Added paramiko.GSS_EXCEPTIONS: exception types used by GSSAPI

This new constant is a tuple of the exception types used by the
underlying GSSAPI/SSPI implementation.

2 files changed, 17 insertions, 6 deletions

diff --git a/paramiko/__init__.py b/paramiko/__init__.py
index 197f519a..01dc973c 100644
--- a/paramiko/__init__.py
+++ b/paramiko/__init__.py
@@ -34,7 +34,7 @@ from paramiko.client import (
     WarningPolicy,
 )
 from paramiko.auth_handler import AuthHandler
-from paramiko.ssh_gss import GSSAuth, GSS_AUTH_AVAILABLE
+from paramiko.ssh_gss import GSSAuth, GSS_AUTH_AVAILABLE, GSS_EXCEPTIONS
 from paramiko.channel import Channel, ChannelFile
 from paramiko.ssh_exception import (
     SSHException, PasswordRequiredException, BadAuthenticationType,
diff --git a/paramiko/ssh_gss.py b/paramiko/ssh_gss.py
index 414485f9..d8d32b5d 100644
--- a/paramiko/ssh_gss.py
+++ b/paramiko/ssh_gss.py
@@ -39,11 +39,15 @@ import sys
 """
 GSS_AUTH_AVAILABLE = True
 
+"""
+:var tuple GSS_EXCEPTIONS:
+    The exception types used by the underlying GSSAPI implementation.
+"""
+GSS_EXCEPTIONS = ()
+
 from pyasn1.type.univ import ObjectIdentifier
 from pyasn1.codec.der import encoder, decoder
 
-from paramiko.common import MSG_USERAUTH_REQUEST
-from paramiko.ssh_exception import SSHException
 
 """
 :var str _API: Constraint for the used API
@@ -52,15 +56,21 @@ _API = "MIT"
 
 try:
     import gssapi
+    GSS_EXCEPTIONS = (gssapi.GSSException,)
 except (ImportError, OSError):
     try:
+        import pywintypes
         import sspicon
         import sspi
         _API = "SSPI"
+        GSS_EXCEPTIONS = (pywintypes.error,)
     except ImportError:
         GSS_AUTH_AVAILABLE = False
         _API = None
 
+from paramiko.common import MSG_USERAUTH_REQUEST
+from paramiko.ssh_exception import SSHException
+
 
 def GSSAuth(auth_method, gss_deleg_creds=True):
     """
@@ -438,9 +448,10 @@ class _SSH_SSPI(_SSH_GSSAuth):
                                                  targetspn=targ_name)
             error, token = self._gss_ctxt.authorize(recv_token)
             token = token[0].Buffer
-        except:
-            raise Exception("{0}, Target: {1}".format(sys.exc_info()[1],
-                                                      self._gss_host))
+        except pywintypes.error as e:
+            e.strerror += ", Target: {1}".format(e, self._gss_host)
+            raise
+
         if error == 0:
             """
             if the status is GSS_COMPLETE (error = 0) the context is fully