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view src/md5/hmac_md5.c @ 203:45acc5727493
removed --with-glib-static configure option
linking glib statically is interesting if no other program uses it
on today's systems glib is widely used
if one cares on linking statically, he can link everything statically
the special case for glib will not get special care anymore
| author | meillo@marmaro.de |
|---|---|
| date | Fri, 16 Jul 2010 14:48:17 +0200 |
| parents | 08114f7dcc23 |
| children | 10da50168dab |
line source
1 /*
2 ** Function: hmac_md5
3 */
5 #include <string.h>
6 #include "global.h"
7 #include "md5.h"
8 #include "hmac_md5.h"
10 void
11 hmac_md5(unsigned char *text, int text_len, unsigned char *key, int key_len, unsigned char *digest)
12 /* text; pointer to data stream */
13 /* text_len; length of data stream */
14 /* key; pointer to authentication key */
15 /* key_len; length of authentication key */
16 /* digest; caller digest to be filled in */
17 {
18 MD5_CTX context;
19 unsigned char k_ipad[65]; /* inner padding - key XORd with ipad */
20 unsigned char k_opad[65]; /* outer padding - key XORd with opad */
21 unsigned char tk[16];
22 int i;
23 /* if key is longer than 64 bytes reset it to key=MD5(key) */
24 if (key_len > 64) {
26 MD5_CTX tctx;
28 MD5Init(&tctx);
29 MD5Update(&tctx, key, key_len);
30 MD5Final(tk, &tctx);
32 key = tk;
33 key_len = 16;
34 }
36 /*
37 * the HMAC_MD5 transform looks like:
38 *
39 * MD5(K XOR opad, MD5(K XOR ipad, text))
40 *
41 * where K is an n byte key
42 * ipad is the byte 0x36 repeated 64 times
43 * opad is the byte 0x5c repeated 64 times
44 * and text is the data being protected
45 */
47 /* start out by storing key in pads */
48 bzero(k_ipad, sizeof k_ipad);
49 bzero(k_opad, sizeof k_opad);
50 bcopy(key, k_ipad, key_len);
51 bcopy(key, k_opad, key_len);
53 /* XOR key with ipad and opad values */
54 for (i = 0; i < 64; i++) {
55 k_ipad[i] ^= 0x36;
56 k_opad[i] ^= 0x5c;
57 }
58 /*
59 * perform inner MD5
60 */
61 MD5Init(&context); /* init context for 1st pass */
62 MD5Update(&context, k_ipad, 64); /* start with inner pad */
63 MD5Update(&context, text, text_len); /* then text of datagram */
64 MD5Final(digest, &context); /* finish up 1st pass */
65 /*
66 * perform outer MD5
67 */
68 MD5Init(&context); /* init context for 2nd pass */
69 MD5Update(&context, k_opad, 64); /* start with outer pad */
70 MD5Update(&context, digest, 16); /* then results of 1st hash */
71 MD5Final(digest, &context); /* finish up 2nd pass */
72 }