Add support for verifying encryption status of data with gpg.

1 files changed, 86 insertions, 6 deletions

diff --git a/util.py b/util.py
index 09bca6b4..2103c056 100644
--- a/util.py
+++ b/util.py
@@ -5,7 +5,40 @@ Utilities for Soledad.
 import os
 import gnupg
 import re
-from gnupg import logger
+from gnupg import (
+    logger,
+    _is_sequence,
+    _make_binary_stream,
+)
+
+
+class ListPackets():
+    """
+    Handle status messages for --list-packets.
+    """
+
+    def __init__(self, gpg):
+        self.gpg = gpg
+        self.nodata = None
+        self.key = None
+        self.need_passphrase = None
+        self.need_passphrase_sym = None
+        self.userid_hint = None
+
+    def handle_status(self, key, value):
+        # TODO: write tests for handle_status
+        if key == 'NODATA':
+            self.nodata = True
+        if key == 'ENC_TO':
+            # This will only capture keys in our keyring. In the future we
+            # may want to include multiple unknown keys in this list.
+            self.key, _, _ = value.split()
+        if key == 'NEED_PASSPHRASE':
+            self.need_passphrase = True
+        if key == 'NEED_PASSPHRASE_SYM':
+            self.need_passphrase_sym = True
+        if key == 'USERID_HINT':
+            self.userid_hint = value.strip().split()
 
 
 class GPGWrapper(gnupg.GPG):
@@ -17,11 +50,17 @@ class GPGWrapper(gnupg.GPG):
     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):
-        super(GPGWrapper, self).__init__(gnupghome=gpghome,
-                                         gpgbinary=gpgbinary)
+    def __init__(self, gpgbinary=GNUPG_BINARY, gnupghome=GNUPG_HOME,
+                 verbose=False, use_agent=False, keyring=None, options=None):
+        super(GPGWrapper, self).__init__(gnupghome=gnupghome,
+                                         gpgbinary=gpgbinary,
+                                         verbose=verbose,
+                                         use_agent=use_agent,
+                                         keyring=keyring,
+                                         options=options)
+        self.result_map['list-packets'] = ListPackets
 
-    def find_key(self, email):
+    def find_key_by_email(self, email):
         """
         Find user's key based on their email.
         """
@@ -29,7 +68,16 @@ class GPGWrapper(gnupg.GPG):
             for uid in key['uids']:
                 if re.search(email, uid):
                     return key
-        raise LookupError("GnuPG public key for %s not found!" % email)
+        raise LookupError("GnuPG public key for email %s not found!" % email)
+
+    def find_key_by_subkey(self, subkey):
+        for key in self.list_keys():
+            for sub in key['subkeys']:
+                #print sub[0]
+                if sub[0] == subkey:
+                    return key
+        raise LookupError(
+            "GnuPG public key for subkey %s not found!" % subkey)
 
     def encrypt(self, data, recipient, sign=None, always_trust=True,
                 passphrase=None, symmetric=False):
@@ -96,3 +144,35 @@ class GPGWrapper(gnupg.GPG):
         self._handle_io(args, file, result, passphrase=passphrase, binary=True)
         logger.debug('encrypt result: %r', result.data)
         return result
+
+    def list_packets(self, raw_data):
+        args = ["--list-packets"]
+        result = self.result_map['list-packets'](self)
+        self._handle_io(
+            args,
+            _make_binary_stream(raw_data, self.encoding),
+            result,
+        )
+        return result
+
+    def encrypted_to(self, raw_data):
+        """
+        Return the key to which raw_data is encrypted to.
+        """
+        # TODO: make this support multiple keys.
+        result = self.list_packets(raw_data)
+        if not result.encrypted_sym:
+            raise LookupError(
+                "Content is not encrypted to a GnuPG key!")
+        return self.find_key_by_subkey(result.key)
+
+    def is_encrypted_sym(self, raw_data):
+        result = self.list_packets(raw_data)
+        return bool(result.need_passphrase_sym)
+
+    def is_encrypted_asym(self, raw_data):
+        result = self.list_packets(raw_data)
+        return bool(result.need_passphrase)
+
+    def is_encrypted(self, raw_data):
+        self.is_encrypted_asym() or self.is_encrypted_sym()