Question

我正在尝试在Qt中编写一个简单的客户端 - 服务器应用程序，它将通过SSL进行通信。我尝试使用QSslSockets，但我一直遇到各种问题。

看看这个：

客户端：

#define dumpvar(x) qDebug()<<#x<<'='<<x

int main(int argc, char** argv)
{
    QApplication a(argc, argv);

    QSslSocket s;
    auto cert = QSslCertificate::fromPath("/home/piotrek/cert.pem");
    Q_ASSERT(!cert.isEmpty());
    s.setCaCertificates({cert});
    s.connectToHostEncrypted("localhost", 1234);
    qDebug()<<"waiting for encrypted";
    if (!s.waitForEncrypted(10000)){
        dumpvar(s.errorString());
        dumpvar(s.sslErrors());
        return 0;
    }

    qDebug()<<"client connected";
}

服务器：

#define dumpvar(x) qDebug()<<#x<<'='<<x

class SslServer: public QTcpServer
{
    // QTcpServer interface
protected:
    void incomingConnection(qintptr handle) override
    {
        QSslSocket s;
        if (!s.setSocketDescriptor(handle)){
            dumpvar(s.errorString());
            return;
        }
        s.setLocalCertificate("/home/piotrek/cert.pem");
        s.setPrivateKey("/home/piotrek/pkey.pem", QSsl::Rsa, QSsl::Pem, "test");
        s.startServerEncryption();
        qDebug()<<"waiting for encrypted";
        if(!s.waitForEncrypted(10000)){
            dumpvar(s.errorString());
            dumpvar(s.sslErrors());
            return;
        }

        qDebug()<<"server encrypted";

        handleConnection(&s);
    }
};

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

    SslServer s;

    s.listen(QHostAddress::Any, 1234);
    return a.exec();
}

客户打印：

qt.network.ssl: QSslSocket: cannot resolve SSLv2_client_method
qt.network.ssl: QSslSocket: cannot resolve SSLv2_server_method
waiting for encrypted
<10 second pause>
s.errorString() = "Network operation timed out"
s.sslErrors() = ()

服务器打印：

qt.network.ssl: QSslSocket: cannot resolve SSLv2_client_method
qt.network.ssl: QSslSocket: cannot resolve SSLv2_server_method
waiting for encrypted
<10 second pause>
s.errorString() = "The remote host closed the connection"
s.sslErrors() = (

我做错了什么？

Answer 1

警告的解释是Ubuntu中的OpenSSL编译时没有不安全的sslv2，但Qt 5.8尝试在运行时加载这些函数。 Qt默认情况下仅使用安全协议，因此除非您使用QSsl::SslV2明确调用QSslSocket::setProtocol（这当然不适用于您的openssl），否则这些警告不会对您产生影响。

显然你的自签名有问题吗？证书即可。此外，除非明确忽略主机名不匹配，否则无论如何，连接都会失败并使用自签名证书。

如果您使用自签名证书，可以使用here找到的说明重新生成证书。

请在下面找到工作代码示例。在类似环境（意外！）Ubuntu 16.10, OpenSSL 1.0.2g 1 Mar 2016, Qt 5.8.0上进行测试。

服务器

class SslServer: public QTcpServer
{
    // QTcpServer interface
protected:
    void incomingConnection(qintptr handle) override
    {
        QSslSocket s;
        if (!s.setSocketDescriptor(handle)){
            dumpvar(s.errorString());
            return;
        }
        const QString serverCertPath("/path/to/server1.pem");
        const QString serverKeyPath("/path/to/server1.key");
        s.setLocalCertificate(serverCertPath);
        s.setPrivateKey(serverKeyPath, QSsl::Rsa, QSsl::Pem, "test");
        s.startServerEncryption();
        qDebug()<<"waiting for encrypted";
        if(!s.waitForEncrypted(10000)){
            dumpvar(s.errorString());
            dumpvar(s.sslErrors());
            return;
        }
        qDebug()<<"server encrypted";
        s.write("Hello client");
        s.flush();
        s.waitForBytesWritten(3000);
        s.close();
    }
};

客户端

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

    QSslSocket s;
    const QString rootCAPath("/path/to/rootCA.pem");
    auto rootCACert = QSslCertificate::fromPath(rootCAPath);
    Q_ASSERT(!rootCACert.isEmpty());
    s.setCaCertificates(rootCACert);

    // ignore SSL host name mismatch error for server certificate
    QList<QSslError> errorsToIgnore;
    const QString serverCertPath("/path/to/server1.pem");
    auto serverCert = QSslCertificate::fromPath(serverCertPath);
    Q_ASSERT(!serverCert.isEmpty());
    errorsToIgnore<<QSslError(QSslError::HostNameMismatch, serverCert.at(0));
    s.ignoreSslErrors(errorsToIgnore);

    s.connectToHostEncrypted("localhost", 1234);
    qDebug()<<"waiting for encrypted";
    if (!s.waitForEncrypted(10000)){
        dumpvar(s.errorString());
        dumpvar(s.sslErrors());
        return 0;
    }
    qDebug()<<"client connected";
    s.waitForReadyRead(3000);
    qDebug() << "Reading: " << s.bytesAvailable();
    qDebug() << s.readAll();
    s.close();
}

服务器输出：

qt.network.ssl: QSslSocket: cannot resolve SSLv2_client_method
qt.network.ssl: QSslSocket: cannot resolve SSLv2_server_method
waiting for encrypted
server encrypted

客户端输出：

qt.network.ssl: QSslSocket: cannot resolve SSLv2_client_method
qt.network.ssl: QSslSocket: cannot resolve SSLv2_server_method
waiting for encrypted
client connected
Reading:  12
"Hello client"
Press <RETURN> to close this window...

无法让QSslSocket工作

1 个答案:

服务器

客户端