jehanne/sys/src/lib/sec/port/pbkdf2.c

35 lines
794 B
C

#include "os.h"
#include <libsec.h>
/* rfc2898 */
void
pbkdf2_x(p, plen, s, slen, rounds, d, dlen, x, xlen)
uint8_t *p, *s, *d;
uint32_t plen, slen, dlen, rounds;
DigestState* (*x)(uint8_t*, uint32_t, uint8_t*, uint32_t, uint8_t*, DigestState*);
int xlen;
{
uint8_t block[256], tmp[256];
uint32_t i, j, k, n;
DigestState *ds;
assert(xlen <= sizeof(tmp));
for(i = 1; dlen > 0; i++, d += n, dlen -= n){
tmp[3] = i;
tmp[2] = i >> 8;
tmp[1] = i >> 16;
tmp[0] = i >> 24;
ds = (*x)(s, slen, p, plen, nil, nil);
(*x)(tmp, 4, p, plen, block, ds);
jehanne_memmove(tmp, block, xlen);
for(j = 1; j < rounds; j++){
(*x)(tmp, xlen, p, plen, tmp, nil);
for(k=0; k<xlen; k++)
block[k] ^= tmp[k];
}
n = dlen > xlen ? xlen : dlen;
jehanne_memmove(d, block, n);
}
}