Merge upstream/master into merge/upstream-full

Merge profanity-im/profanity master (373 commits) into cproof fork.

Source changes (manual merge):
- src/command/: cmd_defs, cmd_funcs, cmd_ac — upstream g_new0, auto_gchar,
  launch_editor callback; keep our XEP-0308 LMC, force-encryption, CWE-134
- src/config/: preferences, tlscerts, account — upstream UNIQUE dedup,
  dynamic pad capacity; keep our db_history_result_t, scroll logic
- src/database.*: upstream g_new0 memory mgmt; keep our return types,
  add null-check fix for msg->timestamp
- src/omemo/, src/pgp/: upstream _gpgme_key_get_email, g_new0;
  keep our replace_id in omemo_on_message_send
- src/tools/: editor, http_upload, bookmark_ignore — upstream launch_editor
  callback API
- src/ui/: console, window, chatwin, mucwin, inputwin, buffer —
  upstream win_warn_needed/sent dedup, PAD_MIN_HEIGHT dynamic pads;
  keep our y_start_pos scroll, _truncate_datetime_suffix
- src/xmpp/: message, stanza, presence, roster_list, iq, session —
  upstream connection_get_available_resources; keep our LMC stanza logic
- src/common.c: fix format-security (cons_show)

Build system:
- Makefile.am: updated test paths to subdirectory structure, added
  test_cmd_ac, test_forced_encryption
- Restored autotools files deleted by upstream meson migration:
  bootstrap.sh, autogen.sh, m4/ax_valgrind_check.m4, configure-debug

Tests:
- Unit tests: upstream unittests.c base + our forced_encryption tests
  (482 passed, 0 failed across all 4 configurations)
- Functional tests: kept our version (93 passed, 0 failed)
  upstream version requires stbbr_for_xmlns not yet in our stabber fork
- Updated test stubs: stub_xmpp.c, stub_omemo.c from upstream

Compile fixes:
- src/common.c: cons_show(errmsg) -> cons_show("%s", errmsg)
- src/database.c: null-check before msg->timestamp access
- src/ui/console.c: size_t -> (int) cast for format width
- src/config/tlscerts.c: %d -> %zu for size_t

src/xmpp/omemo.c

@@ -4,33 +4,7 @@
  *
  * Copyright (C) 2019 Paul Fariello <paul@fariello.eu>
  *
- * This file is part of Profanity.
- *
- * Profanity is free software: you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * Profanity is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with Profanity.  If not, see <https://www.gnu.org/licenses/>.
- *
- * In addition, as a special exception, the copyright holders give permission to
- * link the code of portions of this program with the OpenSSL library under
- * certain conditions as described in each individual source file, and
- * distribute linked combinations including the two.
- *
- * You must obey the GNU General Public License in all respects for all of the
- * code used other than OpenSSL. If you modify file(s) with this exception, you
- * may extend this exception to your version of the file(s), but you are not
- * obligated to do so. If you do not wish to do so, delete this exception
- * statement from your version. If you delete this exception statement from all
- * source files in the program, then also delete it here.
- *
+ * SPDX-License-Identifier: GPL-3.0-or-later WITH OpenSSL-exception
  */
 
 #include "config.h"
@@ -116,6 +90,11 @@ omemo_devicelist_request(const char* const jid)
 void
 omemo_bundle_publish(gboolean first)
 {
+    if (!connection_supports(XMPP_FEATURE_PUBSUB_PUBLISH_OPTIONS)) {
+        cons_show("OMEMO: Cannot publish bundle: no PUBSUB feature announced");
+        log_debug("[OMEMO] Cannot publish bundle: no PUBSUB feature announced");
+        return;
+    }
     log_debug("[OMEMO] publish own OMEMO bundle");
     xmpp_ctx_t* const ctx = connection_get_ctx();
     unsigned char* identity_key = NULL;
@@ -141,14 +120,10 @@ omemo_bundle_publish(gboolean first)
     g_list_free(lengths);
     g_list_free(ids);
 
-    if (connection_supports(XMPP_FEATURE_PUBSUB_PUBLISH_OPTIONS)) {
-        stanza_attach_publish_options_va(ctx, iq,
-                                         4, // 2 * number of key-value pairs
-                                         "pubsub#persist_items", "true",
-                                         "pubsub#access_model", "open");
-    } else {
-        log_debug("[OMEMO] Cannot publish bundle: no PUBSUB feature announced");
-    }
+    stanza_attach_publish_options_va(ctx, iq,
+                                     4, // 2 * number of key-value pairs
+                                     "pubsub#persist_items", "true",
+                                     "pubsub#access_model", "open");
 
     iq_id_handler_add(id, _omemo_bundle_publish_result, NULL, GINT_TO_POINTER(first));
 
@@ -243,7 +218,7 @@ omemo_start_device_session_handle_bundle(xmpp_stanza_t* const stanza, void* cons
             continue;
         }
 
-        omemo_key_t* key = malloc(sizeof(omemo_key_t));
+        omemo_key_t* key = g_new0(omemo_key_t, 1);
         key->data = NULL;
 
         const char* prekey_id_text = xmpp_stanza_get_attribute(prekey, "preKeyId");
@@ -349,8 +324,12 @@ out:
 }
 
 char*
-omemo_receive_message(xmpp_stanza_t* const stanza, gboolean* trusted)
+omemo_receive_message(xmpp_stanza_t* const stanza, gboolean* trusted, omemo_error_t* error)
 {
+    if (!stanza || !trusted || !error) {
+        return NULL;
+    }
+
     char* plaintext = NULL;
     const char* type = xmpp_stanza_get_type(stanza);
     const char* from = xmpp_stanza_get_from(stanza);
@@ -359,6 +338,9 @@ omemo_receive_message(xmpp_stanza_t* const stanza, gboolean* trusted)
     unsigned char* payload_raw = NULL;
     char* iv_text = NULL;
     char* payload_text = NULL;
+    size_t payload_len = 0;
+
+    *error = OMEMO_ERR_NONE;
 
     xmpp_stanza_t* encrypted = xmpp_stanza_get_child_by_ns(stanza, STANZA_NS_OMEMO);
     if (!encrypted) {
@@ -367,41 +349,44 @@ omemo_receive_message(xmpp_stanza_t* const stanza, gboolean* trusted)
 
     xmpp_stanza_t* header = xmpp_stanza_get_child_by_name(encrypted, "header");
     if (!header) {
+        *error = OMEMO_ERR_OTHER;
         return NULL;
     }
 
     const char* sid_text = xmpp_stanza_get_attribute(header, "sid");
     if (!sid_text) {
+        *error = OMEMO_ERR_OTHER;
         return NULL;
     }
     uint32_t sid = strtoul(sid_text, NULL, 10);
 
     xmpp_stanza_t* iv = xmpp_stanza_get_child_by_name(header, "iv");
     if (!iv) {
+        *error = OMEMO_ERR_OTHER;
         return NULL;
     }
     iv_text = xmpp_stanza_get_text(iv);
     if (!iv_text) {
+        *error = OMEMO_ERR_OTHER;
         return NULL;
     }
     size_t iv_len;
     iv_raw = g_base64_decode(iv_text, &iv_len);
     if (!iv_raw) {
+        *error = OMEMO_ERR_OTHER;
         return NULL;
     }
 
     xmpp_stanza_t* payload = xmpp_stanza_get_child_by_name(encrypted, "payload");
-    if (!payload) {
-        goto quit;
-    }
-    payload_text = xmpp_stanza_get_text(payload);
-    if (!payload_text) {
-        goto quit;
-    }
-    size_t payload_len;
-    payload_raw = g_base64_decode(payload_text, &payload_len);
-    if (!payload_raw) {
-        goto quit;
+    if (payload) {
+        payload_text = xmpp_stanza_get_text(payload);
+        if (payload_text) {
+            payload_raw = g_base64_decode(payload_text, &payload_len);
+            if (!payload_raw) {
+                *error = OMEMO_ERR_OTHER;
+                goto quit;
+            }
+        }
     }
 
     xmpp_stanza_t* key_stanza;
@@ -410,7 +395,7 @@ omemo_receive_message(xmpp_stanza_t* const stanza, gboolean* trusted)
             continue;
         }
 
-        omemo_key_t* key = malloc(sizeof(omemo_key_t));
+        omemo_key_t* key = g_new0(omemo_key_t, 1);
         char* key_text = xmpp_stanza_get_text(key_stanza);
         if (!key_text) {
             free(key);
@@ -437,7 +422,7 @@ omemo_receive_message(xmpp_stanza_t* const stanza, gboolean* trusted)
 
     plaintext = omemo_on_message_recv(from, sid, iv_raw, iv_len,
                                       keys, payload_raw, payload_len,
-                                      g_strcmp0(type, STANZA_TYPE_GROUPCHAT) == 0, trusted);
+                                      g_strcmp0(type, STANZA_TYPE_GROUPCHAT) == 0, trusted, error);
 
     if (keys) {
         g_list_free_full(keys, (GDestroyNotify)omemo_key_free);
@@ -722,3 +707,24 @@ _omemo_bundle_publish_configure_result(xmpp_stanza_t* const stanza, void* const
 
     return 0;
 }
+
+char*
+omemo_error_to_string(omemo_error_t error)
+{
+    switch (error) {
+    case OMEMO_ERR_NO_KEY:
+        return g_strdup("OMEMO message received but no key for this device found.");
+    case OMEMO_ERR_NOT_TRUSTED:
+        return g_strdup("OMEMO message received but sender identity is untrusted.");
+    case OMEMO_ERR_NO_SESSION:
+        return g_strdup("OMEMO message received but no session found. Try '/omemo start'.");
+    case OMEMO_ERR_DECRYPT_FAILED:
+        return g_strdup("OMEMO message received but decryption failed.");
+    case OMEMO_ERR_KEY_TRANSPORT:
+        return NULL;
+    case OMEMO_ERR_NONE:
+        return NULL;
+    default:
+        return g_strdup("OMEMO message received but could not be decrypted.");
+    }
+}