omemo: add supported_tab_types and trust_states plugin attributes

- supported tab types is a list of tabs this plugin should be active in
 (only chattabs)
- trust_states is a dict[str → set] containing only two keys: accepted
 and rejected, whose values are the internal plugin states that should
 allow encryption and the ones that should not

poezio/plugin_e2ee.py

@@ -10,7 +10,7 @@
     Interface for E2EE (End-to-end Encryption) plugins.
 """
 
-from typing import Callable, Dict, List, Optional, Union, Tuple
+from typing import Callable, Dict, List, Optional, Union, Tuple, Set
 
 from slixmpp import InvalidJID, JID, Message
 from slixmpp.xmlstream import StanzaBase
@@ -24,6 +24,8 @@ from poezio.tabs import (
 )
 from poezio.plugin import BasePlugin
 from poezio.theming import get_theme, dump_tuple
+from poezio.config import config
+from poezio.decorators import command_args_parser
 
 from asyncio import iscoroutinefunction
 
@@ -114,7 +116,16 @@ class E2EEPlugin(BasePlugin):
     # time
     _enabled_tabs = {}  # type: Dict[JID, Callable]
 
+    # Tabs that support this encryption mechanism
+    supported_tab_types = []  # type: List[ChatTabs]
+
+    # States for each remote entity
+    trust_states = {'accepted': set(), 'rejected': set()}  # type: Dict[str, Set[str]]
+
     def init(self):
+        self._all_trust_states = self.trust_states['accepted'].union(
+            self.trust_states['rejected']
+        )
         if self.encryption_name is None and self.encryption_short_name is None:
             raise NotImplementedError
 
@@ -138,7 +149,7 @@ class E2EEPlugin(BasePlugin):
         # sure poezio is not sneaking anything past us.
         self.core.xmpp.add_filter('out', self._encrypt_wrapper)
 
-        for tab_t in (DynamicConversationTab, StaticConversationTab, PrivateTab, MucTab):
+        for tab_t in self.supported_tab_types:
             self.api.add_tab_command(
                 tab_t,
                 self.encryption_short_name,
@@ -148,6 +159,25 @@ class E2EEPlugin(BasePlugin):
                 help='Toggle automatic {} encryption for tab.'.format(self.encryption_name),
             )
 
+        trust_msg = 'Set {name} state to {state} for this fingerprint on this JID.'
+        for state in self._all_trust_states:
+            for tab_t in self.supported_tab_types:
+                self.api.add_tab_command(
+                    tab_t,
+                    self.encryption_short_name + '_' + state,
+                    lambda args: self.__command_set_state_local(args, state),
+                    usage='<fingerprint>',
+                    short=trust_msg.format(name=self.encryption_short_name, state=state),
+                    help=trust_msg.format(name=self.encryption_short_name, state=state),
+                )
+            self.api.add_command(
+                self.encryption_short_name + '_' + state,
+                lambda args: self.__command_set_state_global(args, state),
+                usage='<JID> <fingerprint>',
+                short=trust_msg.format(name=self.encryption_short_name, state=state),
+                help=trust_msg.format(name=self.encryption_short_name, state=state),
+            )
+
         ConversationTab.add_information_element(
             self.encryption_short_name,
             self._display_encryption_status,
@@ -161,6 +191,15 @@ class E2EEPlugin(BasePlugin):
             self._display_encryption_status,
         )
 
+        self.__load_encrypted_states()
+
+    def __load_encrypted_states(self) -> None:
+        """Load previously stored encryption states for jids."""
+        for section in config.sections():
+            value = config.get('encryption', section=section)
+            if value and value == self.encryption_short_name:
+                self._enabled_tabs[section] = self.encrypt
+
     def cleanup(self):
         ConversationTab.remove_information_element(self.encryption_short_name)
         MucTab.remove_information_element(self.encryption_short_name)
@@ -184,19 +223,40 @@ class E2EEPlugin(BasePlugin):
     def _toggle_tab(self, _input: str) -> None:
         jid = self.api.current_tab().jid  # type: JID
 
-        if self._encryption_enabled(jid):
+        if self._enabled_tabs.get(jid) == self.encrypt:
             del self._enabled_tabs[jid]
+            config.remove_and_save('encryption', section=jid)
             self.api.information(
                 '{} encryption disabled for {}'.format(self.encryption_name, jid),
                 'Info',
             )
         else:
             self._enabled_tabs[jid] = self.encrypt
+            config.set_and_save('encryption', self.encryption_short_name, section=jid)
             self.api.information(
                 '{} encryption enabled for {}'.format(self.encryption_name, jid),
                 'Info',
             )
 
+    @command_args_parser.quoted(2)
+    def __command_set_state_global(self, args, state='') -> None:
+        jid, fpr = args
+        if state not in self._all_trust_states:
+            self.api.information('Unknown state for plugin %s: %s' % (self.encryption_short_name, state), 'Error')
+            return
+        self.store_trust(jid, state, fpr)
+
+    @command_args_parser.quoted(1)
+    def __command_set_state_local(self, args, state='') -> None:
+        if isinstance(self.api.current_tab(), MucTab):
+            return
+        jid = self.api.get_current_tab().name
+        fpr = args[0]
+        if state not in self._all_trust_states:
+            self.api.information('Unknown state for plugin %s: %s' % (self.encryption_short_name, state), 'Error')
+            return
+        self.store_trust(jid, state, fpr)
+
     def _encryption_enabled(self, jid: JID) -> bool:
         return jid in self._enabled_tabs and self._enabled_tabs[jid] == self.encrypt
 
@@ -306,6 +366,17 @@ class E2EEPlugin(BasePlugin):
         log.debug('Encrypted %s message: %r', self.encryption_name, message)
         return message
 
+    def store_trust(self, jid: JID, state: str, fingerprint: str) -> None:
+        """Store trust for a fingerprint and a jid."""
+        option_name = '%s:%s' % (self.encryption_short_name, fingerprint)
+        config.silent_set(option=option_name, value=state, section=jid)
+
+    def fetch_trust(self, jid: JID, fingerprint: str) -> str:
+        """Fetch trust of a fingerprint and a jid.
+        """
+        option_name = '%s:%s' % (self.encryption_short_name, fingerprint)
+        return config.get(option=option_name, section=jid)
+
     async def decrypt(self, _message: Message, tab: ChatTabs):
         """Decryption method