1 /*
2 * MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
3 *
4 * Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
5 * rights reserved.
6 *
7 * License to copy and use this software is granted provided that it
8 * is identified as the "RSA Data Security, Inc. MD5 Message-Digest
9 * Algorithm" in all material mentioning or referencing this software
10 * or this function.
11 *
12 * License is also granted to make and use derivative works provided
13 * that such works are identified as "derived from the RSA Data
14 * Security, Inc. MD5 Message-Digest Algorithm" in all material
15 * mentioning or referencing the derived work.
16 *
17 * RSA Data Security, Inc. makes no representations concerning either
18 * the merchantability of this software or the suitability of this
19 * software for any particular purpose. It is provided "as is"
20 * without express or implied warranty of any kind.
21 *
22 * These notices must be retained in any copies of any part of this
23 * documentation and/or software.
24 *
25 * This code is the same as the code published by RSA Inc. It has been
26 * edited for clarity and style only.
27 */
28
29 #include <sys/types.h>
30 #include <string.h>
31
32 #include "./md5.h"
33
34 static void MD5Transform(unsigned int [4], const unsigned char [64]);
35
36 #if (BYTE_ORDER == LITTLE_ENDIAN)
37 #define Encode memcpy
38 #define Decode memcpy
39 #else
40
41 /*
42 * OS X doesn't have le32toh() or htole32()
43 */
44 #ifdef __APPLE__
45 #include <libkern/OSByteOrder.h>
46 #define le32toh(x) OSSwapLittleToHostInt32(x)
47 #define htole32(x) OSSwapHostToLittleInt32(x)
48 #endif
49
50 /*
51 * Encodes input (unsigned int) into output (unsigned char). Assumes len is
52 * a multiple of 4.
53 */
54
55 static void
Encode(unsigned char * output,unsigned int * input,unsigned int len)56 Encode (unsigned char *output, unsigned int *input, unsigned int len)
57 {
58 unsigned int i;
59 unsigned int *op = (unsigned int *)output;
60
61 for (i = 0; i < len / 4; i++)
62 op[i] = htole32(input[i]);
63 }
64
65 /*
66 * Decodes input (unsigned char) into output (unsigned int). Assumes len is
67 * a multiple of 4.
68 */
69
70 static void
Decode(unsigned int * output,const unsigned char * input,unsigned int len)71 Decode (unsigned int *output, const unsigned char *input, unsigned int len)
72 {
73 unsigned int i;
74 const unsigned int *ip = (const unsigned int *)input;
75
76 for (i = 0; i < len / 4; i++)
77 output[i] = le32toh(ip[i]);
78 }
79 #endif
80
81 static unsigned char PADDING[64] = {
82 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
83 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
84 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
85 };
86
87 /* F, G, H and I are basic MD5 functions. */
88 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
89 #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
90 #define H(x, y, z) ((x) ^ (y) ^ (z))
91 #define I(x, y, z) ((y) ^ ((x) | (~z)))
92
93 /* ROTATE_LEFT rotates x left n bits. */
94 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
95
96 /*
97 * FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
98 * Rotation is separate from addition to prevent recomputation.
99 */
100 #define FF(a, b, c, d, x, s, ac) { \
101 (a) += F ((b), (c), (d)) + (x) + (unsigned int)(ac); \
102 (a) = ROTATE_LEFT ((a), (s)); \
103 (a) += (b); \
104 }
105 #define GG(a, b, c, d, x, s, ac) { \
106 (a) += G ((b), (c), (d)) + (x) + (unsigned int)(ac); \
107 (a) = ROTATE_LEFT ((a), (s)); \
108 (a) += (b); \
109 }
110 #define HH(a, b, c, d, x, s, ac) { \
111 (a) += H ((b), (c), (d)) + (x) + (unsigned int)(ac); \
112 (a) = ROTATE_LEFT ((a), (s)); \
113 (a) += (b); \
114 }
115 #define II(a, b, c, d, x, s, ac) { \
116 (a) += I ((b), (c), (d)) + (x) + (unsigned int)(ac); \
117 (a) = ROTATE_LEFT ((a), (s)); \
118 (a) += (b); \
119 }
120
121 /* MD5 initialization. Begins an MD5 operation, writing a new context. */
122
123 void
MD5Init(context)124 MD5Init (context)
125 MD5_CTX *context;
126 {
127
128 context->count[0] = context->count[1] = 0;
129
130 /* Load magic initialization constants. */
131 context->state[0] = 0x67452301;
132 context->state[1] = 0xefcdab89;
133 context->state[2] = 0x98badcfe;
134 context->state[3] = 0x10325476;
135 }
136
137 /*
138 * MD5 block update operation. Continues an MD5 message-digest
139 * operation, processing another message block, and updating the
140 * context.
141 */
142
143 void
MD5Update(context,in,inputLen)144 MD5Update (context, in, inputLen)
145 MD5_CTX *context;
146 const void *in;
147 unsigned int inputLen;
148 {
149 unsigned int i, idx, partLen;
150 const unsigned char *input = in;
151
152 /* Compute number of bytes mod 64 */
153 idx = (unsigned int)((context->count[0] >> 3) & 0x3F);
154
155 /* Update number of bits */
156 if ((context->count[0] += ((unsigned int)inputLen << 3))
157 < ((unsigned int)inputLen << 3))
158 context->count[1]++;
159 context->count[1] += ((unsigned int)inputLen >> 29);
160
161 partLen = 64 - idx;
162
163 /* Transform as many times as possible. */
164 if (inputLen >= partLen) {
165 memcpy((void *)&context->buffer[idx], (const void *)input,
166 partLen);
167 MD5Transform (context->state, context->buffer);
168
169 for (i = partLen; i + 63 < inputLen; i += 64)
170 MD5Transform (context->state, &input[i]);
171
172 idx = 0;
173 }
174 else
175 i = 0;
176
177 /* Buffer remaining input */
178 memcpy ((void *)&context->buffer[idx], (const void *)&input[i],
179 inputLen-i);
180 }
181
182 /*
183 * MD5 padding. Adds padding followed by original length.
184 */
185
186 void
MD5Pad(context)187 MD5Pad (context)
188 MD5_CTX *context;
189 {
190 unsigned char bits[8];
191 unsigned int idx, padLen;
192
193 /* Save number of bits */
194 Encode (bits, context->count, 8);
195
196 /* Pad out to 56 mod 64. */
197 idx = (unsigned int)((context->count[0] >> 3) & 0x3f);
198 padLen = (idx < 56) ? (56 - idx) : (120 - idx);
199 MD5Update (context, PADDING, padLen);
200
201 /* Append length (before padding) */
202 MD5Update (context, bits, 8);
203 }
204
205 /*
206 * MD5 finalization. Ends an MD5 message-digest operation, writing the
207 * the message digest and zeroizing the context.
208 */
209
210 void
MD5Final(digest,context)211 MD5Final (digest, context)
212 unsigned char digest[16];
213 MD5_CTX *context;
214 {
215 /* Do padding. */
216 MD5Pad (context);
217
218 /* Store state in digest */
219 Encode (digest, context->state, 16);
220
221 /* Zeroize sensitive information. */
222 memset ((void *)context, 0, sizeof (*context));
223 }
224
225 /* MD5 basic transformation. Transforms state based on block. */
226
227 static void
MD5Transform(state,block)228 MD5Transform (state, block)
229 unsigned int state[4];
230 const unsigned char block[64];
231 {
232 unsigned int a = state[0], b = state[1], c = state[2], d = state[3], x[16];
233
234 Decode (x, block, 64);
235
236 /* Round 1 */
237 #define S11 7
238 #define S12 12
239 #define S13 17
240 #define S14 22
241 FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
242 FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
243 FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
244 FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
245 FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
246 FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
247 FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
248 FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
249 FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
250 FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
251 FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
252 FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
253 FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
254 FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
255 FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
256 FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
257
258 /* Round 2 */
259 #define S21 5
260 #define S22 9
261 #define S23 14
262 #define S24 20
263 GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
264 GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
265 GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
266 GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
267 GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
268 GG (d, a, b, c, x[10], S22, 0x2441453); /* 22 */
269 GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
270 GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
271 GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
272 GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
273 GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
274 GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
275 GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
276 GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
277 GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
278 GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
279
280 /* Round 3 */
281 #define S31 4
282 #define S32 11
283 #define S33 16
284 #define S34 23
285 HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
286 HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
287 HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
288 HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
289 HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
290 HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
291 HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
292 HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
293 HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
294 HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
295 HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
296 HH (b, c, d, a, x[ 6], S34, 0x4881d05); /* 44 */
297 HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
298 HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
299 HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
300 HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
301
302 /* Round 4 */
303 #define S41 6
304 #define S42 10
305 #define S43 15
306 #define S44 21
307 II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
308 II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
309 II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
310 II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
311 II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
312 II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
313 II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
314 II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
315 II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
316 II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
317 II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
318 II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
319 II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
320 II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
321 II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
322 II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
323
324 state[0] += a;
325 state[1] += b;
326 state[2] += c;
327 state[3] += d;
328
329 /* Zeroize sensitive information. */
330 memset ((void *)x, 0, sizeof (x));
331 }
332