// 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 #include #include #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 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 */ const unsigned int cacert_pem_bytes; /*!< Size of Certificate Authority certificate pointed to by cacert_pem_buf */ 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 */ } 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 an X.509 certificate */ int sockfd; /*!< Underlying socket file descriptor. */ ssize_t (*read)(struct esp_tls *tls, char *data, size_t datalen); /*!< Callback function for reading data from TLS/SSL connection. */ ssize_t (*write)(struct esp_tls *tls, const char *data, size_t datalen); /*!< Callback function for writing data to TLS/SSL connection. */ } esp_tls_t; /** * @brief Create a new TLS/SSL connection * * This function establishes a TLS/SSL connection with the specified host. * * @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 TLS/SSL connection with a given "HTTP" url * * The behaviour is same as esp_tls_conn_new() API. However this API accepts host's url. * * @param[in] url url of 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_http_new(const char *url, const esp_tls_cfg_t *cfg); /** * @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->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->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); #ifdef __cplusplus } #endif #endif /* ! _ESP_TLS_H_ */