/****************************************************************************
**
** Copyright (C) 2021 The Qt Company Ltd.
** Contact: https://www.qt.io/licensing/
**
** This file is part of the QtNetwork module of the Qt Toolkit.
**
** $QT_BEGIN_LICENSE:LGPL$
** Commercial License Usage
** Licensees holding valid commercial Qt licenses may use this file in
** accordance with the commercial license agreement provided with the
** Software or, alternatively, in accordance with the terms contained in
** a written agreement between you and The Qt Company. For licensing terms
** and conditions see https://www.qt.io/terms-conditions. For further
** information use the contact form at https://www.qt.io/contact-us.
**
** GNU Lesser General Public License Usage
** Alternatively, this file may be used under the terms of the GNU Lesser
** General Public License version 3 as published by the Free Software
** Foundation and appearing in the file LICENSE.LGPL3 included in the
** packaging of this file. Please review the following information to
** ensure the GNU Lesser General Public License version 3 requirements
** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
**
** GNU General Public License Usage
** Alternatively, this file may be used under the terms of the GNU
** General Public License version 2.0 or (at your option) the GNU General
** Public license version 3 or any later version approved by the KDE Free
** Qt Foundation. The licenses are as published by the Free Software
** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
** included in the packaging of this file. Please review the following
** information to ensure the GNU General Public License requirements will
** be met: https://www.gnu.org/licenses/gpl-2.0.html and
** https://www.gnu.org/licenses/gpl-3.0.html.
**
** $QT_END_LICENSE$
**
****************************************************************************/

#include "qtlsbackend_st_p.h"
#include "qtlskey_st_p.h"
#include "qx509_st_p.h"
#include "qtls_st_p.h"

#include <QtCore/qsysinfo.h>
#include <QtCore/qmutex.h>

QT_BEGIN_NAMESPACE

Q_GLOBAL_STATIC(QRecursiveMutex, qt_securetransport_mutex)

Q_LOGGING_CATEGORY(lcTlsBackend, "qt.tlsbackend.securetransport");

namespace QTlsPrivate {

QList<QSslCertificate> systemCaCertificates(); // defined in qsslsocket_mac_shared.cpp

SSLContextRef qt_createSecureTransportContext(QSslSocket::SslMode mode);

QSslCipher QSslCipher_from_SSLCipherSuite(SSLCipherSuite cipher)
{
    QString name;
    switch (cipher) {
    // Sorted as in CipherSuite.h (and groupped by their RFC)
    // TLS addenda using AES, per RFC 3268
    case TLS_RSA_WITH_AES_128_CBC_SHA:
        name = QLatin1String("AES128-SHA");
        break;
    case TLS_DHE_RSA_WITH_AES_128_CBC_SHA:
        name = QLatin1String("DHE-RSA-AES128-SHA");
        break;
    case TLS_RSA_WITH_AES_256_CBC_SHA:
        name = QLatin1String("AES256-SHA");
        break;
    case TLS_DHE_RSA_WITH_AES_256_CBC_SHA:
        name = QLatin1String("DHE-RSA-AES256-SHA");
        break;

    // ECDSA addenda, RFC 4492
    case TLS_ECDH_ECDSA_WITH_NULL_SHA:
        name = QLatin1String("ECDH-ECDSA-NULL-SHA");
        break;
    case TLS_ECDH_ECDSA_WITH_RC4_128_SHA:
        name = QLatin1String("ECDH-ECDSA-RC4-SHA");
        break;
    case TLS_ECDH_ECDSA_WITH_3DES_EDE_CBC_SHA:
        name = QLatin1String("ECDH-ECDSA-DES-CBC3-SHA");
        break;
    case TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA:
        name = QLatin1String("ECDH-ECDSA-AES128-SHA");
        break;
    case TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA:
        name = QLatin1String("ECDH-ECDSA-AES256-SHA");
        break;
    case TLS_ECDHE_ECDSA_WITH_NULL_SHA:
        name = QLatin1String("ECDHE-ECDSA-NULL-SHA");
        break;
    case TLS_ECDHE_ECDSA_WITH_RC4_128_SHA:
        name = QLatin1String("ECDHE-ECDSA-RC4-SHA");
        break;
    case TLS_ECDHE_ECDSA_WITH_3DES_EDE_CBC_SHA:
        name = QLatin1String("ECDHE-ECDSA-DES-CBC3-SHA");
        break;
    case TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA:
        name = QLatin1String("ECDHE-ECDSA-AES128-SHA");
        break;
    case TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA:
        name = QLatin1String("ECDHE-ECDSA-AES256-SHA");
        break;
    case TLS_ECDH_RSA_WITH_NULL_SHA:
        name = QLatin1String("ECDH-RSA-NULL-SHA");
        break;
    case TLS_ECDH_RSA_WITH_RC4_128_SHA:
        name = QLatin1String("ECDH-RSA-RC4-SHA");
        break;
    case TLS_ECDH_RSA_WITH_3DES_EDE_CBC_SHA:
        name = QLatin1String("ECDH-RSA-DES-CBC3-SHA");
        break;
    case TLS_ECDH_RSA_WITH_AES_128_CBC_SHA:
        name = QLatin1String("ECDH-RSA-AES128-SHA");
        break;
    case TLS_ECDH_RSA_WITH_AES_256_CBC_SHA:
        name = QLatin1String("ECDH-RSA-AES256-SHA");
        break;
    case TLS_ECDHE_RSA_WITH_NULL_SHA:
        name = QLatin1String("ECDHE-RSA-NULL-SHA");
        break;
    case TLS_ECDHE_RSA_WITH_RC4_128_SHA:
        name = QLatin1String("ECDHE-RSA-RC4-SHA");
        break;
    case TLS_ECDHE_RSA_WITH_3DES_EDE_CBC_SHA:
        name = QLatin1String("ECDHE-RSA-DES-CBC3-SHA");
        break;
    case TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA:
        name = QLatin1String("ECDHE-RSA-AES128-SHA");
        break;
    case TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA:
        name = QLatin1String("ECDHE-RSA-AES256-SHA");
        break;

    // TLS 1.2 addenda, RFC 5246
    case TLS_RSA_WITH_3DES_EDE_CBC_SHA:
        name = QLatin1String("DES-CBC3-SHA");
        break;
    case TLS_RSA_WITH_AES_128_CBC_SHA256:
        name = QLatin1String("AES128-SHA256");
        break;
    case TLS_RSA_WITH_AES_256_CBC_SHA256:
        name = QLatin1String("AES256-SHA256");
        break;
    case TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA:
        name = QLatin1String("DHE-RSA-DES-CBC3-SHA");
        break;
    case TLS_DHE_RSA_WITH_AES_128_CBC_SHA256:
        name = QLatin1String("DHE-RSA-AES128-SHA256");
        break;
    case TLS_DHE_RSA_WITH_AES_256_CBC_SHA256:
        name = QLatin1String("DHE-RSA-AES256-SHA256");
        break;

    // Addendum from RFC 4279, TLS PSK
    // all missing atm.

    // RFC 4785 - Pre-Shared Key (PSK) Ciphersuites with NULL Encryption
    // all missing atm.

    // Addenda from rfc 5288 AES Galois Counter Mode (CGM) Cipher Suites for TLS
    case TLS_RSA_WITH_AES_256_GCM_SHA384:
        name = QLatin1String("AES256-GCM-SHA384");
        break;

    // RFC 5487 - PSK with SHA-256/384 and AES GCM
    // all missing atm.

    // Addenda from rfc 5289 Elliptic Curve Cipher Suites with HMAC SHA-256/384
    case TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256:
        name = QLatin1String("ECDHE-ECDSA-AES128-SHA256");
        break;
    case TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384:
        name = QLatin1String("ECDHE-ECDSA-AES256-SHA384");
        break;
    case TLS_ECDH_ECDSA_WITH_AES_128_CBC_SHA256:
        name = QLatin1String("ECDH-ECDSA-AES128-SHA256");
        break;
    case TLS_ECDH_ECDSA_WITH_AES_256_CBC_SHA384:
        name = QLatin1String("ECDH-ECDSA-AES256-SHA384");
        break;
    case TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256:
        name = QLatin1String("ECDHE-RSA-AES128-SHA256");
        break;
    case TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384:
        name = QLatin1String("ECDHE-RSA-AES256-SHA384");
        break;
    case TLS_ECDH_RSA_WITH_AES_128_CBC_SHA256:
        name = QLatin1String("ECDH-RSA-AES128-SHA256");
        break;
    case TLS_ECDH_RSA_WITH_AES_256_CBC_SHA384:
        name = QLatin1String("ECDH-RSA-AES256-SHA384");
        break;

    // Addenda from rfc 5289 Elliptic Curve Cipher Suites
    // with SHA-256/384 and AES Galois Counter Mode (GCM)
    case TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384:
        name = QLatin1String("ECDHE-RSA-AES256-GCM-SHA384");
        break;

    default:
        return {};
    }

    return QTlsBackend::createCiphersuite(name, QSsl::TlsV1_2, QLatin1String("TLSv1.2"));
}

} // namespace QTlsPrivate

bool QSecureTransportBackend::s_loadedCiphersAndCerts = false;

QString QSecureTransportBackend::tlsLibraryVersionString() const
{
    return QLatin1String("Secure Transport, ") + QSysInfo::prettyProductName();
}

QString QSecureTransportBackend::tlsLibraryBuildVersionString() const
{
    return tlsLibraryVersionString();
}

void QSecureTransportBackend::ensureInitialized() const
{
    const QMutexLocker locker(qt_securetransport_mutex());
    if (s_loadedCiphersAndCerts)
        return;

    // We have to set it before setDefaultSupportedCiphers,
    // since this function can trigger static (global)'s initialization
    // and as a result - recursive ensureInitialized call
    // from QSslCertificatePrivate's ctor.
    s_loadedCiphersAndCerts = true;

    const QTlsPrivate::QSecureTransportContext context(QTlsPrivate::qt_createSecureTransportContext(QSslSocket::SslClientMode));
    if (context) {
        QList<QSslCipher> ciphers;
        QList<QSslCipher> defaultCiphers;

        size_t numCiphers = 0;
        // Fails only if any of parameters is null.
        SSLGetNumberSupportedCiphers(context, &numCiphers);
        QList<SSLCipherSuite> cfCiphers(numCiphers);
        // Fails only if any of parameter is null or number of ciphers is wrong.
        SSLGetSupportedCiphers(context, cfCiphers.data(), &numCiphers);

        for (size_t i = 0; i < size_t(cfCiphers.size()); ++i) {
            const QSslCipher ciph(QTlsPrivate::QSslCipher_from_SSLCipherSuite(cfCiphers.at(i)));
            if (!ciph.isNull()) {
                ciphers << ciph;
                if (ciph.usedBits() >= 128)
                    defaultCiphers << ciph;
            }
        }

        setDefaultSupportedCiphers(ciphers);
        setDefaultCiphers(defaultCiphers);

        if (!QSslSocketPrivate::rootCertOnDemandLoadingSupported())
            setDefaultCaCertificates(systemCaCertificates());
    } else {
        s_loadedCiphersAndCerts = false;
    }
}

QString QSecureTransportBackend::backendName() const
{
    return builtinBackendNames[nameIndexSecureTransport];
}

QTlsPrivate::TlsKey *QSecureTransportBackend::createKey() const
{
    return new QTlsPrivate::TlsKeySecureTransport;
}

QTlsPrivate::X509Certificate *QSecureTransportBackend::createCertificate() const
{
    return new QTlsPrivate::X509CertificateSecureTransport;
}

QList<QSslCertificate> QSecureTransportBackend::systemCaCertificates() const
{
    return QTlsPrivate::systemCaCertificates();
}

QList<QSsl::SslProtocol> QSecureTransportBackend::supportedProtocols() const
{
    QList<QSsl::SslProtocol> protocols;

    protocols << QSsl::AnyProtocol;
    protocols << QSsl::SecureProtocols;
    protocols << QSsl::TlsV1_0;
    protocols << QSsl::TlsV1_0OrLater;
    protocols << QSsl::TlsV1_1;
    protocols << QSsl::TlsV1_1OrLater;
    protocols << QSsl::TlsV1_2;
    protocols << QSsl::TlsV1_2OrLater;

    return protocols;
}

QList<QSsl::SupportedFeature> QSecureTransportBackend::supportedFeatures() const
{
    QList<QSsl::SupportedFeature> features;
    features << QSsl::SupportedFeature::ClientSideAlpn;

    return features;
}

QList<QSsl::ImplementedClass> QSecureTransportBackend::implementedClasses() const
{
    QList<QSsl::ImplementedClass> classes;
    classes << QSsl::ImplementedClass::Socket;
    classes << QSsl::ImplementedClass::Certificate;
    classes << QSsl::ImplementedClass::Key;

    return classes;
}

QTlsPrivate::X509PemReaderPtr QSecureTransportBackend::X509PemReader() const
{
    return QTlsPrivate::X509CertificateGeneric::certificatesFromPem;
}

QTlsPrivate::X509DerReaderPtr QSecureTransportBackend::X509DerReader() const
{
    return QTlsPrivate::X509CertificateGeneric::certificatesFromDer;
}

QTlsPrivate::TlsCryptograph *QSecureTransportBackend::createTlsCryptograph() const
{
    return new QTlsPrivate::TlsCryptographSecureTransport;
}

QT_END_NAMESPACE