r46798 - Merge conch-regression-8208: Make Conch accept PyCrypto keys again.

Author: mithrandi
Date: Mon Feb 15 03:24:17 2016
New Revision: 46798

Added:
   trunk/twisted/conch/topfiles/8208.misc
Modified:
   trunk/twisted/conch/ssh/keys.py
   trunk/twisted/conch/test/test_keys.py

Log:
Merge conch-regression-8208: Make Conch accept PyCrypto keys again.

Author: mithrandi
Reviewer: glyph
Fixes: #8208

`twisted.conch.ssh.keys.Key` now accepts PyCrypto keys again, although a
deprecation warning is emitted.

Modified: trunk/twisted/conch/ssh/keys.py
==============================================================================
--- trunk/twisted/conch/ssh/keys.py	(original)
+++ trunk/twisted/conch/ssh/keys.py	Mon Feb 15 03:24:17 2016
@@ -10,6 +10,7 @@
 
 import base64
 import itertools
+import warnings
 from hashlib import md5
 
 from cryptography.exceptions import InvalidSignature
@@ -34,7 +35,7 @@
 from twisted.conch.ssh.common import int_from_bytes, int_to_bytes
 from twisted.python import randbytes
 from twisted.python.compat import iterbytes, long, izip, nativeString, _PY3
-from twisted.python.deprecate import deprecated
+from twisted.python.deprecate import deprecated, getDeprecationWarningString
 from twisted.python.versions import Version
 
 
@@ -601,7 +602,16 @@
         @param keyObject: Low level key.
         @type keyObject: C{cryptography.hazmat.primitives.asymmetric} key.
         """
-        self._keyObject = keyObject
+        # Avoid importing PyCrypto if at all possible
+        if keyObject.__class__.__module__.startswith('Crypto.PublicKey'):
+            warningString = getDeprecationWarningString(
+                Key,
+                Version("Twisted", 16, 0, 0),
+                replacement='passing a cryptography key object')
+            warnings.warn(warningString, DeprecationWarning, stacklevel=2)
+            self.keyObject = keyObject
+        else:
+            self._keyObject = keyObject
 
 
     def __eq__(self, other):

Modified: trunk/twisted/conch/test/test_keys.py
==============================================================================
--- trunk/twisted/conch/test/test_keys.py	(original)
+++ trunk/twisted/conch/test/test_keys.py	Mon Feb 15 03:24:17 2016
@@ -15,6 +15,8 @@
 
 try:
     import Crypto.Cipher.DES3
+    import Crypto.PublicKey.RSA
+    import Crypto.PublicKey.DSA
 except ImportError:
     # we'll have to skip some tests without PyCypto
     Crypto = None
@@ -32,6 +34,7 @@
 from twisted.python import randbytes
 from twisted.trial import unittest
 from twisted.python.compat import long, _PY3
+from twisted.python.versions import Version
 
 
 
@@ -1136,3 +1139,23 @@
             'x': keydata.DSAData['x'],
             },
             key.data())
+
+
+    def test_constructorPyCrypto(self):
+        """
+        Passing a PyCrypto key object to L{keys.Key} is deprecated.
+        """
+        pycryptoKey = Crypto.PublicKey.RSA.construct((
+            keydata.RSAData['n'],
+            keydata.RSAData['e']))
+        key = self.callDeprecated(
+            (Version('Twisted', 16, 0, 0),
+             'passing a cryptography key object'),
+            keys.Key,
+            pycryptoKey)
+        self.assertEqual('RSA', key.type())
+        self.assertEqual({
+            'n': keydata.RSAData['n'],
+            'e': keydata.RSAData['e'],
+            },
+            key.data())