passwd: make legacy mode explicit

Passwd used to produce a very confusing error
about DES not being enabled whenever the password
was mistyped. This happened because we attempted
to guess what authentication method to use, and
preseneted the error from the wrong one on failure.

This puts the legacy mode behind a flag, so that
we don't even try the old method unless it's
explicitly requested.

1 files changed, 13 insertions, 20 deletions

diff --git a/sys/src/cmd/auth/passwd.c b/sys/src/cmd/auth/passwd.c
index db551d67c..eb14ddca8 100644
--- a/sys/src/cmd/auth/passwd.c
+++ b/sys/src/cmd/auth/passwd.c
@@ -7,7 +7,7 @@
 void
 main(int argc, char **argv)
 {
-	int fd, n, try;
+	int fd, n, dp9ik;
 	Ticketreq tr;
 	Ticket t;
 	Passwordreq pr;
@@ -15,7 +15,14 @@ main(int argc, char **argv)
 	char buf[512];
 	char *s, *user;
 
+	dp9ik = 1;
 	ARGBEGIN{
+	case '1':
+		dp9ik = 0;
+		break;
+	default:
+		fprint(2, "%s [-1]\n", argv0);
+		exits("usage");
 	}ARGEND
 
 	argv0 = "passwd";
@@ -48,31 +55,17 @@ main(int argc, char **argv)
 	memset(&pr, 0, sizeof(pr));
 	getpass(&key, pr.old, 0, 0);
 
-	/*
-	 *  negotiate PAK key. we need to retry in case the AS does
-	 *  not support the AuthPAK request or when the user has
-	 *  not yet setup a new key and the AS made one up.
-	 */
-	try = 0;
-	authpak_hash(&key, tr.uid);
-	if(_asgetpakkey(fd, &tr, &key) < 0){
-Retry:
-		try++;
-		close(fd);
-		fd = authdial(nil, s);
-		if(fd < 0)
-			error("authdial: %r");
+	if(dp9ik){
+		authpak_hash(&key, tr.uid);
+		if(_asgetpakkey(fd, &tr, &key) < 0)
+			error("%r");
 	}
-	/* send ticket request to AS */
 	if(_asrequest(fd, &tr) < 0)
 		error("%r");
 	if(_asgetresp(fd, &t, nil, &key) < 0)
 		error("%r");
-	if(t.num != AuthTp || strcmp(t.cuid, tr.uid) != 0){
-		if(try == 0)
-			goto Retry;
+	if(t.num != AuthTp || strcmp(t.cuid, tr.uid) != 0)
 		error("bad password");
-	}
 
 	/* loop trying new passwords */
 	for(;;){