summaryrefslogtreecommitdiff
path: root/md5.c
blob: 0fb1a78a73b222711d3ad63ab06946a7585b74cf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
/*
 * $Id: md5.c,v 1.1 2002-05-11 14:42:35 cpbotha Exp $
 *
 * This code implements the MD5 message-digest algorithm.
 * The algorithm is due to Ron Rivest.  This code was
 * written by Colin Plumb in 1993, no copyright is claimed.
 * This code is in the public domain; do with it what you wish.
 *
 * Equivalent code is available from RSA Data Security, Inc.
 * This code has been tested against that, and is equivalent,
 * except that you don't need to include two pages of legalese
 * with every copy.
 *
 * To compute the message digest of a chunk of bytes, declare an
 * MD5Context structure, pass it to MD5Init, call MD5Update as
 * needed on buffers full of bytes, and then call MD5Final, which
 * will fill a supplied 16-byte array with the digest.
 *
 */

#include <string.h>
#include "md5.h"

#ifndef HIGHFIRST
#define byteReverse(buf, len)	/* Nothing */
#else
static void byteReverse(unsigned char *buf, unsigned longs);

#ifndef ASM_MD5
/*
 * Note: this code is harmless on little-endian machines.
 */
static void byteReverse(unsigned char *buf, unsigned longs)
{
	uint32 t;
	do {
		t = (uint32) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
		    ((unsigned) buf[1] << 8 | buf[0]);
		*(uint32 *) buf = t;
		buf += 4;
	} while (--longs);
}
#endif
#endif

/*
 * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
 * initialization constants.
 */
void MD5Name(MD5Init)(struct MD5Context *ctx)
{
	ctx->buf[0] = 0x67452301U;
	ctx->buf[1] = 0xefcdab89U;
	ctx->buf[2] = 0x98badcfeU;
	ctx->buf[3] = 0x10325476U;

	ctx->bits[0] = 0;
	ctx->bits[1] = 0;
}

/*
 * Update context to reflect the concatenation of another buffer full
 * of bytes.
 */
void MD5Name(MD5Update)(struct MD5Context *ctx, unsigned const char *buf, unsigned len)
{
	uint32 t;

	/* Update bitcount */

	t = ctx->bits[0];
	if ((ctx->bits[0] = t + ((uint32) len << 3)) < t)
		ctx->bits[1]++;	/* Carry from low to high */
	ctx->bits[1] += len >> 29;

	t = (t >> 3) & 0x3f;	/* Bytes already in shsInfo->data */

	/* Handle any leading odd-sized chunks */

	if (t) {
		unsigned char *p = (unsigned char *) ctx->in + t;

		t = 64 - t;
		if (len < t) {
			memcpy(p, buf, len);
			return;
		}
		memcpy(p, buf, t);
		byteReverse(ctx->in, 16);
		MD5Name(MD5Transform)(ctx->buf, (uint32 *) ctx->in);
		buf += t;
		len -= t;
	}
	/* Process data in 64-byte chunks */

	while (len >= 64) {
		memcpy(ctx->in, buf, 64);
		byteReverse(ctx->in, 16);
		MD5Name(MD5Transform)(ctx->buf, (uint32 *) ctx->in);
		buf += 64;
		len -= 64;
	}

	/* Handle any remaining bytes of data. */

	memcpy(ctx->in, buf, len);
}

/*
 * Final wrapup - pad to 64-byte boundary with the bit pattern 
 * 1 0* (64-bit count of bits processed, MSB-first)
 */
void MD5Name(MD5Final)(unsigned char digest[16], struct MD5Context *ctx)
{
	unsigned count;
	unsigned char *p;

	/* Compute number of bytes mod 64 */
	count = (ctx->bits[0] >> 3) & 0x3F;

	/* Set the first char of padding to 0x80.  This is safe since there is
	   always at least one byte free */
	p = ctx->in + count;
	*p++ = 0x80;

	/* Bytes of padding needed to make 64 bytes */
	count = 64 - 1 - count;

	/* Pad out to 56 mod 64 */
	if (count < 8) {
		/* Two lots of padding:  Pad the first block to 64 bytes */
		memset(p, 0, count);
		byteReverse(ctx->in, 16);
		MD5Name(MD5Transform)(ctx->buf, (uint32 *) ctx->in);

		/* Now fill the next block with 56 bytes */
		memset(ctx->in, 0, 56);
	} else {
		/* Pad block to 56 bytes */
		memset(p, 0, count - 8);
	}
	byteReverse(ctx->in, 14);

	/* Append length in bits and transform */
	((uint32 *) ctx->in)[14] = ctx->bits[0];
	((uint32 *) ctx->in)[15] = ctx->bits[1];

	MD5Name(MD5Transform)(ctx->buf, (uint32 *) ctx->in);
	byteReverse((unsigned char *) ctx->buf, 4);
	memcpy(digest, ctx->buf, 16);
	memset(ctx, 0, sizeof(ctx));	/* In case it's sensitive */
}

#ifndef ASM_MD5

/* The four core functions - F1 is optimized somewhat */

/* #define F1(x, y, z) (x & y | ~x & z) */
#define F1(x, y, z) (z ^ (x & (y ^ z)))
#define F2(x, y, z) F1(z, x, y)
#define F3(x, y, z) (x ^ y ^ z)
#define F4(x, y, z) (y ^ (x | ~z))

/* This is the central step in the MD5 algorithm. */
#define MD5STEP(f, w, x, y, z, data, s) \
	( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )

/*
 * The core of the MD5 algorithm, this alters an existing MD5 hash to
 * reflect the addition of 16 longwords of new data.  MD5Update blocks
 * the data and converts bytes into longwords for this routine.
 */
void MD5Name(MD5Transform)(uint32 buf[4], uint32 const in[16])
{
	register uint32 a, b, c, d;

	a = buf[0];
	b = buf[1];
	c = buf[2];
	d = buf[3];

	MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478U, 7);
	MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756U, 12);
	MD5STEP(F1, c, d, a, b, in[2] + 0x242070dbU, 17);
	MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceeeU, 22);
	MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0fafU, 7);
	MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62aU, 12);
	MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613U, 17);
	MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501U, 22);
	MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8U, 7);
	MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7afU, 12);
	MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1U, 17);
	MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7beU, 22);
	MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122U, 7);
	MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193U, 12);
	MD5STEP(F1, c, d, a, b, in[14] + 0xa679438eU, 17);
	MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821U, 22);

	MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562U, 5);
	MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340U, 9);
	MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51U, 14);
	MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aaU, 20);
	MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105dU, 5);
	MD5STEP(F2, d, a, b, c, in[10] + 0x02441453U, 9);
	MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681U, 14);
	MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8U, 20);
	MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6U, 5);
	MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6U, 9);
	MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87U, 14);
	MD5STEP(F2, b, c, d, a, in[8] + 0x455a14edU, 20);
	MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905U, 5);
	MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8U, 9);
	MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9U, 14);
	MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8aU, 20);

	MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942U, 4);
	MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681U, 11);
	MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122U, 16);
	MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380cU, 23);
	MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44U, 4);
	MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9U, 11);
	MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60U, 16);
	MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70U, 23);
	MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6U, 4);
	MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127faU, 11);
	MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085U, 16);
	MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05U, 23);
	MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039U, 4);
	MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5U, 11);
	MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8U, 16);
	MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665U, 23);

	MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244U, 6);
	MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97U, 10);
	MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7U, 15);
	MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039U, 21);
	MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3U, 6);
	MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92U, 10);
	MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47dU, 15);
	MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1U, 21);
	MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4fU, 6);
	MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0U, 10);
	MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314U, 15);
	MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1U, 21);
	MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82U, 6);
	MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235U, 10);
	MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bbU, 15);
	MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391U, 21);

	buf[0] += a;
	buf[1] += b;
	buf[2] += c;
	buf[3] += d;
}

#endif