From b8f0ce7155c4a9748c6e49e9678a8d9e65735400 Mon Sep 17 00:00:00 2001
From: Cyril Jaquier <cyril.jaquier@fail2ban.org>
Date: Sat, 23 Dec 2006 23:20:16 +0000
Subject: [PATCH] - Do not accept empty regular expression - Do not send an
 empty string if the option is not defined

git-svn-id: https://fail2ban.svn.sourceforge.net/svnroot/fail2ban/trunk@505 a942ae1a-1317-0410-a47c-b1dcaea8d605
---
 client/filterreader.py | 8 ++++++--
 client/jailreader.py   | 4 +++-
 server/regex.py        | 2 ++
 3 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/client/filterreader.py b/client/filterreader.py
index 30cca818..4bb36fda 100644
--- a/client/filterreader.py
+++ b/client/filterreader.py
@@ -68,9 +68,13 @@ class FilterReader(ConfigReader):
 				stream.append(["set", self.__name, "timepattern", self.__opts[opt]])
 			elif opt == "failregex":
 				for regex in self.__opts[opt].split('\n'):
-					stream.append(["set", self.__name, "addfailregex", regex])
+					# Do not send a command if the rule is empty.
+					if regex != '':
+						stream.append(["set", self.__name, "addfailregex", regex])
 			elif opt == "ignoreregex":
 				for regex in self.__opts[opt].split('\n'):
-					stream.append(["set", self.__name, "addignoreregex", regex])		
+					# Do not send a command if the rule is empty.
+					if regex != '':
+						stream.append(["set", self.__name, "addignoreregex", regex])		
 		return stream
 		
\ No newline at end of file
diff --git a/client/jailreader.py b/client/jailreader.py
index bb408876..aa26d789 100644
--- a/client/jailreader.py
+++ b/client/jailreader.py
@@ -112,7 +112,9 @@ class JailReader(ConfigReader):
 				stream.append(["set", self.__name, "maxretry", self.__opts[opt]])
 			elif opt == "ignoreip":
 				for ip in self.__opts[opt].split():
-					stream.append(["set", self.__name, "addignoreip", ip])
+					# Do not send a command if the rule is empty.
+					if ip != '':
+						stream.append(["set", self.__name, "addignoreip", ip])
 			elif opt == "findtime":
 				stream.append(["set", self.__name, "findtime", self.__opts[opt]])
 			elif opt == "bantime":
diff --git a/server/regex.py b/server/regex.py
index c4e9c8ec..d3d6eee4 100644
--- a/server/regex.py
+++ b/server/regex.py
@@ -42,6 +42,8 @@ class Regex:
 	
 	def __init__(self, regex):
 		self._matchCache = None
+		if regex.lstrip() == '':
+			raise RegexException("Cannot add empty regex")
 		try:
 			self._regexObj = re.compile(regex)
 			self._regex = regex