xref: /freebsd/sys/kern/md5c.c (revision ae83180158c4c937f170e31eff311b18c0286a93)
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  * This code is the same as the code published by RSA Inc.  It has been
26  * edited for clarity and style only.
27  */
28 
29 /*
30  * This file should be kept in sync with src/lib/libmd/md5c.c
31  */
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
34 
35 #include <sys/types.h>
36 
37 #ifdef _KERNEL
38 #include <sys/systm.h>
39 #else
40 #include <string.h>
41 #endif
42 
43 #include <machine/endian.h>
44 #include <sys/endian.h>
45 #include <sys/md5.h>
46 
47 static void MD5Transform(u_int32_t [4], const unsigned char [64]);
48 
49 #ifdef _KERNEL
50 #define memset(x,y,z)	bzero(x,z);
51 #define memcpy(x,y,z)	bcopy(y, x, z)
52 #endif
53 
54 #if (BYTE_ORDER == LITTLE_ENDIAN)
55 #define Encode memcpy
56 #define Decode memcpy
57 #else
58 
59 /*
60  * Encodes input (u_int32_t) into output (unsigned char). Assumes len is
61  * a multiple of 4.
62  */
63 
64 static void
65 Encode (unsigned char *output, u_int32_t *input, unsigned int len)
66 {
67 	unsigned int i;
68 	u_int32_t *op = (u_int32_t *)output;
69 
70 	for (i = 0; i < len / 4; i++)
71 		op[i] = htole32(input[i]);
72 }
73 
74 /*
75  * Decodes input (unsigned char) into output (u_int32_t). Assumes len is
76  * a multiple of 4.
77  */
78 
79 static void
80 Decode (u_int32_t *output, const unsigned char *input, unsigned int len)
81 {
82 	unsigned int i;
83 	const u_int32_t *ip = (const u_int32_t *)input;
84 
85 	for (i = 0; i < len / 4; i++)
86 		output[i] = le32toh(ip[i]);
87 }
88 #endif
89 
90 static unsigned char PADDING[64] = {
91   0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
92   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
93   0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
94 };
95 
96 /* F, G, H and I are basic MD5 functions. */
97 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
98 #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
99 #define H(x, y, z) ((x) ^ (y) ^ (z))
100 #define I(x, y, z) ((y) ^ ((x) | (~z)))
101 
102 /* ROTATE_LEFT rotates x left n bits. */
103 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
104 
105 /*
106  * FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
107  * Rotation is separate from addition to prevent recomputation.
108  */
109 #define FF(a, b, c, d, x, s, ac) { \
110 	(a) += F ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
111 	(a) = ROTATE_LEFT ((a), (s)); \
112 	(a) += (b); \
113 	}
114 #define GG(a, b, c, d, x, s, ac) { \
115 	(a) += G ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
116 	(a) = ROTATE_LEFT ((a), (s)); \
117 	(a) += (b); \
118 	}
119 #define HH(a, b, c, d, x, s, ac) { \
120 	(a) += H ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
121 	(a) = ROTATE_LEFT ((a), (s)); \
122 	(a) += (b); \
123 	}
124 #define II(a, b, c, d, x, s, ac) { \
125 	(a) += I ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
126 	(a) = ROTATE_LEFT ((a), (s)); \
127 	(a) += (b); \
128 	}
129 
130 /* MD5 initialization. Begins an MD5 operation, writing a new context. */
131 
132 void
133 MD5Init (context)
134 	MD5_CTX *context;
135 {
136 
137 	context->count[0] = context->count[1] = 0;
138 
139 	/* Load magic initialization constants.  */
140 	context->state[0] = 0x67452301;
141 	context->state[1] = 0xefcdab89;
142 	context->state[2] = 0x98badcfe;
143 	context->state[3] = 0x10325476;
144 }
145 
146 /*
147  * MD5 block update operation. Continues an MD5 message-digest
148  * operation, processing another message block, and updating the
149  * context.
150  */
151 
152 void
153 MD5Update (context, input, inputLen)
154 	MD5_CTX *context;
155 	const unsigned char *input;
156 	unsigned int inputLen;
157 {
158 	unsigned int i, index, partLen;
159 
160 	/* Compute number of bytes mod 64 */
161 	index = (unsigned int)((context->count[0] >> 3) & 0x3F);
162 
163 	/* Update number of bits */
164 	if ((context->count[0] += ((u_int32_t)inputLen << 3))
165 	    < ((u_int32_t)inputLen << 3))
166 		context->count[1]++;
167 	context->count[1] += ((u_int32_t)inputLen >> 29);
168 
169 	partLen = 64 - index;
170 
171 	/* Transform as many times as possible. */
172 	if (inputLen >= partLen) {
173 		memcpy((void *)&context->buffer[index], (const void *)input,
174 		    partLen);
175 		MD5Transform (context->state, context->buffer);
176 
177 		for (i = partLen; i + 63 < inputLen; i += 64)
178 			MD5Transform (context->state, &input[i]);
179 
180 		index = 0;
181 	}
182 	else
183 		i = 0;
184 
185 	/* Buffer remaining input */
186 	memcpy ((void *)&context->buffer[index], (const void *)&input[i],
187 	    inputLen-i);
188 }
189 
190 /*
191  * MD5 padding. Adds padding followed by original length.
192  */
193 
194 void
195 MD5Pad (context)
196 	MD5_CTX *context;
197 {
198 	unsigned char bits[8];
199 	unsigned int index, padLen;
200 
201 	/* Save number of bits */
202 	Encode (bits, context->count, 8);
203 
204 	/* Pad out to 56 mod 64. */
205 	index = (unsigned int)((context->count[0] >> 3) & 0x3f);
206 	padLen = (index < 56) ? (56 - index) : (120 - index);
207 	MD5Update (context, PADDING, padLen);
208 
209 	/* Append length (before padding) */
210 	MD5Update (context, bits, 8);
211 }
212 
213 /*
214  * MD5 finalization. Ends an MD5 message-digest operation, writing the
215  * the message digest and zeroizing the context.
216  */
217 
218 void
219 MD5Final (digest, context)
220 	unsigned char digest[16];
221 	MD5_CTX *context;
222 {
223 	/* Do padding. */
224 	MD5Pad (context);
225 
226 	/* Store state in digest */
227 	Encode (digest, context->state, 16);
228 
229 	/* Zeroize sensitive information. */
230 	memset ((void *)context, 0, sizeof (*context));
231 }
232 
233 /* MD5 basic transformation. Transforms state based on block. */
234 
235 static void
236 MD5Transform (state, block)
237 	u_int32_t state[4];
238 	const unsigned char block[64];
239 {
240 	u_int32_t a = state[0], b = state[1], c = state[2], d = state[3], x[16];
241 
242 	Decode (x, block, 64);
243 
244 	/* Round 1 */
245 #define S11 7
246 #define S12 12
247 #define S13 17
248 #define S14 22
249 	FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
250 	FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
251 	FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
252 	FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
253 	FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
254 	FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
255 	FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
256 	FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
257 	FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
258 	FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
259 	FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
260 	FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
261 	FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
262 	FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
263 	FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
264 	FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
265 
266 	/* Round 2 */
267 #define S21 5
268 #define S22 9
269 #define S23 14
270 #define S24 20
271 	GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
272 	GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
273 	GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
274 	GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
275 	GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
276 	GG (d, a, b, c, x[10], S22,  0x2441453); /* 22 */
277 	GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
278 	GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
279 	GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
280 	GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
281 	GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
282 	GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
283 	GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
284 	GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
285 	GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
286 	GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
287 
288 	/* Round 3 */
289 #define S31 4
290 #define S32 11
291 #define S33 16
292 #define S34 23
293 	HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
294 	HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
295 	HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
296 	HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
297 	HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
298 	HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
299 	HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
300 	HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
301 	HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
302 	HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
303 	HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
304 	HH (b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
305 	HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
306 	HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
307 	HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
308 	HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
309 
310 	/* Round 4 */
311 #define S41 6
312 #define S42 10
313 #define S43 15
314 #define S44 21
315 	II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
316 	II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
317 	II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
318 	II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
319 	II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
320 	II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
321 	II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
322 	II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
323 	II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
324 	II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
325 	II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
326 	II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
327 	II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
328 	II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
329 	II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
330 	II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
331 
332 	state[0] += a;
333 	state[1] += b;
334 	state[2] += c;
335 	state[3] += d;
336 
337 	/* Zeroize sensitive information. */
338 	memset ((void *)x, 0, sizeof (x));
339 }
340