Tested and fixed file copying from Crypto.decrypt_project

In the function for grabbing project files (`Config.get_project_files`)
I was overcomplicating getting the current working directory.
Simplified the process and removed the bug!

pappyproxy/crypto.py

@@ -9,6 +9,7 @@ import shutil
 import twisted
 
 from . import compress
+from .util import PappyException
 from base64 import b64encode, b64decode
 from cryptography.fernet import Fernet
 from twisted.internet import reactor, defer
@@ -56,9 +57,10 @@ class Crypto(object):
         # Get the password and salt, then derive the key
         self.crypto_ramp_up()
 
-        # Create crypto working directory 
         crypto_path = os.path.join(os.getcwd(), self.config.crypt_dir)
-        os.mkdir(crypto_path)
+        
+        if not os.path.isdir(crypto_path):
+            os.mkdir(crypto_path)
 
         if os.path.isfile(self.config.crypt_file):
             # Derive the key
@@ -113,7 +115,7 @@ class Crypto(object):
     def set_salt_from_file(self):
         try:
             salt_file = open(self.config.salt_file, 'rb')
-            self.config.salt = salt_file.readline().strip()
+            self.salt = salt_file.readline().strip()
         except:
             raise PappyException("Unable to read project.salt")
 
@@ -121,7 +123,7 @@ class Crypto(object):
         if os.path.isfile(self.config.salt_file):
             self.set_salt_from_file()
         else:
-            self.config.salt = os.urandom(16) 
+            self.salt = os.urandom(16) 
     
     def get_password(self):
         """
@@ -166,6 +168,8 @@ class Crypto(object):
     
         try:
             if not self.key:
-                self.key = scrypt.hash(self.password, self.salt, bufflen=32)
-        except e:
-            raise PappyException("Error deriving the key: ", e)
+                self.key = scrypt.hash(self.password, self.salt, buflen=32)
+        except TypeError, e:
+            raise PappyException("Scrypt failed with type error: ", e)
+        except scrypt.error, e:
+            raise PappyException("Scrypt failed with internal error: ", e)