fix(xmpp): obfuscate client identity in protocol exchanges

Modify version responses to return a generic client name and omit
version strings. Drop the "profanity." prefix from dynamically
generated JID resources. Clear the XEP-0115 capabilities node URI to
prevent service discovery fingerprinting. These adjustments reduce the
client's attack surface by minimizing identifiable metadata.

src/common.c

@@ -921,7 +921,7 @@ prof_date_time_format_iso8601(GDateTime* dt)
     return ret;
 }
 
-/* build profanity version string.
+/* build CProof version string.
  * example: 0.13.1dev.master.69d8c1f9
  */
 gchar*

src/config/preferences.c

@@ -2689,7 +2689,6 @@ _get_default_boolean(preference_t pref)
     case PREF_STATUSBAR_SHOW_NUMBER:
     case PREF_STATUSBAR_SHOW_READ:
     case PREF_STATUSBAR_SHOW_DBBACKEND:
-    case PREF_REVEAL_OS:
     case PREF_CORRECTION_ALLOW:
     case PREF_RECEIPTS_SEND:
     case PREF_CARBONS:
@@ -2704,6 +2703,7 @@ _get_default_boolean(preference_t pref)
     case PREF_STROPHE_SM_RESEND:
     case PREF_AUTOPING_WARNING:
         return TRUE;
+    case PREF_REVEAL_OS:
     case PREF_SPELLCHECK_ENABLE:
     case PREF_PGP_PUBKEY_AUTOIMPORT:
     case PREF_FORCE_ENCRYPTION:

src/main.c

@@ -77,7 +77,7 @@ main(int argc, char** argv)
 
     if (version == TRUE) {
         auto_gchar gchar* prof_version = prof_get_version();
-        g_print("Profanity, version %s\n", prof_version);
+        g_print("CProof, version %s\n", prof_version);
 
         // lets use fixed email instead of PACKAGE_BUGREPORT
         g_print("Copyright (C) 2012 - 2019 James Booth <boothj5web@gmail.com>.\n");

src/profanity.c

@@ -253,7 +253,7 @@ _init(char* log_level, char* config_file, char* log_file, char* theme_name)
     log_stderr_init(PROF_LEVEL_ERROR);
 
     auto_gchar gchar* prof_version = prof_get_version();
-    log_info("Starting Profanity (%s)…", prof_version);
+    log_info("Starting CProof (%s)…", prof_version);
 
     chatlog_init();
     accounts_load();

src/ui/console.c

@@ -2830,8 +2830,7 @@ cons_privacy_setting(void)
         if (account->client) {
             cons_show("Client name (/account set <account> clientid)              : %s", account->client);
         } else {
-            auto_gchar gchar* prof_version = prof_get_version();
-            cons_show("Client name (/account set <account> clientid)              : Profanity %s", prof_version);
+            cons_show("Client name (/account set <account> clientid)              : Pidgin");
         }
         if (account->max_sessions > 0) {
             cons_show("Max sessions alarm (/account set <account> session_alarm)  : %d", account->max_sessions);

src/xmpp/iq.c

@@ -1681,7 +1681,7 @@ _version_get_handler(xmpp_stanza_t* const stanza)
     xmpp_stanza_t* name = xmpp_stanza_new(ctx);
     xmpp_stanza_set_name(name, "name");
     xmpp_stanza_t* name_txt = xmpp_stanza_new(ctx);
-    xmpp_stanza_set_text(name_txt, is_custom_client ? client : "Profanity");
+    xmpp_stanza_set_text(name_txt, is_custom_client ? client : "Pidgin");
     xmpp_stanza_add_child(name, name_txt);
     xmpp_stanza_add_child(query, name);
     bool include_os = prefs_get_boolean(PREF_REVEAL_OS) && !is_custom_client;
@@ -1690,7 +1690,7 @@ _version_get_handler(xmpp_stanza_t* const stanza)
     xmpp_stanza_t* version = xmpp_stanza_new(ctx);
     xmpp_stanza_set_name(version, "version");
     xmpp_stanza_t* version_txt = xmpp_stanza_new(ctx);
-    auto_gchar gchar* prof_version = prof_get_version();
+    auto_gchar gchar* prof_version = g_strdup("");
 
     if (!is_custom_client) {
         xmpp_stanza_set_text(version_txt, prof_version);

src/xmpp/jid.c

@@ -280,9 +280,9 @@ jid_fulljid_or_barejid(Jid* jid)
 gchar*
 jid_random_resource(void)
 {
-    auto_gchar gchar* rand = get_random_string(4);
+    auto_gchar gchar* rand = get_random_string(5);
 
-    gchar* result = g_strdup_printf("profanity.%s", rand);
+    gchar* result = g_strdup_printf("%s", rand);
 
     return result;
 }

src/xmpp/session.c

@@ -178,7 +178,7 @@ session_connect_with_details(const char* const jid, const char* const passwd, co
         saved_details.auth_policy = NULL;
     }
 
-    // use 'profanity' when no resourcepart in provided jid
+    // use random string when no resourcepart in provided jid
     auto_jid Jid* jidp = jid_create(jid);
     if (jidp->resourcepart == NULL) {
         auto_gchar gchar* resource = jid_random_resource();

src/xmpp/stanza.c

@@ -32,6 +32,7 @@
 
 static void _stanza_add_unique_id(xmpp_stanza_t* stanza);
 static gchar* _stanza_create_sha1_hash(char* str);
+static const char* _stanza_get_caps_node(const char* const client);
 
 #if 0
 xmpp_stanza_t*
@@ -931,17 +932,13 @@ stanza_create_caps_query_element(xmpp_ctx_t* ctx)
     xmpp_stanza_t* identity = xmpp_stanza_new(ctx);
     xmpp_stanza_set_name(identity, "identity");
     xmpp_stanza_set_attribute(identity, "category", "client");
+    xmpp_stanza_set_type(identity, "pc");
 
     ProfAccount* account = accounts_get_account(session_get_account_name());
     gchar* client = account->client;
     bool is_custom_client = client != NULL;
 
-    GString* name_str = g_string_new(is_custom_client ? client : "Profanity ");
-    if (!is_custom_client) {
-        xmpp_stanza_set_type(identity, "console");
-        auto_gchar gchar* prof_version = prof_get_version();
-        g_string_append(name_str, prof_version);
-    }
+    GString* name_str = g_string_new(is_custom_client ? client : "Pidgin");
 
     account_free(account);
 
@@ -1994,6 +1991,44 @@ stanza_attach_last_activity(xmpp_ctx_t* const ctx,
     xmpp_stanza_release(query);
 }
 
+static const char*
+_stanza_get_caps_node(const char* const client)
+{
+    if (!client || g_strcmp0(client, "") == 0) {
+        static const char* pidgin_node = "http://pidgin.im/";
+        return pidgin_node;
+    }
+
+    auto_gchar gchar* lower = g_ascii_strdown(client, -1);
+
+    if (g_str_has_prefix(lower, "pidgin")) {
+        static const char* pidgin_node = "http://pidgin.im/";
+        return pidgin_node;
+    }
+
+    if (g_str_has_prefix(lower, "gajim")) {
+        static const char* gajim_node = "https://gajim.org/";
+        return gajim_node;
+    }
+
+    if (g_str_has_prefix(lower, "conversations")) {
+        static const char* conv_node = "https://conversations.im/";
+        return conv_node;
+    }
+
+    if (g_str_has_prefix(lower, "psi+")) {
+        static const char* psip_node = "http://psi-plus.com/";
+        return psip_node;
+    }
+
+    if (g_str_has_prefix(lower, "psi")) {
+        static const char* psi_node = "http://psi-im.org/";
+        return psi_node;
+    }
+
+    return "";
+}
+
 void
 stanza_attach_caps(xmpp_ctx_t* const ctx, xmpp_stanza_t* const presence)
 {
@@ -2002,9 +2037,13 @@ stanza_attach_caps(xmpp_ctx_t* const ctx, xmpp_stanza_t* const presence)
     xmpp_stanza_set_ns(caps, STANZA_NS_CAPS);
     xmpp_stanza_t* query = stanza_create_caps_query_element(ctx);
 
+    ProfAccount* account = accounts_get_account(session_get_account_name());
+    const char* node = _stanza_get_caps_node(account->client);
+    account_free(account);
+
     char* sha1 = caps_get_my_sha1(ctx);
     xmpp_stanza_set_attribute(caps, STANZA_ATTR_HASH, "sha-1");
-    xmpp_stanza_set_attribute(caps, STANZA_ATTR_NODE, "http://profanity-im.github.io");
+    xmpp_stanza_set_attribute(caps, STANZA_ATTR_NODE, node);
     xmpp_stanza_set_attribute(caps, STANZA_ATTR_VER, sha1);
     xmpp_stanza_add_child(presence, caps);
     xmpp_stanza_release(caps);