[PATCH] Catch SSL errors

[Michael Tremer <michael.tremer@ipfire.org>]

[-- Attachment #1: Type: text/plain, Size: 1912 bytes --]

Properly catch SSL errors. When a connection could not be
established, the ddns client will try again. If an invalid
certificate is presented future updates are held back for
the usual time.

Signed-off-by: Michael Tremer <michael.tremer(a)ipfire.org>
---
 src/ddns/errors.py | 15 +++++++++++++++
 src/ddns/system.py | 11 +++++++++++
 2 files changed, 26 insertions(+)

diff --git a/src/ddns/errors.py b/src/ddns/errors.py
index 58928f3..637cf59 100644
--- a/src/ddns/errors.py
+++ b/src/ddns/errors.py
@@ -64,6 +64,13 @@ class DDNSBlockedError(DDNSError):
 	reason = N_("The server denies any updates from this client")
 
 
+class DDNSCertificateError(DDNSError):
+	"""
+		Thrown when a server presented an invalid certificate.
+	"""
+	reason = N_("Invalid certificate")
+
+
 class DDNSConfigurationError(DDNSError):
 	"""
 		Thrown when invalid or insufficient
@@ -125,6 +132,14 @@ class DDNSResolveError(DDNSNetworkError):
 	reason = N_("Could not resolve DNS entry")
 
 
+class DDNSSSLError(DDNSNetworkError):
+	"""
+		Raised when a SSL connection could not be
+		negotiated.
+	"""
+	reason = N_("SSL negotiation error")
+
+
 class DDNSServiceUnavailableError(DDNSNetworkError):
 	"""
 		Equivalent to HTTP error code 503.
diff --git a/src/ddns/system.py b/src/ddns/system.py
index 79bf192..832de6b 100644
--- a/src/ddns/system.py
+++ b/src/ddns/system.py
@@ -21,6 +21,7 @@
 
 import base64
 import re
+import ssl
 import socket
 import urllib
 import urllib2
@@ -193,6 +194,16 @@ class DDNSSystem(object):
 
 		except urllib2.URLError, e:
 			if e.reason:
+				# Handle SSL errors
+				if isinstance(e.reason, ssl.SSLError):
+					e = e.reason
+
+					if e.reason == "CERTIFICATE_VERIFY_FAILED":
+						raise DDNSCertificateError
+
+					# Raise all other SSL errors
+					raise DDNSSSLError(e.reason)
+
 				# Name or service not known
 				if e.reason.errno == -2:
 					raise DDNSResolveError
-- 
2.4.3