Init data before trying to use it
[l2tpns.git] / md5.c
1 /* MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
2 */
3
4 /* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
5 rights reserved.
6
7 License to copy and use this software is granted provided that it
8 is identified as the "RSA Data Security, Inc. MD5 Message-Digest
9 Algorithm" in all material mentioning or referencing this software
10 or this function.
11
12 License is also granted to make and use derivative works provided
13 that such works are identified as "derived from the RSA Data
14 Security, Inc. MD5 Message-Digest Algorithm" in all material
15 mentioning or referencing the derived work.
16
17 RSA Data Security, Inc. makes no representations concerning either
18 the merchantability of this software or the suitability of this
19 software for any particular purpose. It is provided "as is"
20 without express or implied warranty of any kind.
21
22 These notices must be retained in any copies of any part of this
23 documentation and/or software.
24 */
25
26 #include "md5.h"
27
28 /* Constants for MD5Transform routine.
29 */
30
31 #define S11 7
32 #define S12 12
33 #define S13 17
34 #define S14 22
35 #define S21 5
36 #define S22 9
37 #define S23 14
38 #define S24 20
39 #define S31 4
40 #define S32 11
41 #define S33 16
42 #define S34 23
43 #define S41 6
44 #define S42 10
45 #define S43 15
46 #define S44 21
47
48 static void MD5Transform PROTO_LIST((UINT4[4], unsigned char[64]));
49 static void Encode PROTO_LIST((unsigned char *, UINT4 *, unsigned int));
50 static void Decode PROTO_LIST((UINT4 *, unsigned char *, unsigned int));
51 static void MD5_memcpy PROTO_LIST((POINTER, POINTER, unsigned int));
52 static void MD5_memset PROTO_LIST((POINTER, int, unsigned int));
53
54 static unsigned char PADDING[64] = {
55 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
56 0, 0, 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
58 };
59
60 /* F, G, H and I are basic MD5 functions.
61 */
62 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
63 #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
64 #define H(x, y, z) ((x) ^ (y) ^ (z))
65 #define I(x, y, z) ((y) ^ ((x) | (~z)))
66
67 /* ROTATE_LEFT rotates x left n bits.
68 */
69 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
70
71 /* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
72 Rotation is separate from addition to prevent recomputation.
73 */
74 #define FF(a, b, c, d, x, s, ac) { \
75 (a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); \
76 (a) = ROTATE_LEFT ((a), (s)); \
77 (a) += (b); \
78 }
79 #define GG(a, b, c, d, x, s, ac) { \
80 (a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
81 (a) = ROTATE_LEFT ((a), (s)); \
82 (a) += (b); \
83 }
84 #define HH(a, b, c, d, x, s, ac) { \
85 (a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
86 (a) = ROTATE_LEFT ((a), (s)); \
87 (a) += (b); \
88 }
89 #define II(a, b, c, d, x, s, ac) { \
90 (a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
91 (a) = ROTATE_LEFT ((a), (s)); \
92 (a) += (b); \
93 }
94
95 /* MD5 initialization. Begins an MD5 operation, writing a new context.
96 */
97 void
98 MD5Init(context)
99 MD5_CTX *context; /* context */
100 {
101 context->count[0] = context->count[1] = 0;
102 /* Load magic initialization constants.
103 */
104 context->state[0] = 0x67452301;
105 context->state[1] = 0xefcdab89;
106 context->state[2] = 0x98badcfe;
107 context->state[3] = 0x10325476;
108 }
109
110 /* MD5 block update operation. Continues an MD5 message-digest
111 operation, processing another message block, and updating the
112 context.
113 */
114 void
115 MD5Update(context, input, inputLen)
116 MD5_CTX *context; /* context */
117 unsigned char *input; /* input block */
118 unsigned int inputLen; /* length of input block */
119 {
120 unsigned int i,
121 index,
122 partLen;
123
124 /* Compute number of bytes mod 64 */
125 index = (unsigned int) ((context->count[0] >> 3) & 0x3F);
126
127 /* Update number of bits */
128 if ((context->count[0] += ((UINT4) inputLen << 3)) < ((UINT4) inputLen << 3))
129 context->count[1]++;
130 context->count[1] += ((UINT4) inputLen >> 29);
131
132 partLen = 64 - index;
133
134 /* Transform as many times as possible.
135 */
136 if (inputLen >= partLen)
137 {
138 MD5_memcpy((POINTER) & context->buffer[index], (POINTER) input, partLen);
139 MD5Transform(context->state, context->buffer);
140
141 for (i = partLen; i + 63 < inputLen; i += 64)
142 MD5Transform(context->state, &input[i]);
143
144 index = 0;
145 }
146 else
147 i = 0;
148
149 /* Buffer remaining input */
150 MD5_memcpy((POINTER) & context->buffer[index], (POINTER) & input[i], inputLen - i);
151 }
152
153 /* MD5 finalization. Ends an MD5 message-digest operation, writing the
154 the message digest and zeroizing the context.
155 */
156 void
157 MD5Final(digest, context)
158 unsigned char digest[16]; /* message digest */
159 MD5_CTX *context; /* context */
160 {
161 unsigned char bits[8];
162 unsigned int index,
163 padLen;
164
165 /* Save number of bits */
166 Encode(bits, context->count, 8);
167
168 /* Pad out to 56 mod 64.
169 */
170 index = (unsigned int) ((context->count[0] >> 3) & 0x3f);
171 padLen = (index < 56) ? (56 - index) : (120 - index);
172 MD5Update(context, PADDING, padLen);
173
174 /* Append length (before padding) */
175 MD5Update(context, bits, 8);
176
177 /* Store state in digest */
178 Encode(digest, context->state, 16);
179
180 /* Zeroize sensitive information.
181 */
182 MD5_memset((POINTER) context, 0, sizeof(*context));
183 }
184
185 /* MD5 basic transformation. Transforms state based on block.
186 */
187 static void
188 MD5Transform(state, block)
189 UINT4 state[4];
190 unsigned char block[64];
191 {
192 UINT4 a = state[0],
193 b = state[1],
194 c = state[2],
195 d = state[3],
196 x[16];
197
198 Decode(x, block, 64);
199
200 /* Round 1 */
201 FF(a, b, c, d, x[0], S11, 0xd76aa478); /* 1 */
202 FF(d, a, b, c, x[1], S12, 0xe8c7b756); /* 2 */
203 FF(c, d, a, b, x[2], S13, 0x242070db); /* 3 */
204 FF(b, c, d, a, x[3], S14, 0xc1bdceee); /* 4 */
205 FF(a, b, c, d, x[4], S11, 0xf57c0faf); /* 5 */
206 FF(d, a, b, c, x[5], S12, 0x4787c62a); /* 6 */
207 FF(c, d, a, b, x[6], S13, 0xa8304613); /* 7 */
208 FF(b, c, d, a, x[7], S14, 0xfd469501); /* 8 */
209 FF(a, b, c, d, x[8], S11, 0x698098d8); /* 9 */
210 FF(d, a, b, c, x[9], S12, 0x8b44f7af); /* 10 */
211 FF(c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
212 FF(b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
213 FF(a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
214 FF(d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
215 FF(c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
216 FF(b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
217
218 /* Round 2 */
219 GG(a, b, c, d, x[1], S21, 0xf61e2562); /* 17 */
220 GG(d, a, b, c, x[6], S22, 0xc040b340); /* 18 */
221 GG(c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
222 GG(b, c, d, a, x[0], S24, 0xe9b6c7aa); /* 20 */
223 GG(a, b, c, d, x[5], S21, 0xd62f105d); /* 21 */
224 GG(d, a, b, c, x[10], S22, 0x2441453); /* 22 */
225 GG(c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
226 GG(b, c, d, a, x[4], S24, 0xe7d3fbc8); /* 24 */
227 GG(a, b, c, d, x[9], S21, 0x21e1cde6); /* 25 */
228 GG(d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
229 GG(c, d, a, b, x[3], S23, 0xf4d50d87); /* 27 */
230
231 GG(b, c, d, a, x[8], S24, 0x455a14ed); /* 28 */
232 GG(a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
233 GG(d, a, b, c, x[2], S22, 0xfcefa3f8); /* 30 */
234 GG(c, d, a, b, x[7], S23, 0x676f02d9); /* 31 */
235 GG(b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
236
237 /* Round 3 */
238 HH(a, b, c, d, x[5], S31, 0xfffa3942); /* 33 */
239 HH(d, a, b, c, x[8], S32, 0x8771f681); /* 34 */
240 HH(c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
241 HH(b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
242 HH(a, b, c, d, x[1], S31, 0xa4beea44); /* 37 */
243 HH(d, a, b, c, x[4], S32, 0x4bdecfa9); /* 38 */
244 HH(c, d, a, b, x[7], S33, 0xf6bb4b60); /* 39 */
245 HH(b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
246 HH(a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
247 HH(d, a, b, c, x[0], S32, 0xeaa127fa); /* 42 */
248 HH(c, d, a, b, x[3], S33, 0xd4ef3085); /* 43 */
249 HH(b, c, d, a, x[6], S34, 0x4881d05); /* 44 */
250 HH(a, b, c, d, x[9], S31, 0xd9d4d039); /* 45 */
251 HH(d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
252 HH(c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
253 HH(b, c, d, a, x[2], S34, 0xc4ac5665); /* 48 */
254
255 /* Round 4 */
256 II(a, b, c, d, x[0], S41, 0xf4292244); /* 49 */
257 II(d, a, b, c, x[7], S42, 0x432aff97); /* 50 */
258 II(c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
259 II(b, c, d, a, x[5], S44, 0xfc93a039); /* 52 */
260 II(a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
261 II(d, a, b, c, x[3], S42, 0x8f0ccc92); /* 54 */
262 II(c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
263 II(b, c, d, a, x[1], S44, 0x85845dd1); /* 56 */
264 II(a, b, c, d, x[8], S41, 0x6fa87e4f); /* 57 */
265 II(d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
266 II(c, d, a, b, x[6], S43, 0xa3014314); /* 59 */
267 II(b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
268 II(a, b, c, d, x[4], S41, 0xf7537e82); /* 61 */
269 II(d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
270 II(c, d, a, b, x[2], S43, 0x2ad7d2bb); /* 63 */
271 II(b, c, d, a, x[9], S44, 0xeb86d391); /* 64 */
272
273 state[0] += a;
274 state[1] += b;
275 state[2] += c;
276 state[3] += d;
277
278 /* Zeroize sensitive information.
279
280 */
281 MD5_memset((POINTER) x, 0, sizeof(x));
282 }
283
284 /* Encodes input (UINT4) into output (unsigned char). Assumes len is
285 a multiple of 4.
286 */
287 static void
288 Encode(output, input, len)
289 unsigned char *output;
290 UINT4 *input;
291 unsigned int len;
292 {
293 unsigned int i,
294 j;
295
296 for (i = 0, j = 0; j < len; i++, j += 4)
297 {
298 output[j] = (unsigned char) (input[i] & 0xff);
299 output[j + 1] = (unsigned char) ((input[i] >> 8) & 0xff);
300 output[j + 2] = (unsigned char) ((input[i] >> 16) & 0xff);
301 output[j + 3] = (unsigned char) ((input[i] >> 24) & 0xff);
302 }
303 }
304
305 /* Decodes input (unsigned char) into output (UINT4). Assumes len is
306 a multiple of 4.
307 */
308 static void
309 Decode(output, input, len)
310 UINT4 *output;
311 unsigned char *input;
312 unsigned int len;
313 {
314 unsigned int i,
315 j;
316
317 for (i = 0, j = 0; j < len; i++, j += 4)
318 output[i] = ((UINT4) input[j]) | (((UINT4) input[j + 1]) << 8) | (((UINT4) input[j + 2]) << 16) | (((UINT4) input[j + 3]) << 24);
319 }
320
321 /* Note: Replace "for loop" with standard memcpy if possible.
322 */
323
324 static void
325 MD5_memcpy(output, input, len)
326 POINTER output;
327 POINTER input;
328 unsigned int len;
329 {
330 unsigned int i;
331
332 for (i = 0; i < len; i++)
333
334 output[i] = input[i];
335 }
336
337 /* Note: Replace "for loop" with standard memset if possible.
338 */
339 static void
340 MD5_memset(output, value, len)
341 POINTER output;
342 int value;
343 unsigned int len;
344 {
345 unsigned int i;
346
347 for (i = 0; i < len; i++)
348 ((char *) output)[i] = (char) value;
349 }