Two problems:

- RFC 2034 Section 3 (item 4) requires that the status code is always followed
  by one or more spaces. However, OpenSMTPD has a colon right after the status
  code in many of the replies it sends.
- RFC 2034 Section 4 states: "When responses are continued across multiple lines
  the same status code must appear at the beginning of the text in each line of
  the response." However, OpenSMTPD only has the enhanced status code for the
  last reply line it sends. Still, there is only one case in which it sends
  such a multi-line reply: the HELP command.

diff from Stephan Bosch

1 files changed, 32 insertions, 31 deletions

diff --git a/usr.sbin/smtpd/smtp_session.c b/usr.sbin/smtpd/smtp_session.c
index 5f21b31460e..c70c46b0e0d 100644
--- a/usr.sbin/smtpd/smtp_session.c
+++ b/usr.sbin/smtpd/smtp_session.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: smtp_session.c,v 1.400 2019/07/11 21:40:03 gilles Exp $	*/
+/*	$OpenBSD: smtp_session.c,v 1.401 2019/07/24 19:50:10 gilles Exp $	*/
 
 /*
  * Copyright (c) 2008 Gilles Chehade <gilles@poolp.org>
@@ -715,7 +715,7 @@ smtp_session_imsg(struct mproc *p, struct imsg *imsg)
 			break;
 		case LKA_TEMPFAIL:
 			smtp_tx_free(s->tx);
-			smtp_reply(s, "421 %s: Temporary Error",
+			smtp_reply(s, "421 %s Temporary Error",
 			    esc_code(ESC_STATUS_TEMPFAIL, ESC_OTHER_MAIL_SYSTEM_STATUS));
 			break;
 		}
@@ -775,11 +775,11 @@ smtp_session_imsg(struct mproc *p, struct imsg *imsg)
 			s->tx->evp.id = msgid_to_evpid(msgid);
 			s->tx->rcptcount = 0;
 			report_smtp_tx_begin("smtp-in", s->id, s->tx->msgid);
-			smtp_reply(s, "250 %s: Ok",
+			smtp_reply(s, "250 %s Ok",
 			    esc_code(ESC_STATUS_OK, ESC_OTHER_STATUS));
 		} else {
 			smtp_tx_free(s->tx);
-			smtp_reply(s, "421 %s: Temporary Error",
+			smtp_reply(s, "421 %s Temporary Error",
 			    esc_code(ESC_STATUS_TEMPFAIL, ESC_OTHER_MAIL_SYSTEM_STATUS));
 			smtp_enter_state(s, STATE_QUIT);
 		}
@@ -796,7 +796,7 @@ smtp_session_imsg(struct mproc *p, struct imsg *imsg)
 		if (!success || imsg->fd == -1) {
 			if (imsg->fd != -1)
 				close(imsg->fd);
-			smtp_reply(s, "421 %s: Temporary Error",
+			smtp_reply(s, "421 %s Temporary Error",
 			    esc_code(ESC_STATUS_TEMPFAIL, ESC_OTHER_MAIL_SYSTEM_STATUS));
 			smtp_enter_state(s, STATE_QUIT);
 			return;
@@ -822,7 +822,7 @@ smtp_session_imsg(struct mproc *p, struct imsg *imsg)
 		if (!success || imsg->fd == -1) {
 			if (imsg->fd != -1)
 				close(imsg->fd);
-			smtp_reply(s, "421 %s: Temporary Error",
+			smtp_reply(s, "421 %s Temporary Error",
 			    esc_code(ESC_STATUS_TEMPFAIL, ESC_OTHER_MAIL_SYSTEM_STATUS));
 			smtp_enter_state(s, STATE_QUIT);
 			return;
@@ -864,7 +864,7 @@ smtp_session_imsg(struct mproc *p, struct imsg *imsg)
 			 * RCPT only so we must cancel the whole transaction
 			 * and close the connection.
 			 */
-			smtp_reply(s, "421 %s: Temporary failure",
+			smtp_reply(s, "421 %s Temporary failure",
 			    esc_code(ESC_STATUS_TEMPFAIL, ESC_OTHER_MAIL_SYSTEM_STATUS));
 			smtp_enter_state(s, STATE_QUIT);
 		}
@@ -891,13 +891,13 @@ smtp_session_imsg(struct mproc *p, struct imsg *imsg)
 		s = tree_xpop(&wait_queue_commit, reqid);
 		if (!success) {
 			smtp_tx_free(s->tx);
-			smtp_reply(s, "421 %s: Temporary failure",
+			smtp_reply(s, "421 %s Temporary failure",
 			    esc_code(ESC_STATUS_TEMPFAIL, ESC_OTHER_MAIL_SYSTEM_STATUS));
 			smtp_enter_state(s, STATE_QUIT);
 			return;
 		}
 
-		smtp_reply(s, "250 %s: %08x Message accepted for delivery",
+		smtp_reply(s, "250 %s %08x Message accepted for delivery",
 		    esc_code(ESC_STATUS_OK, ESC_OTHER_STATUS),
 		    s->tx->msgid);
 
@@ -940,7 +940,7 @@ smtp_session_imsg(struct mproc *p, struct imsg *imsg)
 			    s->id, user);
 			s->flags |= SF_AUTHENTICATED;
 			report_smtp_link_auth("smtp-in", s->id, user, "pass");
-			smtp_reply(s, "235 %s: Authentication succeeded",
+			smtp_reply(s, "235 %s Authentication succeeded",
 			    esc_code(ESC_STATUS_OK, ESC_OTHER_STATUS));
 		}
 		else if (success == LKA_PERMFAIL) {
@@ -958,7 +958,7 @@ smtp_session_imsg(struct mproc *p, struct imsg *imsg)
 			    "result=tempfail",
 			    s->id, user);
 			report_smtp_link_auth("smtp-in", s->id, user, "error");
-			smtp_reply(s, "421 %s: Temporary failure",
+			smtp_reply(s, "421 %s Temporary failure",
 			    esc_code(ESC_STATUS_TEMPFAIL, ESC_OTHER_MAIL_SYSTEM_STATUS));
 		}
 		else
@@ -1085,7 +1085,7 @@ smtp_io(struct io *io, int evt, void *arg)
 		if ((line == NULL && io_datalen(s->io) >= SMTP_LINE_MAX) ||
 		    (line && len >= SMTP_LINE_MAX)) {
 			s->flags |= SF_BADINPUT;
-			smtp_reply(s, "500 %s: Line too long",
+			smtp_reply(s, "500 %s Line too long",
 			    esc_code(ESC_STATUS_PERMFAIL, ESC_OTHER_STATUS));
 			smtp_enter_state(s, STATE_QUIT);
 			io_set_write(io);
@@ -1098,7 +1098,7 @@ smtp_io(struct io *io, int evt, void *arg)
 
 		if (strchr(line, '\r')) {
 			s->flags |= SF_BADINPUT;
-			smtp_reply(s, "500 %s: <CR> is only allowed before <LF>",
+			smtp_reply(s, "500 %s <CR> is only allowed before <LF>",
 			    esc_code(ESC_STATUS_PERMFAIL, ESC_OTHER_STATUS));
 			smtp_enter_state(s, STATE_QUIT);
 			io_set_write(io);
@@ -1141,7 +1141,7 @@ smtp_io(struct io *io, int evt, void *arg)
 		/* Must be a command */
 		if (strlcpy(s->cmd, line, sizeof(s->cmd)) >= sizeof(s->cmd)) {
 			s->flags |= SF_BADINPUT;
-			smtp_reply(s, "500 %s: Command line too long",
+			smtp_reply(s, "500 %s Command line too long",
 			    esc_code(ESC_STATUS_PERMFAIL, ESC_OTHER_STATUS));
 			smtp_enter_state(s, STATE_QUIT);
 			io_set_write(io);
@@ -1536,7 +1536,7 @@ smtp_check_mail_from(struct smtp_session *s, const char *args)
 	}
 
 	if (!smtp_tx(s)) {
-		smtp_reply(s, "421 %s: Temporary Error",
+		smtp_reply(s, "421 %s Temporary Error",
 		    esc_code(ESC_STATUS_TEMPFAIL, ESC_OTHER_MAIL_SYSTEM_STATUS));
 		smtp_enter_state(s, STATE_QUIT);
 		return 0;
@@ -1544,7 +1544,7 @@ smtp_check_mail_from(struct smtp_session *s, const char *args)
 
 	if (smtp_mailaddr(&s->tx->evp.sender, copy, 1, &copy,
 		s->tx->session->smtpname) == 0) {
-		smtp_reply(s, "553 %s: Sender address syntax error",
+		smtp_reply(s, "553 %s Sender address syntax error",
 		    esc_code(ESC_STATUS_PERMFAIL, ESC_OTHER_ADDRESS_STATUS));
 		smtp_tx_free(s->tx);
 		return 0;
@@ -1579,7 +1579,7 @@ smtp_check_rcpt_to(struct smtp_session *s, const char *args)
 	if (smtp_mailaddr(&s->tx->evp.rcpt, copy, 0, &copy,
 		s->tx->session->smtpname) == 0) {
 		smtp_reply(s->tx->session,
-		    "501 %s: Recipient address syntax error",
+		    "501 %s Recipient address syntax error",
 		    esc_code(ESC_STATUS_PERMFAIL,
 		        ESC_BAD_DESTINATION_MAILBOX_ADDRESS_SYNTAX));
 		return 0;
@@ -1726,7 +1726,7 @@ smtp_proceed_rset(struct smtp_session *s, const char *args)
 
 	report_smtp_link_reset("smtp-in", s->id);
 
-	smtp_reply(s, "250 %s: Reset state",
+	smtp_reply(s, "250 %s Reset state",
 	    esc_code(ESC_STATUS_OK, ESC_OTHER_STATUS));
 }
 
@@ -1801,7 +1801,7 @@ smtp_proceed_auth(struct smtp_session *s, const char *args)
 static void
 smtp_proceed_starttls(struct smtp_session *s, const char *args)
 {
-	smtp_reply(s, "220 %s: Ready to start TLS",
+	smtp_reply(s, "220 %s Ready to start TLS",
 	    esc_code(ESC_STATUS_OK, ESC_OTHER_STATUS));
 	smtp_enter_state(s, STATE_TLS);
 }
@@ -1827,7 +1827,7 @@ smtp_proceed_data(struct smtp_session *s, const char *args)
 static void
 smtp_proceed_quit(struct smtp_session *s, const char *args)
 {
-	smtp_reply(s, "221 %s: Bye",
+	smtp_reply(s, "221 %s Bye",
 	    esc_code(ESC_STATUS_OK, ESC_OTHER_STATUS));
 	smtp_enter_state(s, STATE_QUIT);
 }
@@ -1835,19 +1835,20 @@ smtp_proceed_quit(struct smtp_session *s, const char *args)
 static void
 smtp_proceed_noop(struct smtp_session *s, const char *args)
 {
-	smtp_reply(s, "250 %s: Ok",
+	smtp_reply(s, "250 %s Ok",
 	    esc_code(ESC_STATUS_OK, ESC_OTHER_STATUS));
 }
 
 static void
 smtp_proceed_help(struct smtp_session *s, const char *args)
 {
-	smtp_reply(s, "214- This is " SMTPD_NAME);
-	smtp_reply(s, "214- To report bugs in the implementation, "
-	    "please contact bugs@openbsd.org");
-	smtp_reply(s, "214- with full details");
-	smtp_reply(s, "214 %s: End of HELP info",
-	    esc_code(ESC_STATUS_OK, ESC_OTHER_STATUS));
+	const char *code = esc_code(ESC_STATUS_OK, ESC_OTHER_STATUS);
+
+	smtp_reply(s, "214-%s This is " SMTPD_NAME, code);
+	smtp_reply(s, "214-%s To report bugs in the implementation, "
+	    "please contact bugs@openbsd.org", code);
+	smtp_reply(s, "214-%s with full details", code);
+	smtp_reply(s, "214 %s End of HELP info", code);
 }
 
 static void
@@ -2398,7 +2399,7 @@ smtp_tx_mail_from(struct smtp_tx *tx, const char *line)
 
 	if (smtp_mailaddr(&tx->evp.sender, copy, 1, &copy,
 		tx->session->smtpname) == 0) {
-		smtp_reply(tx->session, "553 %s: Sender address syntax error",
+		smtp_reply(tx->session, "553 %s Sender address syntax error",
 		    esc_code(ESC_STATUS_PERMFAIL, ESC_OTHER_ADDRESS_STATUS));
 		smtp_tx_free(tx);
 		return;
@@ -2487,7 +2488,7 @@ smtp_tx_rcpt_to(struct smtp_tx *tx, const char *line)
 	if (smtp_mailaddr(&tx->evp.rcpt, copy, 0, &copy,
 	    tx->session->smtpname) == 0) {
 		smtp_reply(tx->session,
-		    "501 %s: Recipient address syntax error",
+		    "501 %s Recipient address syntax error",
 		    esc_code(ESC_STATUS_PERMFAIL,
 		        ESC_BAD_DESTINATION_MAILBOX_ADDRESS_SYNTAX));
 		return;
@@ -2727,7 +2728,7 @@ smtp_message_fd(struct smtp_tx *tx, int fd)
 
 	if ((tx->ofile = fdopen(fd, "w")) == NULL) {
 		close(fd);
-		smtp_reply(s, "421 %s: Temporary Error",
+		smtp_reply(s, "421 %s Temporary Error",
 		    esc_code(ESC_STATUS_TEMPFAIL, ESC_OTHER_MAIL_SYSTEM_STATUS));
 		smtp_enter_state(s, STATE_QUIT);
 		return 0;
@@ -2874,7 +2875,7 @@ smtp_message_end(struct smtp_tx *tx)
 
 	case TX_ERROR_IO:
 	case TX_ERROR_RESOURCES:
-		smtp_reply(s, "421 %s: Temporary Error",
+		smtp_reply(s, "421 %s Temporary Error",
 		    esc_code(ESC_STATUS_TEMPFAIL, ESC_OTHER_MAIL_SYSTEM_STATUS));
 		break;