OVMS3-idf/components/tcp_transport/transport_ssl.c

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// Copyright 2015-2018 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <string.h>
#include <stdlib.h>
#include "freertos/FreeRTOS.h"
#include "freertos/task.h"
#include "esp_tls.h"
#include "esp_log.h"
#include "esp_system.h"
#include "transport.h"
#include "transport_ssl.h"
#include "transport_utils.h"
static const char *TAG = "TRANS_SSL";
typedef enum {
TRANS_SSL_INIT = 0,
TRANS_SSL_CONNECTING,
} transport_ssl_conn_state_t;
/**
* mbedtls specific transport data
*/
typedef struct {
esp_tls_t *tls;
esp_tls_cfg_t cfg;
bool ssl_initialized;
bool verify_server;
transport_ssl_conn_state_t conn_state;
} transport_ssl_t;
transport_handle_t transport_get_handle(transport_handle_t t);
static int ssl_close(transport_handle_t t);
static int ssl_connect_async(transport_handle_t t, const char *host, int port, int timeout_ms)
{
transport_ssl_t *ssl = transport_get_context_data(t);
if (ssl->conn_state == TRANS_SSL_INIT) {
if (ssl->cfg.cacert_pem_buf) {
ssl->verify_server = true;
}
ssl->cfg.timeout_ms = timeout_ms;
ssl->cfg.non_block = true;
ssl->ssl_initialized = true;
ssl->tls = calloc(1, sizeof(esp_tls_t));
if (!ssl->tls) {
return -1;
}
ssl->conn_state = TRANS_SSL_CONNECTING;
}
if (ssl->conn_state == TRANS_SSL_CONNECTING) {
return esp_tls_conn_new_async(host, strlen(host), port, &ssl->cfg, ssl->tls);
}
return 0;
}
static int ssl_connect(transport_handle_t t, const char *host, int port, int timeout_ms)
{
transport_ssl_t *ssl = transport_get_context_data(t);
if (ssl->cfg.cacert_pem_buf) {
ssl->verify_server = true;
}
ssl->cfg.timeout_ms = timeout_ms;
ssl->ssl_initialized = true;
ssl->tls = esp_tls_conn_new(host, strlen(host), port, &ssl->cfg);
if (!ssl->tls) {
ESP_LOGE(TAG, "Failed to open a new connection");
return -1;
}
return 0;
}
static int ssl_poll_read(transport_handle_t t, int timeout_ms)
{
transport_ssl_t *ssl = transport_get_context_data(t);
fd_set readset;
FD_ZERO(&readset);
FD_SET(ssl->tls->sockfd, &readset);
struct timeval timeout;
transport_utils_ms_to_timeval(timeout_ms, &timeout);
return select(ssl->tls->sockfd + 1, &readset, NULL, NULL, &timeout);
}
static int ssl_poll_write(transport_handle_t t, int timeout_ms)
{
transport_ssl_t *ssl = transport_get_context_data(t);
fd_set writeset;
FD_ZERO(&writeset);
FD_SET(ssl->tls->sockfd, &writeset);
struct timeval timeout;
transport_utils_ms_to_timeval(timeout_ms, &timeout);
return select(ssl->tls->sockfd + 1, NULL, &writeset, NULL, &timeout);
}
static int ssl_write(transport_handle_t t, const char *buffer, int len, int timeout_ms)
{
int poll, ret;
transport_ssl_t *ssl = transport_get_context_data(t);
if ((poll = transport_poll_write(t, timeout_ms)) <= 0) {
ESP_LOGW(TAG, "Poll timeout or error, errno=%s, fd=%d, timeout_ms=%d", strerror(errno), ssl->tls->sockfd, timeout_ms);
return poll;
}
ret = esp_tls_conn_write(ssl->tls, (const unsigned char *) buffer, len);
if (ret <= 0) {
ESP_LOGE(TAG, "esp_tls_conn_write error, errno=%s", strerror(errno));
}
return ret;
}
static int ssl_read(transport_handle_t t, char *buffer, int len, int timeout_ms)
{
int poll, ret;
transport_ssl_t *ssl = transport_get_context_data(t);
if (esp_tls_get_bytes_avail(ssl->tls) <= 0) {
if ((poll = transport_poll_read(t, timeout_ms)) <= 0) {
return poll;
}
}
ret = esp_tls_conn_read(ssl->tls, (unsigned char *)buffer, len);
if (ret <= 0) {
ESP_LOGE(TAG, "esp_tls_conn_read error, errno=%s", strerror(errno));
}
return ret;
}
static int ssl_close(transport_handle_t t)
{
int ret = -1;
transport_ssl_t *ssl = transport_get_context_data(t);
if (ssl->ssl_initialized) {
esp_tls_conn_delete(ssl->tls);
ssl->ssl_initialized = false;
ssl->verify_server = false;
}
return ret;
}
static int ssl_destroy(transport_handle_t t)
{
transport_ssl_t *ssl = transport_get_context_data(t);
transport_close(t);
free(ssl);
return 0;
}
void transport_ssl_set_cert_data(transport_handle_t t, const char *data, int len)
{
transport_ssl_t *ssl = transport_get_context_data(t);
if (t && ssl) {
ssl->cfg.cacert_pem_buf = (void *)data;
ssl->cfg.cacert_pem_bytes = len + 1;
}
}
transport_handle_t transport_ssl_init()
{
transport_handle_t t = transport_init();
transport_ssl_t *ssl = calloc(1, sizeof(transport_ssl_t));
TRANSPORT_MEM_CHECK(TAG, ssl, return NULL);
transport_set_context_data(t, ssl);
transport_set_func(t, ssl_connect, ssl_read, ssl_write, ssl_close, ssl_poll_read, ssl_poll_write, ssl_destroy, transport_get_handle);
transport_set_async_connect_func(t, ssl_connect_async);
return t;
}