1/*	$NetBSD: md5c.c,v 1.2 2016/06/14 20:47:08 agc Exp $	*/
2
3/*
4 * This file is derived from the RSA Data Security, Inc. MD5 Message-Digest
5 * Algorithm and has been modified by Jason R. Thorpe <thorpej@NetBSD.org>
6 * for portability and formatting.
7 */
8
9/*
10 * Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
11 * rights reserved.
12 *
13 * License to copy and use this software is granted provided that it
14 * is identified as the "RSA Data Security, Inc. MD5 Message-Digest
15 * Algorithm" in all material mentioning or referencing this software
16 * or this function.
17 *
18 * License is also granted to make and use derivative works provided
19 * that such works are identified as "derived from the RSA Data
20 * Security, Inc. MD5 Message-Digest Algorithm" in all material
21 * mentioning or referencing the derived work.
22 *
23 * RSA Data Security, Inc. makes no representations concerning either
24 * the merchantability of this software or the suitability of this
25 * software for any particular purpose. It is provided "as is"
26 * without express or implied warranty of any kind.
27 *
28 * These notices must be retained in any copies of any part of this
29 * documentation and/or software.
30 */
31
32#include <sys/types.h>
33#include <assert.h>
34#include <string.h>
35
36#include "md5.h"
37
38#if !HAVE_MD5_H
39
40#define	ZEROIZE(d, l)		memset((d), 0, (l))
41
42typedef unsigned char *POINTER;
43typedef uint16_t UINT2;
44typedef uint32_t UINT4;
45
46/*
47 * Constants for MD5Transform routine.
48 */
49#define S11 7
50#define S12 12
51#define S13 17
52#define S14 22
53#define S21 5
54#define S22 9
55#define S23 14
56#define S24 20
57#define S31 4
58#define S32 11
59#define S33 16
60#define S34 23
61#define S41 6
62#define S42 10
63#define S43 15
64#define S44 21
65
66static void MD5Transform(UINT4 [4], const unsigned char [64]);
67
68static void Encode(unsigned char *, UINT4 *, unsigned int);
69static void Decode(UINT4 *, const unsigned char *, unsigned int);
70
71/*
72 * Encodes input (UINT4) into output (unsigned char).  Assumes len is
73 * a multiple of 4.
74 */
75static void
76Encode (unsigned char *output,
77	UINT4 *input,
78	unsigned int len)
79{
80	unsigned int i, j;
81
82	for (i = 0, j = 0; j < len; i++, j += 4) {
83		output[j] = (unsigned char)(input[i] & 0xff);
84		output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
85		output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
86		output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
87	}
88}
89
90/*
91 * Decodes input (unsigned char) into output (UINT4).  Assumes len is
92 * a multiple of 4.
93 */
94static void
95Decode (UINT4 *output,
96	const unsigned char *input,
97	unsigned int len)
98{
99	unsigned int i, j;
100
101	for (i = 0, j = 0; j < len; i++, j += 4)
102		output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
103		    (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
104}
105
106static const unsigned char PADDING[64] = {
107	0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
108	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
109	0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
110};
111
112/*
113 * F, G, H and I are basic MD5 functions.
114 */
115#define F(x, y, z)	(((x) & (y)) | ((~x) & (z)))
116#define G(x, y, z)	(((x) & (z)) | ((y) & (~z)))
117#define H(x, y, z)	((x) ^ (y) ^ (z))
118#define I(x, y, z)	((y) ^ ((x) | (~z)))
119
120/*
121 * ROTATE_LEFT rotates x left n bits.
122 */
123#define ROTATE_LEFT(x, n)	(((x) << (n)) | ((x) >> (32-(n))))
124
125/*
126 * FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
127 * Rotation is separate from addition to prevent recomputation.
128 */
129#define FF(a, b, c, d, x, s, ac) { \
130	(a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); \
131	(a) = ROTATE_LEFT ((a), (s)); \
132	(a) += (b); \
133}
134
135#define GG(a, b, c, d, x, s, ac) { \
136	(a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
137	(a) = ROTATE_LEFT ((a), (s)); \
138	(a) += (b); \
139}
140
141#define HH(a, b, c, d, x, s, ac) { \
142	(a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
143	(a) = ROTATE_LEFT ((a), (s)); \
144	(a) += (b); \
145}
146
147#define II(a, b, c, d, x, s, ac) { \
148	(a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
149	(a) = ROTATE_LEFT ((a), (s)); \
150	(a) += (b); \
151}
152
153/*
154 * MD5 initialization. Begins an MD5 operation, writing a new context.
155 */
156void
157netpgpv_MD5Init(NETPGPV_MD5_CTX *context)
158{
159
160	context->count[0] = context->count[1] = 0;
161
162	/* Load magic initialization constants. */
163	context->state[0] = 0x67452301;
164	context->state[1] = 0xefcdab89;
165	context->state[2] = 0x98badcfe;
166	context->state[3] = 0x10325476;
167}
168
169/*
170 * MD5 block update operation.  Continues an MD5 message-digest
171 * operation, processing another message block, and updating the
172 * context.
173 */
174void
175netpgpv_MD5Update(NETPGPV_MD5_CTX *context,
176	const unsigned char *input,	/* input block */
177	unsigned int inputLen)		/* length of input block */
178{
179	unsigned int i, idx, partLen;
180
181	/* Compute number of bytes mod 64 */
182	idx = (unsigned int)((context->count[0] >> 3) & 0x3F);
183
184	/* Update number of bits */
185	if ((context->count[0] += ((UINT4)inputLen << 3))
186	    < ((UINT4)inputLen << 3))
187		context->count[1]++;
188	context->count[1] += ((UINT4)inputLen >> 29);
189
190	partLen = 64 - idx;
191
192	/* Transform as many times as possible. */
193	if (inputLen >= partLen) {
194		memcpy((POINTER)&context->buffer[idx], input, partLen);
195		MD5Transform(context->state, context->buffer);
196
197		for (i = partLen; i + 63 < inputLen; i += 64)
198			MD5Transform(context->state, &input[i]);
199
200		idx = 0;
201	} else
202		i = 0;
203
204	/* Buffer remaining input */
205	memcpy(&context->buffer[idx], &input[i], inputLen - i);
206}
207
208/*
209 * MD5 finalization.  Ends an MD5 message-digest operation, writing the
210 * message digest and zeroing the context.
211 */
212void
213netpgpv_MD5Final(unsigned char digest[16],	/* message digest */
214	NETPGPV_MD5_CTX *context)		/* context */
215{
216	unsigned char bits[8];
217	unsigned int idx, padLen;
218
219	/* Save number of bits */
220	Encode(bits, context->count, 8);
221
222	/* Pad out to 56 mod 64. */
223	idx = (unsigned int)((context->count[0] >> 3) & 0x3f);
224	padLen = (idx < 56) ? (56 - idx) : (120 - idx);
225	netpgpv_MD5Update (context, PADDING, padLen);
226
227	/* Append length (before padding) */
228	netpgpv_MD5Update(context, bits, 8);
229
230	/* Store state in digest */
231	Encode(digest, context->state, 16);
232
233	/* Zeroize sensitive information. */
234	ZEROIZE((POINTER)(void *)context, sizeof(*context));
235}
236
237/*
238 * MD5 basic transformation. Transforms state based on block.
239 */
240static void
241MD5Transform(UINT4 state[4], const unsigned char block[64])
242{
243	UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
244
245	Decode(x, block, 64);
246
247	/* Round 1 */
248	FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
249	FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
250	FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
251	FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
252	FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
253	FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
254	FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
255	FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
256	FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
257	FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
258	FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
259	FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
260	FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
261	FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
262	FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
263	FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
264
265	/* Round 2 */
266	GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
267	GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
268	GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
269	GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
270	GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
271	GG (d, a, b, c, x[10], S22,  0x2441453); /* 22 */
272	GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
273	GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
274	GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
275	GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
276	GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
277	GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
278	GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
279	GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
280	GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
281	GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
282
283	/* Round 3 */
284	HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
285	HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
286	HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
287	HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
288	HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
289	HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
290	HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
291	HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
292	HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
293	HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
294	HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
295	HH (b, c, d, a, x[ 6], S34,  0x4881d05); /* 44 */
296	HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
297	HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
298	HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
299	HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
300
301	/* Round 4 */
302	II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
303	II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
304	II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
305	II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
306	II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
307	II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
308	II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
309	II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
310	II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
311	II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
312	II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
313	II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
314	II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
315	II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
316	II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
317	II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
318
319	state[0] += a;
320	state[1] += b;
321	state[2] += c;
322	state[3] += d;
323
324	/* Zeroize sensitive information. */
325	ZEROIZE((POINTER)(void *)x, sizeof (x));
326}
327
328#endif /* HAVE_MD5_H */
329