Bug fix in documentation Tim found.
[awesomized/libmemcached] / libmemcached / md5.c
1 /*
2 This Library has been modified from its original form by
3 Brian Aker (brian@tangent.org)
4
5 See below for original Copyright.
6 */
7 /* MD5C.C - RSA Data Security, Inc., MD5 message-digest algorithm
8 */
9
10 /* Copyright (C) 1991-2, RSA Data Security, Inc. Created 1991. All
11 rights reserved.
12
13 License to copy and use this software is granted provided that it
14 is identified as the "RSA Data Security, Inc. MD5 Message-Digest
15 Algorithm" in all material mentioning or referencing this software
16 or this function.
17
18 License is also granted to make and use derivative works provided
19 that such works are identified as "derived from the RSA Data
20 Security, Inc. MD5 Message-Digest Algorithm" in all material
21 mentioning or referencing the derived work.
22
23 RSA Data Security, Inc. makes no representations concerning either
24 the merchantability of this software or the suitability of this
25 software for any particular purpose. It is provided "as is"
26 without express or implied warranty of any kind.
27
28 These notices must be retained in any copies of any part of this
29 documentation and/or software.
30 */
31
32
33 #include <string.h>
34 #include <sys/types.h>
35
36 /* POINTER defines a generic pointer type */
37 typedef unsigned char *POINTER;
38
39
40 /* UINT4 defines a four byte word */
41 typedef unsigned int UINT4;
42
43
44 /* MD5 context. */
45 typedef struct {
46 UINT4 state[4]; /* state (ABCD) */
47 UINT4 count[2]; /* number of bits, modulo 2^64 (lsb first) */
48 unsigned char buffer[64]; /* input buffer */
49 } MD5_CTX;
50
51 static void MD5Init (MD5_CTX *context); /* context */
52 static void MD5Update ( MD5_CTX *context, /* context */
53 const unsigned char *input, /* input block */
54 unsigned int inputLen); /* length of input block */
55 static void MD5Final ( unsigned char digest[16], /* message digest */
56 MD5_CTX *context); /* context */
57
58 /* Constants for MD5Transform routine. */
59
60 #define S11 7
61 #define S12 12
62 #define S13 17
63 #define S14 22
64 #define S21 5
65 #define S22 9
66 #define S23 14
67 #define S24 20
68 #define S31 4
69 #define S32 11
70 #define S33 16
71 #define S34 23
72 #define S41 6
73 #define S42 10
74 #define S43 15
75 #define S44 21
76
77
78 static void MD5Transform (UINT4 state[4],
79 unsigned char block[64]);
80 static void Encode (unsigned char *output,
81 UINT4 *input,
82 unsigned int len);
83 static void Decode(UINT4 *output, unsigned char *input, unsigned int len);
84
85 static unsigned char PADDING[64] = {
86 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
87 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
88 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
89 };
90
91 /* F, G, H and I are basic MD5 functions.
92 */
93 #define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
94 #define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
95 #define H(x, y, z) ((x) ^ (y) ^ (z))
96 #define I(x, y, z) ((y) ^ ((x) | (~z)))
97
98 /* ROTATE_LEFT rotates x left n bits.
99 */
100 #define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
101
102 /* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
103 Rotation is separate from addition to prevent recomputation.
104 */
105 #define FF(a, b, c, d, x, s, ac) { \
106 (a) += F ((b), (c), (d)) + (x) + (UINT4)(ac); \
107 (a) = ROTATE_LEFT ((a), (s)); \
108 (a) += (b); \
109 }
110 #define GG(a, b, c, d, x, s, ac) { \
111 (a) += G ((b), (c), (d)) + (x) + (UINT4)(ac); \
112 (a) = ROTATE_LEFT ((a), (s)); \
113 (a) += (b); \
114 }
115 #define HH(a, b, c, d, x, s, ac) { \
116 (a) += H ((b), (c), (d)) + (x) + (UINT4)(ac); \
117 (a) = ROTATE_LEFT ((a), (s)); \
118 (a) += (b); \
119 }
120 #define II(a, b, c, d, x, s, ac) { \
121 (a) += I ((b), (c), (d)) + (x) + (UINT4)(ac); \
122 (a) = ROTATE_LEFT ((a), (s)); \
123 (a) += (b); \
124 }
125
126
127 /*
128 Just a simple method for getting the signature
129 result must be == 16
130 */
131 void md5_signature(const unsigned char *key, unsigned int length, unsigned char *result)
132 {
133 MD5_CTX my_md5;
134
135 MD5Init(&my_md5);
136 (void)MD5Update(&my_md5, key, length);
137 MD5Final(result, &my_md5);
138 }
139
140 /* MD5 initialization. Begins an MD5 operation, writing a new context.
141 */
142 static void MD5Init (MD5_CTX *context) /* context */
143 {
144 context->count[0] = context->count[1] = 0;
145 /* Load magic initialization constants.
146 */
147 context->state[0] = 0x67452301;
148 context->state[1] = 0xefcdab89;
149 context->state[2] = 0x98badcfe;
150 context->state[3] = 0x10325476;
151 }
152
153 /* MD5 block update operation. Continues an MD5 message-digest
154 operation, processing another message block, and updating the
155 context.
156 */
157
158 static void MD5Update (
159 MD5_CTX *context, /* context */
160 const unsigned char *input, /* input block */
161 unsigned int inputLen) /* length of input block */
162 {
163 unsigned int i, idx, partLen;
164
165 /* Compute number of bytes mod 64 */
166 idx = (unsigned int)((context->count[0] >> 3) & 0x3F);
167
168
169 /* Update number of bits */
170 if ((context->count[0] += ((UINT4)inputLen << 3))
171 < ((UINT4)inputLen << 3))
172 context->count[1]++;
173 context->count[1] += ((UINT4)inputLen >> 29);
174
175 partLen = 64 - idx;
176
177 /* Transform as many times as possible.
178 */
179 if (inputLen >= partLen) {
180 memcpy((POINTER)&context->buffer[idx], (POINTER)input, partLen);
181 MD5Transform(context->state, context->buffer);
182
183 for (i = partLen; i + 63 < inputLen; i += 64)
184 MD5Transform (context->state, (unsigned char *)&input[i]);
185
186 idx = 0;
187 }
188 else
189 i = 0;
190
191 /* Buffer remaining input */
192 memcpy((POINTER)&context->buffer[idx], (POINTER)&input[i],
193 inputLen-i);
194 }
195
196 /* MD5 finalization. Ends an MD5 message-digest operation, writing the
197 the message digest and zeroizing the context.
198 */
199
200 static void MD5Final (
201 unsigned char digest[16], /* message digest */
202 MD5_CTX *context) /* context */
203 {
204 unsigned char bits[8];
205 unsigned int idx, padLen;
206
207 /* Save number of bits */
208 Encode (bits, context->count, 8);
209
210 /* Pad out to 56 mod 64.
211 */
212 idx = (unsigned int)((context->count[0] >> 3) & 0x3f);
213 padLen = (idx < 56) ? (56 - idx) : (120 - idx);
214 MD5Update (context, PADDING, padLen);
215
216 /* Append length (before padding) */
217 MD5Update (context, bits, 8);
218
219 /* Store state in digest */
220 Encode (digest, context->state, 16);
221
222 /* Zeroize sensitive information.
223 */
224 memset((POINTER)context, 0, sizeof (*context));
225 }
226
227 /* MD5 basic transformation. Transforms state based on block.
228 */
229 static void MD5Transform (
230 UINT4 state[4],
231 unsigned char block[64])
232 {
233 UINT4 a = state[0], b = state[1], c = state[2], d = state[3], x[16];
234
235 Decode (x, block, 64);
236
237 /* Round 1 */
238 FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
239 FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
240 FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
241 FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
242 FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
243 FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
244 FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
245 FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
246 FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
247 FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
248 FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
249 FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
250 FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
251 FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
252 FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
253 FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
254
255 /* Round 2 */
256 GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
257 GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
258 GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
259 GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
260 GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
261 GG (d, a, b, c, x[10], S22, 0x2441453); /* 22 */
262 GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
263 GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
264 GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
265 GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
266 GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
267 GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
268 GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
269 GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
270 GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
271 GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
272
273 /* Round 3 */
274 HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
275 HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
276 HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
277 HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
278 HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
279 HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
280 HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
281 HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
282 HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
283 HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
284 HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
285 HH (b, c, d, a, x[ 6], S34, 0x4881d05); /* 44 */
286 HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
287 HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
288 HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
289 HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
290
291 /* Round 4 */
292 II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
293 II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
294 II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
295 II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
296 II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
297 II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
298 II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
299 II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
300 II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
301 II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
302 II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
303 II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
304 II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
305 II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
306 II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
307 II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
308
309
310 state[0] += a;
311 state[1] += b;
312 state[2] += c;
313 state[3] += d;
314
315 /* Zeroize sensitive information.
316 */
317 memset((POINTER)x, 0, sizeof (x));
318 }
319
320 /* Encodes input (UINT4) into output (unsigned char). Assumes len is
321 a multiple of 4.
322 */
323 static void Encode (
324 unsigned char *output,
325 UINT4 *input,
326 unsigned int len)
327 {
328 unsigned int i, j;
329
330 for (i = 0, j = 0; j < len; i++, j += 4) {
331 output[j] = (unsigned char)(input[i] & 0xff);
332 output[j+1] = (unsigned char)((input[i] >> 8) & 0xff);
333 output[j+2] = (unsigned char)((input[i] >> 16) & 0xff);
334 output[j+3] = (unsigned char)((input[i] >> 24) & 0xff);
335 }
336 }
337
338
339 /* Decodes input (unsigned char) into output (UINT4). Assumes len is
340 a multiple of 4.
341 */
342 static void Decode (
343 UINT4 *output,
344 unsigned char *input,
345 unsigned int len)
346 {
347 unsigned int i, j;
348
349 for (i = 0, j = 0; j < len; i++, j += 4)
350 output[i] = ((UINT4)input[j]) | (((UINT4)input[j+1]) << 8) |
351 (((UINT4)input[j+2]) << 16) | (((UINT4)input[j+3]) << 24);
352 }