Add OMEMO policy

There is 3 policy:

- manual: OMEMO session are only started manually
- automatic: OMEMO session are only started if they have been started
  manually before
- always: OMEMO session are always started unless they have been ended
  manually before

Closes #1040 and fixes #1052

4 files changed, 56 insertions, 3 deletions

diff --git a/src/command/cmd_ac.c b/src/command/cmd_ac.c
index 0cc28bb3..a2d73671 100644
--- a/src/command/cmd_ac.c
+++ b/src/command/cmd_ac.c
@@ -164,6 +164,7 @@ static Autocomplete otr_log_ac;
 static Autocomplete otr_policy_ac;
 static Autocomplete omemo_ac;
 static Autocomplete omemo_log_ac;
+static Autocomplete omemo_policy_ac;
 static Autocomplete connect_property_ac;
 static Autocomplete tls_property_ac;
 static Autocomplete alias_ac;
@@ -591,12 +592,18 @@ cmd_ac_init(void)
     autocomplete_add(omemo_ac, "untrust");
     autocomplete_add(omemo_ac, "fingerprint");
     autocomplete_add(omemo_ac, "clear_device_list");
+    autocomplete_add(omemo_ac, "policy");
 
     omemo_log_ac = autocomplete_new();
     autocomplete_add(omemo_log_ac, "on");
     autocomplete_add(omemo_log_ac, "off");
     autocomplete_add(omemo_log_ac, "redact");
 
+    omemo_policy_ac = autocomplete_new();
+    autocomplete_add(omemo_policy_ac, "manual");
+    autocomplete_add(omemo_policy_ac, "automatic");
+    autocomplete_add(omemo_policy_ac, "always");
+
     connect_property_ac = autocomplete_new();
     autocomplete_add(connect_property_ac, "server");
     autocomplete_add(connect_property_ac, "port");
@@ -1080,6 +1087,7 @@ cmd_ac_reset(ProfWin *window)
     autocomplete_reset(otr_policy_ac);
     autocomplete_reset(omemo_ac);
     autocomplete_reset(omemo_log_ac);
+    autocomplete_reset(omemo_policy_ac);
     autocomplete_reset(connect_property_ac);
     autocomplete_reset(tls_property_ac);
     autocomplete_reset(alias_ac);
@@ -1209,6 +1217,7 @@ cmd_ac_uninit(void)
     autocomplete_free(otr_policy_ac);
     autocomplete_free(omemo_ac);
     autocomplete_free(omemo_log_ac);
+    autocomplete_free(omemo_policy_ac);
     autocomplete_free(connect_property_ac);
     autocomplete_free(tls_property_ac);
     autocomplete_free(alias_ac);
@@ -2191,6 +2200,11 @@ _omemo_autocomplete(ProfWin *window, const char *const input, gboolean previous)
         return found;
     }
 
+    found = autocomplete_param_with_ac(input, "/omemo policy", omemo_policy_ac, TRUE, previous);
+    if (found) {
+        return found;
+    }
+
     found = autocomplete_param_with_ac(input, "/omemo", omemo_ac, TRUE, previous);
     if (found) {
         return found;
diff --git a/src/command/cmd_defs.c b/src/command/cmd_defs.c
index ee86aaba..358c8d40 100644
--- a/src/command/cmd_defs.c
+++ b/src/command/cmd_defs.c
@@ -2342,6 +2342,7 @@ static struct cmd_t command_defs[] =
             { "untrust", cmd_omemo_untrust },
             { "fingerprint", cmd_omemo_fingerprint },
             { "char", cmd_omemo_char },
+            { "policy", cmd_omemo_policy },
             { "clear_device_list", cmd_omemo_clear_device_list })
         CMD_NOMAINFUNC
         CMD_TAGS(
@@ -2355,6 +2356,7 @@ static struct cmd_t command_defs[] =
             "/omemo end",
             "/omemo fingerprint [<contact>]",
             "/omemo char <char>",
+            "/omemo policy manual|automatic|always",
             "/omemo clear_device_list")
         CMD_DESC(
             "OMEMO commands to manage keys, and perform encryption during chat sessions.")
@@ -2366,6 +2368,9 @@ static struct cmd_t command_defs[] =
             { "log redact",              "Log OMEMO encrypted messages, but replace the contents with [redacted]. This is the default." },
             { "fingerprint [<contact>]", "Show contact fingerprints, or current recipient if omitted." },
             { "char <char>",             "Set the character to be displayed next to OMEMO encrypted messages." },
+            { "policy manual",           "Set the global OMEMO policy to manual, OMEMO sessions must be started manually." },
+            { "policy automatic",        "Set the global OMEMO policy to opportunistic, an OMEMO session will be attempted upon starting a conversation." },
+            { "policy always",           "Set the global OMEMO policy to always, an error will be displayed if an OMEMO session cannot be initiated upon starting a conversation." },
             { "clear_device_list",       "Clear your own device list on server side. Each client will reannounce itself when connected back."})
         CMD_EXAMPLES(
             "/omemo gen",
diff --git a/src/command/cmd_funcs.c b/src/command/cmd_funcs.c
index 3bba5cb5..abd83492 100644
--- a/src/command/cmd_funcs.c
+++ b/src/command/cmd_funcs.c
@@ -2152,7 +2152,7 @@ cmd_msg(ProfWin *window, const char *const command, gchar **args)
 
 #ifdef HAVE_OMEMO
 #ifndef HAVE_LIBOTR
-        if (omemo_is_trusted_jid(barejid)) {
+        if (omemo_automatic_start(barejid)) {
             omemo_start_session(barejid);
             chatwin->is_omemo = TRUE;
         }
@@ -2167,10 +2167,10 @@ cmd_msg(ProfWin *window, const char *const command, gchar **args)
 
 #ifdef HAVE_OMEMO
 #ifdef HAVE_LIBOTR
-        if (omemo_is_trusted_jid(barejid) && otr_is_secure(barejid)) {
+        if (omemo_automatic_start(barejid) && otr_is_secure(barejid)) {
             win_println(window, THEME_DEFAULT, '!', "Chat could be either OMEMO or OTR encrypted. Use '/omemo start %s' or '/otr start %s' to start a session.", usr, usr);
             return TRUE;
-        } else if (omemo_is_trusted_jid(barejid)) {
+        } else if (omemo_automatic_start(barejid)) {
             omemo_start_session(barejid);
             chatwin->is_omemo = TRUE;
         }
@@ -8005,6 +8005,7 @@ cmd_omemo_start(ProfWin *window, const char *const command, gchar **args)
             return TRUE;
         }
 
+        accounts_add_omemo_state(session_get_account_name(), barejid, TRUE);
         omemo_start_session(barejid);
         chatwin->is_omemo = TRUE;
     } else {
@@ -8026,6 +8027,7 @@ cmd_omemo_start(ProfWin *window, const char *const command, gchar **args)
                 return TRUE;
             }
 
+            accounts_add_omemo_state(session_get_account_name(), chatwin->barejid, TRUE);
             omemo_start_session(chatwin->barejid);
             chatwin->is_omemo = TRUE;
         } else if (window->type == WIN_MUC) {
@@ -8033,6 +8035,7 @@ cmd_omemo_start(ProfWin *window, const char *const command, gchar **args)
             assert(mucwin->memcheck == PROFMUCWIN_MEMCHECK);
 
             if (muc_anonymity_type(mucwin->roomjid) == MUC_ANONYMITY_TYPE_NONANONYMOUS) {
+                accounts_add_omemo_state(session_get_account_name(), mucwin->roomjid, TRUE);
                 omemo_start_muc_sessions(mucwin->roomjid);
                 mucwin->is_omemo = TRUE;
             } else {
@@ -8119,6 +8122,7 @@ cmd_omemo_end(ProfWin *window, const char *const command, gchar **args)
         }
 
         chatwin->is_omemo = FALSE;
+        accounts_add_omemo_state(session_get_account_name(), chatwin->barejid, FALSE);
     } else if (window->type == WIN_MUC) {
         ProfMucWin *mucwin = (ProfMucWin*)window;
         assert(mucwin->memcheck == PROFMUCWIN_MEMCHECK);
@@ -8129,6 +8133,7 @@ cmd_omemo_end(ProfWin *window, const char *const command, gchar **args)
         }
 
         mucwin->is_omemo = FALSE;
+        accounts_add_omemo_state(session_get_account_name(), mucwin->roomjid, FALSE);
     } else {
         win_println(window, THEME_DEFAULT, '-', "You must be in a regular chat window to start an OMEMO session.");
         return TRUE;
@@ -8366,3 +8371,31 @@ cmd_omemo_clear_device_list(ProfWin *window, const char *const command, gchar **
     return TRUE;
 #endif
 }
+
+gboolean
+cmd_omemo_policy(ProfWin *window, const char *const command, gchar **args)
+{
+#ifdef HAVE_OMEMO
+    if (args[1] == NULL) {
+        char *policy = prefs_get_string(PREF_OMEMO_POLICY);
+        cons_show("OMEMO policy is now set to: %s", policy);
+        prefs_free_string(policy);
+        return TRUE;
+    }
+
+    char *choice = args[1];
+    if ((g_strcmp0(choice, "manual") != 0) &&
+            (g_strcmp0(choice, "automatic") != 0) &&
+            (g_strcmp0(choice, "always") != 0)) {
+        cons_show("OMEMO policy can be set to: manual, automatic or always.");
+        return TRUE;
+    }
+
+    prefs_set_string(PREF_OMEMO_POLICY, choice);
+    cons_show("OMEMO policy is now set to: %s", choice);
+    return TRUE;
+#else
+    cons_show("This version of Profanity has not been built with OMEMO support enabled");
+    return TRUE;
+#endif
+}
diff --git a/src/command/cmd_funcs.h b/src/command/cmd_funcs.h
index 249b50fe..8f8d60a9 100644
--- a/src/command/cmd_funcs.h
+++ b/src/command/cmd_funcs.h
@@ -222,6 +222,7 @@ gboolean cmd_omemo_end(ProfWin *window, const char *const command, gchar **args)
 gboolean cmd_omemo_fingerprint(ProfWin *window, const char *const command, gchar **args);
 gboolean cmd_omemo_trust(ProfWin *window, const char *const command, gchar **args);
 gboolean cmd_omemo_untrust(ProfWin *window, const char *const command, gchar **args);
+gboolean cmd_omemo_policy(ProfWin *window, const char *const command, gchar **args);
 gboolean cmd_omemo_clear_device_list(ProfWin *window, const char *const command, gchar **args);
 
 #endif