From feaab90b1fe29c9f059e4b548540f00b6df79ff1 Mon Sep 17 00:00:00 2001
From: vanhauser-thc <vh@thc.org>
Date: Thu, 3 Nov 2022 17:05:41 +0100
Subject: [PATCH] fix smtp

---
 CHANGES      |  5 +++--
 hydra-smtp.c | 10 ++++++++++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/CHANGES b/CHANGES
index 55d74e9..2c27d84 100644
--- a/CHANGES
+++ b/CHANGES
@@ -2,10 +2,11 @@ Changelog for hydra
 -------------------
 
 Release 9.5-dev
+* The help for http-form was wrong. the condition variable must always be
+  the *last* parameter, not the third
 * smb2: fix for updated libsmb2 which resulted in correct guessing attempts
   not being detected
-* The help for http forms was wrong. the condition variable must always be
-  the *last* parameter, not the third
+* smtp: break early if the server does not allow authentication
 
 
 Release 9.4
diff --git a/hydra-smtp.c b/hydra-smtp.c
index dc6e54a..97d5b72 100644
--- a/hydra-smtp.c
+++ b/hydra-smtp.c
@@ -61,6 +61,10 @@ int32_t start_smtp(int32_t s, char *ip, int32_t port, unsigned char options, cha
       return 1;
     if (strstr(buf, "334") == NULL) {
       hydra_report(stderr, "[ERROR] SMTP PLAIN AUTH : %s\n", buf);
+      if (strstr(buf, "503") != NULL) {
+        free(buf);
+        return 4;
+      }
       free(buf);
       return 3;
     }
@@ -438,6 +442,12 @@ void service_smtp(char *ip, int32_t sp, unsigned char options, char *miscptr, FI
       }
       hydra_child_exit(0);
       return;
+    case 4: /* error exit */
+      if (sock >= 0) {
+        sock = hydra_disconnect(sock);
+      }
+      hydra_child_exit(3);
+      return;
     default:
       hydra_report(stderr, "[ERROR] Caught unknown return code, exiting!\n");
       hydra_child_exit(0);