tests/krb5: Use more compact dict lookup

Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Andreas Schneider <asn@samba.org>
BUG: https://bugzilla.samba.org/show_bug.cgi?id=14817
(cherry picked from commit 38b3a361819c716adb773fb3b4507c28d7d26c0d)

python/samba/tests/krb5/kdc_base_test.py

@@ -722,10 +722,7 @@ class KDCBaseTest(RawKerberosTest):
         ticket_data = self.der_encode(ticket, asn1Spec=krb5_asn1.Ticket())
 
         authtime = enc_part['authtime']
-        try:
-            starttime = enc_part['starttime']
-        except KeyError:
-            starttime = authtime
+        starttime = enc_part.get('starttime', authtime)
         endtime = enc_part['endtime']
 
         cred = krb5ccache.CREDENTIAL()

python/samba/tests/krb5/raw_testcase.py

@@ -279,9 +279,7 @@ class KerberosCredentials(Credentials):
 
     def get_forced_key(self, etype):
         etype = int(etype)
-        if etype in self.forced_keys:
-            return self.forced_keys[etype]
-        return None
+        return self.forced_keys.get(etype, None)
 
     def set_forced_salt(self, salt):
         self.forced_salt = bytes(salt)
@@ -789,12 +787,7 @@ class RawKerberosTest(TestCaseInTempDir):
         self.assertIsNotNone(value)
 
     def getElementValue(self, obj, elem):
-        v = None
-        try:
-            v = obj[elem]
-        except KeyError:
-            pass
-        return v
+        return obj.get(elem, None)
 
     def assertElementMissing(self, obj, elem):
         v = self.getElementValue(obj, elem)
@@ -879,11 +872,8 @@ class RawKerberosTest(TestCaseInTempDir):
 
     def PasswordKey_from_etype_info2(self, creds, etype_info2, kvno=None):
         e = etype_info2['etype']
-        salt = None
-        try:
-            salt = etype_info2['salt']
-        except Exception:
-            pass
+
+        salt = etype_info2.get('salt', None)
 
         if e == kcrypto.Enctype.RC4:
             nthash = creds.get_nt_hash()