[feat] add fetch key by fingerprint to keymanager

- Resolves: #9023

4 files changed, 77 insertions, 0 deletions

diff --git a/src/leap/bitmask/cli/keys.py b/src/leap/bitmask/cli/keys.py
index 82de386..ab73bff 100644
--- a/src/leap/bitmask/cli/keys.py
+++ b/src/leap/bitmask/cli/keys.py
@@ -41,6 +41,7 @@ SUBCOMMANDS:
 
    list       List all known keys
    export     Export a given key
+   fetch      Fetch key by fingerprint
    insert     Insert a key to the key storage
    delete     Delete a key from the key storage
 '''.format(name=command.appname)
@@ -97,6 +98,26 @@ SUBCOMMANDS:
 
         return self._send(self._print_key)
 
+    def fetch(self, raw_args):
+        parser = argparse.ArgumentParser(
+            description='Bitmask fetch key by fingerprint',
+            prog='%s %s %s' % tuple(sys.argv[:3]))
+        parser.add_argument('-u', '--userid', default='',
+                            help='Select the userid of the keyring')
+        parser.add_argument('address', nargs=1,
+                            help='email address to pin to the key')
+        parser.add_argument('fingerprint', nargs=1,
+                            help='fingerprint to fetch of the key')
+        subargs = parser.parse_args(raw_args)
+
+        userid = subargs.userid
+        if not userid:
+            userid = self.cfg.get('bonafide', 'active', default='')
+        self.data += ['fetch', userid, subargs.address[0],
+                      subargs.fingerprint[0]]
+
+        return self._send(self._print_key)
+
     def insert(self, raw_args):
         parser = argparse.ArgumentParser(
             description='Bitmask import key',
diff --git a/src/leap/bitmask/core/dispatcher.py b/src/leap/bitmask/core/dispatcher.py
index 91168d8..f2b3e8c 100644
--- a/src/leap/bitmask/core/dispatcher.py
+++ b/src/leap/bitmask/core/dispatcher.py
@@ -363,6 +363,16 @@ class KeysCmd(SubCommand):
         return service.do_export(uid, address, private, fetch_remote)
 
     @register_method('dict')
+    def do_FETCH(self, service, *parts, **kw):
+        if len(parts) < 5:
+            raise ValueError("An email address is needed")
+        uid = parts[2]
+        address = parts[3]
+        fingerprint = parts[4]
+
+        return service.do_fetch(uid, address, fingerprint)
+
+    @register_method('dict')
     def do_INSERT(self, service, *parts, **kw):
         if len(parts) < 6:
             raise ValueError("An email address is needed")
diff --git a/src/leap/bitmask/core/mail_services.py b/src/leap/bitmask/core/mail_services.py
index 31c2736..23105c7 100644
--- a/src/leap/bitmask/core/mail_services.py
+++ b/src/leap/bitmask/core/mail_services.py
@@ -422,6 +422,15 @@ class KeymanagerService(HookableService):
         d.addCallback(lambda key: dict(key))
         return d
 
+    def do_fetch(self, userid, address, fingerprint):
+        km = self._container.get_instance(userid)
+        if km is None:
+            return defer.fail(ValueError("User " + userid + " has no active "
+                                         "keymanager"))
+        d = km.fetch_key_fingerprint(address, fingerprint)
+        d.addCallback(lambda key: dict(key))
+        return d
+
     def do_insert(self, userid, address, rawkey, validation='Fingerprint'):
         km = self._container.get_instance(userid)
         if km is None:
diff --git a/src/leap/bitmask/keymanager/__init__.py b/src/leap/bitmask/keymanager/__init__.py
index 45b7e58..e3ff3b8 100644
--- a/src/leap/bitmask/keymanager/__init__.py
+++ b/src/leap/bitmask/keymanager/__init__.py
@@ -261,6 +261,43 @@ class KeyManager(object):
         d.addCallbacks(key_found, key_not_found)
         return d
 
+    @defer.inlineCallbacks
+    def fetch_key_fingerprint(self, address, fingerprint):
+        """
+        Fetch a key from the key servers by fingerprint.
+
+        It will replace any key assigned to the address in the keyring and have
+        validation level Fingerprint.
+
+        :param address: The address bound to the key.
+        :type address: str
+        :param fingerprint: The fingerprint of the key to fetch.
+        :type fingerprint: str
+
+        :return: A Deferred which fires with an EncryptionKey fetched,
+                 or which fails with KeyNotFound if no key was found in the
+                 keyserver for this fingerprint.
+        :rtype: Deferred
+        """
+        key_data = yield self._nicknym.fetch_key_with_fingerprint(fingerprint)
+        key, _ = self._openpgp.parse_key(key_data, address)
+        key.validation = ValidationLevels.Fingerprint
+
+        if key.fingerprint != fingerprint:
+            raise keymanager_errors.KeyNotFound("Got wrong fingerprint")
+
+        try:
+            old_key = yield self._openpgp.get_key(address)
+            if old_key.fingerprint == key.fingerprint:
+                key.last_audited_at = old_key.last_audited_at
+                key.encr_used = old_key.encr_used
+                key.sign_used = old_key.sign_used
+        except keymanager_errors.KeyNotFound:
+            pass
+
+        yield self._openpgp.put_key(key)
+        defer.returnValue(key)
+
     def get_all_keys(self, private=False):
         """
         Return all keys stored in local database.