1/*-
2 * SPDX-License-Identifier: RSA-MD
3 *
4 * MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
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 * This code is the same as the code published by RSA Inc.  It has been
28 * edited for clarity and style only.
29 */
30
31#include <sys/types.h>
32
33#ifdef _KERNEL
34#include <sys/systm.h>
35#else
36#include <string.h>
37#endif
38
39#include <machine/endian.h>
40#include <sys/endian.h>
41#include "md5.h"
42
43static void MD5Transform(u_int32_t [4], const unsigned char [64]);
44
45#ifdef _KERNEL
46#define memset(x,y,z)	bzero(x,z);
47#define memcpy(x,y,z)	bcopy(y, x, z)
48#endif
49
50#if (BYTE_ORDER == LITTLE_ENDIAN)
51#define Encode memcpy
52#define Decode memcpy
53#else
54
55/*
56 * Encodes input (u_int32_t) into output (unsigned char). Assumes len is
57 * a multiple of 4.
58 */
59
60static void
61Encode (unsigned char *output, u_int32_t *input, unsigned int len)
62{
63	unsigned int i;
64	u_int32_t *op = (u_int32_t *)output;
65
66	for (i = 0; i < len / 4; i++)
67		op[i] = htole32(input[i]);
68}
69
70/*
71 * Decodes input (unsigned char) into output (u_int32_t). Assumes len is
72 * a multiple of 4.
73 */
74
75static void
76Decode (u_int32_t *output, const unsigned char *input, unsigned int len)
77{
78	unsigned int i;
79	const u_int32_t *ip = (const u_int32_t *)input;
80
81	for (i = 0; i < len / 4; i++)
82		output[i] = le32toh(ip[i]);
83}
84#endif
85
86static unsigned char PADDING[64] = {
87  0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
88  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
89  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
90};
91
92/* F, G, H and I are basic MD5 functions. */
93#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
94#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
95#define H(x, y, z) ((x) ^ (y) ^ (z))
96#define I(x, y, z) ((y) ^ ((x) | (~z)))
97
98/* ROTATE_LEFT rotates x left n bits. */
99#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
100
101/*
102 * FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
103 * Rotation is separate from addition to prevent recomputation.
104 */
105#define FF(a, b, c, d, x, s, ac) { \
106	(a) += F ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
107	(a) = ROTATE_LEFT ((a), (s)); \
108	(a) += (b); \
109	}
110#define GG(a, b, c, d, x, s, ac) { \
111	(a) += G ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
112	(a) = ROTATE_LEFT ((a), (s)); \
113	(a) += (b); \
114	}
115#define HH(a, b, c, d, x, s, ac) { \
116	(a) += H ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
117	(a) = ROTATE_LEFT ((a), (s)); \
118	(a) += (b); \
119	}
120#define II(a, b, c, d, x, s, ac) { \
121	(a) += I ((b), (c), (d)) + (x) + (u_int32_t)(ac); \
122	(a) = ROTATE_LEFT ((a), (s)); \
123	(a) += (b); \
124	}
125
126/* MD5 initialization. Begins an MD5 operation, writing a new context. */
127
128void
129MD5Init (MD5_CTX *context)
130{
131
132	context->count[0] = context->count[1] = 0;
133
134	/* Load magic initialization constants.  */
135	context->state[0] = 0x67452301;
136	context->state[1] = 0xefcdab89;
137	context->state[2] = 0x98badcfe;
138	context->state[3] = 0x10325476;
139}
140
141/*
142 * MD5 block update operation. Continues an MD5 message-digest
143 * operation, processing another message block, and updating the
144 * context.
145 */
146
147void
148MD5Update (MD5_CTX *context, const void *in, unsigned int inputLen)
149{
150	unsigned int i, idx, partLen;
151	const unsigned char *input = in;
152
153	/* Compute number of bytes mod 64 */
154	idx = (unsigned int)((context->count[0] >> 3) & 0x3F);
155
156	/* Update number of bits */
157	if ((context->count[0] += ((u_int32_t)inputLen << 3))
158	    < ((u_int32_t)inputLen << 3))
159		context->count[1]++;
160	context->count[1] += ((u_int32_t)inputLen >> 29);
161
162	partLen = 64 - idx;
163
164	/* Transform as many times as possible. */
165	if (inputLen >= partLen) {
166		memcpy((void *)&context->buffer[idx], (const void *)input,
167		    partLen);
168		MD5Transform (context->state, context->buffer);
169
170		for (i = partLen; i + 63 < inputLen; i += 64)
171			MD5Transform (context->state, &input[i]);
172
173		idx = 0;
174	}
175	else
176		i = 0;
177
178	/* Buffer remaining input */
179	memcpy ((void *)&context->buffer[idx], (const void *)&input[i],
180	    inputLen-i);
181}
182
183/*
184 * MD5 padding. Adds padding followed by original length.
185 */
186
187void
188MD5Pad (MD5_CTX *context)
189{
190	unsigned char bits[8];
191	unsigned int idx, padLen;
192
193	/* Save number of bits */
194	Encode (bits, context->count, 8);
195
196	/* Pad out to 56 mod 64. */
197	idx = (unsigned int)((context->count[0] >> 3) & 0x3f);
198	padLen = (idx < 56) ? (56 - idx) : (120 - idx);
199	MD5Update (context, PADDING, padLen);
200
201	/* Append length (before padding) */
202	MD5Update (context, bits, 8);
203}
204
205/*
206 * MD5 finalization. Ends an MD5 message-digest operation, writing the
207 * the message digest and zeroizing the context.
208 */
209
210void
211MD5Final (unsigned char digest[16], MD5_CTX *context)
212{
213	/* Do padding. */
214	MD5Pad (context);
215
216	/* Store state in digest */
217	Encode (digest, context->state, 16);
218
219	/* Zeroize sensitive information. */
220	explicit_bzero(context, sizeof(*context));
221}
222
223/* MD5 basic transformation. Transforms state based on block. */
224
225static void
226MD5Transform (u_int32_t state[4], const unsigned char block[64])
227{
228	u_int32_t a = state[0], b = state[1], c = state[2], d = state[3], x[16];
229
230	Decode (x, block, 64);
231
232	/* Round 1 */
233#define S11 7
234#define S12 12
235#define S13 17
236#define S14 22
237	FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
238	FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
239	FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
240	FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
241	FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
242	FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
243	FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
244	FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
245	FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
246	FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
247	FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
248	FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
249	FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
250	FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
251	FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
252	FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
253
254	/* Round 2 */
255#define S21 5
256#define S22 9
257#define S23 14
258#define S24 20
259	GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
260	GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
261	GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
262	GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
263	GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
264	GG (d, a, b, c, x[10], S22,  0x2441453); /* 22 */
265	GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
266	GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
267	GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
268	GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
269	GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
270	GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
271	GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
272	GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
273	GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
274	GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
275
276	/* Round 3 */
277#define S31 4
278#define S32 11
279#define S33 16
280#define S34 23
281	HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
282	HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
283	HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
284	HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
285	HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
286	HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
287	HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
288	HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
289	HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
290	HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
291	HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
292	HH (b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
293	HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
294	HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
295	HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
296	HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
297
298	/* Round 4 */
299#define S41 6
300#define S42 10
301#define S43 15
302#define S44 21
303	II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
304	II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
305	II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
306	II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
307	II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
308	II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
309	II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
310	II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
311	II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
312	II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
313	II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
314	II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
315	II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
316	II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
317	II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
318	II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
319
320	state[0] += a;
321	state[1] += b;
322	state[2] += c;
323	state[3] += d;
324
325	/* Zeroize sensitive information. */
326	memset ((void *)x, 0, sizeof (x));
327}
328
329#ifdef WEAK_REFS
330/* When building libmd, provide weak references. Note: this is not
331   activated in the context of compiling these sources for internal
332   use in libcrypt.
333 */
334#undef MD5Init
335__weak_reference(_libmd_MD5Init, MD5Init);
336#undef MD5Update
337__weak_reference(_libmd_MD5Update, MD5Update);
338#undef MD5Pad
339__weak_reference(_libmd_MD5Pad, MD5Pad);
340#undef MD5Final
341__weak_reference(_libmd_MD5Final, MD5Final);
342#undef MD5Transform
343__weak_reference(_libmd_MD5Transform, MD5Transform);
344#endif
345