Add postgres with encryption

src/keystore/__init__.py

@@ -0,0 +1 @@
+from keystore.postgres import ReferenceDatabase

src/keystore/postgres.py

@@ -0,0 +1,43 @@
+import logging
+import base64
+
+from cryptography.fernet import Fernet
+import psycopg2
+from psycopg2 import sql
+
+logging.basicConfig(level=logging.DEBUG)
+logg = logging.getLogger(__file__)
+
+
+class ReferenceDatabase:
+
+
+        def __init__(self, dbname, **kwargs):
+            logg.debug(kwargs)
+            self.conn = psycopg2.connect('dbname='+dbname)
+            self.cur = self.conn.cursor()
+            self.cryptengine = None
+            if kwargs.get('symmetric_key') != None:
+                be = kwargs.get('symmetric_key')
+                self.cryptengine = Fernet(base64.b64encode(be))
+
+
+        def get(self, address):
+            s = sql.SQL('SELECT key_ciphertext FROM ethereum WHERE wallet_address_hex = %s')
+            logg.debug(address)
+            self.cur.execute(s, [ address ] )
+            k = self.cur.fetchone()[0]
+            return self.decrypt(k)
+
+
+        def decrypt(self, c):
+            if self.cryptengine == None:
+                return c
+            logg.debug('decryption')
+            return self.cryptengine.decrypt(c.encode('utf-8'))
+             
+
+        def __exit__(self):
+            self.conn
+            self.cur.close()
+            self.conn.close()

src/signer/defaultsigner.py

@@ -10,15 +10,19 @@ logg = logging.getLogger(__name__)
 
 class Signer:
 
+
     def __init__(self, keyGetter):
         self.keyGetter = keyGetter
 
+
     def signTransaction(self, tx):
         raise NotImplementedError
 
 
+
 class ReferenceSigner(Signer):
-    
+   
+
     def __init__(self, keyGetter):
         super(ReferenceSigner, self).__init__(keyGetter)
 
@@ -34,6 +38,3 @@ class ReferenceSigner(Signer):
         tx.r = z[:32]
         tx.s = z[32:64]
         return z
-
-
-