Refactor and symmetric encryption

1 files changed, 78 insertions, 167 deletions

diff --git a/__init__.py b/__init__.py
index 45034561..835111a5 100644
--- a/__init__.py
+++ b/__init__.py
@@ -3,170 +3,81 @@
 """A U1DB implementation for using Object Stores as its persistence layer."""
 
 import os
-import gnupg
-
-class GPGWrapper():
-    """
-    This is a temporary class for handling GPG requests, and should be
-    replaced by a more general class used throughout the project.
-    """
-
-    GNUPG_HOME    = os.environ['HOME'] + "/.config/leap/gnupg"
-    GNUPG_BINARY  = "/usr/bin/gpg" # this has to be changed based on OS
-
-    def __init__(self, gpghome=GNUPG_HOME, gpgbinary=GNUPG_BINARY):
-        self.gpg = gnupg.GPG(gnupghome=gpghome, gpgbinary=gpgbinary)
-
-    def find_key(self, email):
-        """
-        Find user's key based on their email.
-        """
-        for key in self.gpg.list_keys():
-            for uid in key['uids']:
-                if re.search(email, uid):
-                    return key
-        raise LookupError("GnuPG public key for %s not found!" % email)
-
-    def encrypt(self, data, recipient, sign=None, always_trust=False,
-                passphrase=None, symmetric=False):
-        return self.gpg.encrypt(data, recipient, sign=sign,
-                                always_trust=always_trust,
-                                passphrase=passphrase, symmetric=symmetric)
-
-    def decrypt(self, data, always_trust=False, passphrase=None):
-        return self.gpg.decrypt(data, always_trust=always_trust,
-                                passphrase=passphrase)
-
-    def import_keys(self, data):
-        return self.gpg.import_keys(data)
-
-
-#----------------------------------------------------------------------------
-# u1db Transaction and Sync logs.
-#----------------------------------------------------------------------------
-
-class SimpleLog(object):
-    def __init__(self):
-        self._log = []
-
-    def _set_log(self, log):
-        self._log = log
-
-    def _get_log(self):
-        return self._log
-
-    log = property(
-        _get_log, _set_log, doc="Log contents.")
-
-    def append(self, msg):
-        self._log.append(msg)
-
-    def reduce(self, func, initializer=None):
-        return reduce(func, self.log, initializer)
-
-    def map(self, func):
-        return map(func, self.log)
-
-    def filter(self, func):
-        return filter(func, self.log)
-
-
-class TransactionLog(SimpleLog):
-    """
-    An ordered list of (generation, doc_id, transaction_id) tuples.
-    """
-
-    def _set_log(self, log):
-        self._log = log
-
-    def _get_log(self):
-        return sorted(self._log, reverse=True)
-
-    log = property(
-        _get_log, _set_log, doc="Log contents.")
-
-    def get_generation(self):
-        """
-        Return the current generation.
-        """
-        gens = self.map(lambda x: x[0])
-        if not gens:
-            return 0
-        return max(gens)
-
-    def get_generation_info(self):
-        """
-        Return the current generation and transaction id.
-        """
-        if not self._log:
-            return(0, '')
-        info = self.map(lambda x: (x[0], x[2]))
-        return reduce(lambda x, y: x if (x[0] > y[0]) else y, info)
-
-    def get_trans_id_for_gen(self, gen):
-        """
-        Get the transaction id corresponding to a particular generation.
-        """
-        log = self.reduce(lambda x, y: y if y[0] == gen else x)
-        if log is None:
-            return None
-        return log[2]
-
-    def whats_changed(self, old_generation):
-        """
-        Return a list of documents that have changed since old_generation.
-        """
-        results = self.filter(lambda x: x[0] > old_generation)
-        seen = set()
-        changes = []
-        newest_trans_id = ''
-        for generation, doc_id, trans_id in results:
-            if doc_id not in seen:
-                changes.append((doc_id, generation, trans_id))
-                seen.add(doc_id)
-        if changes:
-            cur_gen = changes[0][1]  # max generation
-            newest_trans_id = changes[0][2]
-            changes.reverse()
-        else:
-            results = self.log
-            if not results:
-                cur_gen = 0
-                newest_trans_id = ''
-            else:
-                cur_gen, _, newest_trans_id = results[0]
-
-        return cur_gen, newest_trans_id, changes
-        
-
-
-class SyncLog(SimpleLog):
-    """
-    A list of (replica_id, generation, transaction_id) tuples.
-    """
-
-    def find_by_replica_uid(self, replica_uid):
-        if not self.log:
-            return ()
-        return self.reduce(lambda x, y: y if y[0] == replica_uid else x)
-
-    def get_replica_gen_and_trans_id(self, other_replica_uid):
-        """
-        Return the last known generation and transaction id for the other db
-        replica.
-        """
-        info = self.find_by_replica_uid(other_replica_uid)
-        if not info:
-            return (0, '')
-        return (info[1], info[2])
-
-    def set_replica_gen_and_trans_id(self, other_replica_uid,
-                                      other_generation, other_transaction_id):
-        """
-        Set the last-known generation and transaction id for the other
-        database replica.
-        """
-        self.log = self.filter(lambda x: x[0] != other_replica_uid)
-        self.append((other_replica_uid, other_generation,
-                     other_transaction_id))
-
+import string
+import random
+import cStringIO
+from soledad.util import GPGWrapper
+
+class Soledad(object):
+
+    PREFIX        = os.environ['HOME']  + '/.config/leap/soledad'
+    SECRET_PATH   = PREFIX + '/secret.gpg'
+    GNUPG_HOME    = PREFIX + '/gnupg'
+    SECRET_LENGTH = 50
+
+    def __init__(self, user_email, gpghome=None):
+        self._user_email = user_email
+        if not os.path.isdir(self.PREFIX):
+            os.makedirs(self.PREFIX)
+        if not gpghome:
+            gpghome = self.GNUPG_HOME
+        self._gpg = GPGWrapper(gpghome=gpghome)
+        # load OpenPGP keypair
+        if not self._has_openpgp_keypair():
+            self._gen_openpgp_keypair()
+        self._load_openpgp_keypair()
+        # load secret
+        if not self._has_secret():
+            self._gen_secret()
+        self._load_secret()
+
+    def _has_secret(self):
+        if os.path.isfile(self.SECRET_PATH):
+            return True
+        return False
+
+    def _load_secret(self):
+        try:
+            with open(self.SECRET_PATH) as f:
+               self._secret = self._gpg.decrypt(f.read())
+        except IOError as e:
+           raise IOError('Failed to open secret file %s.' % self.SECRET_PATH)
+
+    def _gen_secret(self):
+        self._secret = ''.join(random.choice(string.ascii_uppercase + string.digits) for x in range(self.SECRET_LENGTH))
+        cyphertext = self._gpg.encrypt(self._secret, self._fingerprint, self._fingerprint)
+        f = open(self.SECRET_PATH, 'w')
+        f.write(str(cyphertext))
+        f.close()
+
+
+    def _has_openpgp_keypair(self):
+        if self._gpg.find_key(self._user_email):
+            return True
+        return False
+
+    def _gen_openpgp_keypair(self):
+        params = self._gpg.gen_key_input(
+          key_type='RSA',
+          key_length=4096,
+          name_real=self._user_email,
+          name_email=self._user_email,
+          name_comment='Generated by LEAP Soledad.')
+        self._gpg.gen_key(params)
+
+    def _load_openpgp_keypair(self):
+        self._fingerprint = self._gpg.find_key(self._user_email)['fingerprint']
+
+    def encrypt(self, data, sign=None, passphrase=None, symmetric=False):
+        return str(self._gpg.encrypt(data, self._fingerprint, sign=sign,
+                                     passphrase=passphrase, symmetric=symmetric))
+
+    def encrypt_symmetric(self, data, sign=None):
+        return self.encrypt(data, sign=sign, passphrase=self._secret,
+                            symmetric=True)
+
+    def decrypt(self, data, passphrase=None, symmetric=False):
+        return str(self._gpg.decrypt(data, passphrase=passphrase))
+
+    def decrypt_symmetric(self, data):
+        return self.decrypt(data, passphrase=self._secret)