1 #include "os.h"
2 #include <libsec.h>
3 
4 /* rfc2104 */
5 static DigestState*
6 hmac_x(uchar *p, ulong len, uchar *key, ulong klen, uchar *digest, DigestState *s,
7 	DigestState*(*x)(uchar*, ulong, uchar*, DigestState*), int xlen)
8 {
9 	int i;
10 	uchar pad[65], innerdigest[256];
11 
12 	if(xlen > sizeof(innerdigest))
13 		return nil;
14 
15 	if(klen>64)
16 		return nil;
17 
18 	/* first time through */
19 	if(s == nil){
20 		for(i=0; i<64; i++)
21 			pad[i] = 0x36;
22 		pad[64] = 0;
23 		for(i=0; i<klen; i++)
24 			pad[i] ^= key[i];
25 		s = (*x)(pad, 64, nil, nil);
26 		if(s == nil)
27 			return nil;
28 	}
29 
30 	s = (*x)(p, len, nil, s);
31 	if(digest == nil)
32 		return s;
33 
34 	/* last time through */
35 	for(i=0; i<64; i++)
36 		pad[i] = 0x5c;
37 	pad[64] = 0;
38 	for(i=0; i<klen; i++)
39 		pad[i] ^= key[i];
40 	(*x)(nil, 0, innerdigest, s);
41 	s = (*x)(pad, 64, nil, nil);
42 	(*x)(innerdigest, xlen, digest, s);
43 	return nil;
44 }
45 
46 DigestState*
47 hmac_sha1(uchar *p, ulong len, uchar *key, ulong klen, uchar *digest, DigestState *s)
48 {
49 	return hmac_x(p, len, key, klen, digest, s, sha1, SHA1dlen);
50 }
51 
52 DigestState*
53 hmac_md5(uchar *p, ulong len, uchar *key, ulong klen, uchar *digest, DigestState *s)
54 {
55 	return hmac_x(p, len, key, klen, digest, s, md5, MD5dlen);
56 }