kopia lustrzana https://github.com/espressif/esp-idf
389 wiersze
13 KiB
C
389 wiersze
13 KiB
C
/* SSL server using plain mbedTLS sockets
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*
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* Adapted from the ssl_server example in mbedtls.
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*
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* Original Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
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* Additions Copyright (C) Copyright 2019 Espressif Systems (Shanghai) PTE LTD, Apache 2.0 License.
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*
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "esp_err.h"
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#include "esp_log.h"
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#include "freertos/FreeRTOS.h"
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#include "freertos/task.h"
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#include "freertos/semphr.h"
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#include "mbedtls/entropy.h"
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#include "mbedtls/ctr_drbg.h"
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#include "mbedtls/certs.h"
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#include "mbedtls/x509.h"
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#include "mbedtls/ssl.h"
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#include "mbedtls/net_sockets.h"
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#include "mbedtls/error.h"
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#include "mbedtls/debug.h"
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#include "esp_crt_bundle.h"
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#include "unity.h"
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#include "test_utils.h"
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#define SERVER_ADDRESS "localhost"
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#define SERVER_PORT "4433"
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extern const uint8_t server_cert_chain_pem_start[] asm("_binary_server_cert_chain_pem_start");
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extern const uint8_t server_cert_chain_pem_end[] asm("_binary_server_cert_chain_pem_end");
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extern const uint8_t server_pk_start[] asm("_binary_prvtkey_pem_start");
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extern const uint8_t server_pk_end[] asm("_binary_prvtkey_pem_end");
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extern const uint8_t server_cert_bundle_start[] asm("_binary_server_cert_bundle_start");
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extern const uint8_t server_cert_bundle_end[] asm("_binary_server_cert_bundle_end");
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extern const uint8_t bad_md_crt_pem_start[] asm("_binary_bad_md_crt_pem_start");
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extern const uint8_t bad_md_crt_pem_end[] asm("_binary_bad_md_crt_pem_end");
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extern const uint8_t wrong_sig_crt_pem_start[] asm("_binary_wrong_sig_crt_esp32_com_pem_start");
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extern const uint8_t wrong_sig_crt_pem_end[] asm("_binary_wrong_sig_crt_esp32_com_pem_end");
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extern const uint8_t correct_sig_crt_pem_start[] asm("_binary_correct_sig_crt_esp32_com_pem_start");
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extern const uint8_t correct_sig_crt_pem_end[] asm("_binary_correct_sig_crt_esp32_com_pem_end");
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typedef struct {
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mbedtls_ssl_context ssl;
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mbedtls_net_context listen_fd;
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mbedtls_net_context client_fd;
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mbedtls_entropy_context entropy;
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mbedtls_ctr_drbg_context ctr_drbg;
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mbedtls_ssl_config conf;
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mbedtls_x509_crt cert;
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mbedtls_pk_context pkey;
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} mbedtls_endpoint_t;
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typedef enum {
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ESP_CRT_VALIDATE_UNKNOWN,
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ESP_CRT_VALIDATE_OK,
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ESP_CRT_VALIDATE_FAIL,
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}esp_crt_validate_res_t;
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int esp_crt_verify_callback(void *buf, mbedtls_x509_crt *crt, int data, uint32_t *flags);
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static const char *TAG = "cert_bundle_test";
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static volatile bool exit_flag;
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esp_err_t endpoint_teardown(mbedtls_endpoint_t *endpoint);
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esp_err_t server_setup(mbedtls_endpoint_t *server)
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{
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int ret;
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mbedtls_ssl_config_init( &server->conf );
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mbedtls_net_init( &server->listen_fd );
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mbedtls_net_init( &server->client_fd );
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mbedtls_ssl_init( &server->ssl );
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mbedtls_x509_crt_init( &server->cert );
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mbedtls_pk_init( &server->pkey );
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mbedtls_entropy_init( &server->entropy );
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mbedtls_ctr_drbg_init( &server->ctr_drbg );
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ESP_LOGI(TAG, "Loading the server cert and key");
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ret = mbedtls_x509_crt_parse( &server->cert, server_cert_chain_pem_start,
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server_cert_chain_pem_end - server_cert_chain_pem_start);
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if ( ret != 0 ) {
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ESP_LOGE(TAG, "mbedtls_x509_crt_parse returned %d", ret );
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return ESP_FAIL;
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}
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ret = mbedtls_pk_parse_key( &server->pkey, (const unsigned char *)server_pk_start,
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server_pk_end - server_pk_start, NULL, 0 );
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if ( ret != 0 ) {
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ESP_LOGE(TAG, "mbedtls_pk_parse_key returned %d", ret );
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return ESP_FAIL;
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}
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ESP_LOGI(TAG, "Bind on https://%s:%s/", SERVER_ADDRESS, SERVER_PORT );
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if ( ( ret = mbedtls_net_bind( &server->listen_fd, NULL, SERVER_PORT, MBEDTLS_NET_PROTO_TCP ) ) != 0 ) {
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ESP_LOGE(TAG, "mbedtls_net_bind returned %d", ret );
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return ESP_FAIL;
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}
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mbedtls_net_set_nonblock(&server->listen_fd);
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ESP_LOGI(TAG, "Seeding the random number generator");
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if ( ( ret = mbedtls_ctr_drbg_seed( &server->ctr_drbg, mbedtls_entropy_func, &server->entropy,
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NULL, 0) ) != 0 ) {
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ESP_LOGE(TAG, "mbedtls_ctr_drbg_seed returned %d", ret );
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return ESP_FAIL;
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}
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ESP_LOGI(TAG, "Setting up the SSL data");
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if ( ( ret = mbedtls_ssl_config_defaults( &server->conf,
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MBEDTLS_SSL_IS_SERVER,
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MBEDTLS_SSL_TRANSPORT_STREAM,
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MBEDTLS_SSL_PRESET_DEFAULT ) ) != 0 ) {
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ESP_LOGE(TAG, "mbedtls_ssl_config_defaults returned %d", ret );
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return ESP_FAIL;
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}
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mbedtls_ssl_conf_rng( &server->conf, mbedtls_ctr_drbg_random, &server->ctr_drbg );
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if (( ret = mbedtls_ssl_conf_own_cert( &server->conf, &server->cert, &server->pkey ) ) != 0 ) {
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ESP_LOGE(TAG, "mbedtls_ssl_conf_own_cert returned %d", ret );
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return ESP_FAIL;
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}
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if (( ret = mbedtls_ssl_setup( &server->ssl, &server->conf ) ) != 0 ) {
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ESP_LOGE(TAG, "mbedtls_ssl_setup returned %d", ret );
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return ESP_FAIL;
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}
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return ESP_OK;
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}
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void server_task(void *pvParameters)
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{
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int ret;
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mbedtls_endpoint_t server;
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xSemaphoreHandle *sema = (xSemaphoreHandle *) pvParameters;
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if (server_setup(&server) != ESP_OK) {
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ESP_LOGE(TAG, "SSL server setup failed");
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goto exit;
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}
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bool connected = false;
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while (!exit_flag) {
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ret = mbedtls_net_accept( &server.listen_fd, &server.client_fd, NULL, 0, NULL );
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if (ret == 0) {
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connected = true;
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}
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if (connected) {
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mbedtls_ssl_set_bio( &server.ssl, &server.client_fd, mbedtls_net_send, mbedtls_net_recv, NULL );
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ret = mbedtls_ssl_handshake( &server.ssl );
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mbedtls_ssl_session_reset(&server.ssl);
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connected = false;
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}
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vTaskDelay(20 / portTICK_PERIOD_MS);
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}
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ESP_LOGE(TAG, "Server shutdown");
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exit:
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endpoint_teardown(&server);
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xSemaphoreGive(*sema);
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vTaskDelete(NULL);
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}
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esp_err_t endpoint_teardown(mbedtls_endpoint_t *endpoint)
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{
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mbedtls_net_free( &endpoint->client_fd );
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mbedtls_net_free( &endpoint->listen_fd );
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mbedtls_x509_crt_free( &endpoint->cert );
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mbedtls_pk_free( &endpoint->pkey );
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mbedtls_ssl_free( &endpoint->ssl );
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mbedtls_ssl_config_free( &endpoint->conf );
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mbedtls_ctr_drbg_free( &endpoint->ctr_drbg );
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mbedtls_entropy_free( &endpoint->entropy );
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return ESP_OK;
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}
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esp_err_t client_setup(mbedtls_endpoint_t *client)
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{
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int ret;
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mbedtls_ssl_config_init( &client->conf );
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mbedtls_net_init( &client->client_fd );
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mbedtls_ssl_init( &client->ssl );
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mbedtls_x509_crt_init( &client->cert );
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mbedtls_pk_init( &client->pkey );
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mbedtls_entropy_init( &client->entropy );
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mbedtls_ctr_drbg_init( &client->ctr_drbg );
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ESP_LOGI(TAG, "Seeding the random number generator");
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if ((ret = mbedtls_ctr_drbg_seed(&client->ctr_drbg, mbedtls_entropy_func, &client->entropy,
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NULL, 0)) != 0) {
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ESP_LOGE(TAG, "mbedtls_ctr_drbg_seed returned %d", ret);
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return ESP_FAIL;
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}
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ESP_LOGI(TAG, "Setting hostname for TLS session...");
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/* Hostname set here should match CN in server certificate */
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if ((ret = mbedtls_ssl_set_hostname(&client->ssl, SERVER_ADDRESS)) != 0) {
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ESP_LOGE(TAG, "mbedtls_ssl_set_hostname returned -0x%x", -ret);
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return ESP_FAIL;
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}
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ESP_LOGI(TAG, "Setting up the SSL/TLS structure...");
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if ((ret = mbedtls_ssl_config_defaults(&client->conf,
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MBEDTLS_SSL_IS_CLIENT,
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MBEDTLS_SSL_TRANSPORT_STREAM,
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MBEDTLS_SSL_PRESET_DEFAULT)) != 0) {
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ESP_LOGE(TAG, "mbedtls_ssl_config_defaults returned %d", ret);
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return ESP_FAIL;
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}
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mbedtls_ssl_conf_rng(&client->conf, mbedtls_ctr_drbg_random, &client->ctr_drbg);
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if ((ret = mbedtls_ssl_setup(&client->ssl, &client->conf)) != 0) {
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ESP_LOGE(TAG, "mbedtls_ssl_setup returned -0x%x\n\n", -ret);
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return ESP_FAIL;
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}
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return ESP_OK;
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}
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int client_task(const uint8_t *bundle, esp_crt_validate_res_t *res)
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{
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int ret = ESP_FAIL;
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mbedtls_endpoint_t client;
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*res = ESP_CRT_VALIDATE_UNKNOWN;
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if (client_setup(&client) != ESP_OK) {
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ESP_LOGE(TAG, "SSL client setup failed");
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goto exit;
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}
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esp_crt_bundle_attach(&client.conf);
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if (bundle) {
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/* Set a bundle different from the menuconfig bundle */
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esp_crt_bundle_set(bundle);
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}
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ESP_LOGI(TAG, "Connecting to %s:%s...", SERVER_ADDRESS, SERVER_PORT);
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if ((ret = mbedtls_net_connect(&client.client_fd, SERVER_ADDRESS, SERVER_PORT, MBEDTLS_NET_PROTO_TCP)) != 0) {
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ESP_LOGE(TAG, "mbedtls_net_connect returned -%x", -ret);
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goto exit;
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}
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ESP_LOGI(TAG, "Connected.");
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mbedtls_ssl_set_bio(&client.ssl, &client.client_fd, mbedtls_net_send, mbedtls_net_recv, NULL);
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ESP_LOGI(TAG, "Performing the SSL/TLS handshake with bundle that is missing the server root certificate");
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while ( ( ret = mbedtls_ssl_handshake( &client.ssl ) ) != 0 ) {
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if ( ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE ) {
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printf( "mbedtls_ssl_handshake failed with -0x%x\n", -ret );
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break;
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}
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}
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ESP_LOGI(TAG, "Verifying peer X.509 certificate for bundle ...");
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ret = mbedtls_ssl_get_verify_result(&client.ssl);
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*res = (ret == 0) ? ESP_CRT_VALIDATE_OK : ESP_CRT_VALIDATE_FAIL;
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// Reset session before new connection
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mbedtls_ssl_close_notify(&client.ssl);
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mbedtls_ssl_session_reset(&client.ssl);
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mbedtls_net_free( &client.client_fd);
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exit:
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mbedtls_ssl_close_notify(&client.ssl);
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mbedtls_ssl_session_reset(&client.ssl);
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esp_crt_bundle_detach(&client.conf);
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endpoint_teardown(&client);
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return ret;
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}
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TEST_CASE("custom certificate bundle", "[mbedtls]")
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{
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esp_crt_validate_res_t validate_res;
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test_case_uses_tcpip();
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xSemaphoreHandle exit_sema = xSemaphoreCreateBinary();
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exit_flag = false;
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xTaskCreate(server_task, "server task", 8192, &exit_sema, 10, NULL);
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// Wait for the server to start up
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vTaskDelay(100 / portTICK_PERIOD_MS);
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/* Test with default crt bundle that doesnt contain the ca crt */
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client_task(NULL, &validate_res);
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TEST_ASSERT(validate_res == ESP_CRT_VALIDATE_FAIL);
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/* Test with bundle that does contain the CA crt */
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client_task(server_cert_bundle_start, &validate_res);
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TEST_ASSERT(validate_res == ESP_CRT_VALIDATE_OK);
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exit_flag = true;
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if (!xSemaphoreTake(exit_sema, 10000 / portTICK_PERIOD_MS)) {
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TEST_FAIL_MESSAGE("exit_sem not released by server task");
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}
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vSemaphoreDelete(exit_sema);
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}
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TEST_CASE("custom certificate bundle - weak hash", "[mbedtls]")
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{
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/* A weak signature hash on the trusted certificate should not stop
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us from verifying the chain, since we already trust it a weak signature hash is
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not a security issue */
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mbedtls_x509_crt crt;
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uint32_t flags = 0;
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esp_crt_bundle_attach(NULL);
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mbedtls_x509_crt_init( &crt );
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mbedtls_x509_crt_parse(&crt, bad_md_crt_pem_start, bad_md_crt_pem_end - bad_md_crt_pem_start);
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TEST_ASSERT(mbedtls_x509_crt_verify(&crt, NULL, NULL, NULL, &flags, esp_crt_verify_callback, NULL) == 0);
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mbedtls_x509_crt_free(&crt);
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esp_crt_bundle_detach(NULL);
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}
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TEST_CASE("custom certificate bundle - wrong signature", "[mbedtls]")
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{
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/* Check that the bundle will not verify a valid certificate from trusted root where the signature is wrong */
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mbedtls_x509_crt crt;
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uint32_t flags = 0;
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esp_crt_bundle_attach(NULL);
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mbedtls_x509_crt_init( &crt );
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/* esp32.com cert chain where 1 byte in the signature is changed */
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printf("Testing certificate with wrong signature\n");
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mbedtls_x509_crt_parse(&crt, wrong_sig_crt_pem_start, wrong_sig_crt_pem_end - wrong_sig_crt_pem_start);
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TEST_ASSERT(mbedtls_x509_crt_verify(&crt, NULL, NULL, NULL, &flags, esp_crt_verify_callback, NULL) != 0);
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mbedtls_x509_crt_free(&crt);
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mbedtls_x509_crt_init( &crt );
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/* the correct esp32.com cert chain*/
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printf("Testing certificate with correct signature\n");
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mbedtls_x509_crt_parse(&crt, correct_sig_crt_pem_start, correct_sig_crt_pem_end - correct_sig_crt_pem_start);
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TEST_ASSERT(mbedtls_x509_crt_verify(&crt, NULL, NULL, NULL, &flags, esp_crt_verify_callback, NULL) == 0);
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mbedtls_x509_crt_free(&crt);
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esp_crt_bundle_detach(NULL);
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}
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