1/*
2 * This code implements the MD5 message-digest algorithm.
3 * The algorithm is due to Ron Rivest.  This code was
4 * written by Colin Plumb in 1993, no copyright is claimed.
5 * This code is in the public domain; do with it what you wish.
6 *
7 * Equivalent code is available from RSA Data Security, Inc.
8 * This code has been tested against that, and is equivalent,
9 * except that you don't need to include two pages of legalese
10 * with every copy.
11 *
12 * To compute the message digest of a chunk of bytes, declare an
13 * MD5Context structure, pass it to MD5Init, call MD5Update as
14 * needed on buffers full of bytes, and then call MD5Final, which
15 * will fill a supplied 16-byte array with the digest.
16 */
17#include <string.h>	/* for memcpy() */
18#include "md5.h"
19
20#ifndef HIGHFIRST
21#define byteReverse(buf, len)	/* Nothing */
22#else
23void byteReverse(unsigned char *buf, unsigned longs);
24
25#ifndef ASM_MD5
26/*
27 * Note: this code is harmless on little-endian machines.
28 */
29void byteReverse(unsigned char *buf, unsigned longs)
30{
31	uint32 t;
32	do {
33		t = (uint32)((unsigned)buf[3]<<8 | buf[2]) << 16 |
34		            ((unsigned)buf[1]<<8 | buf[0]);
35		*(uint32 *)buf = t;
36		buf += 4;
37	} while (--longs);
38}
39#endif
40#endif
41
42/*
43 * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
44 * initialization constants.
45 */
46void
47MD5Init(struct MD5Context *ctx)
48{
49	ctx->buf[0] = 0x67452301;
50	ctx->buf[1] = 0xefcdab89;
51	ctx->buf[2] = 0x98badcfe;
52	ctx->buf[3] = 0x10325476;
53
54	ctx->bits[0] = 0;
55	ctx->bits[1] = 0;
56}
57
58/*
59 * Update context to reflect the concatenation of another buffer full
60 * of bytes.
61 */
62void
63MD5Update(struct MD5Context *ctx, unsigned char const *buf, unsigned len)
64{
65	uint32 t;
66
67	/* Update bitcount */
68
69	t = ctx->bits[0];
70	if ((ctx->bits[0] = t + ((uint32)len << 3)) < t)
71		ctx->bits[1]++;	/* Carry from low to high */
72	ctx->bits[1] += len >> 29;
73
74	t = (t >> 3) & 0x3f;	/* Bytes already in shsInfo->data */
75
76	/* Handle any leading odd-sized chunks */
77
78	if ( t ) {
79		unsigned char *p = (unsigned char *)ctx->in + t;
80
81		t = 64-t;
82		if (len < t) {
83			memcpy(p, buf, len);
84			return;
85		}
86		memcpy(p, buf, t);
87		byteReverse(ctx->in, 16);
88		MD5Transform(ctx->buf, (uint32 *)ctx->in);
89		buf += t;
90		len -= t;
91	}
92
93	/* Process data in 64-byte chunks */
94
95	while (len >= 64) {
96		memcpy(ctx->in, buf, 64);
97		byteReverse(ctx->in, 16);
98		MD5Transform(ctx->buf, (uint32 *)ctx->in);
99		buf += 64;
100		len -= 64;
101	}
102
103	/* Handle any remaining bytes of data. */
104
105	memcpy(ctx->in, buf, len);
106}
107
108/*
109 * Final wrapup - pad to 64-byte boundary with the bit pattern
110 * 1 0* (64-bit count of bits processed, MSB-first)
111 */
112void
113MD5Final(unsigned char digest[16], struct MD5Context *ctx)
114{
115	unsigned count;
116	unsigned char *p;
117
118	/* Compute number of bytes mod 64 */
119	count = (ctx->bits[0] >> 3) & 0x3F;
120
121	/* Set the first char of padding to 0x80.  This is safe since there is
122	   always at least one byte free */
123	p = (unsigned char*)(ctx->in) + count;
124	*p++ = 0x80;
125
126	/* Bytes of padding needed to make 64 bytes */
127	count = 64 - 1 - count;
128
129	/* Pad out to 56 mod 64 */
130	if (count < 8) {
131		/* Two lots of padding:  Pad the first block to 64 bytes */
132		memset(p, 0, count);
133		byteReverse(ctx->in, 16);
134		MD5Transform(ctx->buf, (uint32 *)ctx->in);
135
136		/* Now fill the next block with 56 bytes */
137		memset(ctx->in, 0, 56);
138	} else {
139		/* Pad block to 56 bytes */
140		memset(p, 0, count-8);
141	}
142	byteReverse(ctx->in, 14);
143
144	/* Append length in bits and transform */
145	((uint32 *)ctx->in)[ 14 ] = ctx->bits[0];
146	((uint32 *)ctx->in)[ 15 ] = ctx->bits[1];
147
148	MD5Transform(ctx->buf, (uint32 *)ctx->in);
149	byteReverse((unsigned char *)ctx->buf, 4);
150	memcpy(digest, ctx->buf, 16);
151	memset(ctx, 0, sizeof(ctx));	/* In case it's sensitive */
152}
153
154#ifndef ASM_MD5
155
156/* The four core functions - F1 is optimized somewhat */
157
158/* #define F1(x, y, z) (x & y | ~x & z) */
159#define F1(x, y, z) (z ^ (x & (y ^ z)))
160#define F2(x, y, z) F1(z, x, y)
161#define F3(x, y, z) (x ^ y ^ z)
162#define F4(x, y, z) (y ^ (x | ~z))
163
164/* This is the central step in the MD5 algorithm. */
165#define MD5STEP(f, w, x, y, z, data, s) \
166	( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
167
168/*
169 * The core of the MD5 algorithm, this alters an existing MD5 hash to
170 * reflect the addition of 16 longwords of new data.  MD5Update blocks
171 * the data and converts bytes into longwords for this routine.
172 */
173void
174MD5Transform(uint32 buf[4], uint32 const in[16])
175{
176	register uint32 a, b, c, d;
177
178	a = buf[0];
179	b = buf[1];
180	c = buf[2];
181	d = buf[3];
182
183	MD5STEP(F1, a, b, c, d, in[ 0]+0xd76aa478,  7);
184	MD5STEP(F1, d, a, b, c, in[ 1]+0xe8c7b756, 12);
185	MD5STEP(F1, c, d, a, b, in[ 2]+0x242070db, 17);
186	MD5STEP(F1, b, c, d, a, in[ 3]+0xc1bdceee, 22);
187	MD5STEP(F1, a, b, c, d, in[ 4]+0xf57c0faf,  7);
188	MD5STEP(F1, d, a, b, c, in[ 5]+0x4787c62a, 12);
189	MD5STEP(F1, c, d, a, b, in[ 6]+0xa8304613, 17);
190	MD5STEP(F1, b, c, d, a, in[ 7]+0xfd469501, 22);
191	MD5STEP(F1, a, b, c, d, in[ 8]+0x698098d8,  7);
192	MD5STEP(F1, d, a, b, c, in[ 9]+0x8b44f7af, 12);
193	MD5STEP(F1, c, d, a, b, in[10]+0xffff5bb1, 17);
194	MD5STEP(F1, b, c, d, a, in[11]+0x895cd7be, 22);
195	MD5STEP(F1, a, b, c, d, in[12]+0x6b901122,  7);
196	MD5STEP(F1, d, a, b, c, in[13]+0xfd987193, 12);
197	MD5STEP(F1, c, d, a, b, in[14]+0xa679438e, 17);
198	MD5STEP(F1, b, c, d, a, in[15]+0x49b40821, 22);
199
200	MD5STEP(F2, a, b, c, d, in[ 1]+0xf61e2562,  5);
201	MD5STEP(F2, d, a, b, c, in[ 6]+0xc040b340,  9);
202	MD5STEP(F2, c, d, a, b, in[11]+0x265e5a51, 14);
203	MD5STEP(F2, b, c, d, a, in[ 0]+0xe9b6c7aa, 20);
204	MD5STEP(F2, a, b, c, d, in[ 5]+0xd62f105d,  5);
205	MD5STEP(F2, d, a, b, c, in[10]+0x02441453,  9);
206	MD5STEP(F2, c, d, a, b, in[15]+0xd8a1e681, 14);
207	MD5STEP(F2, b, c, d, a, in[ 4]+0xe7d3fbc8, 20);
208	MD5STEP(F2, a, b, c, d, in[ 9]+0x21e1cde6,  5);
209	MD5STEP(F2, d, a, b, c, in[14]+0xc33707d6,  9);
210	MD5STEP(F2, c, d, a, b, in[ 3]+0xf4d50d87, 14);
211	MD5STEP(F2, b, c, d, a, in[ 8]+0x455a14ed, 20);
212	MD5STEP(F2, a, b, c, d, in[13]+0xa9e3e905,  5);
213	MD5STEP(F2, d, a, b, c, in[ 2]+0xfcefa3f8,  9);
214	MD5STEP(F2, c, d, a, b, in[ 7]+0x676f02d9, 14);
215	MD5STEP(F2, b, c, d, a, in[12]+0x8d2a4c8a, 20);
216
217	MD5STEP(F3, a, b, c, d, in[ 5]+0xfffa3942,  4);
218	MD5STEP(F3, d, a, b, c, in[ 8]+0x8771f681, 11);
219	MD5STEP(F3, c, d, a, b, in[11]+0x6d9d6122, 16);
220	MD5STEP(F3, b, c, d, a, in[14]+0xfde5380c, 23);
221	MD5STEP(F3, a, b, c, d, in[ 1]+0xa4beea44,  4);
222	MD5STEP(F3, d, a, b, c, in[ 4]+0x4bdecfa9, 11);
223	MD5STEP(F3, c, d, a, b, in[ 7]+0xf6bb4b60, 16);
224	MD5STEP(F3, b, c, d, a, in[10]+0xbebfbc70, 23);
225	MD5STEP(F3, a, b, c, d, in[13]+0x289b7ec6,  4);
226	MD5STEP(F3, d, a, b, c, in[ 0]+0xeaa127fa, 11);
227	MD5STEP(F3, c, d, a, b, in[ 3]+0xd4ef3085, 16);
228	MD5STEP(F3, b, c, d, a, in[ 6]+0x04881d05, 23);
229	MD5STEP(F3, a, b, c, d, in[ 9]+0xd9d4d039,  4);
230	MD5STEP(F3, d, a, b, c, in[12]+0xe6db99e5, 11);
231	MD5STEP(F3, c, d, a, b, in[15]+0x1fa27cf8, 16);
232	MD5STEP(F3, b, c, d, a, in[ 2]+0xc4ac5665, 23);
233
234	MD5STEP(F4, a, b, c, d, in[ 0]+0xf4292244,  6);
235	MD5STEP(F4, d, a, b, c, in[ 7]+0x432aff97, 10);
236	MD5STEP(F4, c, d, a, b, in[14]+0xab9423a7, 15);
237	MD5STEP(F4, b, c, d, a, in[ 5]+0xfc93a039, 21);
238	MD5STEP(F4, a, b, c, d, in[12]+0x655b59c3,  6);
239	MD5STEP(F4, d, a, b, c, in[ 3]+0x8f0ccc92, 10);
240	MD5STEP(F4, c, d, a, b, in[10]+0xffeff47d, 15);
241	MD5STEP(F4, b, c, d, a, in[ 1]+0x85845dd1, 21);
242	MD5STEP(F4, a, b, c, d, in[ 8]+0x6fa87e4f,  6);
243	MD5STEP(F4, d, a, b, c, in[15]+0xfe2ce6e0, 10);
244	MD5STEP(F4, c, d, a, b, in[ 6]+0xa3014314, 15);
245	MD5STEP(F4, b, c, d, a, in[13]+0x4e0811a1, 21);
246	MD5STEP(F4, a, b, c, d, in[ 4]+0xf7537e82,  6);
247	MD5STEP(F4, d, a, b, c, in[11]+0xbd3af235, 10);
248	MD5STEP(F4, c, d, a, b, in[ 2]+0x2ad7d2bb, 15);
249	MD5STEP(F4, b, c, d, a, in[ 9]+0xeb86d391, 21);
250
251	buf[0] += a;
252	buf[1] += b;
253	buf[2] += c;
254	buf[3] += d;
255}
256#endif
257