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/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

@@ -931,17 +931,13 @@ 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);
 
@@ -2004,7 +2000,7 @@ stanza_attach_caps(xmpp_ctx_t* const ctx, xmpp_stanza_t* const presence)
 
     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, "");
     xmpp_stanza_set_attribute(caps, STANZA_ATTR_VER, sha1);
     xmpp_stanza_add_child(presence, caps);
     xmpp_stanza_release(caps);