fix(otr): prevent sending message when contact goes offline

docs/profanity.1

@@ -153,9 +153,23 @@ You can only enable one of them per correspondent at a time.
 OMEMO (/omemo) is defined in XEP-0384. It uses an implementation of the Signal protocol for key management and to synchronize messages among different clients. It works even when other clients are offline. And offers Perfect Forward Secrecy and Plausible deniability. Servers need to support PEP (XEP-0163).
 We implement the "siacs" version of OMEMO. Version 0.3.0, which is currently the widest adopted option.
 OMEMO is the only encryption option in Profanity that also supports encryption for MUCs (XEP-0045) and file transfer via HTTP upload (XEP-0363).
+.PP
+The OMEMO session status is shown in the title bar of the chat window:
+.br
+- \fB[OMEMO] [untrusted]\fR: OMEMO is enabled, but one or more active devices for the contact are untrusted.
+.br
+- \fB[OMEMO] [trusted]\fR: OMEMO is enabled, and all active devices for the contact are trusted.
 .TP
 .BR OTR
 OTR (/otr) is defined in XEP-0364. It uses a combination of the AES symmetric-key algorithm, the Diffie–Hellman key exchange, and the SHA-1 hash function. It offers deniable authentication and Perfect Forward Secrecy. To initialize a session both clients need to be online at the same time. A session is between two clients, so multiclient chats are not working. Which is a feature not a bug. OTR does by design not work for MUCs.
+.PP
+The OTR session status is shown in the title bar of the chat window:
+.br
+- \fB[OTR] [inactive]\fR: OTR is enabled but the secure session is currently inactive or ended (can happen when the contact went offline). Outgoing messages are blocked from being sent in plaintext. You must start OTR again or use \fB/otr end\fR to disable the safety guard.
+.br
+- \fB[OTR] [untrusted]\fR: OTR session is active but the contact's fingerprint is unverified.
+.br
+- \fB[OTR] [trusted]\fR: OTR session is active and the contact's identity is authenticated.
 .TP
 .BR OpenPGP
 OpenPGP (/pgp) is defined in XEP-0027. Is uses a public and secret key. It is also known as Legacy OpenPGP and has been deprecated. It doesn't provide protection against replay attacks. MUCs and file transfer via HTTP upload are not specified and thus not supported.

src/command/cmd_defs.c

@@ -1808,7 +1808,11 @@ static const struct cmd_t command_defs[] = {
               "/otr char <char>",
               "/otr sendfile on|off")
       CMD_DESC(
-              "Off The Record (OTR) commands to manage keys, and perform OTR encryption during chat sessions.")
+              "Off The Record (OTR) commands to manage keys, and perform OTR encryption during chat sessions.\n"
+              "The title bar will show the OTR session status:\n"
+              "[OTR] [inactive]: session inactive, plaintext blocked\n"
+              "[OTR] [untrusted]: session active, unverified fingerprint\n"
+              "[OTR] [trusted]: session active, authenticated.")
       CMD_ARGS(
               { "libver", "Show which version of the libotr library is being used." },
               { "gen", "Generate your private key." },
@@ -2328,8 +2332,8 @@ static const struct cmd_t command_defs[] = {
         CMD_DESC(
             "OMEMO commands to manage keys, and perform encryption during chat sessions.\n"
             "The title bar will show the OMEMO session status:\n"
-            "[OMEMO][trusted]   - All active devices for the contact are trusted.\n"
-            "[OMEMO][untrusted] - One or more active devices for the contact are untrusted.\n")
+            "[OMEMO] [trusted]   - All active devices for the contact are trusted.\n"
+            "[OMEMO] [untrusted] - One or more active devices for the contact are untrusted.")
         CMD_ARGS(
             { "gen",                     "Generate OMEMO cryptographic materials for current account." },
             { "start [<contact>]",       "Start an OMEMO session with contact, or current recipient if omitted." },

src/command/cmd_funcs.c

@@ -8000,7 +8000,7 @@ cmd_otr_end(ProfWin* window, const char* const command, gchar** args)
         return TRUE;
     }
 
-    chatwin_otr_unsecured(chatwin);
+    chatwin_otr_unsecured(chatwin, TRUE);
     otr_end_session(chatwin->barejid);
     return TRUE;
 #else

src/event/server_events.c

@@ -195,7 +195,7 @@ sv_ev_lost_connection(void)
         char* barejid = curr->data;
         ProfChatWin* chatwin = wins_get_chat(barejid);
         if (chatwin && otr_is_secure(barejid)) {
-            chatwin_otr_unsecured(chatwin);
+            chatwin_otr_unsecured(chatwin, FALSE);
             otr_end_session(barejid);
         }
         curr = g_slist_next(curr);
@@ -798,14 +798,6 @@ sv_ev_contact_offline(char* barejid, char* resource, char* status)
         ui_contact_offline(barejid, resource, status);
     }
 
-#ifdef HAVE_LIBOTR
-    ProfChatWin* chatwin = wins_get_chat(barejid);
-    if (chatwin && otr_is_secure(barejid)) {
-        chatwin_otr_unsecured(chatwin);
-        otr_end_session(chatwin->barejid);
-    }
-#endif
-
     rosterwin_roster();
     chat_session_remove(barejid);
 }

src/otr/otr.c

@@ -318,6 +318,12 @@ otr_on_message_send(ProfChatWin* chatwin, const char* const message, gboolean re
         return TRUE;
     }
 
+    if (chatwin->is_otr && !otr_is_secure(chatwin->barejid)) {
+        win_println((ProfWin*)chatwin, THEME_ERROR, "-", "%s", "Failed to send message: OTR session is not active.");
+        win_println((ProfWin*)chatwin, THEME_DEFAULT, "-", "%s", "Use '/otr end' to intentionally send unencrypted messages.");
+        return TRUE;
+    }
+
     // tag and send for policy opportunistic
     if (policy == PROF_OTRPOLICY_OPPORTUNISTIC) {
         auto_char char* otr_tagged_msg = otr_tag_message(message);
@@ -691,7 +697,7 @@ otr_decrypt_message(const char* const from, const char* const message, gboolean*
                 otrl_context_force_plaintext(context);
                 ProfChatWin* chatwin = wins_get_chat(from);
                 if (chatwin) {
-                    chatwin_otr_unsecured(chatwin);
+                    chatwin_otr_unsecured(chatwin, FALSE);
                 }
             }
         }

src/plugins/api.c

@@ -519,7 +519,7 @@ api_encryption_reset(const char* const barejid)
 
 #ifdef HAVE_LIBOTR
     if (chatwin->is_otr) {
-        chatwin_otr_unsecured(chatwin);
+        chatwin_otr_unsecured(chatwin, TRUE);
         otr_end_session(chatwin->barejid);
     }
 #endif

src/ui/chatwin.c

@@ -169,11 +169,13 @@ chatwin_otr_secured(ProfChatWin* chatwin, gboolean trusted)
 }
 
 void
-chatwin_otr_unsecured(ProfChatWin* chatwin)
+chatwin_otr_unsecured(ProfChatWin* chatwin, gboolean disable_otr)
 {
     assert(chatwin != NULL);
 
-    chatwin->is_otr = FALSE;
+    if (disable_otr) {
+        chatwin->is_otr = FALSE;
+    }
     chatwin->otr_is_trusted = FALSE;
 
     ProfWin* window = (ProfWin*)chatwin;

src/ui/titlebar.c

@@ -28,6 +28,9 @@
 #endif
 #include "xmpp/roster_list.h"
 #include "xmpp/chat_session.h"
+#ifdef HAVE_LIBOTR
+#include "otr/otr.h"
+#endif
 
 static WINDOW* win;
 static contact_presence_t current_presence;
@@ -454,8 +457,10 @@ _show_privacy(ProfChatWin* chatwin)
     int bracket_attrs = theme_attrs(THEME_TITLE_BRACKET);
     int encrypted_attrs = theme_attrs(THEME_TITLE_ENCRYPTED);
     int unencrypted_attrs = theme_attrs(THEME_TITLE_UNENCRYPTED);
+#if defined(HAVE_LIBOTR) || defined(HAVE_OMEMO)
     int trusted_attrs = theme_attrs(THEME_TITLE_TRUSTED);
     int untrusted_attrs = theme_attrs(THEME_TITLE_UNTRUSTED);
+#endif
 
     if (chatwin->enctext) {
         wprintw(win, " ");
@@ -491,34 +496,61 @@ _show_privacy(ProfChatWin* chatwin)
         wprintw(win, "[");
         wattroff(win, bracket_attrs);
         wattron(win, encrypted_attrs);
-        wprintw(win, "OTR");
-        wattroff(win, encrypted_attrs);
-        wattron(win, bracket_attrs);
-        wprintw(win, "]");
-        wattroff(win, bracket_attrs);
-        if (chatwin->otr_is_trusted) {
-            wprintw(win, " ");
+#ifdef HAVE_LIBOTR
+        if (otr_is_secure(chatwin->barejid)) {
+            wprintw(win, "OTR");
+            wattroff(win, encrypted_attrs);
             wattron(win, bracket_attrs);
-            wprintw(win, "[");
+            wprintw(win, "]");
             wattroff(win, bracket_attrs);
-            wattron(win, trusted_attrs);
-            wprintw(win, "trusted");
-            wattroff(win, trusted_attrs);
+            if (chatwin->otr_is_trusted) {
+                wprintw(win, " ");
+                wattron(win, bracket_attrs);
+                wprintw(win, "[");
+                wattroff(win, bracket_attrs);
+                wattron(win, trusted_attrs);
+                wprintw(win, "trusted");
+                wattroff(win, trusted_attrs);
+                wattron(win, bracket_attrs);
+                wprintw(win, "]");
+                wattroff(win, bracket_attrs);
+            } else {
+                wprintw(win, " ");
+                wattron(win, bracket_attrs);
+                wprintw(win, "[");
+                wattroff(win, bracket_attrs);
+                wattron(win, untrusted_attrs);
+                wprintw(win, "untrusted");
+                wattroff(win, untrusted_attrs);
+                wattron(win, bracket_attrs);
+                wprintw(win, "]");
+                wattroff(win, bracket_attrs);
+            }
+        } else {
+            wprintw(win, "OTR");
+            wattroff(win, encrypted_attrs);
             wattron(win, bracket_attrs);
             wprintw(win, "]");
             wattroff(win, bracket_attrs);
-        } else {
+
             wprintw(win, " ");
             wattron(win, bracket_attrs);
             wprintw(win, "[");
             wattroff(win, bracket_attrs);
-            wattron(win, untrusted_attrs);
-            wprintw(win, "untrusted");
-            wattroff(win, untrusted_attrs);
+            wattron(win, unencrypted_attrs);
+            wprintw(win, "inactive");
+            wattroff(win, unencrypted_attrs);
             wattron(win, bracket_attrs);
             wprintw(win, "]");
             wattroff(win, bracket_attrs);
         }
+#else
+        wprintw(win, "OTR");
+        wattroff(win, encrypted_attrs);
+        wattron(win, bracket_attrs);
+        wprintw(win, "]");
+        wattroff(win, bracket_attrs);
+#endif
 
         return;
     }

src/ui/ui.h

@@ -112,7 +112,7 @@ void chatwin_contact_offline(ProfChatWin* chatwin, char* resource, char* status)
 gchar* chatwin_get_string(ProfChatWin* chatwin);
 #ifdef HAVE_LIBOTR
 void chatwin_otr_secured(ProfChatWin* chatwin, gboolean trusted);
-void chatwin_otr_unsecured(ProfChatWin* chatwin);
+void chatwin_otr_unsecured(ProfChatWin* chatwin, gboolean disable_otr);
 void chatwin_otr_trust(ProfChatWin* chatwin);
 void chatwin_otr_untrust(ProfChatWin* chatwin);
 void chatwin_otr_smp_event(ProfChatWin* chatwin, prof_otr_smp_event_t event, void* data);

tests/unittests/ui/stub_ui.c

@@ -97,7 +97,7 @@ chatwin_otr_secured(ProfChatWin* chatwin, gboolean trusted)
 {
 }
 void
-chatwin_otr_unsecured(ProfChatWin* chatwin)
+chatwin_otr_unsecured(ProfChatWin* chatwin, gboolean disable_otr)
 {
 }
 void