Prevent a memory leak in digest.c
[deb_shairplay.git] / src / lib / crypto / md5.c
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1/*
2 * Copyright (c) 2007, Cameron Rich
3 *
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
8 *
9 * * Redistributions of source code must retain the above copyright notice,
10 * this list of conditions and the following disclaimer.
11 * * Redistributions in binary form must reproduce the above copyright notice,
12 * this list of conditions and the following disclaimer in the documentation
13 * and/or other materials provided with the distribution.
14 * * Neither the name of the axTLS project nor the names of its contributors
15 * may be used to endorse or promote products derived from this software
16 * without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
19 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
20 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
21 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
22 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
23 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
24 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
25 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
26 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
27 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
28 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29 */
30
31/**
32 * This file implements the MD5 algorithm as defined in RFC1321
33 */
34
35#include <string.h>
36#include "os_port.h"
37#include "crypto.h"
38
39/* Constants for MD5Transform routine.
40 */
41#define S11 7
42#define S12 12
43#define S13 17
44#define S14 22
45#define S21 5
46#define S22 9
47#define S23 14
48#define S24 20
49#define S31 4
50#define S32 11
51#define S33 16
52#define S34 23
53#define S41 6
54#define S42 10
55#define S43 15
56#define S44 21
57
58/* ----- static functions ----- */
59static void MD5Transform(uint32_t state[4], const uint8_t block[64]);
60static void Encode(uint8_t *output, uint32_t *input, uint32_t len);
61static void Decode(uint32_t *output, const uint8_t *input, uint32_t len);
62
63static const uint8_t PADDING[64] =
64{
65 0x80, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
66 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
67 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
68};
69
70/* F, G, H and I are basic MD5 functions.
71 */
72#define F(x, y, z) (((x) & (y)) | ((~x) & (z)))
73#define G(x, y, z) (((x) & (z)) | ((y) & (~z)))
74#define H(x, y, z) ((x) ^ (y) ^ (z))
75#define I(x, y, z) ((y) ^ ((x) | (~z)))
76
77/* ROTATE_LEFT rotates x left n bits. */
78#define ROTATE_LEFT(x, n) (((x) << (n)) | ((x) >> (32-(n))))
79
80/* FF, GG, HH, and II transformations for rounds 1, 2, 3, and 4.
81 Rotation is separate from addition to prevent recomputation. */
82#define FF(a, b, c, d, x, s, ac) { \
83 (a) += F ((b), (c), (d)) + (x) + (uint32_t)(ac); \
84 (a) = ROTATE_LEFT ((a), (s)); \
85 (a) += (b); \
86 }
87#define GG(a, b, c, d, x, s, ac) { \
88 (a) += G ((b), (c), (d)) + (x) + (uint32_t)(ac); \
89 (a) = ROTATE_LEFT ((a), (s)); \
90 (a) += (b); \
91 }
92#define HH(a, b, c, d, x, s, ac) { \
93 (a) += H ((b), (c), (d)) + (x) + (uint32_t)(ac); \
94 (a) = ROTATE_LEFT ((a), (s)); \
95 (a) += (b); \
96 }
97#define II(a, b, c, d, x, s, ac) { \
98 (a) += I ((b), (c), (d)) + (x) + (uint32_t)(ac); \
99 (a) = ROTATE_LEFT ((a), (s)); \
100 (a) += (b); \
101 }
102
103/**
104 * MD5 initialization - begins an MD5 operation, writing a new ctx.
105 */
106EXP_FUNC void STDCALL MD5_Init(MD5_CTX *ctx)
107{
108 ctx->count[0] = ctx->count[1] = 0;
109
110 /* Load magic initialization constants.
111 */
112 ctx->state[0] = 0x67452301;
113 ctx->state[1] = 0xefcdab89;
114 ctx->state[2] = 0x98badcfe;
115 ctx->state[3] = 0x10325476;
116}
117
118/**
119 * Accepts an array of octets as the next portion of the message.
120 */
121EXP_FUNC void STDCALL MD5_Update(MD5_CTX *ctx, const uint8_t * msg, int len)
122{
123 uint32_t x;
124 int i, partLen;
125
126 /* Compute number of bytes mod 64 */
127 x = (uint32_t)((ctx->count[0] >> 3) & 0x3F);
128
129 /* Update number of bits */
130 if ((ctx->count[0] += ((uint32_t)len << 3)) < ((uint32_t)len << 3))
131 ctx->count[1]++;
132 ctx->count[1] += ((uint32_t)len >> 29);
133
134 partLen = 64 - x;
135
136 /* Transform as many times as possible. */
137 if (len >= partLen)
138 {
139 memcpy(&ctx->buffer[x], msg, partLen);
140 MD5Transform(ctx->state, ctx->buffer);
141
142 for (i = partLen; i + 63 < len; i += 64)
143 MD5Transform(ctx->state, &msg[i]);
144
145 x = 0;
146 }
147 else
148 i = 0;
149
150 /* Buffer remaining input */
151 memcpy(&ctx->buffer[x], &msg[i], len-i);
152}
153
154/**
155 * Return the 128-bit message digest into the user's array
156 */
157EXP_FUNC void STDCALL MD5_Final(uint8_t *digest, MD5_CTX *ctx)
158{
159 uint8_t bits[8];
160 uint32_t x, padLen;
161
162 /* Save number of bits */
163 Encode(bits, ctx->count, 8);
164
165 /* Pad out to 56 mod 64.
166 */
167 x = (uint32_t)((ctx->count[0] >> 3) & 0x3f);
168 padLen = (x < 56) ? (56 - x) : (120 - x);
169 MD5_Update(ctx, PADDING, padLen);
170
171 /* Append length (before padding) */
172 MD5_Update(ctx, bits, 8);
173
174 /* Store state in digest */
175 Encode(digest, ctx->state, MD5_SIZE);
176}
177
178/**
179 * MD5 basic transformation. Transforms state based on block.
180 */
181static void MD5Transform(uint32_t state[4], const uint8_t block[64])
182{
183 uint32_t a = state[0], b = state[1], c = state[2],
184 d = state[3], x[MD5_SIZE];
185
186 Decode(x, block, 64);
187
188 /* Round 1 */
189 FF (a, b, c, d, x[ 0], S11, 0xd76aa478); /* 1 */
190 FF (d, a, b, c, x[ 1], S12, 0xe8c7b756); /* 2 */
191 FF (c, d, a, b, x[ 2], S13, 0x242070db); /* 3 */
192 FF (b, c, d, a, x[ 3], S14, 0xc1bdceee); /* 4 */
193 FF (a, b, c, d, x[ 4], S11, 0xf57c0faf); /* 5 */
194 FF (d, a, b, c, x[ 5], S12, 0x4787c62a); /* 6 */
195 FF (c, d, a, b, x[ 6], S13, 0xa8304613); /* 7 */
196 FF (b, c, d, a, x[ 7], S14, 0xfd469501); /* 8 */
197 FF (a, b, c, d, x[ 8], S11, 0x698098d8); /* 9 */
198 FF (d, a, b, c, x[ 9], S12, 0x8b44f7af); /* 10 */
199 FF (c, d, a, b, x[10], S13, 0xffff5bb1); /* 11 */
200 FF (b, c, d, a, x[11], S14, 0x895cd7be); /* 12 */
201 FF (a, b, c, d, x[12], S11, 0x6b901122); /* 13 */
202 FF (d, a, b, c, x[13], S12, 0xfd987193); /* 14 */
203 FF (c, d, a, b, x[14], S13, 0xa679438e); /* 15 */
204 FF (b, c, d, a, x[15], S14, 0x49b40821); /* 16 */
205
206 /* Round 2 */
207 GG (a, b, c, d, x[ 1], S21, 0xf61e2562); /* 17 */
208 GG (d, a, b, c, x[ 6], S22, 0xc040b340); /* 18 */
209 GG (c, d, a, b, x[11], S23, 0x265e5a51); /* 19 */
210 GG (b, c, d, a, x[ 0], S24, 0xe9b6c7aa); /* 20 */
211 GG (a, b, c, d, x[ 5], S21, 0xd62f105d); /* 21 */
212 GG (d, a, b, c, x[10], S22, 0x2441453); /* 22 */
213 GG (c, d, a, b, x[15], S23, 0xd8a1e681); /* 23 */
214 GG (b, c, d, a, x[ 4], S24, 0xe7d3fbc8); /* 24 */
215 GG (a, b, c, d, x[ 9], S21, 0x21e1cde6); /* 25 */
216 GG (d, a, b, c, x[14], S22, 0xc33707d6); /* 26 */
217 GG (c, d, a, b, x[ 3], S23, 0xf4d50d87); /* 27 */
218 GG (b, c, d, a, x[ 8], S24, 0x455a14ed); /* 28 */
219 GG (a, b, c, d, x[13], S21, 0xa9e3e905); /* 29 */
220 GG (d, a, b, c, x[ 2], S22, 0xfcefa3f8); /* 30 */
221 GG (c, d, a, b, x[ 7], S23, 0x676f02d9); /* 31 */
222 GG (b, c, d, a, x[12], S24, 0x8d2a4c8a); /* 32 */
223
224 /* Round 3 */
225 HH (a, b, c, d, x[ 5], S31, 0xfffa3942); /* 33 */
226 HH (d, a, b, c, x[ 8], S32, 0x8771f681); /* 34 */
227 HH (c, d, a, b, x[11], S33, 0x6d9d6122); /* 35 */
228 HH (b, c, d, a, x[14], S34, 0xfde5380c); /* 36 */
229 HH (a, b, c, d, x[ 1], S31, 0xa4beea44); /* 37 */
230 HH (d, a, b, c, x[ 4], S32, 0x4bdecfa9); /* 38 */
231 HH (c, d, a, b, x[ 7], S33, 0xf6bb4b60); /* 39 */
232 HH (b, c, d, a, x[10], S34, 0xbebfbc70); /* 40 */
233 HH (a, b, c, d, x[13], S31, 0x289b7ec6); /* 41 */
234 HH (d, a, b, c, x[ 0], S32, 0xeaa127fa); /* 42 */
235 HH (c, d, a, b, x[ 3], S33, 0xd4ef3085); /* 43 */
236 HH (b, c, d, a, x[ 6], S34, 0x4881d05); /* 44 */
237 HH (a, b, c, d, x[ 9], S31, 0xd9d4d039); /* 45 */
238 HH (d, a, b, c, x[12], S32, 0xe6db99e5); /* 46 */
239 HH (c, d, a, b, x[15], S33, 0x1fa27cf8); /* 47 */
240 HH (b, c, d, a, x[ 2], S34, 0xc4ac5665); /* 48 */
241
242 /* Round 4 */
243 II (a, b, c, d, x[ 0], S41, 0xf4292244); /* 49 */
244 II (d, a, b, c, x[ 7], S42, 0x432aff97); /* 50 */
245 II (c, d, a, b, x[14], S43, 0xab9423a7); /* 51 */
246 II (b, c, d, a, x[ 5], S44, 0xfc93a039); /* 52 */
247 II (a, b, c, d, x[12], S41, 0x655b59c3); /* 53 */
248 II (d, a, b, c, x[ 3], S42, 0x8f0ccc92); /* 54 */
249 II (c, d, a, b, x[10], S43, 0xffeff47d); /* 55 */
250 II (b, c, d, a, x[ 1], S44, 0x85845dd1); /* 56 */
251 II (a, b, c, d, x[ 8], S41, 0x6fa87e4f); /* 57 */
252 II (d, a, b, c, x[15], S42, 0xfe2ce6e0); /* 58 */
253 II (c, d, a, b, x[ 6], S43, 0xa3014314); /* 59 */
254 II (b, c, d, a, x[13], S44, 0x4e0811a1); /* 60 */
255 II (a, b, c, d, x[ 4], S41, 0xf7537e82); /* 61 */
256 II (d, a, b, c, x[11], S42, 0xbd3af235); /* 62 */
257 II (c, d, a, b, x[ 2], S43, 0x2ad7d2bb); /* 63 */
258 II (b, c, d, a, x[ 9], S44, 0xeb86d391); /* 64 */
259
260 state[0] += a;
261 state[1] += b;
262 state[2] += c;
263 state[3] += d;
264}
265
266/**
267 * Encodes input (uint32_t) into output (uint8_t). Assumes len is
268 * a multiple of 4.
269 */
270static void Encode(uint8_t *output, uint32_t *input, uint32_t len)
271{
272 uint32_t i, j;
273
274 for (i = 0, j = 0; j < len; i++, j += 4)
275 {
276 output[j] = (uint8_t)(input[i] & 0xff);
277 output[j+1] = (uint8_t)((input[i] >> 8) & 0xff);
278 output[j+2] = (uint8_t)((input[i] >> 16) & 0xff);
279 output[j+3] = (uint8_t)((input[i] >> 24) & 0xff);
280 }
281}
282
283/**
284 * Decodes input (uint8_t) into output (uint32_t). Assumes len is
285 * a multiple of 4.
286 */
287static void Decode(uint32_t *output, const uint8_t *input, uint32_t len)
288{
289 uint32_t i, j;
290
291 for (i = 0, j = 0; j < len; i++, j += 4)
292 output[i] = ((uint32_t)input[j]) | (((uint32_t)input[j+1]) << 8) |
293 (((uint32_t)input[j+2]) << 16) | (((uint32_t)input[j+3]) << 24);
294}