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md5c.c

 

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mrw   Initial commit. Latest amendment: 1 on 2024-10-15

1
2 /* MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
3 */
4
5 /* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
6 rights reserved.
7
8 License to copy and use this software is granted provided that it
9 is identified as the "RSA Data Security, Inc. MD5 Message-Digest
10 Algorithm" in all material mentioning or referencing this software
11 or this function.
12
13 License is also granted to make and use derivative works provided
14 that such works are identified as "derived from the RSA Data
15 Security, Inc. MD5 Message-Digest Algorithm" in all material
16 mentioning or referencing the derived work.
17
18 RSA Data Security, Inc. makes no representations concerning either
19 the merchantability of this software or the suitability of this
20 software for any particular purpose. It is provided "as is"
21 without express or implied warranty of any kind.
22
23 These notices must be retained in any copies of any part of this
24 documentation and/or software.
25 */
26
27 #include "global.h"
28 #include "md5.h"
29
30 /* Constants for MD5Transform routine.
31 */
32 #define S11 7
33 #define S12 12
34 #define S13 17
35 #define S14 22
36 #define S21 5
37 #define S22 9
38 #define S23 14
39 #define S24 20
40 #define S31 4
41 #define S32 11
42 #define S33 16
43 #define S34 23
44 #define S41 6
45 #define S42 10
46 #define S43 15
47 #define S44 21
48
49 static void MD5Transform PROTO_LIST ((UINT4 [4], unsigned char [64]));
50 static void Encode PROTO_LIST
51 ((unsigned char *, UINT4 *, unsigned int));
52 static void Decode PROTO_LIST
53 ((UINT4 *, unsigned char *, unsigned int));
54 static void MD5_memcpy PROTO_LIST ((POINTER, POINTER, unsigned int));
55 static void MD5_memset PROTO_LIST ((POINTER, int, unsigned int));
56
57 #ifdef _MD5_EXPLICIT_INIT
58 static unsigned char *PADDING;
59 #else
60 static unsigned char PADDING[64] = {
61 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
62 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
63 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
64 };
65 #endif
66
67 /* F, G, H and I are basic MD5 functions.
68 */
69 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
70 #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
71 #define H(x, y, z) ((x) ^ (y) ^ (z))
72 #define I(x, y, z) ((y) ^ ((x) | (~z)))
73
74 /* ROTATE_LEFT rotates x left n bits.
75 */
76 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
77
78 /* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
79 Rotation is separate from addition to prevent recomputation.
80 */
81 #define FF(a, b, c, d, x, s, ac) { \
82 (a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); \
83 (a) = ROTATE_LEFT ((a), (s)); \
84 (a) += (b); \
85 }
86 #define GG(a, b, c, d, x, s, ac) { \
87 (a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
88 (a) = ROTATE_LEFT ((a), (s)); \
89 (a) += (b); \
90 }
91 #define HH(a, b, c, d, x, s, ac) { \
92 (a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
93 (a) = ROTATE_LEFT ((a), (s)); \
94 (a) += (b); \
95 }
96 #define II(a, b, c, d, x, s, ac) { \
97 (a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
98 (a) = ROTATE_LEFT ((a), (s)); \
99 (a) += (b); \
100 }
101
102 /* MD5 initialization. Begins an MD5 operation, writing a new context.
103 */
104 void MD5Init (context)
105 MD5_CTX *context; /* context */
106 {
107 context->count[0] = context->count[1] = 0;
108 /* Load magic initialization constants.
109 */
110 context->state[0] = 0x67452301;
111 context->state[1] = 0xefcdab89;
112 context->state[2] = 0x98badcfe;
113 context->state[3] = 0x10325476;
114 }
115
116 /* MD5 block update operation. Continues an MD5 message-digest
117 operation, processing another message block, and updating the
118 context.
119 */
120 void MD5Update (context, input, inputLen)
121 MD5_CTX *context; /* context */
122 unsigned char *input; /* input block */
123 unsigned int inputLen; /* length of input block */
124 {
125 unsigned int i, index, partLen;
126
127 /* Compute number of bytes mod 64 */
128 index = (unsigned int)((context->count[0] >> 3) & 0x3F);
129
130 /* Update number of bits */
131 if ((context->count[0] += ((UINT4)inputLen << 3))
132 < ((UINT4)inputLen << 3))
133 context->count[1]++;
134 context->count[1] += ((UINT4)inputLen >> 29);
135
136 partLen = 64 - index;
137
138 /* Transform as many times as possible.
139 */
140 if (inputLen >= partLen) {
141 MD5_memcpy
142 ((POINTER)&context->buffer[index], (POINTER)input, partLen);
143 MD5Transform (context->state, context->buffer);
144
145 for (i = partLen; i + 63 < inputLen; i += 64)
146 MD5Transform (context->state, &input[i]);
147
148 index = 0;
149 }
150 else
151 i = 0;
152
153 /* Buffer remaining input */
154 MD5_memcpy
155 ((POINTER)&context->buffer[index], (POINTER)&input[i],
156 inputLen-i);
157 }
158
159 /* MD5 finalization. Ends an MD5 message-digest operation, writing the
160 the message digest and zeroizing the context.
161 */
162 void MD5Final (digest, context)
163 unsigned char digest[16]; /* message digest */
164 MD5_CTX *context; /* context */
165 {
166 unsigned char bits[8];
167 unsigned int index, padLen;
168
169 /* Save number of bits */
170 Encode (bits, context->count, 8);
171
172 /* Pad out to 56 mod 64.
173 */
174 index = (unsigned int)((context->count[0] >> 3) & 0x3f);
175 padLen = (index < 56) ? (56 - index) : (120 - index);
176 MD5Update (context, PADDING, padLen);
177
178 /* Append length (before padding) */
179 MD5Update (context, bits, 8);
180 /* Store state in digest */
181 Encode (digest, context->state, 16);
182
183 /* Zeroize sensitive information.
184 */
185 MD5_memset ((POINTER)context, 0, sizeof (*context));
186 }
187
188 /* MD5 basic transformation. Transforms state based on block.
189 */
190 static void MD5Transform (state, block)
191 UINT4 state[4];
192 unsigned char block[64];
193 {
194 UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
195
196 Decode (x, block, 64);
197
198 /* Round 1 */
199 FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
200 FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
201 FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
202 FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
203 FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
204 FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
205 FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
206 FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
207 FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
208 FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
209 FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
210 FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
211 FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
212 FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
213 FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
214 FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
215
216 /* Round 2 */
217 GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
218 GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
219 GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
220 GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
221 GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
222 GG (d, a, b, c, x[10], S22, 0x2441453); /* 22 */
223 GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
224 GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
225 GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
226 GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
227 GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
228 GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
229 GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
230 GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
231 GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
232 GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
233
234 /* Round 3 */
235 HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
236 HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
237 HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
238 HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
239 HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
240 HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
241 HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
242 HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
243 HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
244 HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
245 HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
246 HH (b, c, d, a, x[ 6], S34, 0x4881d05); /* 44 */
247 HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
248 HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
249 HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
250 HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
251
252 /* Round 4 */
253 II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
254 II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
255 II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
256 II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
257 II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
258 II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
259 II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
260 II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
261 II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
262 II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
263 II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
264 II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
265 II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
266 II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
267 II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
268 II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
269
270 state[0] += a;
271 state[1] += b;
272 state[2] += c;
273 state[3] += d;
274
275 /* Zeroize sensitive information.
276 */
277 MD5_memset ((POINTER)x, 0, sizeof (x));
278 }
279
280 /* Encodes input (UINT4) into output (unsigned char). Assumes len is
281 a multiple of 4.
282 */
283 static void Encode (output, input, len)
284 unsigned char *output;
285 UINT4 *input;
286 unsigned int len;
287 {
288 unsigned int i, j;
289
290 for (i = 0, j = 0; j < len; i++, j += 4) {
291 output[j] = (unsigned char)(input[i] & 0xff);
292 output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
293 output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
294 output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
295 }
296 }
297
298 /* Decodes input (unsigned char) into output (UINT4). Assumes len is
299 a multiple of 4.
300 */
301 static void Decode (output, input, len)
302 UINT4 *output;
303 unsigned char *input;
304 unsigned int len;
305 {
306 unsigned int i, j;
307
308 for (i = 0, j = 0; j < len; i++, j += 4)
309 output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
310 (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
311 }
312
313 /* Note: Replace "for loop" with standard memcpy if possible.
314 */
315
316 static void MD5_memcpy (output, input, len)
317 POINTER output;
318 POINTER input;
319 unsigned int len;
320 {
321 unsigned int i;
322
323 for (i = 0; i < len; i++)
324 output[i] = input[i];
325 }
326
327 /* Note: Replace "for loop" with standard memset if possible.
328 */
329 static void MD5_memset (output, value, len)
330 POINTER output;
331 int value;
332 unsigned int len;
333 {
334 unsigned int i;
335
336 for (i = 0; i < len; i++)
337 ((char *)output)[i] = (char)value;
338 }