Disallow writes to filesystems mounted read-only via NULLFS. In this case
[dragonfly.git] / sys / kern / md5c.c
CommitLineData
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1/*
2 * MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
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 * $FreeBSD: src/sys/kern/md5c.c,v 1.17 1999/12/29 04:54:39 peter Exp $
3e2bd555 26 * $DragonFly: src/sys/kern/md5c.c,v 1.4 2005/04/30 23:04:21 swildner Exp $
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27 *
28 * This code is the same as the code published by RSA Inc. It has been
29 * edited for clarity and style only.
30 */
31
32#include <sys/types.h>
33
34#ifdef _KERNEL
35#include <sys/systm.h>
36#else
37#include <string.h>
38#endif
39
40#include <sys/md5.h>
41
42
43#ifdef _KERNEL
44#define memset(x,y,z) bzero(x,z);
45#define memcpy(x,y,z) bcopy(y, x, z)
46#endif
47
3e2bd555 48#if defined(__i386__)
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49#define Encode memcpy
50#define Decode memcpy
51#else /* __i386__ */
52
53/*
54 * Encodes input (u_int32_t) into output (unsigned char). Assumes len is
55 * a multiple of 4.
56 */
57
58/* XXX not prototyped, and not compatible with memcpy(). */
59static void
fbda7fa6 60Encode (unsigned char *output, u_int32_t *input, unsigned int len)
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61{
62 unsigned int i, j;
63
64 for (i = 0, j = 0; j < len; i++, j += 4) {
65 output[j] = (unsigned char)(input[i] & 0xff);
66 output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
67 output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
68 output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
69 }
70}
71
72/*
73 * Decodes input (unsigned char) into output (u_int32_t). Assumes len is
74 * a multiple of 4.
75 */
76
77static void
fbda7fa6 78Decode (u_int32_t *output, const unsigned char *input, unsigned int len)
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79{
80 unsigned int i, j;
81
82 for (i = 0, j = 0; j < len; i++, j += 4)
83 output[i] = ((u_int32_t)input[j]) | (((u_int32_t)input[j+1]) << 8) |
84 (((u_int32_t)input[j+2]) << 16) | (((u_int32_t)input[j+3]) << 24);
85}
86#endif /* i386 */
87
88static unsigned char PADDING[64] = {
89 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
90 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
91 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
92};
93
94/* F, G, H and I are basic MD5 functions. */
95#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
96#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
97#define H(x, y, z) ((x) ^ (y) ^ (z))
98#define I(x, y, z) ((y) ^ ((x) | (~z)))
99
100/* ROTATE_LEFT rotates x left n bits. */
101#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
102
103/*
104 * FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
105 * Rotation is separate from addition to prevent recomputation.
106 */
107#define FF(a, b, c, d, x, s, ac) { \
108 (a) += F ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
109 (a) = ROTATE_LEFT ((a), (s)); \
110 (a) += (b); \
111 }
112#define GG(a, b, c, d, x, s, ac) { \
113 (a) += G ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
114 (a) = ROTATE_LEFT ((a), (s)); \
115 (a) += (b); \
116 }
117#define HH(a, b, c, d, x, s, ac) { \
118 (a) += H ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
119 (a) = ROTATE_LEFT ((a), (s)); \
120 (a) += (b); \
121 }
122#define II(a, b, c, d, x, s, ac) { \
123 (a) += I ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
124 (a) = ROTATE_LEFT ((a), (s)); \
125 (a) += (b); \
126 }
127
128/* MD5 initialization. Begins an MD5 operation, writing a new context. */
129
130void
fbda7fa6 131MD5Init (MD5_CTX *context)
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132{
133
134 context->count[0] = context->count[1] = 0;
135
136 /* Load magic initialization constants. */
137 context->state[0] = 0x67452301;
138 context->state[1] = 0xefcdab89;
139 context->state[2] = 0x98badcfe;
140 context->state[3] = 0x10325476;
141}
142
143/*
144 * MD5 block update operation. Continues an MD5 message-digest
145 * operation, processing another message block, and updating the
146 * context.
147 */
148
149void
fbda7fa6 150MD5Update (MD5_CTX *context, const unsigned char *input, unsigned int inputLen)
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151{
152 unsigned int i, index, partLen;
153
154 /* Compute number of bytes mod 64 */
155 index = (unsigned int)((context->count[0] >> 3) & 0x3F);
156
157 /* Update number of bits */
158 if ((context->count[0] += ((u_int32_t)inputLen << 3))
159 < ((u_int32_t)inputLen << 3))
160 context->count[1]++;
161 context->count[1] += ((u_int32_t)inputLen >> 29);
162
163 partLen = 64 - index;
164
165 /* Transform as many times as possible. */
166 if (inputLen >= partLen) {
167 memcpy((void *)&context->buffer[index], (const void *)input,
168 partLen);
169 MD5Transform (context->state, context->buffer);
170
171 for (i = partLen; i + 63 < inputLen; i += 64)
172 MD5Transform (context->state, &input[i]);
173
174 index = 0;
175 }
176 else
177 i = 0;
178
179 /* Buffer remaining input */
180 memcpy ((void *)&context->buffer[index], (const void *)&input[i],
181 inputLen-i);
182}
183
184/*
185 * MD5 padding. Adds padding followed by original length.
186 */
187
188void
fbda7fa6 189MD5Pad (MD5_CTX *context)
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190{
191 unsigned char bits[8];
192 unsigned int index, padLen;
193
194 /* Save number of bits */
195 Encode (bits, context->count, 8);
196
197 /* Pad out to 56 mod 64. */
198 index = (unsigned int)((context->count[0] >> 3) & 0x3f);
199 padLen = (index < 56) ? (56 - index) : (120 - index);
200 MD5Update (context, PADDING, padLen);
201
202 /* Append length (before padding) */
203 MD5Update (context, bits, 8);
204}
205
206/*
207 * MD5 finalization. Ends an MD5 message-digest operation, writing the
208 * the message digest and zeroizing the context.
209 */
210
211void
fbda7fa6 212MD5Final (unsigned char digest[16], MD5_CTX *context)
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213{
214 /* Do padding. */
215 MD5Pad (context);
216
217 /* Store state in digest */
218 Encode (digest, context->state, 16);
219
220 /* Zeroize sensitive information. */
221 memset ((void *)context, 0, sizeof (*context));
222}
223
224/* MD5 basic transformation. Transforms state based on block. */
225
226void
fbda7fa6 227MD5Transform (u_int32_t state[4], const unsigned char block[64])
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228{
229 u_int32_t a = state[0], b = state[1], c = state[2], d = state[3], x[16];
230
231 Decode (x, block, 64);
232
233 /* Round 1 */
234#define S11 7
235#define S12 12
236#define S13 17
237#define S14 22
238 FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
239 FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
240 FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
241 FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
242 FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
243 FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
244 FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
245 FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
246 FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
247 FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
248 FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
249 FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
250 FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
251 FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
252 FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
253 FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
254
255 /* Round 2 */
256#define S21 5
257#define S22 9
258#define S23 14
259#define S24 20
260 GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
261 GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
262 GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
263 GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
264 GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
265 GG (d, a, b, c, x[10], S22, 0x2441453); /* 22 */
266 GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
267 GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
268 GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
269 GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
270 GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
271 GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
272 GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
273 GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
274 GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
275 GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
276
277 /* Round 3 */
278#define S31 4
279#define S32 11
280#define S33 16
281#define S34 23
282 HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
283 HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
284 HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
285 HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
286 HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
287 HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
288 HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
289 HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
290 HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
291 HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
292 HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
293 HH (b, c, d, a, x[ 6], S34, 0x4881d05); /* 44 */
294 HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
295 HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
296 HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
297 HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
298
299 /* Round 4 */
300#define S41 6
301#define S42 10
302#define S43 15
303#define S44 21
304 II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
305 II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
306 II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
307 II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
308 II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
309 II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
310 II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
311 II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
312 II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
313 II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
314 II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
315 II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
316 II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
317 II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
318 II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
319 II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
320
321 state[0] += a;
322 state[1] += b;
323 state[2] += c;
324 state[3] += d;
325
326 /* Zeroize sensitive information. */
327 memset ((void *)x, 0, sizeof (x));
328}