From 7af62c05faed75844512c82fea77a01619806c07 Mon Sep 17 00:00:00 2001
From: Cyril Jaquier <cyril.jaquier@fail2ban.org>
Date: Sun, 6 Mar 2005 17:51:24 +0000
Subject: [PATCH] - Initial import

git-svn-id: https://fail2ban.svn.sourceforge.net/svnroot/fail2ban/trunk@82 a942ae1a-1317-0410-a47c-b1dcaea8d605
---
 utils/__init__.py | 25 +++++++++++++
 utils/dns.py      | 94 +++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 119 insertions(+)
 create mode 100644 utils/__init__.py
 create mode 100644 utils/dns.py

diff --git a/utils/__init__.py b/utils/__init__.py
new file mode 100644
index 00000000..76dba873
--- /dev/null
+++ b/utils/__init__.py
@@ -0,0 +1,25 @@
+# This file is part of Fail2Ban.
+#
+# Fail2Ban is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# Fail2Ban is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Fail2Ban; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+# Author: Cyril Jaquier
+# 
+# $Revision$
+
+__author__ = "Cyril Jaquier"
+__version__ = "$Revision$"
+__date__ = "$Date$"
+__copyright__ = "Copyright (c) 2004 Cyril Jaquier"
+__license__ = "GPL"
\ No newline at end of file
diff --git a/utils/dns.py b/utils/dns.py
new file mode 100644
index 00000000..13502cbe
--- /dev/null
+++ b/utils/dns.py
@@ -0,0 +1,94 @@
+# This file is part of Fail2Ban.
+#
+# Fail2Ban is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# Fail2Ban is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with Fail2Ban; if not, write to the Free Software
+# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+
+# Author: Cyril Jaquier
+# 
+# $Revision$
+
+__author__ = "Cyril Jaquier"
+__version__ = "$Revision$"
+__date__ = "$Date$"
+__copyright__ = "Copyright (c) 2004 Cyril Jaquier"
+__license__ = "GPL"
+
+import os, re
+
+def dnsToIp(dns):
+	""" Convert a DNS into an IP address using the "host" command.
+		We make sure that there is no malicious usage of this function.
+	"""
+	ipList = list()
+	# Check for command injection
+	if checkInjection(dns):
+		return ipList
+	result = os.popen("host "+dns, 'r')
+	for i in result.readlines():
+		match = re.search("(?:\d{1,3}\.){3}\d{1,3}", i)
+		if match:
+			ipList.append(match.group())
+	return ipList
+
+def checkInjection(command):
+	""" Check that command could not be used to inject shell commands.
+	"""
+	# Characters which have nothing to do in "command"
+	invalid = "<|>|;|\&|\||`|!"
+	match = re.search(invalid, command)
+	if match:
+		return True
+	else:
+		return False
+
+def textToDns(text):
+	""" Search for possible DNS in an arbitrary text.
+	"""
+	match = re.findall("\w*\.\w*\.\w*", text)
+	if match:
+		return match
+	else:
+		return None
+
+def searchIP(text):
+	""" Search if an IP address if directly available and return
+		it.
+	"""
+	match = re.findall("(?:\d{1,3}\.){3}\d{1,3}", text)
+	if match:
+		return match
+	else:
+		return None
+
+def textToIp(text):
+	""" Return the IP of DNS found in a given text.
+	"""
+	ipList = list()
+	# Search for plain IP
+	plainIP = searchIP(text)
+	if plainIP:
+		for element in plainIP:
+			ipList.append(element)
+	else:
+		# Try to get IP from possible DNS
+		dnsList = textToDns(text)
+		for element in dnsList:
+			dns = dnsToIp(element)
+			for e in dns:
+				ipList.append(e)
+	return ipList
+
+if __name__ == "__main__":
+	print textToIp("jlkjlk 123.456.789.000 jlkjl rhost=lslpc49.epfl.ch www.google.ch")
+	
\ No newline at end of file