Add support for Python built without ssl (#939) (#954)

1 files changed, 28 insertions, 17 deletions

diff --git a/kafka/conn.py b/kafka/conn.py
index bb9df69..c7a077c 100644
--- a/kafka/conn.py
+++ b/kafka/conn.py
@@ -7,7 +7,6 @@ import logging
 import io
 from random import shuffle
 import socket
-import ssl
 import time
 import traceback
 
@@ -31,19 +30,28 @@ log = logging.getLogger(__name__)
 
 DEFAULT_KAFKA_PORT = 9092
 
-# support older ssl libraries
 try:
-    ssl.SSLWantReadError
-    ssl.SSLWantWriteError
-    ssl.SSLZeroReturnError
-except:
-    log.warning('Old SSL module detected.'
-                ' SSL error handling may not operate cleanly.'
-                ' Consider upgrading to Python 3.3 or 2.7.9')
-    ssl.SSLWantReadError = ssl.SSLError
-    ssl.SSLWantWriteError = ssl.SSLError
-    ssl.SSLZeroReturnError = ssl.SSLError
-
+    import ssl
+    ssl_available = True
+    try:
+        SSLWantReadError = ssl.SSLWantReadError
+        SSLWantWriteError = ssl.SSLWantWriteError
+        SSLZeroReturnError = ssl.SSLZeroReturnError
+    except:
+        # support older ssl libraries
+        log.warning('Old SSL module detected.'
+                    ' SSL error handling may not operate cleanly.'
+                    ' Consider upgrading to Python 3.3 or 2.7.9')
+        SSLWantReadError = ssl.SSLError
+        SSLWantWriteError = ssl.SSLError
+        SSLZeroReturnError = ssl.SSLError
+except ImportError:
+    # support Python without ssl libraries
+    ssl_available = False
+    class SSLWantReadError(Exception):
+        pass
+    class SSLWantWriteError(Exception):
+        pass
 
 class ConnectionStates(object):
     DISCONNECTING = '<disconnecting>'
@@ -177,6 +185,9 @@ class BrokerConnection(object):
                  (socket.SOL_SOCKET, socket.SO_SNDBUF,
                  self.config['send_buffer_bytes']))
 
+        if self.config['security_protocol'] in ('SSL', 'SASL_SSL'):
+            assert ssl_available, "Python wasn't built with SSL support"
+
         if self.config['security_protocol'] in ('SASL_PLAINTEXT', 'SASL_SSL'):
             assert self.config['sasl_mechanism'] in self.SASL_MECHANISMS, (
                 'sasl_mechanism must be in ' + ', '.join(self.SASL_MECHANISMS))
@@ -368,9 +379,9 @@ class BrokerConnection(object):
             self._sock.do_handshake()
             return True
         # old ssl in python2.6 will swallow all SSLErrors here...
-        except (ssl.SSLWantReadError, ssl.SSLWantWriteError):
+        except (SSLWantReadError, SSLWantWriteError):
             pass
-        except ssl.SSLZeroReturnError:
+        except SSLZeroReturnError:
             log.warning('SSL connection closed by server during handshake.')
             self.close(Errors.ConnectionError('SSL connection closed by server during handshake'))
         # Other SSLErrors will be raised to user
@@ -608,7 +619,7 @@ class BrokerConnection(object):
                     self.close(error=Errors.ConnectionError('socket disconnected'))
                     return None
                 self._rbuffer.write(data)
-            except ssl.SSLWantReadError:
+            except SSLWantReadError:
                 return None
             except ConnectionError as e:
                 if six.PY2 and e.errno == errno.EWOULDBLOCK:
@@ -646,7 +657,7 @@ class BrokerConnection(object):
                     self.close(error=Errors.ConnectionError('socket disconnected'))
                     return None
                 self._rbuffer.write(data)
-            except ssl.SSLWantReadError:
+            except SSLWantReadError:
                 return None
             except ConnectionError as e:
                 # Extremely small chance that we have exactly 4 bytes for a