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 <string.h>
30 #include <endian.h>
31 #include <md5.h>
32
33 static void MD5Transform(uint32_t[4], const unsigned char[64]);
34
35 #define Encode memcpy
36 #define Decode memcpy
37
38 static unsigned char PADDING[64] = {
39 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
40 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
41 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
42 };
43
44 /* F, G, H and I are basic MD5 functions. */
45 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
46 #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
47 #define H(x, y, z) ((x) ^ (y) ^ (z))
48 #define I(x, y, z) ((y) ^ ((x) | (~z)))
49
50 /* ROTATE_LEFT rotates x left n bits. */
51 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
52
53 /*
54 * FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
55 * Rotation is separate from addition to prevent recomputation.
56 */
57 #define FF(a, b, c, d, x, s, ac) { \
58 (a) += F ((b), (c), (d)) + (x) + (uint32_t)(ac); \
59 (a) = ROTATE_LEFT ((a), (s)); \
60 (a) += (b); \
61 }
62 #define GG(a, b, c, d, x, s, ac) { \
63 (a) += G ((b), (c), (d)) + (x) + (uint32_t)(ac); \
64 (a) = ROTATE_LEFT ((a), (s)); \
65 (a) += (b); \
66 }
67 #define HH(a, b, c, d, x, s, ac) { \
68 (a) += H ((b), (c), (d)) + (x) + (uint32_t)(ac); \
69 (a) = ROTATE_LEFT ((a), (s)); \
70 (a) += (b); \
71 }
72 #define II(a, b, c, d, x, s, ac) { \
73 (a) += I ((b), (c), (d)) + (x) + (uint32_t)(ac); \
74 (a) = ROTATE_LEFT ((a), (s)); \
75 (a) += (b); \
76 }
77
78 /* MD5 initialization. Begins an MD5 operation, writing a new context. */
79
MD5Init(MD5_CTX * context)80 void MD5Init(MD5_CTX * context)
81 {
82 context->count[0] = context->count[1] = 0;
83
84 /* Load magic initialization constants. */
85 context->state[0] = 0x67452301;
86 context->state[1] = 0xefcdab89;
87 context->state[2] = 0x98badcfe;
88 context->state[3] = 0x10325476;
89 }
90
91 /*
92 * MD5 block update operation. Continues an MD5 message-digest
93 * operation, processing another message block, and updating the
94 * context.
95 */
96
MD5Update(MD5_CTX * context,const void * in,size_t inputLen)97 void MD5Update(MD5_CTX * context, const void *in, size_t inputLen)
98 {
99 unsigned int i, idx, partLen;
100 const unsigned char *input = in;
101
102 /* Compute number of bytes mod 64 */
103 idx = (unsigned int)((context->count[0] >> 3) & 0x3F);
104
105 /* Update number of bits */
106 if ((context->count[0] += ((uint32_t) inputLen << 3))
107 < ((uint32_t) inputLen << 3))
108 context->count[1]++;
109 context->count[1] += ((uint32_t) inputLen >> 29);
110
111 partLen = 64 - idx;
112
113 /* Transform as many times as possible. */
114 if (inputLen >= partLen) {
115 memcpy((void *)&context->buffer[idx], (const void *)input, partLen);
116 MD5Transform(context->state, context->buffer);
117
118 for (i = partLen; i + 63 < inputLen; i += 64)
119 MD5Transform(context->state, &input[i]);
120
121 idx = 0;
122 } else
123 i = 0;
124
125 /* Buffer remaining input */
126 memcpy((void *)&context->buffer[idx], (const void *)&input[i],
127 inputLen - i);
128 }
129
130 /*
131 * MD5 padding. Adds padding followed by original length.
132 */
133
MD5Pad(MD5_CTX * context)134 static void MD5Pad(MD5_CTX * context)
135 {
136 unsigned char bits[8];
137 unsigned int idx, padLen;
138
139 /* Save number of bits */
140 Encode(bits, context->count, 8);
141
142 /* Pad out to 56 mod 64. */
143 idx = (unsigned int)((context->count[0] >> 3) & 0x3f);
144 padLen = (idx < 56) ? (56 - idx) : (120 - idx);
145 MD5Update(context, PADDING, padLen);
146
147 /* Append length (before padding) */
148 MD5Update(context, bits, 8);
149 }
150
151 /*
152 * MD5 finalization. Ends an MD5 message-digest operation, writing the
153 * the message digest and zeroizing the context.
154 */
155
MD5Final(unsigned char digest[16],MD5_CTX * context)156 void MD5Final(unsigned char digest[16], MD5_CTX * context)
157 {
158 /* Do padding. */
159 MD5Pad(context);
160
161 /* Store state in digest */
162 Encode(digest, context->state, 16);
163
164 /* Zeroize sensitive information. */
165 memset((void *)context, 0, sizeof(*context));
166 }
167
168 /* MD5 basic transformation. Transforms state based on block. */
169
MD5Transform(state,block)170 static void MD5Transform(state, block)
171 uint32_t state[4];
172 const unsigned char block[64];
173 {
174 uint32_t a = state[0], b = state[1], c = state[2], d = state[3], x[16];
175
176 Decode(x, block, 64);
177
178 /* Round 1 */
179 #define S11 7
180 #define S12 12
181 #define S13 17
182 #define S14 22
183 FF(a, b, c, d, x[0], S11, 0xd76aa478); /* 1 */
184 FF(d, a, b, c, x[1], S12, 0xe8c7b756); /* 2 */
185 FF(c, d, a, b, x[2], S13, 0x242070db); /* 3 */
186 FF(b, c, d, a, x[3], S14, 0xc1bdceee); /* 4 */
187 FF(a, b, c, d, x[4], S11, 0xf57c0faf); /* 5 */
188 FF(d, a, b, c, x[5], S12, 0x4787c62a); /* 6 */
189 FF(c, d, a, b, x[6], S13, 0xa8304613); /* 7 */
190 FF(b, c, d, a, x[7], S14, 0xfd469501); /* 8 */
191 FF(a, b, c, d, x[8], S11, 0x698098d8); /* 9 */
192 FF(d, a, b, c, x[9], S12, 0x8b44f7af); /* 10 */
193 FF(c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
194 FF(b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
195 FF(a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
196 FF(d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
197 FF(c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
198 FF(b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
199
200 /* Round 2 */
201 #define S21 5
202 #define S22 9
203 #define S23 14
204 #define S24 20
205 GG(a, b, c, d, x[1], S21, 0xf61e2562); /* 17 */
206 GG(d, a, b, c, x[6], S22, 0xc040b340); /* 18 */
207 GG(c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
208 GG(b, c, d, a, x[0], S24, 0xe9b6c7aa); /* 20 */
209 GG(a, b, c, d, x[5], S21, 0xd62f105d); /* 21 */
210 GG(d, a, b, c, x[10], S22, 0x2441453); /* 22 */
211 GG(c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
212 GG(b, c, d, a, x[4], S24, 0xe7d3fbc8); /* 24 */
213 GG(a, b, c, d, x[9], S21, 0x21e1cde6); /* 25 */
214 GG(d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
215 GG(c, d, a, b, x[3], S23, 0xf4d50d87); /* 27 */
216 GG(b, c, d, a, x[8], S24, 0x455a14ed); /* 28 */
217 GG(a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
218 GG(d, a, b, c, x[2], S22, 0xfcefa3f8); /* 30 */
219 GG(c, d, a, b, x[7], S23, 0x676f02d9); /* 31 */
220 GG(b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
221
222 /* Round 3 */
223 #define S31 4
224 #define S32 11
225 #define S33 16
226 #define S34 23
227 HH(a, b, c, d, x[5], S31, 0xfffa3942); /* 33 */
228 HH(d, a, b, c, x[8], S32, 0x8771f681); /* 34 */
229 HH(c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
230 HH(b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
231 HH(a, b, c, d, x[1], S31, 0xa4beea44); /* 37 */
232 HH(d, a, b, c, x[4], S32, 0x4bdecfa9); /* 38 */
233 HH(c, d, a, b, x[7], S33, 0xf6bb4b60); /* 39 */
234 HH(b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
235 HH(a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
236 HH(d, a, b, c, x[0], S32, 0xeaa127fa); /* 42 */
237 HH(c, d, a, b, x[3], S33, 0xd4ef3085); /* 43 */
238 HH(b, c, d, a, x[6], S34, 0x4881d05); /* 44 */
239 HH(a, b, c, d, x[9], S31, 0xd9d4d039); /* 45 */
240 HH(d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
241 HH(c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
242 HH(b, c, d, a, x[2], S34, 0xc4ac5665); /* 48 */
243
244 /* Round 4 */
245 #define S41 6
246 #define S42 10
247 #define S43 15
248 #define S44 21
249 II(a, b, c, d, x[0], S41, 0xf4292244); /* 49 */
250 II(d, a, b, c, x[7], S42, 0x432aff97); /* 50 */
251 II(c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
252 II(b, c, d, a, x[5], S44, 0xfc93a039); /* 52 */
253 II(a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
254 II(d, a, b, c, x[3], S42, 0x8f0ccc92); /* 54 */
255 II(c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
256 II(b, c, d, a, x[1], S44, 0x85845dd1); /* 56 */
257 II(a, b, c, d, x[8], S41, 0x6fa87e4f); /* 57 */
258 II(d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
259 II(c, d, a, b, x[6], S43, 0xa3014314); /* 59 */
260 II(b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
261 II(a, b, c, d, x[4], S41, 0xf7537e82); /* 61 */
262 II(d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
263 II(c, d, a, b, x[2], S43, 0x2ad7d2bb); /* 63 */
264 II(b, c, d, a, x[9], S44, 0xeb86d391); /* 64 */
265
266 state[0] += a;
267 state[1] += b;
268 state[2] += c;
269 state[3] += d;
270
271 /* Zeroize sensitive information. */
272 memset((void *)x, 0, sizeof(x));
273 }
274