In-house removal of PyCrypto dependency in Heat. This patch is
Solaris-specific and not suitable for upstream.

Convert encrypt() and decrypt() to use M2Crypto instead of PyCrypto.

--- heat-2013.2.3/heat/common/crypt.py.~1~	2014-04-03 11:44:49.000000000 -0700
+++ heat-2013.2.3/heat/common/crypt.py	2014-07-07 03:26:19.115102209 -0700
@@ -14,9 +14,9 @@
 #    under the License.
 
 import base64
-from Crypto.Cipher import AES
 from os import urandom
 
+from M2Crypto.EVP import Cipher
 from oslo.config import cfg
 
 from heat.openstack.common import log as logging
@@ -36,9 +36,12 @@
 def encrypt(auth_info):
     if auth_info is None:
         return None
-    iv = urandom(AES.block_size)
-    cipher = AES.new(cfg.CONF.auth_encryption_key[:32], AES.MODE_CFB, iv)
-    res = base64.b64encode(iv + cipher.encrypt(auth_info))
+    iv = urandom(16)
+    cipher = Cipher(alg='aes_256_cfb', key=cfg.CONF.auth_encryption_key[:32],
+                    iv=iv, op=1)
+    padded = cipher.update(auth_info)
+    padded = padded + cipher.final()
+    res = base64.b64encode(iv + padded)
     return res
 
 
@@ -46,7 +49,9 @@
     if auth_info is None:
         return None
     auth = base64.b64decode(auth_info)
-    iv = auth[:AES.block_size]
-    cipher = AES.new(cfg.CONF.auth_encryption_key[:32], AES.MODE_CFB, iv)
-    res = cipher.decrypt(auth[AES.block_size:])
+    iv = auth[:16]
+    cipher = Cipher(alg='aes_256_cfb', key=cfg.CONF.auth_encryption_key[:32],
+                    iv=iv, op=0)
+    padded = cipher.update(auth[16:])
+    res = padded + cipher.final()
     return res