/*
 * Copyright (C) 2003-2007  Justin Karneges <justin@affinix.com>
 * Copyright (C) 2004,2005,2007  Brad Hards <bradh@frogmouth.net>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301  USA
 *
 */

#include "qca_basic.h"

#include "qcaprovider.h"

#include <QMutexLocker>
#include <QtGlobal>

namespace QCA {

// from qca_core.cpp
QMutex *           global_random_mutex();
Random *           global_random();
Provider::Context *getContext(const QString &type, Provider *p);

// from qca_publickey.cpp
ProviderList allProviders();
Provider *   providerForName(const QString &name);

static void mergeList(QStringList *a, const QStringList &b)
{
    foreach (const QString &s, b) {
        if (!a->contains(s))
            a->append(s);
    }
}

static QStringList get_hash_types(Provider *p)
{
    QStringList  out;
    InfoContext *c = static_cast<InfoContext *>(getContext(QStringLiteral("info"), p));
    if (!c)
        return out;
    out = c->supportedHashTypes();
    delete c;
    return out;
}

static QStringList get_cipher_types(Provider *p)
{
    QStringList  out;
    InfoContext *c = static_cast<InfoContext *>(getContext(QStringLiteral("info"), p));
    if (!c)
        return out;
    out = c->supportedCipherTypes();
    delete c;
    return out;
}

static QStringList get_mac_types(Provider *p)
{
    QStringList  out;
    InfoContext *c = static_cast<InfoContext *>(getContext(QStringLiteral("info"), p));
    if (!c)
        return out;
    out = c->supportedMACTypes();
    delete c;
    return out;
}

static QStringList get_types(QStringList (*get_func)(Provider *p), const QString &provider)
{
    QStringList out;
    if (!provider.isEmpty()) {
        Provider *p = providerForName(provider);
        if (p)
            out = get_func(p);
    } else {
        const ProviderList pl = allProviders();
        foreach (Provider *p, pl)
            mergeList(&out, get_func(p));
    }
    return out;
}

static QStringList supportedHashTypes(const QString &provider)
{
    return get_types(get_hash_types, provider);
}

static QStringList supportedCipherTypes(const QString &provider)
{
    return get_types(get_cipher_types, provider);
}

static QStringList supportedMACTypes(const QString &provider)
{
    return get_types(get_mac_types, provider);
}

//----------------------------------------------------------------------------
// Random
//----------------------------------------------------------------------------
Random::Random(const QString &provider)
    : Algorithm(QStringLiteral("random"), provider)
{
}

Random::Random(const Random &from)
    : Algorithm(from)
{
}

Random::~Random()
{
}

Random &Random::operator=(const Random &from)
{
    Algorithm::operator=(from);
    return *this;
}

uchar Random::nextByte()
{
    return (uchar)(nextBytes(1)[0]);
}

SecureArray Random::nextBytes(int size)
{
    return static_cast<RandomContext *>(context())->nextBytes(size);
}

uchar Random::randomChar()
{
    QMutexLocker locker(global_random_mutex());
    return global_random()->nextByte();
}

int Random::randomInt()
{
    QMutexLocker      locker(global_random_mutex());
    const SecureArray a = global_random()->nextBytes(sizeof(int));
    int               x;
    memcpy(&x, a.data(), a.size());
    return x;
}

SecureArray Random::randomArray(int size)
{
    QMutexLocker locker(global_random_mutex());
    return global_random()->nextBytes(size);
}

//----------------------------------------------------------------------------
// Hash
//----------------------------------------------------------------------------
Hash::Hash(const QString &type, const QString &provider)
    : Algorithm(type, provider)
{
}

Hash::Hash(const Hash &from)
    : Algorithm(from)
    , BufferedComputation(from)
{
}

Hash::~Hash()
{
}

Hash &Hash::operator=(const Hash &from)
{
    Algorithm::operator=(from);
    return *this;
}

QStringList Hash::supportedTypes(const QString &provider)
{
    return supportedHashTypes(provider);
}

QString Hash::type() const
{
    // algorithm type is the same as the hash type
    return Algorithm::type();
}

void Hash::clear()
{
    static_cast<HashContext *>(context())->clear();
}

void Hash::update(const MemoryRegion &a)
{
    static_cast<HashContext *>(context())->update(a);
}

void Hash::update(const QByteArray &a)
{
    update(MemoryRegion(a));
}

void Hash::update(const char *data, int len)
{
    if (len < 0)
        len = qstrlen(data);
    if (len == 0)
        return;

    update(MemoryRegion(QByteArray::fromRawData(data, len)));
}

// Reworked from KMD5, from KDE's kdelibs
void Hash::update(QIODevice *file)
{
    char buffer[1024];
    int  len;

    while ((len = file->read(reinterpret_cast<char *>(buffer), sizeof(buffer))) > 0)
        update(buffer, len);
}

MemoryRegion Hash::final()
{
    return static_cast<HashContext *>(context())->final();
}

MemoryRegion Hash::hash(const MemoryRegion &a)
{
    return process(a);
}

QString Hash::hashToString(const MemoryRegion &a)
{
    return arrayToHex(hash(a).toByteArray());
}

//----------------------------------------------------------------------------
// Cipher
//----------------------------------------------------------------------------
class Cipher::Private
{
public:
    QString              type;
    Cipher::Mode         mode;
    Cipher::Padding      pad;
    Direction            dir;
    SymmetricKey         key;
    InitializationVector iv;
    AuthTag              tag;

    bool ok, done;
};

Cipher::Cipher(const QString &             type,
               Mode                        mode,
               Padding                     pad,
               Direction                   dir,
               const SymmetricKey &        key,
               const InitializationVector &iv,
               const QString &             provider)
    : Algorithm(withAlgorithms(type, mode, pad), provider)
{
    d       = new Private;
    d->type = type;
    d->mode = mode;
    d->pad  = pad;
    if (!key.isEmpty())
        setup(dir, key, iv);
}

Cipher::Cipher(const QString &             type,
               Cipher::Mode                mode,
               Cipher::Padding             pad,
               Direction                   dir,
               const SymmetricKey &        key,
               const InitializationVector &iv,
               const AuthTag &             tag,
               const QString &             provider)
    : Algorithm(withAlgorithms(type, mode, pad), provider)
{
    d       = new Private;
    d->type = type;
    d->mode = mode;
    d->pad  = pad;
    d->tag  = tag;
    if (!key.isEmpty())
        setup(dir, key, iv, tag);
}

Cipher::Cipher(const Cipher &from)
    : Algorithm(from)
    , Filter(from)
{
    d = new Private(*from.d);
}

Cipher::~Cipher()
{
    delete d;
}

Cipher &Cipher::operator=(const Cipher &from)
{
    Algorithm::operator=(from);
    *d                 = *from.d;
    return *this;
}

QStringList Cipher::supportedTypes(const QString &provider)
{
    return supportedCipherTypes(provider);
}

QString Cipher::type() const
{
    return d->type;
}

Cipher::Mode Cipher::mode() const
{
    return d->mode;
}

Cipher::Padding Cipher::padding() const
{
    return d->pad;
}

Direction Cipher::direction() const
{
    return d->dir;
}

KeyLength Cipher::keyLength() const
{
    return static_cast<const CipherContext *>(context())->keyLength();
}

bool Cipher::validKeyLength(int n) const
{
    const KeyLength len = keyLength();
    return ((n >= len.minimum()) && (n <= len.maximum()) && (n % len.multiple() == 0));
}

int Cipher::blockSize() const
{
    return static_cast<const CipherContext *>(context())->blockSize();
}

AuthTag Cipher::tag() const
{
    return static_cast<const CipherContext *>(context())->tag();
}

void Cipher::clear()
{
    d->done = false;
    static_cast<CipherContext *>(context())->setup(d->dir, d->key, d->iv, d->tag);
}

MemoryRegion Cipher::update(const MemoryRegion &a)
{
    SecureArray out;
    if (d->done)
        return out;
    d->ok = static_cast<CipherContext *>(context())->update(a, &out);
    return out;
}

MemoryRegion Cipher::final()
{
    SecureArray out;
    if (d->done)
        return out;
    d->done = true;
    d->ok   = static_cast<CipherContext *>(context())->final(&out);
    return out;
}

bool Cipher::ok() const
{
    return d->ok;
}

void Cipher::setup(Direction dir, const SymmetricKey &key, const InitializationVector &iv)
{
    setup(dir, key, iv, AuthTag());
}

void Cipher::setup(Direction dir, const SymmetricKey &key, const InitializationVector &iv, const AuthTag &tag)
{
    d->dir = dir;
    d->key = key;
    d->iv  = iv;
    d->tag = tag;
    clear();
}

QString Cipher::withAlgorithms(const QString &cipherType, Mode modeType, Padding paddingType)
{
    QString mode;
    switch (modeType) {
    case CBC:
        mode = QStringLiteral("cbc");
        break;
    case CFB:
        mode = QStringLiteral("cfb");
        break;
    case OFB:
        mode = QStringLiteral("ofb");
        break;
    case ECB:
        mode = QStringLiteral("ecb");
        break;
    case CTR:
        mode = QStringLiteral("ctr");
        break;
    case GCM:
        mode = QStringLiteral("gcm");
        break;
    case CCM:
        mode = QStringLiteral("ccm");
        break;
    default:
        Q_ASSERT(0);
    }

    // do the default
    if (paddingType == DefaultPadding) {
        // logic from Botan
        if (modeType == CBC)
            paddingType = PKCS7;
        else
            paddingType = NoPadding;
    }

    QString pad;
    if (paddingType == NoPadding)
        pad = QLatin1String("");
    else
        pad = QStringLiteral("pkcs7");

    QString result = cipherType + QLatin1Char('-') + mode;
    if (!pad.isEmpty())
        result += QStringLiteral("-") + pad;

    return result;
}

//----------------------------------------------------------------------------
// MessageAuthenticationCode
//----------------------------------------------------------------------------
class MessageAuthenticationCode::Private
{
public:
    SymmetricKey key;

    bool         done;
    MemoryRegion buf;
};

MessageAuthenticationCode::MessageAuthenticationCode(const QString &     type,
                                                     const SymmetricKey &key,
                                                     const QString &     provider)
    : Algorithm(type, provider)
{
    d = new Private;
    setup(key);
}

MessageAuthenticationCode::MessageAuthenticationCode(const MessageAuthenticationCode &from)
    : Algorithm(from)
    , BufferedComputation(from)
{
    d = new Private(*from.d);
}

MessageAuthenticationCode::~MessageAuthenticationCode()
{
    delete d;
}

MessageAuthenticationCode &MessageAuthenticationCode::operator=(const MessageAuthenticationCode &from)
{
    Algorithm::operator=(from);
    *d                 = *from.d;
    return *this;
}

QStringList MessageAuthenticationCode::supportedTypes(const QString &provider)
{
    return supportedMACTypes(provider);
}

QString MessageAuthenticationCode::type() const
{
    // algorithm type is the same as the mac type
    return Algorithm::type();
}

KeyLength MessageAuthenticationCode::keyLength() const
{
    return static_cast<const MACContext *>(context())->keyLength();
}

bool MessageAuthenticationCode::validKeyLength(int n) const
{
    const KeyLength len = keyLength();
    return ((n >= len.minimum()) && (n <= len.maximum()) && (n % len.multiple() == 0));
}

void MessageAuthenticationCode::clear()
{
    d->done = false;
    static_cast<MACContext *>(context())->setup(d->key);
}

void MessageAuthenticationCode::update(const MemoryRegion &a)
{
    if (d->done)
        return;
    static_cast<MACContext *>(context())->update(a);
}

MemoryRegion MessageAuthenticationCode::final()
{
    if (!d->done) {
        d->done = true;
        static_cast<MACContext *>(context())->final(&d->buf);
    }
    return d->buf;
}

void MessageAuthenticationCode::setup(const SymmetricKey &key)
{
    d->key = key;
    clear();
}

//----------------------------------------------------------------------------
// Key Derivation Function
//----------------------------------------------------------------------------
KeyDerivationFunction::KeyDerivationFunction(const QString &type, const QString &provider)
    : Algorithm(type, provider)
{
}

KeyDerivationFunction::KeyDerivationFunction(const KeyDerivationFunction &from)
    : Algorithm(from)
{
}

KeyDerivationFunction::~KeyDerivationFunction()
{
}

KeyDerivationFunction &KeyDerivationFunction::operator=(const KeyDerivationFunction &from)
{
    Algorithm::operator=(from);
    return *this;
}

SymmetricKey KeyDerivationFunction::makeKey(const SecureArray &         secret,
                                            const InitializationVector &salt,
                                            unsigned int                keyLength,
                                            unsigned int                iterationCount)
{
    return static_cast<KDFContext *>(context())->makeKey(secret, salt, keyLength, iterationCount);
}

SymmetricKey KeyDerivationFunction::makeKey(const SecureArray &         secret,
                                            const InitializationVector &salt,
                                            unsigned int                keyLength,
                                            int                         msecInterval,
                                            unsigned int *              iterationCount)
{
    return static_cast<KDFContext *>(context())->makeKey(secret, salt, keyLength, msecInterval, iterationCount);
}

QString KeyDerivationFunction::withAlgorithm(const QString &kdfType, const QString &algType)
{
    return (kdfType + QLatin1Char('(') + algType + QLatin1Char(')'));
}

//----------------------------------------------------------------------------
// HKDF
//----------------------------------------------------------------------------
HKDF::HKDF(const QString &algorithm, const QString &provider)
    : Algorithm(QStringLiteral("hkdf(") + algorithm + QLatin1Char(')'), provider)
{
}

HKDF::HKDF(const HKDF &from)
    : Algorithm(from)
{
}

HKDF::~HKDF()
{
}

HKDF &HKDF::operator=(const HKDF &from)
{
    Algorithm::operator=(from);
    return *this;
}

SymmetricKey HKDF::makeKey(const SecureArray &         secret,
                           const InitializationVector &salt,
                           const InitializationVector &info,
                           unsigned int                keyLength)
{
    return static_cast<HKDFContext *>(context())->makeKey(secret, salt, info, keyLength);
}

}