esp-tls: Add support for simplified TLS

This is based on from esp-idf's esp-tls component.

Latest commit ID on esp-idf: dec70a760120d3c6d1d63ac0257dce6a8561879c

Some HTTP convenience APIs have been removed from esp-idf's esp-tls component while porting it ESP8266-RTOS-SDK due to
non-availabilty of http_parser
This commit is contained in:
Jitin George
2018-12-19 12:03:52 +05:30
parent 3dfe25120b
commit 39d1dae06c
4 changed files with 782 additions and 0 deletions

View File

@ -0,0 +1,7 @@
set(COMPONENT_SRCS "esp_tls.c")
set(COMPONENT_ADD_INCLUDEDIRS ".")
set(COMPONENT_REQUIRES mbedtls)
set(COMPONENT_PRIV_REQUIRES lwip nghttp)
register_component()

View File

@ -0,0 +1,7 @@
ifdef CONFIG_SSL_USING_MBEDTLS
COMPONENT_SRCDIRS := .
COMPONENT_ADD_INCLUDEDIRS := .
else
COMPONENT_SRCDIRS :=
COMPONENT_ADD_INCLUDEDIRS :=
endif

View File

@ -0,0 +1,492 @@
// Copyright 2017-2018 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 <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <netdb.h>
#include "esp_tls.h"
#include <errno.h>
static const char *TAG = "esp-tls";
static mbedtls_x509_crt *global_cacert = NULL;
#ifdef ESP_PLATFORM
#include <esp_log.h>
#else
#define ESP_LOGD(TAG, ...) //printf(__VA_ARGS__);
#define ESP_LOGE(TAG, ...) printf(__VA_ARGS__);
#endif
static struct addrinfo *resolve_host_name(const char *host, size_t hostlen)
{
struct addrinfo hints;
memset(&hints, 0, sizeof(hints));
hints.ai_family = AF_UNSPEC;
hints.ai_socktype = SOCK_STREAM;
char *use_host = strndup(host, hostlen);
if (!use_host) {
return NULL;
}
ESP_LOGD(TAG, "host:%s: strlen %lu", use_host, (unsigned long)hostlen);
struct addrinfo *res;
if (getaddrinfo(use_host, NULL, &hints, &res)) {
ESP_LOGE(TAG, "couldn't get hostname for :%s:", use_host);
free(use_host);
return NULL;
}
free(use_host);
return res;
}
static ssize_t tcp_read(esp_tls_t *tls, char *data, size_t datalen)
{
return recv(tls->sockfd, data, datalen, 0);
}
static ssize_t tls_read(esp_tls_t *tls, char *data, size_t datalen)
{
ssize_t ret = mbedtls_ssl_read(&tls->ssl, (unsigned char *)data, datalen);
if (ret < 0) {
if (ret == MBEDTLS_ERR_SSL_PEER_CLOSE_NOTIFY) {
return 0;
}
if (ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE) {
ESP_LOGE(TAG, "read error :%d:", ret);
}
}
return ret;
}
static void ms_to_timeval(int timeout_ms, struct timeval *tv)
{
tv->tv_sec = timeout_ms / 1000;
tv->tv_usec = (timeout_ms % 1000) * 1000;
}
static int esp_tcp_connect(const char *host, int hostlen, int port, int *sockfd, const esp_tls_cfg_t *cfg)
{
int ret = -1;
struct addrinfo *res = resolve_host_name(host, hostlen);
if (!res) {
return ret;
}
int fd = socket(res->ai_family, res->ai_socktype, res->ai_protocol);
if (fd < 0) {
ESP_LOGE(TAG, "Failed to create socket (family %d socktype %d protocol %d)", res->ai_family, res->ai_socktype, res->ai_protocol);
goto err_freeaddr;
}
*sockfd = fd;
void *addr_ptr;
if (res->ai_family == AF_INET) {
struct sockaddr_in *p = (struct sockaddr_in *)res->ai_addr;
p->sin_port = htons(port);
addr_ptr = p;
} else if (res->ai_family == AF_INET6) {
struct sockaddr_in6 *p = (struct sockaddr_in6 *)res->ai_addr;
p->sin6_port = htons(port);
p->sin6_family = AF_INET6;
addr_ptr = p;
} else {
ESP_LOGE(TAG, "Unsupported protocol family %d", res->ai_family);
goto err_freesocket;
}
if (cfg) {
if (cfg->timeout_ms >= 0) {
struct timeval tv;
ms_to_timeval(cfg->timeout_ms, &tv);
setsockopt(fd, SOL_SOCKET, SO_RCVTIMEO, &tv, sizeof(tv));
}
if (cfg->non_block) {
int flags = fcntl(fd, F_GETFL, 0);
fcntl(fd, F_SETFL, flags | O_NONBLOCK);
}
}
ret = connect(fd, addr_ptr, res->ai_addrlen);
if (ret < 0 && !(errno == EINPROGRESS && cfg->non_block)) {
ESP_LOGE(TAG, "Failed to connnect to host (errno %d)", errno);
goto err_freesocket;
}
freeaddrinfo(res);
return 0;
err_freesocket:
close(fd);
err_freeaddr:
freeaddrinfo(res);
return ret;
}
esp_err_t esp_tls_set_global_ca_store(const unsigned char *cacert_pem_buf, const unsigned int cacert_pem_bytes)
{
if (cacert_pem_buf == NULL) {
ESP_LOGE(TAG, "cacert_pem_buf is null");
return ESP_ERR_INVALID_ARG;
}
if (global_cacert != NULL) {
mbedtls_x509_crt_free(global_cacert);
}
global_cacert = (mbedtls_x509_crt *)calloc(1, sizeof(mbedtls_x509_crt));
if (global_cacert == NULL) {
ESP_LOGE(TAG, "global_cacert not allocated");
return ESP_ERR_NO_MEM;
}
mbedtls_x509_crt_init(global_cacert);
int ret = mbedtls_x509_crt_parse(global_cacert, cacert_pem_buf, cacert_pem_bytes);
if (ret < 0) {
ESP_LOGE(TAG, "mbedtls_x509_crt_parse returned -0x%x\n\n", -ret);
mbedtls_x509_crt_free(global_cacert);
global_cacert = NULL;
return ESP_FAIL;
} else if (ret > 0) {
ESP_LOGE(TAG, "mbedtls_x509_crt_parse was partly successful. No. of failed certificates: %d", ret);
}
return ESP_OK;
}
mbedtls_x509_crt *esp_tls_get_global_ca_store()
{
return global_cacert;
}
void esp_tls_free_global_ca_store()
{
if (global_cacert) {
mbedtls_x509_crt_free(global_cacert);
global_cacert = NULL;
}
}
static void verify_certificate(esp_tls_t *tls)
{
int flags;
char buf[100];
if ((flags = mbedtls_ssl_get_verify_result(&tls->ssl)) != 0) {
ESP_LOGI(TAG, "Failed to verify peer certificate!");
bzero(buf, sizeof(buf));
mbedtls_x509_crt_verify_info(buf, sizeof(buf), " ! ", flags);
ESP_LOGI(TAG, "verification info: %s", buf);
} else {
ESP_LOGI(TAG, "Certificate verified.");
}
}
static void mbedtls_cleanup(esp_tls_t *tls)
{
if (!tls) {
return;
}
if (tls->cacert_ptr != global_cacert) {
mbedtls_x509_crt_free(tls->cacert_ptr);
}
tls->cacert_ptr = NULL;
mbedtls_x509_crt_free(&tls->cacert);
mbedtls_x509_crt_free(&tls->clientcert);
mbedtls_pk_free(&tls->clientkey);
mbedtls_entropy_free(&tls->entropy);
mbedtls_ssl_config_free(&tls->conf);
mbedtls_ctr_drbg_free(&tls->ctr_drbg);
mbedtls_ssl_free(&tls->ssl);
mbedtls_net_free(&tls->server_fd);
}
static int create_ssl_handle(esp_tls_t *tls, const char *hostname, size_t hostlen, const esp_tls_cfg_t *cfg)
{
int ret;
mbedtls_net_init(&tls->server_fd);
tls->server_fd.fd = tls->sockfd;
mbedtls_ssl_init(&tls->ssl);
mbedtls_ctr_drbg_init(&tls->ctr_drbg);
mbedtls_ssl_config_init(&tls->conf);
mbedtls_entropy_init(&tls->entropy);
if ((ret = mbedtls_ctr_drbg_seed(&tls->ctr_drbg,
mbedtls_entropy_func, &tls->entropy, NULL, 0)) != 0) {
ESP_LOGE(TAG, "mbedtls_ctr_drbg_seed returned %d", ret);
goto exit;
}
/* Hostname set here should match CN in server certificate */
char *use_host = strndup(hostname, hostlen);
if (!use_host) {
goto exit;
}
if ((ret = mbedtls_ssl_set_hostname(&tls->ssl, use_host)) != 0) {
ESP_LOGE(TAG, "mbedtls_ssl_set_hostname returned -0x%x", -ret);
free(use_host);
goto exit;
}
free(use_host);
if ((ret = mbedtls_ssl_config_defaults(&tls->conf,
MBEDTLS_SSL_IS_CLIENT,
MBEDTLS_SSL_TRANSPORT_STREAM,
MBEDTLS_SSL_PRESET_DEFAULT)) != 0) {
ESP_LOGE(TAG, "mbedtls_ssl_config_defaults returned %d", ret);
goto exit;
}
#ifdef CONFIG_MBEDTLS_SSL_ALPN
if (cfg->alpn_protos) {
mbedtls_ssl_conf_alpn_protocols(&tls->conf, cfg->alpn_protos);
}
#endif
if (cfg->use_global_ca_store == true) {
if (global_cacert == NULL) {
ESP_LOGE(TAG, "global_cacert is NULL");
goto exit;
}
tls->cacert_ptr = global_cacert;
mbedtls_ssl_conf_authmode(&tls->conf, MBEDTLS_SSL_VERIFY_REQUIRED);
mbedtls_ssl_conf_ca_chain(&tls->conf, tls->cacert_ptr, NULL);
} else if (cfg->cacert_pem_buf != NULL) {
tls->cacert_ptr = &tls->cacert;
mbedtls_x509_crt_init(tls->cacert_ptr);
ret = mbedtls_x509_crt_parse(tls->cacert_ptr, cfg->cacert_pem_buf, cfg->cacert_pem_bytes);
if (ret < 0) {
ESP_LOGE(TAG, "mbedtls_x509_crt_parse returned -0x%x\n\n", -ret);
goto exit;
}
mbedtls_ssl_conf_authmode(&tls->conf, MBEDTLS_SSL_VERIFY_REQUIRED);
mbedtls_ssl_conf_ca_chain(&tls->conf, tls->cacert_ptr, NULL);
} else {
mbedtls_ssl_conf_authmode(&tls->conf, MBEDTLS_SSL_VERIFY_NONE);
}
if (cfg->clientcert_pem_buf != NULL && cfg->clientkey_pem_buf != NULL) {
mbedtls_x509_crt_init(&tls->clientcert);
mbedtls_pk_init(&tls->clientkey);
ret = mbedtls_x509_crt_parse(&tls->clientcert, cfg->clientcert_pem_buf, cfg->clientcert_pem_bytes);
if (ret < 0) {
ESP_LOGE(TAG, "mbedtls_x509_crt_parse returned -0x%x\n\n", -ret);
goto exit;
}
ret = mbedtls_pk_parse_key(&tls->clientkey, cfg->clientkey_pem_buf, cfg->clientkey_pem_bytes,
cfg->clientkey_password, cfg->clientkey_password_len);
if (ret < 0) {
ESP_LOGE(TAG, "mbedtls_pk_parse_keyfile returned -0x%x\n\n", -ret);
goto exit;
}
ret = mbedtls_ssl_conf_own_cert(&tls->conf, &tls->clientcert, &tls->clientkey);
if (ret < 0) {
ESP_LOGE(TAG, "mbedtls_ssl_conf_own_cert returned -0x%x\n\n", -ret);
goto exit;
}
} else if (cfg->clientcert_pem_buf != NULL || cfg->clientkey_pem_buf != NULL) {
ESP_LOGE(TAG, "You have to provide both clientcert_pem_buf and clientkey_pem_buf for mutual authentication\n\n");
goto exit;
}
mbedtls_ssl_conf_rng(&tls->conf, mbedtls_ctr_drbg_random, &tls->ctr_drbg);
#ifdef CONFIG_MBEDTLS_DEBUG
mbedtls_esp_enable_debug_log(&tls->conf, 4);
#endif
if ((ret = mbedtls_ssl_setup(&tls->ssl, &tls->conf)) != 0) {
ESP_LOGE(TAG, "mbedtls_ssl_setup returned -0x%x\n\n", -ret);
goto exit;
}
mbedtls_ssl_set_bio(&tls->ssl, &tls->server_fd, mbedtls_net_send, mbedtls_net_recv, NULL);
return 0;
exit:
mbedtls_cleanup(tls);
return -1;
}
/**
* @brief Close the TLS connection and free any allocated resources.
*/
void esp_tls_conn_delete(esp_tls_t *tls)
{
if (tls != NULL) {
mbedtls_cleanup(tls);
if (tls->sockfd) {
close(tls->sockfd);
}
free(tls);
}
};
static ssize_t tcp_write(esp_tls_t *tls, const char *data, size_t datalen)
{
return send(tls->sockfd, data, datalen, 0);
}
static ssize_t tls_write(esp_tls_t *tls, const char *data, size_t datalen)
{
ssize_t ret = mbedtls_ssl_write(&tls->ssl, (unsigned char*) data, datalen);
if (ret < 0) {
if (ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE) {
ESP_LOGE(TAG, "write error :%d:", ret);
}
}
return ret;
}
static int esp_tls_low_level_conn(const char *hostname, int hostlen, int port, const esp_tls_cfg_t *cfg, esp_tls_t *tls)
{
if (!tls) {
ESP_LOGE(TAG, "empty esp_tls parameter");
return -1;
}
/* These states are used to keep a tab on connection progress in case of non-blocking connect,
and in case of blocking connect these cases will get executed one after the other */
switch (tls->conn_state) {
case ESP_TLS_INIT:
;
int sockfd;
int ret = esp_tcp_connect(hostname, hostlen, port, &sockfd, cfg);
if (ret < 0) {
return -1;
}
tls->sockfd = sockfd;
if (!cfg) {
tls->esp_tls_read = tcp_read;
tls->esp_tls_write = tcp_write;
ESP_LOGD(TAG, "non-tls connection established");
return 1;
}
if (cfg->non_block) {
FD_ZERO(&tls->rset);
FD_SET(tls->sockfd, &tls->rset);
tls->wset = tls->rset;
}
tls->conn_state = ESP_TLS_CONNECTING;
/* falls through */
case ESP_TLS_CONNECTING:
if (cfg->non_block) {
ESP_LOGD(TAG, "connecting...");
struct timeval tv;
ms_to_timeval(cfg->timeout_ms, &tv);
/* In case of non-blocking I/O, we use the select() API to check whether
connection has been estbalished or not*/
if (select(tls->sockfd + 1, &tls->rset, &tls->wset, NULL,
cfg->timeout_ms ? &tv : NULL) == 0) {
ESP_LOGD(TAG, "select() timed out");
return 0;
}
if (FD_ISSET(tls->sockfd, &tls->rset) || FD_ISSET(tls->sockfd, &tls->wset)) {
int error;
unsigned int len = sizeof(error);
/* pending error check */
if (getsockopt(tls->sockfd, SOL_SOCKET, SO_ERROR, &error, &len) < 0) {
ESP_LOGD(TAG, "Non blocking connect failed");
tls->conn_state = ESP_TLS_FAIL;
return -1;
}
}
}
/* By now, the connection has been established */
ret = create_ssl_handle(tls, hostname, hostlen, cfg);
if (ret != 0) {
ESP_LOGD(TAG, "create_ssl_handshake failed");
tls->conn_state = ESP_TLS_FAIL;
return -1;
}
tls->esp_tls_read = tls_read;
tls->esp_tls_write = tls_write;
tls->conn_state = ESP_TLS_HANDSHAKE;
/* falls through */
case ESP_TLS_HANDSHAKE:
ESP_LOGD(TAG, "handshake in progress...");
ret = mbedtls_ssl_handshake(&tls->ssl);
if (ret == 0) {
tls->conn_state = ESP_TLS_DONE;
return 1;
} else {
if (ret != MBEDTLS_ERR_SSL_WANT_READ && ret != MBEDTLS_ERR_SSL_WANT_WRITE) {
ESP_LOGE(TAG, "mbedtls_ssl_handshake returned -0x%x", -ret);
if (cfg->cacert_pem_buf != NULL || cfg->use_global_ca_store == true) {
/* This is to check whether handshake failed due to invalid certificate*/
verify_certificate(tls);
}
tls->conn_state = ESP_TLS_FAIL;
return -1;
}
/* Irrespective of blocking or non-blocking I/O, we return on getting MBEDTLS_ERR_SSL_WANT_READ
or MBEDTLS_ERR_SSL_WANT_WRITE during handshake */
return 0;
}
break;
case ESP_TLS_FAIL:
ESP_LOGE(TAG, "failed to open a new connection");;
break;
default:
ESP_LOGE(TAG, "invalid esp-tls state");
break;
}
return -1;
}
/**
* @brief Create a new TLS/SSL connection
*/
esp_tls_t *esp_tls_conn_new(const char *hostname, int hostlen, int port, const esp_tls_cfg_t *cfg)
{
esp_tls_t *tls = (esp_tls_t *)calloc(1, sizeof(esp_tls_t));
if (!tls) {
return NULL;
}
/* esp_tls_conn_new() API establishes connection in a blocking manner thus this loop ensures that esp_tls_conn_new()
API returns only after connection is established unless there is an error*/
while (1) {
int ret = esp_tls_low_level_conn(hostname, hostlen, port, cfg, tls);
if (ret == 1) {
return tls;
} else if (ret == -1) {
esp_tls_conn_delete(tls);
ESP_LOGE(TAG, "Failed to open new connection");
return NULL;
}
}
return NULL;
}
/*
* @brief Create a new TLS/SSL non-blocking connection
*/
int esp_tls_conn_new_async(const char *hostname, int hostlen, int port, const esp_tls_cfg_t *cfg , esp_tls_t *tls)
{
return esp_tls_low_level_conn(hostname, hostlen, port, cfg, tls);
}
size_t esp_tls_get_bytes_avail(esp_tls_t *tls)
{
if (!tls) {
ESP_LOGE(TAG, "empty arg passed to esp_tls_get_bytes_avail()");
return ESP_FAIL;
}
return mbedtls_ssl_get_bytes_avail(&tls->ssl);
}

View File

@ -0,0 +1,276 @@
// Copyright 2017-2018 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.
#ifndef _ESP_TLS_H_
#define _ESP_TLS_H_
#include <stdbool.h>
#include <sys/socket.h>
#include <fcntl.h>
#include "mbedtls/platform.h"
#include "mbedtls/net_sockets.h"
#include "mbedtls/esp_debug.h"
#include "mbedtls/ssl.h"
#include "mbedtls/entropy.h"
#include "mbedtls/ctr_drbg.h"
#include "mbedtls/error.h"
#include "mbedtls/certs.h"
#ifdef __cplusplus
extern "C" {
#endif
/**
* @brief ESP-TLS Connection State
*/
typedef enum esp_tls_conn_state {
ESP_TLS_INIT = 0,
ESP_TLS_CONNECTING,
ESP_TLS_HANDSHAKE,
ESP_TLS_FAIL,
ESP_TLS_DONE,
} esp_tls_conn_state_t;
/**
* @brief ESP-TLS configuration parameters
*/
typedef struct esp_tls_cfg {
const char **alpn_protos; /*!< Application protocols required for HTTP2.
If HTTP2/ALPN support is required, a list
of protocols that should be negotiated.
The format is length followed by protocol
name.
For the most common cases the following is ok:
"\x02h2"
- where the first '2' is the length of the protocol and
- the subsequent 'h2' is the protocol name */
const unsigned char *cacert_pem_buf; /*!< Certificate Authority's certificate in a buffer */
unsigned int cacert_pem_bytes; /*!< Size of Certificate Authority certificate
pointed to by cacert_pem_buf */
const unsigned char *clientcert_pem_buf;/*!< Client certificate in a buffer */
unsigned int clientcert_pem_bytes; /*!< Size of client certificate pointed to by
clientcert_pem_buf */
const unsigned char *clientkey_pem_buf; /*!< Client key in a buffer */
unsigned int clientkey_pem_bytes; /*!< Size of client key pointed to by
clientkey_pem_buf */
const unsigned char *clientkey_password;/*!< Client key decryption password string */
unsigned int clientkey_password_len; /*!< String length of the password pointed to by
clientkey_password */
bool non_block; /*!< Configure non-blocking mode. If set to true the
underneath socket will be configured in non
blocking mode after tls session is established */
int timeout_ms; /*!< Network timeout in milliseconds */
bool use_global_ca_store; /*!< Use a global ca_store for all the connections in which
this bool is set. */
} esp_tls_cfg_t;
/**
* @brief ESP-TLS Connection Handle
*/
typedef struct esp_tls {
mbedtls_ssl_context ssl; /*!< TLS/SSL context */
mbedtls_entropy_context entropy; /*!< mbedTLS entropy context structure */
mbedtls_ctr_drbg_context ctr_drbg; /*!< mbedTLS ctr drbg context structure.
CTR_DRBG is deterministic random
bit generation based on AES-256 */
mbedtls_ssl_config conf; /*!< TLS/SSL configuration to be shared
between mbedtls_ssl_context
structures */
mbedtls_net_context server_fd; /*!< mbedTLS wrapper type for sockets */
mbedtls_x509_crt cacert; /*!< Container for the X.509 CA certificate */
mbedtls_x509_crt *cacert_ptr; /*!< Pointer to the cacert being used. */
mbedtls_x509_crt clientcert; /*!< Container for the X.509 client certificate */
mbedtls_pk_context clientkey; /*!< Container for the private key of the client
certificate */
int sockfd; /*!< Underlying socket file descriptor. */
ssize_t (*esp_tls_read)(struct esp_tls *tls, char *data, size_t datalen); /*!< Callback function for reading data from TLS/SSL
connection. */
ssize_t (*esp_tls_write)(struct esp_tls *tls, const char *data, size_t datalen); /*!< Callback function for writing data to TLS/SSL
connection. */
esp_tls_conn_state_t conn_state; /*!< ESP-TLS Connection state */
fd_set rset; /*!< read file descriptors */
fd_set wset; /*!< write file descriptors */
} esp_tls_t;
/**
* @brief Create a new blocking TLS/SSL connection
*
* This function establishes a TLS/SSL connection with the specified host in blocking manner.
*
* @param[in] hostname Hostname of the host.
* @param[in] hostlen Length of hostname.
* @param[in] port Port number of the host.
* @param[in] cfg TLS configuration as esp_tls_cfg_t. If you wish to open
* non-TLS connection, keep this NULL. For TLS connection,
* a pass pointer to esp_tls_cfg_t. At a minimum, this
* structure should be zero-initialized.
* @return pointer to esp_tls_t, or NULL if connection couldn't be opened.
*/
esp_tls_t *esp_tls_conn_new(const char *hostname, int hostlen, int port, const esp_tls_cfg_t *cfg);
/**
* @brief Create a new non-blocking TLS/SSL connection
*
* This function initiates a non-blocking TLS/SSL connection with the specified host, but due to
* its non-blocking nature, it doesn't wait for the connection to get established.
*
* @param[in] hostname Hostname of the host.
* @param[in] hostlen Length of hostname.
* @param[in] port Port number of the host.
* @param[in] cfg TLS configuration as esp_tls_cfg_t. `non_block` member of
* this structure should be set to be true.
* @param[in] tls pointer to esp-tls as esp-tls handle.
*
* @return
* - -1 If connection establishment fails.
* - 0 If connection establishment is in progress.
* - 1 If connection establishment is successful.
*/
int esp_tls_conn_new_async(const char *hostname, int hostlen, int port, const esp_tls_cfg_t *cfg, esp_tls_t *tls);
/**
* @brief Write from buffer 'data' into specified tls connection.
*
* @param[in] tls pointer to esp-tls as esp-tls handle.
* @param[in] data Buffer from which data will be written.
* @param[in] datalen Length of data buffer.
*
* @return
* - >0 if write operation was successful, the return value is the number
* of bytes actually written to the TLS/SSL connection.
* - 0 if write operation was not successful. The underlying
* connection was closed.
* - <0 if write operation was not successful, because either an
* error occured or an action must be taken by the calling process.
*/
static inline ssize_t esp_tls_conn_write(esp_tls_t *tls, const void *data, size_t datalen)
{
return tls->esp_tls_write(tls, (char *)data, datalen);
}
/**
* @brief Read from specified tls connection into the buffer 'data'.
*
* @param[in] tls pointer to esp-tls as esp-tls handle.
* @param[in] data Buffer to hold read data.
* @param[in] datalen Length of data buffer.
*
* @return
* - >0 if read operation was successful, the return value is the number
* of bytes actually read from the TLS/SSL connection.
* - 0 if read operation was not successful. The underlying
* connection was closed.
* - <0 if read operation was not successful, because either an
* error occured or an action must be taken by the calling process.
*/
static inline ssize_t esp_tls_conn_read(esp_tls_t *tls, void *data, size_t datalen)
{
return tls->esp_tls_read(tls, (char *)data, datalen);
}
/**
* @brief Close the TLS/SSL connection and free any allocated resources.
*
* This function should be called to close each tls connection opened with esp_tls_conn_new() or
* esp_tls_conn_http_new() APIs.
*
* @param[in] tls pointer to esp-tls as esp-tls handle.
*/
void esp_tls_conn_delete(esp_tls_t *tls);
/**
* @brief Return the number of application data bytes remaining to be
* read from the current record
*
* This API is a wrapper over mbedtls's mbedtls_ssl_get_bytes_avail() API.
*
* @param[in] tls pointer to esp-tls as esp-tls handle.
*
* @return
* - -1 in case of invalid arg
* - bytes available in the application data
* record read buffer
*/
size_t esp_tls_get_bytes_avail(esp_tls_t *tls);
/**
* @brief Create a global CA store with the buffer provided in cfg.
*
* This function should be called if the application wants to use the same CA store for
* multiple connections. The application must call this function before calling esp_tls_conn_new().
*
* @param[in] cacert_pem_buf Buffer which has certificates in pem format. This buffer
* is used for creating a global CA store, which can be used
* by other tls connections.
* @param[in] cacert_pem_bytes Length of the buffer.
*
* @return
* - ESP_OK if creating global CA store was successful.
* - Other if an error occured or an action must be taken by the calling process.
*/
esp_err_t esp_tls_set_global_ca_store(const unsigned char *cacert_pem_buf, const unsigned int cacert_pem_bytes);
/**
* @brief Get the pointer to the global CA store currently being used.
*
* The application must first call esp_tls_set_global_ca_store(). Then the same
* CA store could be used by the application for APIs other than esp_tls.
*
* @note Modifying the pointer might cause a failure in verifying the certificates.
*
* @return
* - Pointer to the global CA store currently being used if successful.
* - NULL if there is no global CA store set.
*/
mbedtls_x509_crt *esp_tls_get_global_ca_store();
/**
* @brief Free the global CA store currently being used.
*
* The memory being used by the global CA store to store all the parsed certificates is
* freed up. The application can call this API if it no longer needs the global CA store.
*/
void esp_tls_free_global_ca_store();
#ifdef __cplusplus
}
#endif
#endif /* ! _ESP_TLS_H_ */