From d13f178cf56e5ae38082abfbd28c68245b774f97 Mon Sep 17 00:00:00 2001
From: Manuel Mausz <manuel@mausz.at>
Date: Mon, 16 Aug 2021 12:26:46 +0200
Subject: Require HELO/EHLO before MAIL

---
 qmail-smtpd.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/qmail-smtpd.c b/qmail-smtpd.c
index 20027b0..b722ee4 100644
--- a/qmail-smtpd.c
+++ b/qmail-smtpd.c
@@ -192,6 +192,7 @@ void err_badbounce() { out("550 sorry, bounce messages should have a single enve
 void err_unimpl(arg) char *arg; { out("502 unimplemented (#5.5.1)\r\n"); do_hard_errors(); }
 void err_syntax() { out("555 syntax error (#5.5.4)\r\n"); do_hard_errors(); }
 void err_relay() { out("553 we don't relay (#5.7.1)\r\n"); do_hard_errors(); }
+void err_wanthelo() { out("503 HELO/EHLO first (#5.5.1)\r\n"); do_hard_errors(); }
 void err_wantmail() { out("503 MAIL first (#5.5.1)\r\n"); do_hard_errors(); }
 void err_wantrcpt() { out("503 RCPT first (#5.5.1)\r\n"); do_hard_errors(); }
 void err_noop(arg) char *arg; { out("250 ok\r\n"); }
@@ -550,6 +551,7 @@ int addrrelay()
   return 0;
 }
 
+int seenhelo = 0;
 int seenmail = 0;
 int flagbarfbmf; /* defined if seenmail */
 int flagbarfbmt;
@@ -678,7 +680,7 @@ void smtp_helo(arg) char *arg;
 {
   if(!spp_helo(arg)) return;
   smtp_greet("250 "); out("\r\n");
-  seenmail = 0; dohelo(arg);
+  seenmail = 0; seenhelo = 1; dohelo(arg);
   if (bhelook) flagbarfbhelo = bmcheck(BMCHECK_BHELO);
 }
 void smtp_authout();
@@ -709,7 +711,7 @@ void smtp_ehlo(arg) char *arg;
   smtp_authout();
 #endif
   out("250 SIZE "); out(size); out("\r\n");
-  seenmail = 0; dohelo(arg);
+  seenmail = 0; seenhelo = 1; dohelo(arg);
   if (bhelook) flagbarfbhelo = bmcheck(BMCHECK_BHELO);
 }
 void smtp_rset(arg) char *arg;
@@ -720,6 +722,7 @@ void smtp_rset(arg) char *arg;
 }
 void smtp_mail(arg) char *arg;
 {
+  if (!seenhelo) { err_wanthelo(); return; }
   if (!addrparse(arg)) { err_syntax(); return; }
   flagsize = 0;
   mailfrom_parms(arg);
-- 
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