drawterm/libsec/hmac.c

57 lines
1.1 KiB
C

#include "os.h"
#include <libsec.h>
/* rfc2104 */
static DigestState*
hmac_x(uchar *p, ulong len, uchar *key, ulong klen, uchar *digest, DigestState *s,
DigestState*(*x)(uchar*, ulong, uchar*, DigestState*), int xlen)
{
int i;
uchar pad[65], innerdigest[256];
if(xlen > sizeof(innerdigest))
return nil;
if(klen>64)
return nil;
/* first time through */
if(s == nil){
for(i=0; i<64; i++)
pad[i] = 0x36;
pad[64] = 0;
for(i=0; i<klen; i++)
pad[i] ^= key[i];
s = (*x)(pad, 64, nil, nil);
if(s == nil)
return nil;
}
s = (*x)(p, len, nil, s);
if(digest == nil)
return s;
/* last time through */
for(i=0; i<64; i++)
pad[i] = 0x5c;
pad[64] = 0;
for(i=0; i<klen; i++)
pad[i] ^= key[i];
(*x)(nil, 0, innerdigest, s);
s = (*x)(pad, 64, nil, nil);
(*x)(innerdigest, xlen, digest, s);
return nil;
}
DigestState*
hmac_sha1(uchar *p, ulong len, uchar *key, ulong klen, uchar *digest, DigestState *s)
{
return hmac_x(p, len, key, klen, digest, s, sha1, SHA1dlen);
}
DigestState*
hmac_md5(uchar *p, ulong len, uchar *key, ulong klen, uchar *digest, DigestState *s)
{
return hmac_x(p, len, key, klen, digest, s, md5, MD5dlen);
}