xref: /plan9-contrib/sys/src/libsec/port/pbkdf2.c (revision 5f0225f3bf561adc12ef4a15885b42cd8e117813)
1 #include "os.h"
2 #include <libsec.h>
3 
4 /* rfc2898 */
5 void
pbkdf2_x(p,plen,s,slen,rounds,d,dlen,x,xlen)6 pbkdf2_x(p, plen, s, slen, rounds, d, dlen, x, xlen)
7 	uchar *p, *s, *d;
8 	ulong plen, slen, dlen, rounds;
9 	DigestState* (*x)(uchar*, ulong, uchar*, ulong, uchar*, DigestState*);
10 	int xlen;
11 {
12 	uchar block[256], tmp[256];
13 	ulong i, j, k, n;
14 	DigestState *ds;
15 
16 	assert(xlen <= sizeof(tmp));
17 
18 	for(i = 1; dlen > 0; i++, d += n, dlen -= n){
19 		tmp[3] = i;
20 		tmp[2] = i >> 8;
21 		tmp[1] = i >> 16;
22 		tmp[0] = i >> 24;
23 		ds = (*x)(s, slen, p, plen, nil, nil);
24 		(*x)(tmp, 4, p, plen, block, ds);
25 		memmove(tmp, block, xlen);
26 		for(j = 1; j < rounds; j++){
27 			(*x)(tmp, xlen, p, plen, tmp, nil);
28 			for(k=0; k<xlen; k++)
29 				block[k] ^= tmp[k];
30 		}
31 		n = dlen > xlen ? xlen : dlen;
32 		memmove(d, block, n);
33 	}
34 }
35