更新时间:2024-06-26 GMT+08:00

C

准备环境

以Linux Ubuntu系统为例,首先需要安装SSL相关工具。

  1. 安装openssl库。
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    apt-get install libssl-dev
    
  2. 安装curl库。
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    apt-get install libcurl4-openssl-dev
    

获取SDK

点此下载SDK与Demo

解压时选择解压到当前文件夹,解压后目录结构如下:

名称

说明

signer_common.c

签名SDK代码

signer_common.h

signer.c

signer.h

Makefile

Makefile文件

main.c

示例代码

请求签名与API调用

  1. 在main.c中加入以下引用。

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    #include <stdio.h>
    #include <stdlib.h>
    #include <string.h>
    #include <curl/curl.h>
    #include "signer.h"
    

  2. 生成一个sig_params_t类型的变量, 填入AK和SK。

    1. 本示例以AK和SK保存在环境变量中为例,运行本示例前请先在本地环境中设置环境变量HUAWEICLOUD_SDK_AK和HUAWEICLOUD_SDK_SK。以Linux系统为例在本地将已获取的AK/SK设置为环境变量。
      1. 打开终端,输入以下命令打开环境变量配置文件。

        vi ~/.bashrc

      2. 设置环境变量,保存文件并退出编辑器。
        export HUAWEICLOUD_SDK_AK="已获取AK值" 
        export HUAWEICLOUD_SDK_SK="已获取SK值" 
      3. 输入以下命令使配置文件生效。

        source ~/.bashrc

    2. 生成一个sig_params_t类型的变量, 填入已设置的环境变量。
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      sig_params_t params;
      sig_params_init(&params);
      // Directly writing AK/SK in code is risky. For security, encrypt your AK/SK and store them in the configuration file or environment variables.
      // In this example, the AK/SK are stored in environment variables for identity authentication. Before running this example, set environment variables HUAWEICLOUD_SDK_AK and HUAWEICLOUD_SDK_SK.
      sig_str_t ak = sig_str(getenv("HUAWEICLOUD_SDK_AK"));
      sig_str_t sk = sig_str(getenv("HUAWEICLOUD_SDK_SK"));
      params.key = ak;
      params.secret = sk;
      

  3. 指定方法名、域名、请求uri、查询字符串和body。

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    sig_str_t host = sig_str("service.region.example.com");
    sig_str_t method = sig_str("GET");
    sig_str_t uri = sig_str("/v1/{project_id}/vpcs");
    sig_str_t query_str = sig_str("limit=2");
    sig_str_t payload = sig_str("");
    params.host = host;
    params.method = method;
    params.uri = uri;
    params.query_str = query_str;
    params.payload = payload;
    

  4. 增加头部参数,或者其他用途的头域,如多项目场景中添加X-Project-Id,或者全局服务场景中添加X-Domain-Id。

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    //Add header parameters, for example, X-Domain-Id for invoking a global service and X-Project-Id for invoking a project-level service.
    sig_headers_add(&params.headers, "X-Project-Id", "xxx");
    

  5. 进行签名,执行此函数会将生成的签名头加入request变量中。

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    sig_sign(&params);
    

  6. 使用curl库访问API,查看访问结果。

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    static size_t
    WriteMemoryCallback(void *contents, size_t size, size_t nmemb, void *userp)
    {
        size_t realsize = size * nmemb;
        struct MemoryStruct *mem = (struct MemoryStruct *)userp;
    
        mem->memory = (char*)realloc(mem->memory, mem->size + realsize + 1);
        if (mem->memory == NULL) {
            /* out of memory! */
            printf("not enough memory (realloc returned NULL)\n");
            return 0;
        }
    
        memcpy(&(mem->memory[mem->size]), contents, realsize);
        mem->size += realsize;
        mem->memory[mem->size] = 0;
    
        return realsize;
    }
    
    //send http request using curl library
    int perform_request(RequestParams* request)
    {
        CURL *curl;
        CURLcode res;
        struct MemoryStruct resp_header;
        resp_header.memory = malloc(1);
        resp_header.size = 0;
        struct MemoryStruct resp_body;
        resp_body.memory = malloc(1);
        resp_body.size = 0;
    
        curl_global_init(CURL_GLOBAL_ALL);
        curl = curl_easy_init();
    
        curl_easy_setopt(curl, CURLOPT_CUSTOMREQUEST, params.method.data);
        char url[1024];
        sig_snprintf(url, 1024, "http://%V%V?%V", &params.host, &params.uri, &params.query_str);
        curl_easy_setopt(curl, CURLOPT_URL, url);
        struct curl_slist *chunk = NULL;
        for (int i = 0; i < params.headers.len; i++) {
            char header[1024];
            sig_snprintf(header, 1024, "%V: %V", &params.headers.data[i].name, &params.headers.data[i].value);
            printf("%s\n", header);
            chunk = curl_slist_append(chunk, header);
        }
        printf("-------------\n");
        curl_easy_setopt(curl, CURLOPT_HTTPHEADER, chunk);
        curl_easy_setopt(curl, CURLOPT_POSTFIELDS, params.payload.data);
        curl_easy_setopt(curl, CURLOPT_NOBODY, 0L);
        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, WriteMemoryCallback);
        curl_easy_setopt(curl, CURLOPT_HEADERDATA, (void *)&resp_header);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, (void *)&resp_body);
        //curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
        res = curl_easy_perform(curl);
        if (res != CURLE_OK) {
            fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(res));
        }
        else {
            long status;
            curl_easy_getinfo(curl, CURLINFO_HTTP_CODE, &status);
            printf("status %d\n", status);
            printf(resp_header.memory);
            printf(resp_body.memory);
        }
        free(resp_header.memory);
        free(resp_body.memory);
        curl_easy_cleanup(curl);
    
        curl_global_cleanup();
    
        //free signature params
        sig_params_free(&params);
        return 0;
    }
    

  7. 运行make命令编译,得到可执行文件main,执行main文件,查看结果。