libcurl 进行SSL认证发送邮件,实际例子使用c++

libcurl是一个流行的开源库，用于在C/C++程序中处理URL并传输数据，包括支持HTTP、HTTPS等协议。如果你需要通过libcurl发送带SSL加密的电子邮件，你可以使用它来构建SMTP连接，并设置相应的认证选项。以下是一个简化的C++示例，展示如何使用libcurl发送带有SSL认证的电子邮件：

#include <curl/curl.h>
#include <string>

size_t write_data(void *ptr, size_t size, size_t nmemb, std::string* userp) {
    std::string str((char*) ptr, size * nmemb);
    *userp += str;
    return size * nmemb;
}

void send_email_with_ssl(curl_slist* recipients, const char* smtp_server, const char* username, const char* password) {
    CURLcode res;

    // 初始化libcurl
    curl_global_init(CURL_GLOBAL_DEFAULT);

    // 创建一个CURL会话
    CURL *curl = curl_easy_init();
    if (curl) {
        // 设置SMTP服务器地址
        curl_easy_setopt(curl, CURLOPT_URL, smtp_server);

        // 设置发送邮件的模式
        curl_easy_setopt(curl, CURLOPT_MAIL_FROM, "<your-email@example.com>");

        // 添加收件人列表
        for (auto recipient : recipients) {
            curl_easy_setopt(curl, CURLOPT_MAIL_RCPT, recipient);
        }

        // 设置使用SSL并指定验证信息
        curl_easy_setopt(curl, CURLOPT_USE_SSL, (long)CURLUSESSL_ALL); // 使用SSL/TLS
        curl_easy_setopt(curl, CURLOPT_USERNAME, username);
        curl_easy_setopt(curl, CURLOPT_PASSWORD, password);

        // 设置POST请求头
        struct curl_slist* headers = NULL;
        headers = curl_slist_append(headers, "Content-Type: text/plain; charset=UTF-8");
        curl_easy_setopt(curl, CURLOPT_HTTPHEADER, headers);

        // 设置数据写入函数，这里只是一个简单的示例，实际上应构造邮件内容
        std::string mail_content = "Hello from libcurl!";
        curl_easy_setopt(curl, CURLOPT_READFUNCTION, write_data);
        curl_easy_setopt(curl, CURLOPT_WRITEDATA, &mail_content);

        // 执行请求
        res = curl_easy_perform(curl);

        // 清理
        if (res != CURLE_OK) {
            fprintf(stderr, "curl_easy_perform() failed: %s\n", curl_easy_strerror(res));
        }
        curl_slist_free_all(headers);
        curl_easy_cleanup(curl);

        // 关闭libcurl
        curl_global_cleanup();
    }
}

// 示例：添加收件人地址到链表
std::string to_string_list(const std::vector<std::string>& recipients) {
    std::string result = "";
    for (const auto& email : recipients) {
        result += email + ", ";
    }
    return result.substr(0, result.size() - 2); // 去掉最后一个逗号
}

int main() {
    std::vector<std::string> recipients = {"recipient1@example.com", "recipient2@example.com"};
    std::string smtp_server = "smtp.example.com";
    const char* username = "your_username";
    const char* password = "your_password";

    // 创建收件人链表
    curl_slist* recipients_list = nullptr;
    recipients_list = curl_slist_append(recipients_list, recipients[0].c_str());
    for (size_t i = 1; i < recipients.size(); ++i) {
        recipients_list = curl_slist_append(recipients_list, recipients[i].c_str());
    }

    // 发送邮件
    send_email_with_ssl(recipients_list, smtp_server, username, password);

    // 清理链表
    curl_slist_free_all(recipients_list);

    return 0;
}