Merge branch 'bugfix/bt_bluedroid_same_public_key_attack_v4.1' into 'release/v4.1'

Bluedroid: Fixes for some Bluetooth vulnerabilities. (v4.1)

See merge request espressif/esp-idf!11764

components/bt/host/bluedroid/api/include/api/esp_gap_ble_api.h

@@ -1129,6 +1129,20 @@ esp_err_t esp_ble_gap_clean_duplicate_scan_exceptional_list(esp_duplicate_scan_e
 /**
 * @brief             Set a GAP security parameter value. Overrides the default value.
 *
+*                    Secure connection is highly recommended to avoid some major
+*                    vulnerabilities like 'Impersonation in the Pin Pairing Protocol'
+*                    (CVE-2020-26555) and 'Authentication of the LE Legacy Pairing
+*                    Protocol'.
+*
+*                    To accept only `secure connection mode`, it is necessary do as following:
+*
+*                    1. Set bit `ESP_LE_AUTH_REQ_SC_ONLY` (`param_type` is
+*                    `ESP_BLE_SM_AUTHEN_REQ_MODE`), bit `ESP_LE_AUTH_BOND` and bit
+*                    `ESP_LE_AUTH_REQ_MITM` is optional as required.
+*
+*                    2. Set to `ESP_BLE_ONLY_ACCEPT_SPECIFIED_AUTH_ENABLE` (`param_type` is
+*                    `ESP_BLE_SM_ONLY_ACCEPT_SPECIFIED_SEC_AUTH`).
+*
 * @param[in]       param_type : the type of the param which to be set
 * @param[in]       value  : the param value
 * @param[in]       len : the length of the param value

components/bt/host/bluedroid/stack/smp/smp_act.c

@@ -760,6 +760,19 @@ void smp_process_pairing_public_key(tSMP_CB *p_cb, tSMP_INT_DATA *p_data)
 
     STREAM_TO_ARRAY(p_cb->peer_publ_key.x, p, BT_OCTET32_LEN);
     STREAM_TO_ARRAY(p_cb->peer_publ_key.y, p, BT_OCTET32_LEN);
+
+    /* Check if the peer device's and own public key are not same. If they are same then
+     * return pairing fail. This check is needed to avoid 'Impersonation in Passkey entry
+     * protocol' vulnerability (CVE-2020-26558).*/
+    if ((memcmp(p_cb->loc_publ_key.x, p_cb->peer_publ_key.x, sizeof(BT_OCTET32)) == 0) &&
+        (memcmp(p_cb->loc_publ_key.y, p_cb->peer_publ_key.y, sizeof(BT_OCTET32)) == 0)) {
+        p_cb->status = SMP_PAIR_AUTH_FAIL;
+        p_cb->failure = SMP_PAIR_AUTH_FAIL;
+        reason = SMP_PAIR_AUTH_FAIL;
+        SMP_TRACE_ERROR("%s, Peer and own device cannot have same public key.", __func__);
+        smp_sm_event(p_cb, SMP_PAIRING_FAILED_EVT, &reason);
+        return ;
+    }
     /* In order to prevent the x and y coordinates of the public key from being modified,
        we need to check whether the x and y coordinates are on the given elliptic curve. */
     if (!ECC_CheckPointIsInElliCur_P256((Point *)&p_cb->peer_publ_key)) {