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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 
18 /* Brutally hacked by John Walker back from ANSI C to K&R (no
19    prototypes) to maintain the tradition that Netfone will compile
20    with Sun's original "cc". */
21 
22 #include "md5.h"
23 
24 
25 #ifndef HIGHFIRST
26 #define byteReverse(buf, len)	/* Nothing */
27 #else
28 /*
29  * Note: this code is harmless on little-endian machines.
30  */
31 static void
byteReverse(unsigned char * buf,unsigned longs)32 byteReverse(unsigned char *buf,
33 	    unsigned longs)
34 {
35     uint32_t t;
36     do {
37 	t = (uint32_t) ((unsigned) buf[3] << 8 | buf[2]) << 16 |
38 	    ((unsigned) buf[1] << 8 | buf[0]);
39 	*(uint32_t *) buf = t;
40 	buf += 4;
41     } while (--longs);
42 }
43 #endif
44 
45 
46 /* The four core functions - F1 is optimized somewhat */
47 
48 /* #define F1(x, y, z) (x & y | ~x & z) */
49 #define F1(x, y, z) (z ^ (x & (y ^ z)))
50 #define F2(x, y, z) F1(z, x, y)
51 #define F3(x, y, z) (x ^ y ^ z)
52 #define F4(x, y, z) (y ^ (x | ~z))
53 
54 /* This is the central step in the MD5 algorithm. */
55 #define MD5STEP(f, w, x, y, z, data, s) \
56 	( w += f(x, y, z) + data,  w = w<<s | w>>(32-s),  w += x )
57 
58 /*
59  * The core of the MD5 algorithm, this alters an existing MD5 hash to
60  * reflect the addition of 16 longwords of new data.  MD5Update blocks
61  * the data and converts bytes into longwords for this routine.
62  */
63 static void
MD5Transform(uint32_t buf[4],uint32_t in[16])64 MD5Transform(uint32_t buf[4],
65 	     uint32_t in[16])
66 {
67   uint32_t a, b, c, d;
68 
69     a = buf[0];
70     b = buf[1];
71     c = buf[2];
72     d = buf[3];
73 
74     MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
75     MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
76     MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
77     MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
78     MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
79     MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
80     MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
81     MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
82     MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
83     MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
84     MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
85     MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
86     MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
87     MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
88     MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
89     MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
90 
91     MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
92     MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
93     MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
94     MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
95     MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
96     MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
97     MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
98     MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
99     MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
100     MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
101     MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
102     MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
103     MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
104     MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
105     MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
106     MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
107 
108     MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
109     MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
110     MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
111     MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
112     MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
113     MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
114     MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
115     MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
116     MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
117     MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
118     MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
119     MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
120     MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
121     MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
122     MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
123     MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
124 
125     MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
126     MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
127     MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
128     MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
129     MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
130     MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
131     MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
132     MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
133     MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
134     MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
135     MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
136     MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
137     MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
138     MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
139     MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
140     MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
141 
142     buf[0] += a;
143     buf[1] += b;
144     buf[2] += c;
145     buf[3] += d;
146 }
147 
148 
149 /*
150  * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
151  * initialization constants.
152  */
153 void
MD5Init(struct MD5Context * ctx)154 MD5Init(struct MD5Context *ctx)
155 {
156     ctx->buf[0] = 0x67452301;
157     ctx->buf[1] = 0xefcdab89;
158     ctx->buf[2] = 0x98badcfe;
159     ctx->buf[3] = 0x10325476;
160 
161     ctx->bits[0] = 0;
162     ctx->bits[1] = 0;
163 }
164 
165 /*
166  * Update context to reflect the concatenation of another buffer full
167  * of bytes.
168  */
169 void
MD5Update(struct MD5Context * ctx,const void * data,unsigned len)170 MD5Update(struct MD5Context *ctx,
171 	  const void *data,
172 	  unsigned len)
173 {
174     const unsigned char *buf = data;
175     uint32_t t;
176 
177     /* Update bitcount */
178 
179     t = ctx->bits[0];
180     if ((ctx->bits[0] = t + ((uint32_t) len << 3)) < t)
181 	ctx->bits[1]++; 	/* Carry from low to high */
182     ctx->bits[1] += len >> 29;
183 
184     t = (t >> 3) & 0x3f;	/* Bytes already in shsInfo->data */
185 
186     /* Handle any leading odd-sized chunks */
187 
188     if (t) {
189 	unsigned char *p = (unsigned char *) ctx->in + t;
190 
191 	t = 64 - t;
192 	if (len < t) {
193 	    memcpy(p, buf, len);
194 	    return;
195 	}
196 	memcpy(p, buf, t);
197 	byteReverse(ctx->in, 16);
198 	MD5Transform(ctx->buf, (uint32_t *) ctx->in);
199 	buf += t;
200 	len -= t;
201     }
202     /* Process data in 64-byte chunks */
203 
204     while (len >= 64) {
205 	memcpy(ctx->in, buf, 64);
206 	byteReverse(ctx->in, 16);
207 	MD5Transform(ctx->buf, (uint32_t *) ctx->in);
208 	buf += 64;
209 	len -= 64;
210     }
211 
212     /* Handle any remaining bytes of data. */
213 
214     memcpy(ctx->in, buf, len);
215 }
216 
217 /*
218  * Final wrapup - pad to 64-byte boundary with the bit pattern
219  * 1 0* (64-bit count of bits processed, MSB-first)
220  */
221 void
MD5Final(unsigned char digest[16],struct MD5Context * ctx)222 MD5Final (unsigned char digest[16],
223           struct MD5Context *ctx)
224 {
225   unsigned count;
226   unsigned char *p;
227 
228   /* Compute number of bytes mod 64 */
229   count = (ctx->bits[0] >> 3) & 0x3F;
230 
231   /* Set the first char of padding to 0x80.  This is safe since there is
232      always at least one byte free */
233   p = ctx->in + count;
234   *p++ = 0x80;
235 
236   /* Bytes of padding needed to make 64 bytes */
237   count = 64 - 1 - count;
238 
239   /* Pad out to 56 mod 64 */
240   if (count < 8)
241     {
242       /* Two lots of padding:  Pad the first block to 64 bytes */
243       memset(p, 0, count);
244       byteReverse(ctx->in, 16);
245       MD5Transform(ctx->buf, (uint32_t *) ctx->in);
246 
247       /* Now fill the next block with 56 bytes */
248       memset(ctx->in, 0, 56);
249     }
250   else
251     {
252       /* Pad block to 56 bytes */
253       memset(p, 0, count - 8);
254     }
255   byteReverse(ctx->in, 14);
256 
257   /* Append length in bits and transform */
258   ((uint32_t *) ctx->in)[14] = ctx->bits[0];
259   ((uint32_t *) ctx->in)[15] = ctx->bits[1];
260 
261   MD5Transform(ctx->buf, (uint32_t *) ctx->in);
262   byteReverse((unsigned char *) ctx->buf, 4);
263   memcpy(digest, ctx->buf, 16);
264   memset(ctx, 0, sizeof(struct MD5Context));        /* In case it's sensitive */
265 }
266 
267 /* end of md5.c */
268