2.0.16 release
[l2tpns.git] / md5.c
1 /* MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
2 */
3
4 char const *cvs_id_md5 = "$Id: md5.c,v 1.3 2004/08/13 00:02:50 fred_nerk Exp $";
5
6 /* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
7 rights reserved.
8
9 License to copy and use this software is granted provided that it
10 is identified as the "RSA Data Security, Inc. MD5 Message-Digest
11 Algorithm" in all material mentioning or referencing this software
12 or this function.
13
14 License is also granted to make and use derivative works provided
15 that such works are identified as "derived from the RSA Data
16 Security, Inc. MD5 Message-Digest Algorithm" in all material
17 mentioning or referencing the derived work.
18
19 RSA Data Security, Inc. makes no representations concerning either
20 the merchantability of this software or the suitability of this
21 software for any particular purpose. It is provided "as is"
22 without express or implied warranty of any kind.
23
24 These notices must be retained in any copies of any part of this
25 documentation and/or software.
26 */
27
28 #include <string.h>
29 #include "md5.h"
30
31 /* Constants for MD5Transform routine.
32 */
33
34 #define S11 7
35 #define S12 12
36 #define S13 17
37 #define S14 22
38 #define S21 5
39 #define S22 9
40 #define S23 14
41 #define S24 20
42 #define S31 4
43 #define S32 11
44 #define S33 16
45 #define S34 23
46 #define S41 6
47 #define S42 10
48 #define S43 15
49 #define S44 21
50
51 static void MD5Transform PROTO_LIST((UINT4[4], unsigned char[64]));
52 static void Encode PROTO_LIST((unsigned char *, UINT4 *, unsigned int));
53 static void Decode PROTO_LIST((UINT4 *, unsigned char *, unsigned int));
54
55 static unsigned char PADDING[64] = {
56 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
57 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
58 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
59 };
60
61 /* F, G, H and I are basic MD5 functions.
62 */
63 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
64 #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
65 #define H(x, y, z) ((x) ^ (y) ^ (z))
66 #define I(x, y, z) ((y) ^ ((x) | (~z)))
67
68 /* ROTATE_LEFT rotates x left n bits.
69 */
70 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
71
72 /* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
73 Rotation is separate from addition to prevent recomputation.
74 */
75 #define FF(a, b, c, d, x, s, ac) { \
76 (a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); \
77 (a) = ROTATE_LEFT ((a), (s)); \
78 (a) += (b); \
79 }
80 #define GG(a, b, c, d, x, s, ac) { \
81 (a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
82 (a) = ROTATE_LEFT ((a), (s)); \
83 (a) += (b); \
84 }
85 #define HH(a, b, c, d, x, s, ac) { \
86 (a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
87 (a) = ROTATE_LEFT ((a), (s)); \
88 (a) += (b); \
89 }
90 #define II(a, b, c, d, x, s, ac) { \
91 (a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
92 (a) = ROTATE_LEFT ((a), (s)); \
93 (a) += (b); \
94 }
95
96 /* MD5 initialization. Begins an MD5 operation, writing a new context.
97 */
98 void MD5Init(MD5_CTX *context)
99 {
100 context->count[0] = context->count[1] = 0;
101 // Load magic initialization constants.
102 context->state[0] = 0x67452301;
103 context->state[1] = 0xefcdab89;
104 context->state[2] = 0x98badcfe;
105 context->state[3] = 0x10325476;
106 }
107
108 /* MD5 block update operation. Continues an MD5 message-digest
109 operation, processing another message block, and updating the
110 context.
111 */
112 void MD5Update(MD5_CTX *context, unsigned char *input, unsigned int inputLen)
113
114 {
115 unsigned int i,
116 index,
117 partLen;
118
119 /* Compute number of bytes mod 64 */
120 index = (unsigned int) ((context->count[0] >> 3) & 0x3F);
121
122 /* Update number of bits */
123 if ((context->count[0] += ((UINT4) inputLen << 3)) < ((UINT4) inputLen << 3))
124 context->count[1]++;
125 context->count[1] += ((UINT4) inputLen >> 29);
126
127 partLen = 64 - index;
128
129 /* Transform as many times as possible.
130 */
131 if (inputLen >= partLen)
132 {
133 memcpy(&context->buffer[index], input, partLen);
134 MD5Transform(context->state, context->buffer);
135
136 for (i = partLen; i + 63 < inputLen; i += 64)
137 MD5Transform(context->state, &input[i]);
138
139 index = 0;
140 }
141 else
142 i = 0;
143
144 /* Buffer remaining input */
145 memcpy(&context->buffer[index], &input[i], inputLen - i);
146 }
147
148 /* MD5 finalization. Ends an MD5 message-digest operation, writing the
149 the message digest and zeroizing the context.
150 */
151 void MD5Final(unsigned char digest[16], MD5_CTX *context)
152 {
153 unsigned char bits[8];
154 unsigned int index, padLen;
155
156 /* Save number of bits */
157 Encode(bits, context->count, 8);
158
159 /* Pad out to 56 mod 64.
160 */
161 index = (unsigned int) ((context->count[0] >> 3) & 0x3f);
162 padLen = (index < 56) ? (56 - index) : (120 - index);
163 MD5Update(context, PADDING, padLen);
164
165 /* Append length (before padding) */
166 MD5Update(context, bits, 8);
167
168 /* Store state in digest */
169 Encode(digest, context->state, 16);
170
171 /* Zeroize sensitive information.
172 */
173 memset(context, 0, sizeof(*context));
174 }
175
176 /* MD5 basic transformation. Transforms state based on block.
177 */
178 static void MD5Transform(UINT4 state[4], unsigned char block[64])
179 {
180 UINT4 a = state[0],
181 b = state[1],
182 c = state[2],
183 d = state[3],
184 x[16];
185
186 Decode(x, block, 64);
187
188 /* Round 1 */
189 FF(a, b, c, d, x[0], S11, 0xd76aa478); /* 1 */
190 FF(d, a, b, c, x[1], S12, 0xe8c7b756); /* 2 */
191 FF(c, d, a, b, x[2], S13, 0x242070db); /* 3 */
192 FF(b, c, d, a, x[3], S14, 0xc1bdceee); /* 4 */
193 FF(a, b, c, d, x[4], S11, 0xf57c0faf); /* 5 */
194 FF(d, a, b, c, x[5], S12, 0x4787c62a); /* 6 */
195 FF(c, d, a, b, x[6], S13, 0xa8304613); /* 7 */
196 FF(b, c, d, a, x[7], S14, 0xfd469501); /* 8 */
197 FF(a, b, c, d, x[8], S11, 0x698098d8); /* 9 */
198 FF(d, a, b, c, x[9], S12, 0x8b44f7af); /* 10 */
199 FF(c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
200 FF(b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
201 FF(a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
202 FF(d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
203 FF(c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
204 FF(b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
205
206 /* Round 2 */
207 GG(a, b, c, d, x[1], S21, 0xf61e2562); /* 17 */
208 GG(d, a, b, c, x[6], S22, 0xc040b340); /* 18 */
209 GG(c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
210 GG(b, c, d, a, x[0], S24, 0xe9b6c7aa); /* 20 */
211 GG(a, b, c, d, x[5], S21, 0xd62f105d); /* 21 */
212 GG(d, a, b, c, x[10], S22, 0x2441453); /* 22 */
213 GG(c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
214 GG(b, c, d, a, x[4], S24, 0xe7d3fbc8); /* 24 */
215 GG(a, b, c, d, x[9], S21, 0x21e1cde6); /* 25 */
216 GG(d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
217 GG(c, d, a, b, x[3], S23, 0xf4d50d87); /* 27 */
218
219 GG(b, c, d, a, x[8], S24, 0x455a14ed); /* 28 */
220 GG(a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
221 GG(d, a, b, c, x[2], S22, 0xfcefa3f8); /* 30 */
222 GG(c, d, a, b, x[7], S23, 0x676f02d9); /* 31 */
223 GG(b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
224
225 /* Round 3 */
226 HH(a, b, c, d, x[5], S31, 0xfffa3942); /* 33 */
227 HH(d, a, b, c, x[8], S32, 0x8771f681); /* 34 */
228 HH(c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
229 HH(b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
230 HH(a, b, c, d, x[1], S31, 0xa4beea44); /* 37 */
231 HH(d, a, b, c, x[4], S32, 0x4bdecfa9); /* 38 */
232 HH(c, d, a, b, x[7], S33, 0xf6bb4b60); /* 39 */
233 HH(b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
234 HH(a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
235 HH(d, a, b, c, x[0], S32, 0xeaa127fa); /* 42 */
236 HH(c, d, a, b, x[3], S33, 0xd4ef3085); /* 43 */
237 HH(b, c, d, a, x[6], S34, 0x4881d05); /* 44 */
238 HH(a, b, c, d, x[9], S31, 0xd9d4d039); /* 45 */
239 HH(d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
240 HH(c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
241 HH(b, c, d, a, x[2], S34, 0xc4ac5665); /* 48 */
242
243 /* Round 4 */
244 II(a, b, c, d, x[0], S41, 0xf4292244); /* 49 */
245 II(d, a, b, c, x[7], S42, 0x432aff97); /* 50 */
246 II(c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
247 II(b, c, d, a, x[5], S44, 0xfc93a039); /* 52 */
248 II(a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
249 II(d, a, b, c, x[3], S42, 0x8f0ccc92); /* 54 */
250 II(c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
251 II(b, c, d, a, x[1], S44, 0x85845dd1); /* 56 */
252 II(a, b, c, d, x[8], S41, 0x6fa87e4f); /* 57 */
253 II(d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
254 II(c, d, a, b, x[6], S43, 0xa3014314); /* 59 */
255 II(b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
256 II(a, b, c, d, x[4], S41, 0xf7537e82); /* 61 */
257 II(d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
258 II(c, d, a, b, x[2], S43, 0x2ad7d2bb); /* 63 */
259 II(b, c, d, a, x[9], S44, 0xeb86d391); /* 64 */
260
261 state[0] += a;
262 state[1] += b;
263 state[2] += c;
264 state[3] += d;
265
266 // Zeroize sensitive information.
267 memset(x, 0, sizeof(x));
268 }
269
270 /* Encodes input (UINT4) into output (unsigned char). Assumes len is
271 a multiple of 4.
272 */
273 static void Encode(unsigned char *output, UINT4 *input, unsigned int len)
274 {
275 unsigned int i, j;
276
277 for (i = 0, j = 0; j < len; i++, j += 4)
278 {
279 output[j] = (unsigned char) (input[i] & 0xff);
280 output[j + 1] = (unsigned char) ((input[i] >> 8) & 0xff);
281 output[j + 2] = (unsigned char) ((input[i] >> 16) & 0xff);
282 output[j + 3] = (unsigned char) ((input[i] >> 24) & 0xff);
283 }
284 }
285
286 /* Decodes input (unsigned char) into output (UINT4). Assumes len is
287 a multiple of 4.
288 */
289 static void Decode(UINT4 *output, unsigned char *input, unsigned int len)
290 {
291 unsigned int i, j;
292
293 for (i = 0, j = 0; j < len; i++, j += 4)
294 output[i] = ((UINT4) input[j]) | (((UINT4) input[j + 1]) << 8) | (((UINT4) input[j + 2]) << 16) | (((UINT4) input[j + 3]) << 24);
295 }
296