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 * Changed so as no longer to depend on Colin Plumb's `usual.h' header
18 * definitions
19 *  - Ian Jackson <ian@chiark.greenend.org.uk>.
20 * Still in the public domain.
21 */
22
23#include <sys/types.h>    /* for stupid systems */
24
25#include <string.h>   /* for memcpy() */
26
27#include "md5_utils.h"
28
29void
30byteSwap(UWORD32 *buf, unsigned words)
31{
32    md5byte *p;
33
34    /* Only swap bytes for big endian machines */
35    int i = 1;
36
37    if (*(char *)&i == 1)
38        return;
39
40    p = (md5byte *)buf;
41
42    do
43    {
44        *buf++ = (UWORD32)((unsigned)p[3] << 8 | p[2]) << 16 |
45                 ((unsigned)p[1] << 8 | p[0]);
46        p += 4;
47    }
48    while (--words);
49}
50
51/*
52 * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
53 * initialization constants.
54 */
55void
56MD5Init(struct MD5Context *ctx)
57{
58    ctx->buf[0] = 0x67452301;
59    ctx->buf[1] = 0xefcdab89;
60    ctx->buf[2] = 0x98badcfe;
61    ctx->buf[3] = 0x10325476;
62
63    ctx->bytes[0] = 0;
64    ctx->bytes[1] = 0;
65}
66
67/*
68 * Update context to reflect the concatenation of another buffer full
69 * of bytes.
70 */
71void
72MD5Update(struct MD5Context *ctx, md5byte const *buf, unsigned len)
73{
74    UWORD32 t;
75
76    /* Update byte count */
77
78    t = ctx->bytes[0];
79
80    if ((ctx->bytes[0] = t + len) < t)
81        ctx->bytes[1]++;  /* Carry from low to high */
82
83    t = 64 - (t & 0x3f);  /* Space available in ctx->in (at least 1) */
84
85    if (t > len)
86    {
87        memcpy((md5byte *)ctx->in + 64 - t, buf, len);
88        return;
89    }
90
91    /* First chunk is an odd size */
92    memcpy((md5byte *)ctx->in + 64 - t, buf, t);
93    byteSwap(ctx->in, 16);
94    MD5Transform(ctx->buf, ctx->in);
95    buf += t;
96    len -= t;
97
98    /* Process data in 64-byte chunks */
99    while (len >= 64)
100    {
101        memcpy(ctx->in, buf, 64);
102        byteSwap(ctx->in, 16);
103        MD5Transform(ctx->buf, ctx->in);
104        buf += 64;
105        len -= 64;
106    }
107
108    /* Handle any remaining bytes of data. */
109    memcpy(ctx->in, buf, len);
110}
111
112/*
113 * Final wrapup - pad to 64-byte boundary with the bit pattern
114 * 1 0* (64-bit count of bits processed, MSB-first)
115 */
116void
117MD5Final(md5byte digest[16], struct MD5Context *ctx)
118{
119    int count = ctx->bytes[0] & 0x3f; /* Number of bytes in ctx->in */
120    md5byte *p = (md5byte *)ctx->in + count;
121
122    /* Set the first char of padding to 0x80.  There is always room. */
123    *p++ = 0x80;
124
125    /* Bytes of padding needed to make 56 bytes (-8..55) */
126    count = 56 - 1 - count;
127
128    if (count < 0)    /* Padding forces an extra block */
129    {
130        memset(p, 0, count + 8);
131        byteSwap(ctx->in, 16);
132        MD5Transform(ctx->buf, ctx->in);
133        p = (md5byte *)ctx->in;
134        count = 56;
135    }
136
137    memset(p, 0, count);
138    byteSwap(ctx->in, 14);
139
140    /* Append length in bits and transform */
141    ctx->in[14] = ctx->bytes[0] << 3;
142    ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
143    MD5Transform(ctx->buf, ctx->in);
144
145    byteSwap(ctx->buf, 4);
146    memcpy(digest, ctx->buf, 16);
147    memset(ctx, 0, sizeof(*ctx)); /* In case it's sensitive */
148}
149
150#ifndef ASM_MD5
151
152/* The four core functions - F1 is optimized somewhat */
153
154/* #define F1(x, y, z) (x & y | ~x & z) */
155#define F1(x, y, z) (z ^ (x & (y ^ z)))
156#define F2(x, y, z) F1(z, x, y)
157#define F3(x, y, z) (x ^ y ^ z)
158#define F4(x, y, z) (y ^ (x | ~z))
159
160/* This is the central step in the MD5 algorithm. */
161#define MD5STEP(f,w,x,y,z,in,s) \
162    (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
163
164/*
165 * The core of the MD5 algorithm, this alters an existing MD5 hash to
166 * reflect the addition of 16 longwords of new data.  MD5Update blocks
167 * the data and converts bytes into longwords for this routine.
168 */
169void
170MD5Transform(UWORD32 buf[4], UWORD32 const in[16])
171{
172    register UWORD32 a, b, c, d;
173
174    a = buf[0];
175    b = buf[1];
176    c = buf[2];
177    d = buf[3];
178
179    MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
180    MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
181    MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
182    MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
183    MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
184    MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
185    MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
186    MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
187    MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
188    MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
189    MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
190    MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
191    MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
192    MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
193    MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
194    MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
195
196    MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
197    MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
198    MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
199    MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
200    MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
201    MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
202    MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
203    MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
204    MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
205    MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
206    MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
207    MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
208    MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
209    MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
210    MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
211    MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
212
213    MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
214    MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
215    MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
216    MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
217    MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
218    MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
219    MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
220    MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
221    MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
222    MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
223    MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
224    MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
225    MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
226    MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
227    MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
228    MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
229
230    MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
231    MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
232    MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
233    MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
234    MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
235    MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
236    MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
237    MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
238    MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
239    MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
240    MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
241    MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
242    MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
243    MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
244    MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
245    MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
246
247    buf[0] += a;
248    buf[1] += b;
249    buf[2] += c;
250    buf[3] += d;
251}
252
253#endif
254