Finish lazy-importing of py-bcrypt and pycrypto in config.__init__

earwigbot/commands/crypt.py

@@ -22,8 +22,6 @@
 
 import hashlib
 
-from Crypto.Cipher import Blowfish
-
 from earwigbot import importer
 from earwigbot.commands import Command
 

earwigbot/config/__init__.py

@@ -282,10 +282,18 @@ class BotConfig(object):
         self._setup_logging()
         if self.is_encrypted():
             if not self._decryption_cipher:
+                try:
+                    blowfish_new = Blowfish.new
+                    hashpw = bcrypt.hashpw
+                except ImportError:
+                    url1 = "http://www.mindrot.org/projects/py-bcrypt"
+                    url2 = "https://www.dlitz.net/software/pycrypto/"
+                    e = "Encryption requires the 'py-bcrypt' and 'pycrypto' packages: {0}, {1}"
+                    raise NoConfigError(e.format(url1, url2))
                 key = getpass("Enter key to decrypt bot passwords: ")
-                self._decryption_cipher = Blowfish.new(sha256(key).digest())
+                self._decryption_cipher = blowfish_new(sha256(key).digest())
                 signature = self.metadata["signature"]
-                if bcrypt.hashpw(key, signature) != signature:
+                if hashpw(key, signature) != signature:
                     raise RuntimeError("Incorrect password.")
             for node, nodes in self._decryptable_nodes:
                 self._decrypt(node, nodes)