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#include "qsslkey.h"
#include "qsslkey_p.h"
#include "qasn1element_p.h"

QT_USE_NAMESPACE

static const quint8 bits_table[256] = {
    0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,
    5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,
    6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
    6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,
    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
    7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,
    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
    8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,
};

static int numberOfBits(const QByteArray &modulus)
{
    int bits = modulus.size() * 8;
    for (int i = 0; i < modulus.size(); ++i) {
        quint8 b = modulus[i];
        bits -= 8;
        if (b != 0) {
            bits += bits_table[b];
            break;
        }
    }
    return bits;
}

void QSslKeyPrivate::clear(bool deep)
{
    Q_UNUSED(deep);
    isNull = true;
    derData.clear();
    keyLength = -1;
}

void QSslKeyPrivate::decodeDer(const QByteArray &der, const QByteArray &passPhrase,
                               bool deepClear)
{
    clear(deepClear);

    if (der.isEmpty())
        return;

    if (type == QSsl::PrivateKey && !passPhrase.isEmpty()) {
        Q_UNIMPLEMENTED();
        return;
    }

    QAsn1Element elem;
    if (!elem.read(der) || elem.type() != QAsn1Element::SequenceType)
        return;

    if (type == QSsl::PublicKey) {
        // key info
        QDataStream keyStream(elem.value());
        if (!elem.read(keyStream) || elem.type() != QAsn1Element::SequenceType)
            return;
        QVector<QAsn1Element> infoItems = elem.toVector();
        if (infoItems.size() < 2 || infoItems[0].type() != QAsn1Element::ObjectIdentifierType)
            return;
        if (algorithm == QSsl::Rsa) {
            if (infoItems[0].toObjectId() != "1.2.840.113549.1.1.1")
                return;
            // key data
            if (!elem.read(keyStream) || elem.type() != QAsn1Element::BitStringType || elem.value().isEmpty())
                return;
            if (!elem.read(elem.value().mid(1)) || elem.type() != QAsn1Element::SequenceType)
                return;
            if (!elem.read(elem.value()) || elem.type() != QAsn1Element::IntegerType)
                return;
            keyLength = numberOfBits(elem.value());
        } else if (algorithm == QSsl::Dsa) {
            if (infoItems[0].toObjectId() != "1.2.840.10040.4.1")
                return;
            if (infoItems[1].type() != QAsn1Element::SequenceType)
                return;
            // key params
            QVector<QAsn1Element> params = infoItems[1].toVector();
            if (params.isEmpty() || params[0].type() != QAsn1Element::IntegerType)
                return;
            keyLength = numberOfBits(params[0].value());
        }

    } else {
        QVector<QAsn1Element> items = elem.toVector();
        if (items.isEmpty())
            return;

        // version
        if (items[0].type() != QAsn1Element::IntegerType || items[0].value().toHex() != "00")
            return;

        if (algorithm == QSsl::Rsa) {
            if (items.size() != 9 || items[1].type() != QAsn1Element::IntegerType)
                return;
            keyLength = numberOfBits(items[1].value());
        } else if (algorithm == QSsl::Dsa) {
            if (items.size() != 6 || items[1].type() != QAsn1Element::IntegerType)
                return;
            keyLength = numberOfBits(items[1].value());
        }
    }

    derData = der;
    isNull = false;
}

void QSslKeyPrivate::decodePem(const QByteArray &pem, const QByteArray &passPhrase,
                               bool deepClear)
{
    decodeDer(derFromPem(pem), passPhrase, deepClear);
}

int QSslKeyPrivate::length() const
{
    return keyLength;
}

QByteArray QSslKeyPrivate::toPem(const QByteArray &passPhrase) const
{
    if (type == QSsl::PrivateKey && !passPhrase.isEmpty()) {
        Q_UNIMPLEMENTED();
        return QByteArray();
    }

    return pemFromDer(derData);
}

Qt::HANDLE QSslKeyPrivate::handle() const
{
    return opaque;
}