diff --git a/tools/cgathui_common/tests/test_ble_join.c b/tools/cgathui_common/tests/test_ble_join.c
new file mode 100644
index 00000000..23b41272
--- /dev/null
+++ b/tools/cgathui_common/tests/test_ble_join.c
@@ -0,0 +1,67 @@
+/* Проверка границы доверия: настоящий CCM, подмена, replay, reflection, новый challenge и отмена. */
+#ifdef NDEBUG
+#undef NDEBUG
+#endif
+#include "../ble_join.c"
+#include <assert.h>
+#include <stdio.h>
+
+struct test_radio { struct ll_entry* packet; };
+int ble_channel_tx_ready(struct ble_transport* radio, ble_link_id id, enum ble_channel channel) {
+    (void)id; assert(channel == BLE_CHANNEL_INVITE); return !((struct test_radio*)radio)->packet;
+}
+int ble_channel_tx_put(struct ble_transport* radio, ble_link_id id, enum ble_channel channel, struct ll_entry* packet) {
+    assert(ble_channel_tx_ready(radio, id, channel)); ((struct test_radio*)radio)->packet = packet; return BLE_OK;
+}
+static void wake(void* arg) { (void)arg; }
+static int connect_peer(void* arg, uint64_t peer) { (void)arg; (void)peer; return -1; }
+static void free_packet(struct ll_entry* packet) { queue_dgram_free(packet); queue_entry_free(packet); }
+static void deliver(struct test_radio* radio, struct ble_join* receiver) {
+    struct ll_entry* packet = radio->packet; assert(packet); radio->packet = NULL;
+    assert(ble_join_receive(receiver, 1, packet->dgram, packet->len)); free_packet(packet);
+}
+int main(void) {
+    debug_config_init(); debug_set_level(DEBUG_LEVEL_WARN);
+    size_t baseline = u_get_allocated_count();
+    struct UTUN_INSTANCE inst[2] = {0}; struct test_radio radio[2] = {0}; struct ble_join* b[2];
+    for (int i = 0; i < 2; i++) {
+        assert(sc_generate_keypair(&inst[i].my_keys) == SC_OK);
+        inst[i].node_id = sc_derive_node_id_from_pubkey(inst[i].my_keys.public_key);
+        b[i] = ble_join_create(&inst[i], (struct ble_transport*)&radio[i], connect_peer, wake, NULL); assert(b[i]);
+    }
+    for (int i = 0; i < 2; i++) ble_join_connection(b[i], 1, inst[1-i].node_id, BLE_READY);
+    uint64_t handle = 0; assert(!inst[0].join_carrier->open(b[0], inst[1].my_keys.public_key, &handle) && handle);
+    ble_join_run(b[0]); deliver(&radio[0], b[1]); ble_join_run(b[1]); deliver(&radio[1], b[0]); ble_join_run(b[0]);
+    assert(b[0]->links[0].authenticated && !b[1]->links[0].authenticated);
+    uint8_t wire[CHAT_JOIN_WIRE_MAX] = {ETCP_ID_CHAT_SYNC}; wire[9] = CS_MSG_JOIN_INFO_REQ;
+    assert(!inst[0].join_carrier->send(b[0], handle, wire, sizeof(wire))); ble_join_run(b[0]);
+    struct ll_entry* packet = radio[0].packet; assert(packet && packet->len > BLE_FRAME_MAX);
+    /* Изменённый ciphertext, ключ заголовка и отражение не устанавливают сессию. */
+    packet->dgram[packet->len - 1] ^= 1; assert(ble_join_receive(b[1], 1, packet->dgram, packet->len));
+    assert(!b[1]->links[0].authenticated && !b[1]->links[0].rx_sequence); packet->dgram[packet->len - 1] ^= 1;
+    packet->dgram[2] ^= 1; assert(ble_join_receive(b[1], 1, packet->dgram, packet->len));
+    assert(!b[1]->links[0].rx_sequence); packet->dgram[2] ^= 1;
+    assert(ble_join_receive(b[0], 1, packet->dgram, packet->len)); assert(!b[0]->links[0].rx_sequence);
+    assert(ble_join_receive(b[1], 1, packet->dgram, packet->len));
+    assert(b[1]->links[0].authenticated && b[1]->links[0].rx_sequence == 1);
+    assert(ble_join_receive(b[1], 1, packet->dgram, packet->len)); assert(b[1]->links[0].rx_sequence == 1);
+    /* Старый ciphertext не проходит после нового challenge, даже с тем же статическим ключом. */
+    reset(b[0], &b[0]->links[0], 0); reset(b[1], &b[1]->links[0], 0);
+    uint64_t fresh = 0; assert(!carrier_open(b[0], inst[1].my_keys.public_key, &fresh) && fresh != handle);
+    radio[0].packet = NULL;
+    ble_join_run(b[0]); deliver(&radio[0], b[1]); ble_join_run(b[1]); deliver(&radio[1], b[0]); ble_join_run(b[0]);
+    assert(ble_join_receive(b[1], 1, packet->dgram, packet->len)); assert(!b[1]->links[0].rx_sequence); free_packet(packet);
+    assert(carrier_send(b[0], handle, wire, 18) < 0); /* Старый handle не переиспользуется. */
+    wire[9] = CS_MSG_DB_SYNC_REQ; assert(carrier_send(b[0], fresh, wire, 18) < 0); wire[9] = CS_MSG_JOIN_INFO_REQ;
+    for (int i = 0; i < JOIN_QUEUE; i++) assert(!carrier_send(b[0], fresh, wire, 18));
+    assert(carrier_send(b[0], fresh, wire, 18) < 0 && b[0]->links[0].count == JOIN_QUEUE);
+    reset(b[0], &b[0]->links[0], 0); reset(b[1], &b[1]->links[0], 0);
+    assert(!carrier_open(b[0], inst[1].my_keys.public_key, &fresh));
+    ble_join_run(b[0]); deliver(&radio[0], b[1]); ble_join_run(b[1]); deliver(&radio[1], b[0]); ble_join_run(b[0]);
+    carrier_close(b[0], fresh, 0); ble_join_run(b[0]); deliver(&radio[0], b[1]); ble_join_run(b[0]);
+    assert(!ble_join_holds(b[0], 1) && !ble_join_holds(b[1], 1));
+    for (int i = 0; i < 2; i++) { ble_join_destroy(b[i]); assert(!inst[i].join_carrier && !radio[i].packet); }
+    assert(u_get_allocated_count() == baseline);
+    puts("PASS BLE JOIN trust boundary: CCM tamper, key substitution, reflection, replay, fresh session, whitelist, queue bound, cancellation");
+    return 0;
+}
diff --git a/tools/chatgui/CMakeLists.txt b/tools/chatgui/CMakeLists.txt
index a8953a8b..273d997f 100644
--- a/tools/chatgui/CMakeLists.txt
+++ b/tools/chatgui/CMakeLists.txt
@@ -136,6 +136,10 @@ add_executable(test_ble_etcp ../cgathui_common/tests/test_ble_etcp.c)
 target_link_libraries(test_ble_etcp PRIVATE chat_ble_etcp)
 set_target_properties(test_ble_etcp PROPERTIES AUTOMOC OFF)
 add_test(NAME test_ble_etcp COMMAND test_ble_etcp)
+add_executable(test_ble_join ../cgathui_common/tests/test_ble_join.c)
+target_link_libraries(test_ble_join PRIVATE utun)
+set_target_properties(test_ble_join PROPERTIES AUTOMOC OFF)
+add_test(NAME test_ble_join COMMAND test_ble_join)
 add_executable(ble_etcp_probe ../cgathui_common/tests/ble_etcp_probe.c)
 target_link_libraries(ble_etcp_probe PRIVATE chat_ble_etcp vibechat_ble)
 set_target_properties(ble_etcp_probe PROPERTIES AUTOMOC OFF)