[9fans] Patch to smtpd; set TLS certificate file on command line.

[Dan Cross <cross@math.psu.edu>]

When I originally added STARTTLS support to smtpd, I hard-coded the
certificate filename.  In retrospect, this was a mistake; it hard-
coded a matter of local policy, and didn't correspond well to what
other commands did.

Recently (in the last couple of weeks or so) someone added a ``-t''
flag to smtpd to selectively turn on whether or not it announces
support for STARTTLS.  Internally, this works by setting an integer
flag.  Here's a patch that changes -t to -c, and takes as an
argument a path to the certificate file.  Checks on the flag -t sets
have been changed to tests for nullity against a pointer specifying
the certificate file name.

I think this is better since it removes the policy from smtpd, and
still preserves the semantics of having a flag turn on announcement
of STARTTLS.  I sent this to 9trouble a while back, but people have
been busy and it hasn't made it onto sources yet.

	- Dan C.

term% ape/diff -c smtpd.c /sys/src/cmd/upas/smtp/smtpd.c
*** smtpd.c	Tue Mar  4 08:12:50 2003
--- /sys/src/cmd/upas/smtp/smtpd.c	Wed Mar  5 16:06:22 2003
***************
*** 30,36 ****
  int	authenticate;
  int	authenticated;
  int	passwordinclear;
! int	tlsok;

  List senders;
  List rcvers;
--- 30,36 ----
  int	authenticate;
  int	authenticated;
  int	passwordinclear;
! char	*tlscert;

  List senders;
  List rcvers;
***************
*** 126,133 ****
  	case 'p':
  		passwordinclear = 1;
  		break;
! 	case 't':
! 		tlsok = 1;
  		break;
  	default:
  		fprint(2, "usage: smtpd [-dfhrs] [-n net]\n");
--- 126,133 ----
  	case 'p':
  		passwordinclear = 1;
  		break;
! 	case 'c':
! 		tlscert = ARGF();
  		break;
  	default:
  		fprint(2, "usage: smtpd [-dfhrs] [-n net]\n");
***************
*** 257,263 ****

  	reply("250%c%s you are %s\r\n", extended ? '-' : ' ', dom, him);
  	if (extended) {
! 		if(tlsok)
  			reply("250-STARTTLS\r\n");
  		if (passwordinclear)
  			reply("250 AUTH CRAM-MD5 PLAIN LOGIN\r\n");
--- 257,263 ----

  	reply("250%c%s you are %s\r\n", extended ? '-' : ' ', dom, him);
  	if (extended) {
! 		if(tlscert != nil)
  			reply("250-STARTTLS\r\n");
  		if (passwordinclear)
  			reply("250 AUTH CRAM-MD5 PLAIN LOGIN\r\n");
***************
*** 1031,1037 ****
  	TLSconn *conn;

  	conn = mallocz(sizeof *conn, 1);
! 	cert = readcert("/sys/lib/ssl/smtpd-cert.pem", &certlen);
  	if (conn == nil || cert == nil) {
  		if (conn != nil)
  			free(conn);
--- 1031,1037 ----
  	TLSconn *conn;

  	conn = mallocz(sizeof *conn, 1);
! 	cert = readcert(tlscert, &certlen);
  	if (conn == nil || cert == nil) {
  		if (conn != nil)
  			free(conn);
term%