ref: 80cf8cd0acd5039d149bc86d640b1c2eca7a1f19
dir: /libauthsrv/hkdf_x_plan9.c/
#include <u.h>
#include <libc.h>
#include <libsec.h>
#include <authsrv.h>
void
hkdf_x_plan9(uchar crand[2*NONCELEN], uchar key[NONCELEN], uchar secret[256])
{
static char info[] = "Plan 9 session secret";
hkdf_x(crand, 2*NONCELEN,
(uchar*)info, sizeof(info)-1,
key, NONCELEN,
secret, 256,
hmac_sha2_256, SHA2_256dlen);
}