Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>
#include <auth.h>
#include "../boot/boot.h"

static char *pbmsg = "AS protocol botch";
static char *ccmsg = "can't connect to AS";

long
readn(int fd, void *buf, long len)
{
        int m, n;
        char *p;

        p = buf;
        for(n = 0; n < len; n += m){
                m = read(fd, p+n, len-n);
                if(m <= 0)
                        return -1;
        }
        return n;
}

static char*
fromauth(Method *mp, char *trbuf, char *tbuf)
{
        int afd;
        char t;
        char *msg;
        static char error[2*ERRMAX];

        if(mp->auth == 0)
                fatal("no method for accessing auth server");
        afd = (*mp->auth)();
        if(afd < 0) {
                sprint(error, "%s: %r", ccmsg);
                return error;
        }

        if(write(afd, trbuf, TICKREQLEN) < 0 || read(afd, &t, 1) != 1){
                close(afd);
                sprint(error, "%s: %r", pbmsg);
                return error;
        }
        switch(t){
        case AuthOK:
                msg = 0;
                if(readn(afd, tbuf, 2*TICKETLEN) < 0) {
                        sprint(error, "%s: %r", pbmsg);
                        msg = error;
                }
                break;
        case AuthErr:
                if(readn(afd, error, ERRMAX) < 0) {
                        sprint(error, "%s: %r", pbmsg);
                        msg = error;
                }
                else {
                        error[ERRMAX-1] = 0;
                        msg = error;
                }
                break;
        default:
                msg = pbmsg;
                break;
        }

        close(afd);
        return msg;
}

void
doauthenticate(int fd, Method *mp)
{
        char *msg;
        char trbuf[TICKREQLEN];
        char tbuf[2*TICKETLEN];

        print("session...");
        if(fsession(fd, trbuf, sizeof trbuf) < 0)
                fatal("session command failed");

        /* no authentication required? */
        memset(tbuf, 0, 2*TICKETLEN);
        if(trbuf[0] == 0)
                return;

        /* try getting to an auth server */
        print("getting ticket...");
        msg = fromauth(mp, trbuf, tbuf);
        print("authenticating...");
        if(msg == 0)
                if(fauth(fd, tbuf) >= 0)
                        return;

        /* didn't work, go for the security hole */
        fprint(2, "no authentication server (%s), using your key as server key\n", msg);
}

char*
checkkey(Method *mp, char *name, char *key)
{
        char *msg;
        Ticketreq tr;
        Ticket t;
        char trbuf[TICKREQLEN];
        char tbuf[TICKETLEN];

        memset(&tr, 0, sizeof tr);
        tr.type = AuthTreq;
        strcpy(tr.authid, name);
        strcpy(tr.hostid, name);
        strcpy(tr.uid, name);
        convTR2M(&tr, trbuf);
        msg = fromauth(mp, trbuf, tbuf);
        if(msg == ccmsg){
                fprint(2, "boot: can't contact auth server, passwd unchecked\n");
                return 0;
        }
        if(msg)
                return msg;
        convM2T(tbuf, &t, key);
        if(t.num == AuthTc && strcmp(name, t.cuid)==0)
                return 0;
        return "no match";
}