From c45caf7f37281fd2ae781b344a5cec8cbe81bfbb Mon Sep 17 00:00:00 2001
From: Michel Oosterhof <michel@oosterhof.net>
Date: Sun, 17 Jan 2016 10:32:35 +0400
Subject: [PATCH] authbind docs

---
 INSTALL.md | 15 +++++++++++++--
 start.sh   |  8 +++++++-
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git a/INSTALL.md b/INSTALL.md
index d574091..9e0595f 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -2,7 +2,7 @@
 
 Installing cowrie in six easy steps.
 
-It's recommended to install under a separate non-root user id:
+It's strongly recommended to install under a dedicated non-root user id:
 
 ```
 $ sudo adduser --disabled-password cowrie
@@ -37,13 +37,24 @@ $ ./start.sh
 Starting cowrie in the background...
 ```
 
-Cowry runs by default on port 2222. This can be modified in the configuration file. Running on port 22 is not recommended.
+Cowry runs by default on port 2222. This can be modified in the configuration file.
 The following firewall rule will forward incoming traffic on port 22 to port 2222.
 
 ```
 $ sudo iptables -t nat -A PREROUTING -p tcp --dport 22 -j REDIRECT --to-port 2222
 ```
 
+Alternatively you can run authbind to listen as non-root on port 22 directly:
+
+```
+$ apt-get install authbind
+$ touch /etc/authbind/byport/22
+$ chown cowrie:cowrie /etc/authbind/byport/22
+$ chmod 777 /etc/authbind/byport/22
+```
+
+* Edit start.sh and modify the AUTHBIND_ENABLED setting
+* Change listen_port to 22 in cowrie.cfg
 
 # Bugs and workarounds
 
diff --git a/start.sh b/start.sh
index b1759f3..f439499 100755
--- a/start.sh
+++ b/start.sh
@@ -1,4 +1,5 @@
 #!/bin/sh
+AUTHBIND_ENABLED=no
 
 set -e
 
@@ -25,4 +26,9 @@ then
 fi
 
 echo "Starting cowrie in the background..."
-twistd -l log/cowrie.log --pidfile cowrie.pid cowrie
+if [ $AUTHBIND_ENABLED == "no" ]
+then
+    twistd -l log/cowrie.log --pidfile cowrie.pid cowrie
+else
+    authbind --deep twistd -l log/cowrie.log --pidfile cowrie.pid cowrie
+fi