From: Pieter Lexis <pieter.lexis@os3.nl>
Date: Thu, 26 Jan 2012 13:37:08 +0000 (+0100)
Subject: Add a DNSLookupError class (thanks Warren Kumari)
X-Git-Url: https://git.svenne.dk/?a=commitdiff_plain;h=8a12ccd534f0aa1d7f00e1e1962ebd8f5a62523f;p=public%2Fdnssec-swede-utility.git

Add a DNSLookupError class (thanks Warren Kumari)

 * This patch makes the getTLSA method catch the DNSLookupError when no TLSA record is found
---

diff --git a/swede b/swede
index 4be39b5..2ebaf9b 100755
--- a/swede
+++ b/swede
@@ -24,6 +24,7 @@ from binascii import a2b_hex, b2a_hex
 from hashlib import sha256, sha512
 from ipaddr import IPv4Address, IPv6Address
 
+
 def genTLSA(hostname, protocol, port, certificate, output='draft', usage=1, selector=0, mtype=1):
 	"""This function generates a TLSARecord object using the data passed in the parameters,
 	it then validates the record and returns the RR as a string.
@@ -135,7 +136,7 @@ def getRecords(hostname, rrtype='A', secure=True):
 		# If we are here the data was either secure or insecure data is accepted
 		return result.data.raw
 	else:
-		raise Exception('Error: Unsuccesful lookup or no data returned.')
+		raise DNSLookupError('Unsuccesful lookup or no data returned for rrtype %s.' % rrtype)
 
 def getHash(certificate, mtype):
 	"""Hashes the certificate based on the mtype.
@@ -170,6 +171,9 @@ def getTLSA(hostname, port=443, protocol='tcp', secure=True):
 	except InsecureLookupException, e:
 		print str(e)
 		sys.exit(1)
+	except DNSLookupError, e:
+		print 'Unable to resolve %s: %s' % (hostname, str(e))
+		sys.exit(1)
 	ret = []
 	for record in records:
 		hexdata = b2a_hex(record)
@@ -327,16 +331,13 @@ class AAAARecord:
 
 # Exceptions
 class RecordValidityException(Exception):
-	def __init__(self, value):
-		self.value = value
-	def __str__(self):
-		return self.value
+	pass
 
 class InsecureLookupException(Exception):
-	def __init__(self, value):
-		self.value = value
-	def __str__(self):
-		return self.value
+	pass
+
+class DNSLookupError(Exception):
+	pass
 
 if __name__ == '__main__':
 	import argparse