HTTPS 服务器

[English]

概述

HTTPS 服务器组件建立在 HTTP 服务器 组件的基础上。该服务器借助常规 HTTP 服务器中的钩子注册函数，注册 SSL 会话回调处理函数。

HTTP 服务器 组件的所有文档同样适用于用户按照本文档搭建的服务器。

API 说明

下列 HTTP 服务器 的 API 已不适用于 HTTPS 服务器。这些 API 仅限内部使用，用于处理安全会话和维护内部状态。

其他 API 均可使用，没有其他限制。

如何使用

请参考示例 protocols/https_server 来学习如何搭建安全的服务器。

总体而言，只需生成证书，将其嵌入到固件中，并且在初始化结构体中配置好正确的证书地址和长度后，将其传入服务器启动函数。

通过改变初始化配置结构体中的标志 httpd_ssl_config::transport_mode，可以选择是否需要 SSL 连接来启动服务器。在测试时或在速度比安全性更重要的可信环境中，可以使用此功能。

性能

建立起始会话大约需要两秒，在时钟速度较慢或日志记录冗余信息较多的情况下，可能需要花费更多时间。后续通过已打开的安全套接字建立请求的速度会更快，最快只需不到 100 ms。

事件处理

ESP HTTPS 服务器在特定事件发生时，可以通过 事件循环库 触发事件处理程序。处理程序必须使用 esp_event_handler_register() 进行注册，以帮助 ESP HTTPS 服务器处理事件。

esp_https_server_event_id_t 包含了 ESP HTTPS 服务器可能发生的所有事件。

事件循环中不同 ESP HTTPS 服务器事件的预期数据类型如下所示：

  • HTTPS_SERVER_EVENT_ERROR : esp_https_server_last_error_t

  • HTTPS_SERVER_EVENT_START : NULL

  • HTTPS_SERVER_EVENT_ON_CONNECTED : NULL

  • HTTPS_SERVER_EVENT_ON_DATA : int

  • HTTPS_SERVER_EVENT_SENT_DATA : NULL

  • HTTPS_SERVER_EVENT_DISCONNECTED : NULL

  • HTTPS_SERVER_EVENT_STOP : NULL

API 参考

Header File

  • components/esp_https_server/include/esp_https_server.h

  • This header file can be included with:

    #include "esp_https_server.h"

  • This header file is a part of the API provided by the esp_https_server component. To declare that your component depends on esp_https_server, add the following to your CMakeLists.txt:

    REQUIRES esp_https_server

    or

    PRIV_REQUIRES esp_https_server

Functions

esp_err_t httpd_ssl_start(httpd_handle_t *handle, httpd_ssl_config_t *config)

Create a SSL capable HTTP server (secure mode may be disabled in config)

参数

  • config -- [inout] - server config, must not be const. Does not have to stay valid after calling this function.

  • handle -- [out] - storage for the server handle, must be a valid pointer

返回

success

esp_err_t httpd_ssl_stop(httpd_handle_t handle)

Stop the server. Blocks until the server is shut down.

参数

handle -- [in]

返回

  • ESP_OK: Server stopped successfully

  • ESP_ERR_INVALID_ARG: Invalid argument

  • ESP_FAIL: Failure to shut down server

Structures

struct esp_https_server_user_cb_arg

Callback data struct, contains the ESP-TLS connection handle and the connection state at which the callback is executed.

Public Members

httpd_ssl_user_cb_state_t user_cb_state

State of user callback

esp_tls_t *tls

ESP-TLS connection handle

struct httpd_ssl_config

HTTPS server config struct

Please use HTTPD_SSL_CONFIG_DEFAULT() to initialize it.

Public Members

httpd_config_t httpd

Underlying HTTPD server config

Parameters like task stack size and priority can be adjusted here.

const uint8_t *servercert

Server certificate

size_t servercert_len

Server certificate byte length

const uint8_t *cacert_pem

CA certificate ((CA used to sign clients, or client cert itself)

size_t cacert_len

CA certificate byte length

const uint8_t *prvtkey_pem

Private key

size_t prvtkey_len

Private key byte length

bool use_ecdsa_peripheral

Use ECDSA peripheral to use private key

uint8_t ecdsa_key_efuse_blk

The efuse block where ECDSA key is stored

httpd_ssl_transport_mode_t transport_mode

Transport Mode (default secure)

uint16_t port_secure

Port used when transport mode is secure (default 443)

uint16_t port_insecure

Port used when transport mode is insecure (default 80)

bool session_tickets

Enable tls session tickets

bool use_secure_element

Enable secure element for server session

esp_https_server_user_cb *user_cb

User callback for esp_https_server

void *ssl_userdata

User data to add to the ssl context

esp_tls_handshake_callback cert_select_cb

Certificate selection callback to use. The callback is only applicable when CONFIG_ESP_TLS_SERVER_CERT_SELECT_HOOK is enabled in menuconfig

const char **alpn_protos

Application protocols the server supports in order of prefernece. Used for negotiating during the TLS handshake, first one the client supports is selected. The data structure must live as long as the https server itself

Macros

HTTPD_SSL_CONFIG_DEFAULT()

Default config struct init Notes:

  • port is set when starting the server, according to 'transport_mode'

  • one socket uses ~ 40kB RAM with SSL, we reduce the default socket count to 4

  • SSL sockets are usually long-lived, closing LRU prevents pool exhaustion DOS

  • Stack size may need adjustments depending on the user application

Type Definitions

typedef struct esp_https_server_user_cb_arg esp_https_server_user_cb_arg_t

Callback data struct, contains the ESP-TLS connection handle and the connection state at which the callback is executed.

typedef esp_tls_last_error_t esp_https_server_last_error_t
typedef void esp_https_server_user_cb(esp_https_server_user_cb_arg_t *user_cb)

Callback function prototype Can be used to get connection or client information (SSL context) E.g. Client certificate, Socket FD, Connection state, etc.

Param user_cb

Callback data struct

typedef struct httpd_ssl_config httpd_ssl_config_t

Enumerations

enum esp_https_server_event_id_t

Values:

enumerator HTTPS_SERVER_EVENT_ERROR

This event occurs when there are any errors during execution

enumerator HTTPS_SERVER_EVENT_START

This event occurs when HTTPS Server is started

enumerator HTTPS_SERVER_EVENT_ON_CONNECTED

Once the HTTPS Server has been connected to the client

enumerator HTTPS_SERVER_EVENT_ON_DATA

Occurs when receiving data from the client

enumerator HTTPS_SERVER_EVENT_SENT_DATA

Occurs when an ESP HTTPS server sends data to the client

enumerator HTTPS_SERVER_EVENT_DISCONNECTED

The connection has been disconnected

enumerator HTTPS_SERVER_EVENT_STOP

This event occurs when HTTPS Server is stopped

enum httpd_ssl_transport_mode_t

Values:

enumerator HTTPD_SSL_TRANSPORT_SECURE
enumerator HTTPD_SSL_TRANSPORT_INSECURE
enum httpd_ssl_user_cb_state_t

Indicates the state at which the user callback is executed, i.e at session creation or session close.

Values:

enumerator HTTPD_SSL_USER_CB_SESS_CREATE
enumerator HTTPD_SSL_USER_CB_SESS_CLOSE

提供有关此文档的反馈