Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>
#include <auth.h>
#include <authsrv.h>
#include "authlocal.h"

/*
 * compute the proper response.  We encrypt the ascii of
 * challenge number, with trailing binary zero fill.
 * This process was derived empirically.
 * this was copied from inet's guard.
 */
static void
netresp(char *key, long chal, char *answer)
{
        uchar buf[8];

        memset(buf, 0, sizeof buf);
        snprint((char *)buf, sizeof buf, "%lud", chal);
        if(encrypt(key, buf, 8) < 0)
                abort();
        sprint(answer, "%.8ux", buf[0]<<24 | buf[1]<<16 | buf[2]<<8 | buf[3]);
}

AuthInfo*
auth_userpasswd(char *user, char *passwd)
{
        char key[DESKEYLEN], resp[16];
        AuthInfo *ai;
        Chalstate *ch;

        /*
         * Probably we should have a factotum protocol
         * to check a raw password.  For now, we use
         * p9cr, which is simplest to speak.
         */
        if((ch = auth_challenge("user=%q proto=p9cr role=server", user)) == nil)
                return nil;

        passtokey(key, passwd);
        netresp(key, atol(ch->chal), resp);
        memset(key, 0, sizeof key);

        ch->resp = resp;
        ch->nresp = strlen(resp);
        ai = auth_response(ch);
        auth_freechal(ch);
        return ai;
}