QT实现JWS请求步骤，遵循ACME

ACME (Automated Certificate Management Environment) 是 Let's Encrypt 提供的一种自动化证书管理环境。JWS (JSON Web Signature) 是一种基于 JSON 的签名标准。在 QT 中实现 JWS 请求可以遵循以下步骤：

1. 安装 OpenSSL 库，可以通过 QT 的网络模块进行 HTTPS 请求。
2. 构建 JWS 请求体，包括 header、payload 和 signature 三部分。
3. 使用 OpenSSL 库生成签名，将签名添加到 JWS 中的 signature 部分。
4. 将 JWS 请求体发送到 ACME 服务器，获取证书。

以下是一个简单的示例代码：

#include <QtCore/QCoreApplication>
#include <QtCore/QJsonDocument>
#include <QtCore/QJsonObject>
#include <QtCore/QJsonArray>
#include <QtCore/QByteArray>
#include <QtCore/QUrlQuery>
#include <QtNetwork/QNetworkAccessManager>
#include <QtNetwork/QNetworkRequest>
#include <QtNetwork/QNetworkReply>
#include <openssl/rsa.h>
#include <openssl/evp.h>
#include <openssl/bio.h>
#include <openssl/buffer.h>

// 构建 JWS header
QJsonObject buildHeader()
{
    QJsonObject header;
    header["alg"] = "RS256";
    header["jwk"] = QJsonObject {
        {"e", "AQAB"},
        {"kty", "RSA"},
        {"n", "PUBLIC_KEY"}
    };
    return header;
}

// 构建 JWS payload
QJsonObject buildPayload(QString domain)
{
    QJsonObject payload;
    payload["iss"] = "ACCOUNT_URL";
    payload["aud"] = "ACME_URL";
    payload["nbf"] = QDateTime::currentDateTimeUtc().toTime_t();
    payload["exp"] = QDateTime::currentDateTimeUtc().addSecs(60).toTime_t();
    payload["iat"] = QDateTime::currentDateTimeUtc().toTime_t();
    payload["resource"] = "new-cert";
    payload["csr"] = "CSR_DATA";
    payload["notBefore"] = "CERTIFICATE_NOT_BEFORE";
    payload["notAfter"] = "CERTIFICATE_NOT_AFTER";
    payload["subject"] = QJsonObject {
        {"commonName", domain}
    };
    return payload;
}

// base64 编码
QString base64Encode(const QByteArray& data)
{
    BIO* mem = BIO_new(BIO_s_mem());
    BIO* b64 = BIO_new(BIO_f_base64());
    BIO_push(b64, mem);
    BIO_set_flags(b64, BIO_FLAGS_BASE64_NO_NL);
    BIO_write(b64, data.data(), data.length());
    BIO_flush(b64);
    BUF_MEM* memPtr;
    BIO_get_mem_ptr(b64, &memPtr);
    QString result = QString::fromLatin1(memPtr->data, memPtr->length);
    BIO_free_all(b64);
    return result;
}

// 构建 JWS 签名
QString buildSignature(QJsonObject header, QJsonObject payload, QString privateKey)
{
    QString headerStr = base64Encode(QJsonDocument(header).toJson(QJsonDocument::Compact).toUtf8());
    QString payloadStr = base64Encode(QJsonDocument(payload).toJson(QJsonDocument::Compact).toUtf8());
    QString data = headerStr + "." + payloadStr;
    QByteArray signatureData(4096, '\0');
    unsigned int signatureLength = signatureData.size();
    RSA* rsa = NULL;
    BIO* bio = BIO_new_mem_buf(privateKey.toLatin1().data(), -1);
    rsa = PEM_read_bio_RSAPrivateKey(bio, &rsa, NULL, NULL);
    if (rsa == NULL) {
        qCritical() << "Failed to load private key";
        return "";
    }
    EVP_MD_CTX* mdctx = EVP_MD_CTX_new();
    EVP_DigestSignInit(mdctx, NULL, EVP_sha256(), NULL, rsa);
    EVP_DigestSignUpdate(mdctx, data.toUtf8().data(), data.toUtf8().size());
    EVP_DigestSignFinal(mdctx, (unsigned char*)signatureData.data(), &signatureLength);
    EVP_MD_CTX_free(mdctx);
    RSA_free(rsa);
    signatureData.resize(signatureLength);
    QString signature = base64Encode(signatureData);
    return signature;
}

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);

    // 构建 JWS 请求体
    QJsonObject header = buildHeader();
    QJsonObject payload = buildPayload("example.com");
    QString signature = buildSignature(header, payload, "PRIVATE_KEY");
    QString jws = QString("%1.%2.%3").arg(base64Encode(QJsonDocument(header).toJson(QJsonDocument::Compact).toUtf8()), base64Encode(QJsonDocument(payload).toJson(QJsonDocument::Compact).toUtf8()), signature);

    // 发送 JWS 请求体到 ACME 服务器
    QUrl url("https://acme.example.com/acme/new-cert");
    QNetworkAccessManager manager;
    QNetworkRequest request(url);
    request.setHeader(QNetworkRequest::ContentTypeHeader, "application/jose+json");
    request.setRawHeader("User-Agent", "ACME Client/1.0");
    QNetworkReply* reply = manager.post(request, jws.toUtf8());
    QEventLoop loop;
    QObject::connect(reply, &QNetworkReply::finished, &loop, &QEventLoop::quit);
    loop.exec();

    // 处理服务器响应
    if (reply->error() == QNetworkReply::NoError) {
        QString certificate = QString(reply->readAll());
        // 处理证书
    } else {
        qCritical() << "Failed to request certificate:" << reply->errorString();
    }
    reply->deleteLater();
    return a.exec();
}

需要注意的是，其中的 `PUBLIC_KEY` 和 `PRIVATE_KEY` 分别为公钥和私钥的 PEM 格式字符串。`CSR_DATA`、`CERTIFICATE_NOT_BEFORE` 和 `CERTIFICATE_NOT_AFTER` 需要根据具体情况填写。`ACCOUNT_URL` 和 `ACME_URL` 分别为 ACME 服务器的账号地址和 ACME 服务器地址。