5STEP( F3, c, d, a, b, in[7] + 0xf6bb4b60, 16 );
225     MD5STEP( F3, b, c, d, a, in[10] + 0xbebfbc70, 23 );
226     MD5STEP( F3, a, b, c, d, in[13] + 0x289b7ec6, 4 );
227     MD5STEP( F3, d, a, b, c, in[0] + 0xeaa127fa, 11 );
228     MD5STEP( F3, c, d, a, b, in[3] + 0xd4ef3085, 16 );
229     MD5STEP( F3, b, c, d, a, in[6] + 0x04881d05, 23 );
230     MD5STEP( F3, a, b, c, d, in[9] + 0xd9d4d039, 4 );
231     MD5STEP( F3, d, a, b, c, in[12] + 0xe6db99e5, 11 );
232     MD5STEP( F3, c, d, a, b, in[15] + 0x1fa27cf8, 16 );
233     MD5STEP( F3, b, c, d, a, in[2] + 0xc4ac5665, 23 );
234 
235     MD5STEP( F4, a, b, c, d, in[0] + 0xf4292244, 6 );
236     MD5STEP( F4, d, a, b, c, in[7] + 0x432aff97, 10 );
237     MD5STEP( F4, c, d, a, b, in[14] + 0xab9423a7, 15 );
238     MD5STEP( F4, b, c, d, a, in[5] + 0xfc93a039, 21 );
239     MD5STEP( F4, a, b, c, d, in[12] + 0x655b59c3, 6 );
240     MD5STEP( F4, d, a, b, c, in[3] + 0x8f0ccc92, 10 );
241     MD5STEP( F4, c, d, a, b, in[10] + 0xffeff47d, 15 );
242     MD5STEP( F4, b, c, d, a, in[1] + 0x85845dd1, 21 );
243     MD5STEP( F4, a, b, c, d, in[8] + 0x6fa87e4f, 6 );
244     MD5STEP( F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10 );
245     MD5STEP( F4, c, d, a, b, in[6] + 0xa3014314, 15 );
246     MD5STEP( F4, b, c, d, a, in[13] + 0x4e0811a1, 21 );
247     MD5STEP( F4, a, b, c, d, in[4] + 0xf7537e82, 6 );
248     MD5STEP( F4, d, a, b, c, in[11] + 0xbd3af235, 10 );
249     MD5STEP( F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15 );
250     MD5STEP( F4, b, c, d, a, in[9] + 0xeb86d391, 21 );
251 
252     buf[0] += a;
253     buf[1] += b;
254     buf[2] += c;
255     buf[3] += d;
256 }
257 
258