1 files changed, 158 insertions, 0 deletions
diff --git a/src/leap/soledad/__init__.py b/src/leap/soledad/__init__.py
new file mode 100644
index 00000000..2caee108
--- /dev/null
+++ b/src/leap/soledad/__init__.py
@@ -0,0 +1,158 @@
+# License?
+
+"""A U1DB implementation for using Object Stores as its persistence layer."""
+
+import os
+import string
+import random
+import cStringIO
+import hmac
+from 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/generate OpenPGP keypair
+        if not self._has_openpgp_keypair():
+            self._gen_openpgp_keypair()
+        self._load_openpgp_keypair()
+        # load/generate secret
+        if not self._has_secret():
+            self._gen_secret()
+        self._load_secret()
+
+
+    #-------------------------------------------------------------------------
+    # Management of secret for symmetric encryption
+    #-------------------------------------------------------------------------
+
+    def _has_secret(self):
+        """
+        Verify if secret already exists in a local encrypted file.
+        """
+        if os.path.isfile(self.SECRET_PATH):
+            return True
+        return False
+
+    def _load_secret(self):
+        """
+        Load secret from local encrypted file.
+        """
+        try:
+            with open(self.SECRET_PATH) as f:
+               self._secret = str(self._gpg.decrypt(f.read()))
+        except IOError as e:
+           raise IOError('Failed to open secret file %s.' % self.SECRET_PATH)
+
+    def _gen_secret(self):
+        """
+        Generate secret for symmetric encryption and store it in a local encrypted file.
+        """
+        self._secret = ''.join(random.choice(string.ascii_uppercase + string.digits) for x in range(self.SECRET_LENGTH))
+        ciphertext = self._gpg.encrypt(self._secret, self._fingerprint, self._fingerprint)
+        f = open(self.SECRET_PATH, 'w')
+        f.write(str(ciphertext))
+        f.close()
+
+    #-------------------------------------------------------------------------
+    # Management of OpenPGP keypair
+    #-------------------------------------------------------------------------
+
+    def _has_openpgp_keypair(self):
+        """
+        Verify if a keypair exists for this user.
+        """
+        # TODO: verify if private key exists.
+        try:
+            self._gpg.find_key(self._user_email)
+            return True
+        except LookupError:
+            return False
+
+    def _gen_openpgp_keypair(self):
+        """
+        Generate a keypair for this user.
+        """
+        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):
+        """
+        Load the fingerprint for this user's keypair.
+        """
+        self._fingerprint = self._gpg.find_key(self._user_email)['fingerprint']
+
+    def publish_pubkey(self, keyserver):
+        """
+        Publish OpenPGP public key to a keyserver.
+        """
+        pass
+
+    #-------------------------------------------------------------------------
+    # Data encryption and decription
+    #-------------------------------------------------------------------------
+
+    def encrypt(self, data, sign=None, passphrase=None, symmetric=False):
+        """
+        Encrypt data.
+        """
+        return str(self._gpg.encrypt(data, self._fingerprint, sign=sign,
+                                     passphrase=passphrase, symmetric=symmetric))
+
+    def encrypt_symmetric(self, doc_id, data, sign=None):
+        """
+        Symmetrically encrypt data using this user's secret.
+        """
+        h = hmac.new(self._secret, doc_id).hexdigest()
+        return self.encrypt(data, sign=sign, passphrase=h, symmetric=True)
+
+    def decrypt(self, data, passphrase=None, symmetric=False):
+        """
+        Decrypt data.
+        """
+        return str(self._gpg.decrypt(data, passphrase=passphrase))
+
+    def decrypt_symmetric(self, doc_id, data):
+        """
+        Symmetrically decrypt data using this user's secret.
+        """
+        h = hmac.new(self._secret, doc_id).hexdigest()
+        return self.decrypt(data, passphrase=h)
+
+    #-------------------------------------------------------------------------
+    # Document storage, retrieval and sync
+    #-------------------------------------------------------------------------
+    
+    def put(self, doc_id, data):
+        """
+        Store a document.
+        """
+        pass
+
+    def get(self, doc_id):
+        """
+        Retrieve a document.
+        """
+        pass
+
+    def sync(self):
+        """
+        Synchronize with LEAP server.
+        """
+        pass