1 /* This file is not used by busybox right now.
2  * However, the code here seems to be a tiny bit smaller
3  * than one in md5.c. Need to investigate which one
4  * is better overall...
5  * Hint: grep for md5prime to find places where you can switch
6  * md5.c/md5prime.c
7  */
8 
9 /*
10  * MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
11  *
12  * Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
13  * rights reserved.
14  *
15  * License to copy and use this software is granted provided that it
16  * is identified as the "RSA Data Security, Inc. MD5 Message-Digest
17  * Algorithm" in all material mentioning or referencing this software
18  * or this function.
19  *
20  * License is also granted to make and use derivative works provided
21  * that such works are identified as "derived from the RSA Data
22  * Security, Inc. MD5 Message-Digest Algorithm" in all material
23  * mentioning or referencing the derived work.
24  *
25  * RSA Data Security, Inc. makes no representations concerning either
26  * the merchantability of this software or the suitability of this
27  * software for any particular purpose. It is provided "as is"
28  * without express or implied warranty of any kind.
29  *
30  * These notices must be retained in any copies of any part of this
31  * documentation and/or software.
32  *
33  * $FreeBSD: src/lib/libmd/md5c.c,v 1.9.2.1 1999/08/29 14:57:12 peter Exp $
34  *
35  * This code is the same as the code published by RSA Inc.  It has been
36  * edited for clarity and style only.
37  *
38  * ----------------------------------------------------------------------------
39  * The md5_crypt() function was taken from freeBSD's libcrypt and contains
40  * this license:
41  *    "THE BEER-WARE LICENSE" (Revision 42):
42  *     <phk@login.dknet.dk> wrote this file.  As long as you retain this notice you
43  *     can do whatever you want with this stuff. If we meet some day, and you think
44  *     this stuff is worth it, you can buy me a beer in return.   Poul-Henning Kamp
45  *
46  * $FreeBSD: src/lib/libcrypt/crypt.c,v 1.7.2.1 1999/08/29 14:56:33 peter Exp $
47  *
48  * ----------------------------------------------------------------------------
49  * On April 19th, 2001 md5_crypt() was modified to make it reentrant
50  * by Erik Andersen <andersen@uclibc.org>
51  *
52  * June 28, 2001             Manuel Novoa III
53  *
54  * "Un-inlined" code using loops and static const tables in order to
55  * reduce generated code size (on i386 from approx 4k to approx 2.5k).
56  *
57  * June 29, 2001             Manuel Novoa III
58  *
59  * Completely removed static PADDING array.
60  *
61  * Reintroduced the loop unrolling in md5_transform and added the
62  * MD5_SMALL option for configurability.  Define below as:
63  *       0    fully unrolled loops
64  *       1    partially unrolled (4 ops per loop)
65  *       2    no unrolling -- introduces the need to swap 4 variables (slow)
66  *       3    no unrolling and all 4 loops merged into one with switch
67  *               in each loop (glacial)
68  * On i386, sizes are roughly (-Os -fno-builtin):
69  *     0: 3k     1: 2.5k     2: 2.2k     3: 2k
70  *
71  * Since SuSv3 does not require crypt_r, modified again August 7, 2002
72  * by Erik Andersen to remove reentrance stuff...
73  */
74 
75 #include "libbb.h"
76 
77 /* 1: fastest, 3: smallest */
78 #if CONFIG_MD5_SMALL < 1
79 # define MD5_SMALL 1
80 #elif CONFIG_MD5_SMALL > 3
81 # define MD5_SMALL 3
82 #else
83 # define MD5_SMALL CONFIG_MD5_SMALL
84 #endif
85 
86 #if BB_LITTLE_ENDIAN
87 #define memcpy32_cpu2le memcpy
88 #define memcpy32_le2cpu memcpy
89 #else
90 /* Encodes input (uint32_t) into output (unsigned char).
91  * Assumes len is a multiple of 4. */
92 static void
memcpy32_cpu2le(unsigned char * output,uint32_t * input,unsigned len)93 memcpy32_cpu2le(unsigned char *output, uint32_t *input, unsigned len)
94 {
95 	unsigned i, j;
96 	for (i = 0, j = 0; j < len; i++, j += 4) {
97 		output[j] = input[i];
98 		output[j+1] = (input[i] >> 8);
99 		output[j+2] = (input[i] >> 16);
100 		output[j+3] = (input[i] >> 24);
101 	}
102 }
103 /* Decodes input (unsigned char) into output (uint32_t).
104  * Assumes len is a multiple of 4. */
105 static void
memcpy32_le2cpu(uint32_t * output,const unsigned char * input,unsigned len)106 memcpy32_le2cpu(uint32_t *output, const unsigned char *input, unsigned len)
107 {
108 	unsigned i, j;
109 	for (i = 0, j = 0; j < len; i++, j += 4)
110 		output[i] = ((uint32_t)input[j])
111 			| (((uint32_t)input[j+1]) << 8)
112 			| (((uint32_t)input[j+2]) << 16)
113 			| (((uint32_t)input[j+3]) << 24);
114 }
115 #endif /* i386 */
116 
117 /* F, G, H and I are basic MD5 functions. */
118 #define F(x, y, z) (((x) & (y)) | (~(x) & (z)))
119 #define G(x, y, z) (((x) & (z)) | ((y) & ~(z)))
120 #define H(x, y, z) ((x) ^ (y) ^ (z))
121 #define I(x, y, z) ((y) ^ ((x) | ~(z)))
122 
123 /* rotl32 rotates x left n bits. */
124 #define rotl32(x, n) (((x) << (n)) | ((x) >> (32 - (n))))
125 
126 /*
127  * FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
128  * Rotation is separate from addition to prevent recomputation.
129  */
130 #define FF(a, b, c, d, x, s, ac) { \
131 	(a) += F((b), (c), (d)) + (x) + (uint32_t)(ac); \
132 	(a) = rotl32((a), (s)); \
133 	(a) += (b); \
134 	}
135 #define GG(a, b, c, d, x, s, ac) { \
136 	(a) += G((b), (c), (d)) + (x) + (uint32_t)(ac); \
137 	(a) = rotl32((a), (s)); \
138 	(a) += (b); \
139 	}
140 #define HH(a, b, c, d, x, s, ac) { \
141 	(a) += H((b), (c), (d)) + (x) + (uint32_t)(ac); \
142 	(a) = rotl32((a), (s)); \
143 	(a) += (b); \
144 	}
145 #define II(a, b, c, d, x, s, ac) { \
146 	(a) += I((b), (c), (d)) + (x) + (uint32_t)(ac); \
147 	(a) = rotl32((a), (s)); \
148 	(a) += (b); \
149 	}
150 
151 /* MD5 basic transformation. Transforms state based on block. */
md5_transform(uint32_t state[4],const unsigned char block[64])152 static void md5_transform(uint32_t state[4], const unsigned char block[64])
153 {
154 	uint32_t a, b, c, d, x[16];
155 #if MD5_SMALL > 1
156 	uint32_t temp;
157 	const unsigned char *ps;
158 
159 	static const unsigned char S[] = {
160 		7, 12, 17, 22,
161 		5, 9, 14, 20,
162 		4, 11, 16, 23,
163 		6, 10, 15, 21
164 	};
165 #endif /* MD5_SMALL > 1 */
166 
167 #if MD5_SMALL > 0
168 	const uint32_t *pc;
169 	const unsigned char *pp;
170 	int i;
171 
172 	static const uint32_t C[] = {
173 		/* round 1 */
174 		0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,
175 		0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
176 		0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
177 		0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
178 		/* round 2 */
179 		0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,
180 		0xd62f105d, 0x2441453,  0xd8a1e681, 0xe7d3fbc8,
181 		0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
182 		0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
183 		/* round 3 */
184 		0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,
185 		0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
186 		0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x4881d05,
187 		0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
188 		/* round 4 */
189 		0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039,
190 		0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
191 		0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
192 		0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391
193 	};
194 	static const unsigned char P[] = {
195 		0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, /* 1 */
196 		1, 6, 11, 0, 5, 10, 15, 4, 9, 14, 3, 8, 13, 2, 7, 12, /* 2 */
197 		5, 8, 11, 14, 1, 4, 7, 10, 13, 0, 3, 6, 9, 12, 15, 2, /* 3 */
198 		0, 7, 14, 5, 12, 3, 10, 1, 8, 15, 6, 13, 4, 11, 2, 9  /* 4 */
199 	};
200 
201 #endif /* MD5_SMALL > 0 */
202 
203 	memcpy32_le2cpu(x, block, 64);
204 
205 	a = state[0];
206 	b = state[1];
207 	c = state[2];
208 	d = state[3];
209 
210 #if MD5_SMALL > 2
211 	pc = C;
212 	pp = P;
213 	ps = S - 4;
214 	for (i = 0; i < 64; i++) {
215 		if ((i & 0x0f) == 0) ps += 4;
216 		temp = a;
217 		switch (i>>4) {
218 			case 0:
219 				temp += F(b, c, d);
220 				break;
221 			case 1:
222 				temp += G(b, c, d);
223 				break;
224 			case 2:
225 				temp += H(b, c, d);
226 				break;
227 			case 3:
228 				temp += I(b, c, d);
229 				break;
230 		}
231 		temp += x[*pp++] + *pc++;
232 		temp = rotl32(temp, ps[i & 3]);
233 		temp += b;
234 		a = d; d = c; c = b; b = temp;
235 	}
236 #elif MD5_SMALL > 1
237 	pc = C;
238 	pp = P;
239 	ps = S;
240 	/* Round 1 */
241 	for (i = 0; i < 16; i++) {
242 		FF(a, b, c, d, x[*pp], ps[i & 0x3], *pc); pp++; pc++;
243 		temp = d; d = c; c = b; b = a; a = temp;
244 	}
245 	/* Round 2 */
246 	ps += 4;
247 	for (; i < 32; i++) {
248 		GG(a, b, c, d, x[*pp], ps[i & 0x3], *pc); pp++; pc++;
249 		temp = d; d = c; c = b; b = a; a = temp;
250 	}
251 	/* Round 3 */
252 	ps += 4;
253 	for (; i < 48; i++) {
254 		HH(a, b, c, d, x[*pp], ps[i & 0x3], *pc); pp++; pc++;
255 		temp = d; d = c; c = b; b = a; a = temp;
256 	}
257 	/* Round 4 */
258 	ps += 4;
259 	for (; i < 64; i++) {
260 		II(a, b, c, d, x[*pp], ps[i & 0x3], *pc); pp++; pc++;
261 		temp = d; d = c; c = b; b = a; a = temp;
262 	}
263 #elif MD5_SMALL > 0
264 	pc = C;
265 	pp = P;
266 	/* Round 1 */
267 	for (i = 0; i < 4; i++) {
268 		FF(a, b, c, d, x[*pp],  7, *pc); pp++; pc++;
269 		FF(d, a, b, c, x[*pp], 12, *pc); pp++; pc++;
270 		FF(c, d, a, b, x[*pp], 17, *pc); pp++; pc++;
271 		FF(b, c, d, a, x[*pp], 22, *pc); pp++; pc++;
272 	}
273 	/* Round 2 */
274 	for (i = 0; i < 4; i++) {
275 		GG(a, b, c, d, x[*pp],  5, *pc); pp++; pc++;
276 		GG(d, a, b, c, x[*pp],  9, *pc); pp++; pc++;
277 		GG(c, d, a, b, x[*pp], 14, *pc); pp++; pc++;
278 		GG(b, c, d, a, x[*pp], 20, *pc); pp++; pc++;
279 	}
280 	/* Round 3 */
281 	for (i = 0; i < 4; i++) {
282 		HH(a, b, c, d, x[*pp],  4, *pc); pp++; pc++;
283 		HH(d, a, b, c, x[*pp], 11, *pc); pp++; pc++;
284 		HH(c, d, a, b, x[*pp], 16, *pc); pp++; pc++;
285 		HH(b, c, d, a, x[*pp], 23, *pc); pp++; pc++;
286 	}
287 	/* Round 4 */
288 	for (i = 0; i < 4; i++) {
289 		II(a, b, c, d, x[*pp],  6, *pc); pp++; pc++;
290 		II(d, a, b, c, x[*pp], 10, *pc); pp++; pc++;
291 		II(c, d, a, b, x[*pp], 15, *pc); pp++; pc++;
292 		II(b, c, d, a, x[*pp], 21, *pc); pp++; pc++;
293 	}
294 #else
295 	/* Round 1 */
296 #define S11 7
297 #define S12 12
298 #define S13 17
299 #define S14 22
300 	FF(a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
301 	FF(d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
302 	FF(c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
303 	FF(b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
304 	FF(a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
305 	FF(d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
306 	FF(c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
307 	FF(b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
308 	FF(a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
309 	FF(d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
310 	FF(c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
311 	FF(b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
312 	FF(a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
313 	FF(d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
314 	FF(c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
315 	FF(b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
316 	/* Round 2 */
317 #define S21 5
318 #define S22 9
319 #define S23 14
320 #define S24 20
321 	GG(a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
322 	GG(d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
323 	GG(c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
324 	GG(b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
325 	GG(a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
326 	GG(d, a, b, c, x[10], S22,  0x2441453); /* 22 */
327 	GG(c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
328 	GG(b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
329 	GG(a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
330 	GG(d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
331 	GG(c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
332 	GG(b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
333 	GG(a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
334 	GG(d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
335 	GG(c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
336 	GG(b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
337 	/* Round 3 */
338 #define S31 4
339 #define S32 11
340 #define S33 16
341 #define S34 23
342 	HH(a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
343 	HH(d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
344 	HH(c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
345 	HH(b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
346 	HH(a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
347 	HH(d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
348 	HH(c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
349 	HH(b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
350 	HH(a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
351 	HH(d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
352 	HH(c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
353 	HH(b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
354 	HH(a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
355 	HH(d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
356 	HH(c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
357 	HH(b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
358 	/* Round 4 */
359 #define S41 6
360 #define S42 10
361 #define S43 15
362 #define S44 21
363 	II(a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
364 	II(d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
365 	II(c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
366 	II(b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
367 	II(a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
368 	II(d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
369 	II(c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
370 	II(b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
371 	II(a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
372 	II(d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
373 	II(c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
374 	II(b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
375 	II(a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
376 	II(d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
377 	II(c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
378 	II(b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
379 #endif
380 
381 	state[0] += a;
382 	state[1] += b;
383 	state[2] += c;
384 	state[3] += d;
385 
386 	/* Zeroize sensitive information. */
387 	memset(x, 0, sizeof(x));
388 }
389 
390 
391 /* MD5 initialization. */
md5_begin(md5_ctx_t * context)392 void FAST_FUNC md5_begin(md5_ctx_t *context)
393 {
394 	context->count[0] = context->count[1] = 0;
395 	/* Load magic initialization constants.  */
396 	context->state[0] = 0x67452301;
397 	context->state[1] = 0xefcdab89;
398 	context->state[2] = 0x98badcfe;
399 	context->state[3] = 0x10325476;
400 }
401 
402 /*
403  * MD5 block update operation. Continues an MD5 message-digest
404  * operation, processing another message block, and updating
405  * the context.
406  */
md5_hash(const void * buffer,size_t inputLen,md5_ctx_t * context)407 void FAST_FUNC md5_hash(const void *buffer, size_t inputLen, md5_ctx_t *context)
408 {
409 	unsigned i, idx, partLen;
410 	const unsigned char *input = buffer;
411 
412 	/* Compute number of bytes mod 64 */
413 	idx = (context->count[0] >> 3) & 0x3F;
414 
415 	/* Update number of bits */
416 	context->count[0] += (inputLen << 3);
417 	if (context->count[0] < (inputLen << 3))
418 		context->count[1]++;
419 	context->count[1] += (inputLen >> 29);
420 
421 	/* Transform as many times as possible. */
422 	i = 0;
423 	partLen = 64 - idx;
424 	if (inputLen >= partLen) {
425 		memcpy(&context->buffer[idx], input, partLen);
426 		md5_transform(context->state, context->buffer);
427 		for (i = partLen; i + 63 < inputLen; i += 64)
428 			md5_transform(context->state, &input[i]);
429 		idx = 0;
430 	}
431 
432 	/* Buffer remaining input */
433 	memcpy(&context->buffer[idx], &input[i], inputLen - i);
434 }
435 
436 /*
437  * MD5 finalization. Ends an MD5 message-digest operation,
438  * writing the message digest.
439  */
md5_end(void * digest,md5_ctx_t * context)440 unsigned FAST_FUNC md5_end(void *digest, md5_ctx_t *context)
441 {
442 	unsigned idx, padLen;
443 	unsigned char bits[8];
444 	unsigned char padding[64];
445 
446 	/* Add padding followed by original length. */
447 	memset(padding, 0, sizeof(padding));
448 	padding[0] = 0x80;
449 	/* save number of bits */
450 	memcpy32_cpu2le(bits, context->count, 8);
451 	/* pad out to 56 mod 64 */
452 	idx = (context->count[0] >> 3) & 0x3f;
453 	padLen = (idx < 56) ? (56 - idx) : (120 - idx);
454 	md5_hash(padding, padLen, context);
455 	/* append length (before padding) */
456 	md5_hash(bits, 8, context);
457 
458 	/* Store state in digest */
459 	memcpy32_cpu2le(digest, context->state, 16);
460 	return 16;
461 }
462