src/sieve/sieve.cpp

/*
    sieve.cpp

    SPDX-FileCopyrightText: 2001 Hamish Rodda <meddie@yoyo.cc.monash.edu.au>

    SPDX-License-Identifier: GPL-2.0-only
*/

/**
 * Portions adapted from the SMTP ioslave.
 * SPDX-FileCopyrightText: 2000, 2001 Alex Zepeda <jazepeda@pacbell.net>
 * SPDX-FileCopyrightText: 2001 Michael Häckel <Michael@Haeckel.Net>
 *
 * Policy: the function where the error occurs calls error(). A result of
 * false, where it signifies an error, thus doesn't need to call error() itself.
 */

#include "sieve.h"
#include "../common.h"
#include "sieve_debug.h"

extern "C" {
#include <sasl/sasl.h>
}

#include <QRegularExpression>
#include <QSslSocket>
#include <QUrlQuery>

#include <KLocalizedString>
#include <KMessageBox>
#include <QApplication>
#include <QUrl>
#include <cassert>
#include <sys/stat.h>
namespace
{
auto returnEndLine()
{
    return Qt::endl;
}
}
#define ksDebug qCDebug(SIEVE_LOG)

#define SIEVE_DEFAULT_PORT 2000

static const sasl_callback_t callbacks[] = {{SASL_CB_ECHOPROMPT, nullptr, nullptr},
                                            {SASL_CB_NOECHOPROMPT, nullptr, nullptr},
                                            {SASL_CB_GETREALM, nullptr, nullptr},
                                            {SASL_CB_USER, nullptr, nullptr},
                                            {SASL_CB_AUTHNAME, nullptr, nullptr},
                                            {SASL_CB_PASS, nullptr, nullptr},
                                            {SASL_CB_CANON_USER, nullptr, nullptr},
                                            {SASL_CB_LIST_END, nullptr, nullptr}};

static const unsigned int SIEVE_DEFAULT_RECIEVE_BUFFER = 512;

// Pseudo plugin class to embed meta data
class KIOPluginForMetaData : public QObject
{
    Q_OBJECT
    Q_PLUGIN_METADATA(IID "org.kde.kio.slave.sieve" FILE "sieve.json")
};

using namespace KIO;
extern "C" {
Q_DECL_EXPORT int kdemain(int argc, char **argv)
{
    QApplication app(argc, argv);
    app.setApplicationName(QStringLiteral("kio_sieve"));

    ksDebug << "*** Starting kio_sieve " << returnEndLine();

    if (argc != 4) {
        ksDebug << "Usage: kio_sieve protocol domain-socket1 domain-socket2" << returnEndLine();
        return -1;
    }

    if (!initSASL()) {
        ::exit(-1);
    }

    kio_sieveProtocol slave(argv[2], argv[3]);
    slave.dispatchLoop();

    sasl_done();

    ksDebug << "*** kio_sieve Done" << returnEndLine();
    return 0;
}
}

/* ---------------------------------------------------------------------------------- */
kio_sieveResponse::kio_sieveResponse()
{
    clear();
}

/* ---------------------------------------------------------------------------------- */
const uint &kio_sieveResponse::getType() const
{
    return rType;
}

/* ---------------------------------------------------------------------------------- */
uint kio_sieveResponse::getQuantity() const
{
    return quantity;
}

/* ---------------------------------------------------------------------------------- */
const QByteArray &kio_sieveResponse::getAction() const
{
    return key;
}

/* ---------------------------------------------------------------------------------- */
const QByteArray &kio_sieveResponse::getKey() const
{
    return key;
}

/* ---------------------------------------------------------------------------------- */
const QByteArray &kio_sieveResponse::getVal() const
{
    return val;
}

/* ---------------------------------------------------------------------------------- */
const QByteArray &kio_sieveResponse::getExtra() const
{
    return extra;
}

/* ---------------------------------------------------------------------------------- */
void kio_sieveResponse::setQuantity(uint newQty)
{
    rType = QUANTITY;
    quantity = newQty;
}

/* ---------------------------------------------------------------------------------- */
void kio_sieveResponse::setAction(const QByteArray &newAction)
{
    rType = ACTION;
    key = newAction;
}

/* ---------------------------------------------------------------------------------- */
void kio_sieveResponse::setKey(const QByteArray &newKey)
{
    rType = KEY_VAL_PAIR;
    key = newKey;
}

/* ---------------------------------------------------------------------------------- */
void kio_sieveResponse::setVal(const QByteArray &newVal)
{
    val = newVal;
}

/* ---------------------------------------------------------------------------------- */
void kio_sieveResponse::setExtra(const QByteArray &newExtra)
{
    extra = newExtra;
}

/* ---------------------------------------------------------------------------------- */
void kio_sieveResponse::clear()
{
    rType = NONE;
    extra = key = val = QByteArray();
    quantity = 0;
}

/* ---------------------------------------------------------------------------------- */
kio_sieveProtocol::kio_sieveProtocol(const QByteArray &pool_socket, const QByteArray &app_socket)
    : TCPSlaveBase("sieve", pool_socket, app_socket, false)
    , m_connMode(NORMAL)
    , m_supportsTLS(false)
    , m_shouldBeConnected(false)
    , m_allowUnencrypted(false)
    , m_port(SIEVE_DEFAULT_PORT)
{
}

/* ---------------------------------------------------------------------------------- */
kio_sieveProtocol::~kio_sieveProtocol()
{
    if (isConnected()) {
        disconnect();
    }
}

/* ---------------------------------------------------------------------------------- */
void kio_sieveProtocol::setHost(const QString &host, quint16 port, const QString &user, const QString &pass)
{
    if (isConnected() && (m_sServer != host || m_port != port || m_sUser != user || m_sPass != pass)) {
        disconnect();
    }
    m_sServer = host;
    m_port = port ? port : SIEVE_DEFAULT_PORT;
    m_sUser = user;
    m_sPass = pass;
    m_supportsTLS = false;
}

/* ---------------------------------------------------------------------------------- */
void kio_sieveProtocol::openConnection()
{
    m_connMode = CONNECTION_ORIENTED;
    connect();
}

bool kio_sieveProtocol::parseCapabilities(bool requestCapabilities /* = false*/)
{
    ksDebug << returnEndLine();

    // Setup...
    bool ret = false;

    if (requestCapabilities) {
        sendData("CAPABILITY");
    }

    while (receiveData()) {
        ksDebug << "Looping receive" << returnEndLine();

        if (r.getType() == kio_sieveResponse::ACTION) {
            if (r.getAction().toLower().contains("ok")) {
                ksDebug << "Sieve server ready & awaiting authentication." << returnEndLine();
                break;
            } else {
                ksDebug << "Unknown action " << r.getAction() << "." << returnEndLine();
            }
        } else if (r.getKey() == "IMPLEMENTATION") {
            ksDebug << "Connected to Sieve server: " << r.getVal() << returnEndLine();
            ret = true;
            setMetaData(QStringLiteral("implementation"), QLatin1String(r.getVal()));
            m_implementation = QLatin1String(r.getVal());
        } else if (r.getKey() == "SASL") {
            // Save list of available SASL methods
            const QString val = QLatin1String(r.getVal());
            m_sasl_caps = val.split(QLatin1Char(' '));
            ksDebug << "Server SASL authentication methods: " << m_sasl_caps.join(QLatin1String(", ")) << returnEndLine();
            setMetaData(QStringLiteral("saslMethods"), QLatin1String(r.getVal()));
        } else if (r.getKey() == "SIEVE") {
            // Save script capabilities; report back as meta data:
            const QString val = QLatin1String(r.getVal());
            ksDebug << "Server script capabilities: " << val.split(QLatin1Char(' ')).join(QLatin1String(", ")) << returnEndLine();
            setMetaData(QStringLiteral("sieveExtensions"), QLatin1String(r.getVal()));
        } else if (r.getKey() == "STARTTLS") {
            // The server supports TLS
            ksDebug << "Server supports TLS" << returnEndLine();
            m_supportsTLS = true;
            setMetaData(QStringLiteral("tlsSupported"), QStringLiteral("true"));
        } else {
            ksDebug << "Unrecognised key " << r.getKey() << returnEndLine();
        }
    }

    if (!m_supportsTLS) {
        setMetaData(QStringLiteral("tlsSupported"), QStringLiteral("false"));
    }

    return ret;
}

/* ---------------------------------------------------------------------------------- */
/**
 * Checks if connection parameters have changed.
 * If it it, close the current connection
 */
void kio_sieveProtocol::changeCheck(const QUrl &url)
{
    QString auth;

    // Check the SASL auth mechanism in the 'sasl' metadata...
    if (!metaData(QStringLiteral("sasl")).isEmpty()) {
        auth = metaData(QStringLiteral("sasl")).toUpper();
    } else {
        // ... and if not found, check the x-mech=AUTH query part of the url.
        QString query = url.query();
        if (query.startsWith(QLatin1Char('?'))) {
            query.remove(0, 1);
        }
        QStringList q = query.split(QLatin1Char(','));

        for (QStringList::iterator it = q.begin(), end(q.end()); it != end; ++it) {
            if (((*it).section(QLatin1Char('='), 0, 0)).toLower() == QLatin1String("x-mech")) {
                auth = ((*it).section(QLatin1Char('='), 1)).toUpper();
                break;
            }
        }
    }
    ksDebug << "auth: " << auth << " m_sAuth: " << m_sAuth << returnEndLine();
    if (m_sAuth != auth) {
        m_sAuth = auth;
        if (isConnected()) {
            disconnect();
        }
    }
    // For TLS, only disconnect if we are unencrypted and are
    // no longer allowed (otherwise, it's still fine):
    const bool allowUnencryptedNow = QUrlQuery(url).queryItemValue(QStringLiteral("x-allow-unencrypted")) == QLatin1String("true");
    if (m_allowUnencrypted && !allowUnencryptedNow) {
        if (isConnected()) {
            disconnect();
        }
    }
    m_allowUnencrypted = allowUnencryptedNow;
}

/* ---------------------------------------------------------------------------------- */
/**
 * Connects to the server.
 * returns false and calls error() if an error occurred.
 */
bool kio_sieveProtocol::connect(bool useTLSIfAvailable)
{
    ksDebug << returnEndLine();

    if (isConnected()) {
        return true;
    }

    infoMessage(i18n("Connecting to %1...", m_sServer));

    if (m_connMode == CONNECTION_ORIENTED && m_shouldBeConnected) {
        error(ERR_CONNECTION_BROKEN, i18n("The connection to the server was lost."));
        return false;
    }

    setBlocking(true);

    if (!connectToHost(QStringLiteral("sieve"), m_sServer, m_port)) {
        return false;
    }

    if (!parseCapabilities()) {
        disconnectFromHost();
        error(ERR_UNSUPPORTED_PROTOCOL, i18n("Server identification failed."));
        return false;
    }

    // Attempt to start TLS
    if (!m_allowUnencrypted && !QSslSocket::supportsSsl()) {
        error(ERR_SLAVE_DEFINED, i18n("Can not use TLS since the underlying Qt library does not support it."));
        disconnect();
        return false;
    }

    if (!m_allowUnencrypted && useTLSIfAvailable && QSslSocket::supportsSsl() && !m_supportsTLS
        && messageBox(WarningContinueCancel,
                      i18n("TLS encryption was requested, but your Sieve server does not advertise TLS in its capabilities.\n"
                           "You can choose to try to initiate TLS negotiations nonetheless, or cancel the operation."),
                      i18n("Server Does Not Advertise TLS"),
                      i18n("&Start TLS nonetheless"),
                      i18n("&Cancel"))
            != KMessageBox::Continue) {
        error(ERR_USER_CANCELED, i18n("TLS encryption requested, but not supported by server."));
        disconnect();
        return false;
    }

    // FIXME find a test server and test that this works
    if (useTLSIfAvailable && m_supportsTLS && QSslSocket::supportsSsl()) {
        sendData("STARTTLS");
        if (operationSuccessful()) {
            ksDebug << "TLS has been accepted. Starting TLS..." << returnEndLine() << "WARNING this is untested and may fail.";
            if (startSsl()) {
                ksDebug << "TLS enabled successfully." << returnEndLine();
                // reparse capabilities:
                parseCapabilities(requestCapabilitiesAfterStartTLS());
            } else {
                ksDebug << "TLS initiation failed.";
                if (m_allowUnencrypted) {
                    disconnect(true);
                    return connect(false);
                }
                messageBox(Information,
                           i18n("Your Sieve server claims to support TLS, "
                                "but negotiation was unsuccessful."),
                           i18n("Connection Failed"));
                disconnect(true);
                return false;
            }
        } else if (!m_allowUnencrypted) {
            ksDebug << "Server incapable of TLS.";
            disconnect();
            error(ERR_SLAVE_DEFINED,
                  i18n("The server does not seem to support TLS. "
                       "Disable TLS if you want to connect without encryption."));
            return false;
        } else {
            ksDebug << "Server incapable of TLS. Transmitted documents will be unencrypted." << returnEndLine();
        }
    } else {
        ksDebug << "We are incapable of TLS. Transmitted documents will be unencrypted." << returnEndLine();
    }

    assert(m_allowUnencrypted || isUsingSsl());

    infoMessage(i18n("Authenticating user..."));
    if (!authenticate()) {
        disconnect();
        error(ERR_CANNOT_AUTHENTICATE, i18n("Authentication failed."));
        return false;
    }

    m_shouldBeConnected = true;
    return true;
}

/* ---------------------------------------------------------------------------------- */
void kio_sieveProtocol::closeConnection()
{
    m_connMode = CONNECTION_ORIENTED;
    disconnect();
}

/* ---------------------------------------------------------------------------------- */
void kio_sieveProtocol::disconnect(bool forcibly)
{
    if (!forcibly) {
        sendData("LOGOUT");

        if (!operationSuccessful()) {
            ksDebug << "Server did not logout cleanly." << returnEndLine();
        }
    }

    disconnectFromHost();
    m_shouldBeConnected = false;
}

/* ---------------------------------------------------------------------------------- */
/*void kio_sieveProtocol::slave_status()
{
    slaveStatus(isConnected() ? m_sServer : "", isConnected());

    finished();
}*/

/* ---------------------------------------------------------------------------------- */
void kio_sieveProtocol::special(const QByteArray &data)
{
    int tmp;
    QDataStream stream(data);
    QUrl url;

    stream >> tmp;

    switch (tmp) {
    case 1:
        stream >> url;
        if (!activate(url)) {
            return;
        }
        break;
    case 2:
        if (!deactivate()) {
            return;
        }
        break;
    case 3:
        parseCapabilities(true);
        break;
    }

    infoMessage(i18nc("special command completed", "Done."));

    finished();
}

/* ---------------------------------------------------------------------------------- */
bool kio_sieveProtocol::activate(const QUrl &url)
{
    changeCheck(url);
    if (!connect()) {
        return false;
    }

    infoMessage(i18n("Activating script..."));

    QString filename = url.fileName();

    if (filename.isEmpty()) {
        error(ERR_DOES_NOT_EXIST, url.toDisplayString());
        return false;
    }

    if (!sendData("SETACTIVE \"" + filename.toUtf8() + "\"")) {
        return false;
    }

    if (operationSuccessful()) {
        ksDebug << "Script activation complete." << returnEndLine();
        return true;
    } else {
        error(ERR_INTERNAL_SERVER, i18n("There was an error activating the script."));
        return false;
    }
}

/* ---------------------------------------------------------------------------------- */
bool kio_sieveProtocol::deactivate()
{
    if (!connect()) {
        return false;
    }

    if (!sendData("SETACTIVE \"\"")) {
        return false;
    }

    if (operationSuccessful()) {
        ksDebug << "Script deactivation complete." << returnEndLine();
        return true;
    } else {
        error(ERR_INTERNAL_SERVER, i18n("There was an error deactivating the script."));
        return false;
    }
}

static void append_lf2crlf(QByteArray &out, const QByteArray &in)
{
    if (in.isEmpty()) {
        return;
    }
    const unsigned int oldOutSize = out.size();
    out.resize(oldOutSize + 2 * in.size());
    const char *s = in.begin();
    const char *const end = in.end();
    char *d = out.begin() + oldOutSize;
    char last = '\0';
    while (s < end) {
        if (*s == '\n' && last != '\r') {
            *d++ = '\r';
        }
        *d++ = last = *s++;
    }
    out.resize(d - out.begin());
}

void kio_sieveProtocol::put(const QUrl &url, int /*permissions*/, KIO::JobFlags)
{
    changeCheck(url);
    if (!connect()) {
        return;
    }

    infoMessage(i18n("Sending data..."));

    QString filename = url.fileName();

    if (filename.isEmpty()) {
        error(ERR_MALFORMED_URL, url.toDisplayString());
        return;
    }

    QByteArray data;
    for (;;) {
        dataReq();
        QByteArray buffer;
        const int newSize = readData(buffer);
        append_lf2crlf(data, buffer);
        if (newSize < 0) {
            // read error: network in unknown state so disconnect
            error(ERR_CANNOT_READ, i18n("KIO data supply error."));
            return;
        }
        if (newSize == 0) {
            break;
        }
    }

    // script size
    int bufLen = (int)data.size();
    totalSize(bufLen);

    // timsieved 1.1.0:
    // C: HAVESPACE "rejected" 74
    // S: NO "Number expected"
    // C: HAVESPACE 74
    // S: NO "Missing script name"
    // S: HAVESPACE "rejected" "74"
    // C: NO "Number expected"
    // => broken, we can't use it :-(
    // (will be fixed in Cyrus 2.1.10)

    if (!sendData("PUTSCRIPT \"" + filename.toUtf8() + "\" {" + QByteArray::number(bufLen) + "+}")) {
        return;
    }

    // atEnd() lies so the code below doesn't work.
    /*if (!atEnd()) {
        // We are not expecting any data here, so if the server has responded
        // with anything but OK we treat it as an error.
        char * buf = new char[2];
        while (!atEnd()) {
                ksDebug << "Reading..." << returnEndLine();
                read(buf, 1);
                ksDebug << "Trailing [" << buf[0] << "]" << returnEndLine();
        }
        ksDebug << "End of data." << returnEndLine();
        delete[] buf;

        if (!operationSuccessful()) {
                error(ERR_UNSUPPORTED_PROTOCOL, i18n("A protocol error occurred "
                                        "while trying to negotiate script uploading.\n"
                                        "The server responded:\n%1")
                                                .arg(r.getAction().right(r.getAction().length() - 3)));
                return;
        }
    }*/

    // upload data to the server
    if (write(data.constData(), bufLen) != bufLen) {
        error(ERR_CANNOT_WRITE, i18n("Network error."));
        disconnect(true);
        return;
    }

    // finishing CR/LF
    if (!sendData("")) {
        return;
    }

    processedSize(bufLen);

    infoMessage(i18n("Verifying upload completion..."));

    if (operationSuccessful()) {
        ksDebug << "Script upload complete." << returnEndLine();
    } else {
        /* The managesieve server parses received scripts and rejects
         * scripts which are not syntactically correct. Here we expect
         * to receive a message detailing the error (only the first
         * error is reported. */
        if (r.getAction().length() > 3) {
            // make a copy of the extra info
            QByteArray extra = r.getAction().right(r.getAction().length() - 3);

            // send the extra message off for re-processing
            receiveData(false, extra);

            if (r.getType() == kio_sieveResponse::QUANTITY) {
                // length of the error message
                uint len = r.getQuantity();

                QByteArray errmsg(len, 0);

                read(errmsg.data(), len);

                error(ERR_INTERNAL_SERVER,
                      i18n("The script did not upload successfully.\n"
                           "This is probably due to errors in the script.\n"
                           "The server responded:\n%1",
                           QString::fromLatin1(errmsg.data(), errmsg.size())));

                // clear the rest of the incoming data
                receiveData();
            } else if (r.getType() == kio_sieveResponse::KEY_VAL_PAIR) {
                error(ERR_INTERNAL_SERVER,
                      i18n("The script did not upload successfully.\n"
                           "This is probably due to errors in the script.\n"
                           "The server responded:\n%1",
                           QString::fromUtf8(r.getKey())));
            } else {
                error(ERR_INTERNAL_SERVER,
                      i18n("The script did not upload successfully.\n"
                           "The script may contain errors."));
            }
        } else {
            error(ERR_INTERNAL_SERVER,
                  i18n("The script did not upload successfully.\n"
                       "The script may contain errors."));
        }
    }

    // if ( permissions != -1 )
    //        chmod( url, permissions );

    infoMessage(i18nc("data upload complete", "Done."));

    finished();
}

static void inplace_crlf2lf(QByteArray &in)
{
    if (in.isEmpty()) {
        return;
    }
    QByteArray &out = in; // inplace
    const char *s = in.begin();
    const char *const end = in.end();
    char *d = out.begin();
    char last = '\0';
    while (s < end) {
        if (*s == '\n' && last == '\r') {
            --d;
        }
        *d++ = last = *s++;
    }
    out.resize(d - out.begin());
}

/* ---------------------------------------------------------------------------------- */
void kio_sieveProtocol::get(const QUrl &url)
{
    changeCheck(url);
    if (!connect()) {
        return;
    }

    infoMessage(i18n("Retrieving data..."));

    QString filename = url.fileName();

    if (filename.isEmpty()) {
        error(ERR_MALFORMED_URL, url.toDisplayString());
        return;
    }

    // SlaveBase::mimetype( QString("text/plain") ); // "application/sieve");

    if (!sendData("GETSCRIPT \"" + filename.toUtf8() + "\"")) {
        return;
    }

    if (receiveData() && r.getType() == kio_sieveResponse::QUANTITY) {
        // determine script size
        ssize_t total_len = r.getQuantity();
        totalSize(total_len);

        ssize_t recv_len = 0;
        do {
            // wait for data...
            if (!waitForResponse(600)) {
                error(KIO::ERR_SERVER_TIMEOUT, m_sServer);
                disconnect(true);
                return;
            }

            // ...read data...
            // Only read as much as we need, otherwise we slurp in the OK that
            // operationSuccessful() is expecting below.
            QByteArray dat(qMin(total_len - recv_len, ssize_t(64 * 1024)), '\0');
            ssize_t this_recv_len = read(dat.data(), dat.size());

            if (this_recv_len < 1 && !isConnected()) {
                error(KIO::ERR_CONNECTION_BROKEN, m_sServer);
                disconnect(true);
                return;
            }

            dat.resize(this_recv_len);
            inplace_crlf2lf(dat);
            // send data to slaveinterface
            data(dat);

            recv_len += this_recv_len;
            processedSize(recv_len);
        } while (recv_len < total_len);

        infoMessage(i18n("Finishing up..."));
        data(QByteArray());

        if (operationSuccessful()) {
            ksDebug << "Script retrieval complete." << returnEndLine();
        } else {
            ksDebug << "Script retrieval failed." << returnEndLine();
        }
    } else {
        error(ERR_UNSUPPORTED_PROTOCOL,
              i18n("A protocol error occurred "
                   "while trying to negotiate script downloading."));
        return;
    }

    infoMessage(i18nc("data retrieval complete", "Done."));
    finished();
}

void kio_sieveProtocol::del(const QUrl &url, bool isfile)
{
    if (!isfile) {
        error(ERR_INTERNAL, i18n("Folders are not supported."));
        return;
    }

    changeCheck(url);
    if (!connect()) {
        return;
    }

    infoMessage(i18n("Deleting file..."));

    QString filename = url.fileName();

    if (filename.isEmpty()) {
        error(ERR_MALFORMED_URL, url.toDisplayString());
        return;
    }

    if (!sendData("DELETESCRIPT \"" + filename.toUtf8() + "\"")) {
        return;
    }

    if (operationSuccessful()) {
        ksDebug << "Script deletion successful." << returnEndLine();
    } else {
        error(ERR_INTERNAL_SERVER, i18n("The server would not delete the file."));
        return;
    }

    infoMessage(i18nc("file removal complete", "Done."));

    finished();
}

void kio_sieveProtocol::chmod(const QUrl &url, int permissions)
{
    switch (permissions) {
    case 0700: // activate
        activate(url);
        break;
    case 0600: // deactivate
        deactivate();
        break;
    default: // unsupported
        error(ERR_CANNOT_CHMOD, i18n("Cannot chmod to anything but 0700 (active) or 0600 (inactive script)."));
        return;
    }

    finished();
}

void kio_sieveProtocol::urlStat(const QUrl &url)
{
    changeCheck(url);
    if (!connect()) {
        return;
    }

    UDSEntry entry;

    QString filename = url.fileName();

    if (filename.isEmpty()) {
        entry.fastInsert(KIO::UDSEntry::UDS_NAME, QStringLiteral("/"));

        entry.fastInsert(KIO::UDSEntry::UDS_FILE_TYPE, S_IFDIR);

        entry.fastInsert(KIO::UDSEntry::UDS_ACCESS, 0700);

        statEntry(entry);
    } else {
        if (!sendData("LISTSCRIPTS")) {
            return;
        }

        while (receiveData()) {
            if (r.getType() == kio_sieveResponse::ACTION) {
                if (r.getAction().toLower().count("ok") == 1) {
                    // Script list completed
                    break;
                }
            } else {
                if (filename == QString::fromUtf8(r.getKey())) {
                    entry.clear();

                    entry.fastInsert(KIO::UDSEntry::UDS_NAME, QString::fromUtf8(r.getKey()));

                    entry.fastInsert(KIO::UDSEntry::UDS_FILE_TYPE, S_IFREG);

                    if (r.getExtra() == "ACTIVE") {
                        entry.fastInsert(KIO::UDSEntry::UDS_ACCESS, 0700);
                    } else {
                        entry.fastInsert(KIO::UDSEntry::UDS_ACCESS, 0600);
                    }

                    entry.fastInsert(KIO::UDSEntry::UDS_MIME_TYPE, QStringLiteral("application/sieve"));

                    // setMetaData("active", (r.getExtra() == "ACTIVE") ? "yes" : "no");

                    statEntry(entry);
                    // cannot break here because we need to clear
                    // the rest of the incoming data.
                }
            }
        }
    }

    finished();
}

void kio_sieveProtocol::listDir(const QUrl &url)
{
    changeCheck(url);
    if (!connect()) {
        return;
    }

    if (!sendData("LISTSCRIPTS")) {
        return;
    }

    UDSEntry entry;

    while (receiveData()) {
        if (r.getType() == kio_sieveResponse::ACTION) {
            if (r.getAction().toLower().count("ok") == 1) {
                // Script list completed.
                break;
            }
        } else {
            entry.clear();
            entry.fastInsert(KIO::UDSEntry::UDS_NAME, QString::fromUtf8(r.getKey()));

            entry.fastInsert(KIO::UDSEntry::UDS_FILE_TYPE, S_IFREG);

            if (r.getExtra() == "ACTIVE") {
                entry.fastInsert(KIO::UDSEntry::UDS_ACCESS, 0700); // mark exec'able
            } else {
                entry.fastInsert(KIO::UDSEntry::UDS_ACCESS, 0600);
            }

            entry.fastInsert(KIO::UDSEntry::UDS_MIME_TYPE, QStringLiteral("application/sieve"));

            // asetMetaData("active", (r.getExtra() == "ACTIVE") ? "true" : "false");

            ksDebug << "Listing script " << r.getKey() << returnEndLine();
            listEntry(entry);
        }
    }

    finished();
}

/* ---------------------------------------------------------------------------------- */
bool kio_sieveProtocol::saslInteract(void *in, AuthInfo &ai)
{
    ksDebug << "sasl_interact" << returnEndLine();
    auto *interact = (sasl_interact_t *)in;

    // some mechanisms do not require username && pass, so it doesn't need a popup
    // window for getting this info
    for (; interact->id != SASL_CB_LIST_END; interact++) {
        if (interact->id == SASL_CB_AUTHNAME || interact->id == SASL_CB_PASS) {
            if (m_sUser.isEmpty() || m_sPass.isEmpty()) {
                const int errorCode = openPasswordDialogV2(ai);
                if (errorCode) {
                    // calling error() below is wrong for two reasons:
                    // - ERR_ABORTED is too harsh
                    // - higher layers already call error() and that can't happen twice.
                    // error(ERR_ABORTED, i18n("No authentication details supplied."));
                    error(errorCode, QString());
                    return false;
                }
                m_sUser = ai.username;
                m_sPass = ai.password;
            }
            break;
        }
    }

    interact = (sasl_interact_t *)in;
    while (interact->id != SASL_CB_LIST_END) {
        ksDebug << "SASL_INTERACT id: " << interact->id << returnEndLine();
        switch (interact->id) {
        case SASL_CB_USER:
        case SASL_CB_AUTHNAME:
            ksDebug << "SASL_CB_[AUTHNAME|USER]: '" << m_sUser << "'" << returnEndLine();
            interact->result = strdup(m_sUser.toUtf8().constData());
            interact->len = strlen((const char *)interact->result);
            break;
        case SASL_CB_PASS:
            ksDebug << "SASL_CB_PASS: [hidden] " << returnEndLine();
            interact->result = strdup(m_sPass.toUtf8().constData());
            interact->len = strlen((const char *)interact->result);
            break;
        default:
            interact->result = nullptr;
            interact->len = 0;
            break;
        }
        interact++;
    }
    return true;
}

#define SASLERROR error(ERR_CANNOT_AUTHENTICATE, i18n("An error occurred during authentication: %1", QString::fromUtf8(sasl_errdetail(conn))));

bool kio_sieveProtocol::authenticate()
{
    int result;
    sasl_conn_t *conn = nullptr;
    sasl_interact_t *client_interact = nullptr;
    const char *out = nullptr;
    uint outlen;
    const char *mechusing = nullptr;
    QByteArray challenge;

    /* Retrieve authentication details from user.
     * Note: should this require realm as well as user & pass details
     * before it automatically skips the prompt?
     * Note2: encoding issues with PLAIN login? */
    AuthInfo ai;
    ai.url.setScheme(QStringLiteral("sieve"));
    ai.url.setHost(m_sServer);
    ai.url.setPort(m_port);
    ai.username = m_sUser;
    ai.password = m_sPass;
    ai.keepPassword = true;
    ai.caption = i18n("Sieve Authentication Details");
    ai.comment = i18n(
        "Please enter your authentication details for your sieve account "
        "(usually the same as your email password):");

    result = sasl_client_new("sieve", m_sServer.toLatin1().constData(), nullptr, nullptr, callbacks, 0, &conn);
    if (result != SASL_OK) {
        ksDebug << "sasl_client_new failed with: " << result << returnEndLine();
        SASLERROR
        return false;
    }

    QStringList strList;
    //    strList.append("NTLM");

    if (!m_sAuth.isEmpty()) {
        strList.append(m_sAuth);
    } else {
        strList = m_sasl_caps;
    }

    do {
        result = sasl_client_start(conn, strList.join(QLatin1Char(' ')).toLatin1().constData(), &client_interact, &out, &outlen, &mechusing);

        if (result == SASL_INTERACT) {
            if (!saslInteract(client_interact, ai)) {
                sasl_dispose(&conn);
                return false;
            }
        }
    } while (result == SASL_INTERACT);

    if (result != SASL_CONTINUE && result != SASL_OK) {
        ksDebug << "sasl_client_start failed with: " << result << returnEndLine();
        SASLERROR
        sasl_dispose(&conn);
        return false;
    }

    ksDebug << "Preferred authentication method is " << mechusing << "." << returnEndLine();

    QString firstCommand = QLatin1String("AUTHENTICATE \"") + QString::fromLatin1(mechusing) + QLatin1String("\"");
    challenge = QByteArray::fromRawData(out, outlen).toBase64();
    if (!challenge.isEmpty()) {
        firstCommand += QLatin1String(" \"");
        firstCommand += QString::fromLatin1(challenge.data(), challenge.size());
        firstCommand += QLatin1Char('\"');
    }

    if (!sendData(firstCommand.toLatin1())) {
        return false;
    }

    do {
        receiveData();

        if (operationResult() != OTHER) {
            break;
        }

        ksDebug << "Challenge len  " << r.getQuantity() << returnEndLine();

        if (r.getType() != kio_sieveResponse::QUANTITY) {
            sasl_dispose(&conn);
            error(ERR_UNSUPPORTED_PROTOCOL, QString::fromLatin1(mechusing));
            return false;
        }

        int qty = r.getQuantity();

        receiveData();

        if (r.getType() != kio_sieveResponse::ACTION && r.getAction().length() != qty) {
            sasl_dispose(&conn);
            error(ERR_UNSUPPORTED_PROTOCOL,
                  i18n("A protocol error occurred during authentication.\n"
                       "Choose a different authentication method to %1.",
                       QLatin1String(mechusing)));
            return false;
        }
        challenge = QByteArray::fromBase64(QByteArray::fromRawData(r.getAction().data(), qty));
        //        ksDebug << "S:  [" << r.getAction() << "]." << returnEndLine();

        do {
            result = sasl_client_step(conn, challenge.isEmpty() ? nullptr : challenge.data(), challenge.size(), &client_interact, &out, &outlen);

            if (result == SASL_INTERACT) {
                if (!saslInteract(client_interact, ai)) {
                    sasl_dispose(&conn);
                    return false;
                }
            }
        } while (result == SASL_INTERACT);

        ksDebug << "sasl_client_step: " << result << returnEndLine();
        if (result != SASL_CONTINUE && result != SASL_OK) {
            ksDebug << "sasl_client_step failed with: " << result << returnEndLine();
            SASLERROR
            sasl_dispose(&conn);
            return false;
        }

        sendData('\"' + QByteArray::fromRawData(out, outlen).toBase64() + '\"');
        //    ksDebug << "C-1:  [" << out << "]." << returnEndLine();
    } while (true);

    ksDebug << "Challenges finished." << returnEndLine();
    sasl_dispose(&conn);

    if (operationResult() == OK) {
        // Authentication succeeded.
        return true;
    } else {
        // Authentication failed.
        error(ERR_CANNOT_AUTHENTICATE,
              i18n("Authentication failed.\nMost likely the password is wrong.\nThe server responded:\n%1", QString::fromLatin1(r.getAction())));
        return false;
    }
}

/* --------------------------------------------------------------------------- */
void kio_sieveProtocol::mimetype(const QUrl &url)
{
    ksDebug << "Requesting mimetype for " << url.toDisplayString() << returnEndLine();

    if (url.fileName().isEmpty()) {
        mimeType(QStringLiteral("inode/directory"));
    } else {
        mimeType(QStringLiteral("application/sieve"));
    }

    finished();
}

/* --------------------------------------------------------------------------- */
bool kio_sieveProtocol::sendData(const QByteArray &data)
{
    QByteArray write_buf = data + "\r\n";

    // ksDebug << "C: " << data << returnEndLine();

    // Write the command
    ssize_t write_buf_len = write_buf.length();
    if (write(write_buf.data(), write_buf_len) != write_buf_len) {
        error(ERR_CANNOT_WRITE, i18n("Network error."));
        disconnect(true);
        return false;
    }

    return true;
}

/* --------------------------------------------------------------------------- */
bool kio_sieveProtocol::receiveData(bool waitForData, const QByteArray &reparse)
{
    QByteArray interpret;
    int start;
    int end;

    if (reparse.isEmpty()) {
        if (!waitForData) {
            // is there data waiting?
            if (atEnd()) {
                return false;
            }
        }

        // read data from the server
        char buffer[SIEVE_DEFAULT_RECIEVE_BUFFER];
        const ssize_t numRead = readLine(buffer, SIEVE_DEFAULT_RECIEVE_BUFFER - 1);
        if (numRead < 0) {
            return false;
        }
        buffer[SIEVE_DEFAULT_RECIEVE_BUFFER - 1] = '\0';

        // strip LF/CR
        interpret = QByteArray(buffer, qstrlen(buffer) - 2);
    } else {
        interpret = reparse;
    }

    r.clear();

    // ksDebug << "S: " << interpret << returnEndLine();

    switch (interpret[0]) {
    case '{': {
        // expecting {quantity}
        start = 0;
        end = interpret.indexOf("+}", start + 1);
        // some older versions of Cyrus enclose the literal size just in { } instead of { +}
        if (end == -1) {
            end = interpret.indexOf('}', start + 1);
        }

        bool ok = false;
        r.setQuantity(interpret.mid(start + 1, end - start - 1).toUInt(&ok));
        if (!ok) {
            disconnect();
            error(ERR_INTERNAL_SERVER, i18n("A protocol error occurred."));
            return false;
        }

        return true;
    }
    case '"':
        // expecting "key" "value" pairs
        break;
    default:
        // expecting single string
        r.setAction(interpret);
        return true;
    }

    start = 0;

    end = interpret.indexOf('"', start + 1);
    if (end == -1) {
        ksDebug << "Possible insufficient buffer size." << returnEndLine();
        r.setKey(interpret.right(interpret.length() - start));
        return true;
    }

    r.setKey(interpret.mid(start + 1, end - start - 1));

    start = interpret.indexOf('"', end + 1);
    if (start == -1) {
        if ((int)interpret.length() > end) {
            // skip " and space
            r.setExtra(interpret.right(interpret.length() - end - 2));
        }

        return true;
    }

    end = interpret.indexOf('"', start + 1);
    if (end == -1) {
        ksDebug << "Possible insufficient buffer size." << returnEndLine();
        r.setVal(interpret.right(interpret.length() - start));
        return true;
    }

    r.setVal(interpret.mid(start + 1, end - start - 1));
    return true;
}

bool kio_sieveProtocol::operationSuccessful()
{
    while (receiveData(true)) {
        if (r.getType() == kio_sieveResponse::ACTION) {
            QByteArray response = r.getAction().left(2);
            if (response == "OK") {
                return true;
            } else if (response == "NO") {
                return false;
            }
        }
    }
    return false;
}

int kio_sieveProtocol::operationResult()
{
    if (r.getType() == kio_sieveResponse::ACTION) {
        QByteArray response = r.getAction().left(2);
        if (response == "OK") {
            return OK;
        } else if (response == "NO") {
            return NO;
        } else if (response == "BY" /*E*/) {
            return BYE;
        }
    }

    return OTHER;
}

bool kio_sieveProtocol::requestCapabilitiesAfterStartTLS() const
{
    // Cyrus didn't send CAPABILITIES after STARTTLS until 2.3.11, which is
    // not standard conform, but we need to support that anyway.
    // m_implementation looks like this 'Cyrus timsieved v2.2.12' for Cyrus btw.
    QRegularExpression regExp(QStringLiteral("Cyrus\\stimsieved\\sv(\\d+)\\.(\\d+)\\.(\\d+)([-\\w]*)"), QRegularExpression::CaseInsensitiveOption);
    QRegularExpressionMatch match = regExp.match(m_implementation);
    if (match.hasMatch()) {
        const int major = match.captured(1).toInt();
        const int minor = match.captured(2).toInt();
        const int patch = match.captured(3).toInt();
        const QString vendor = match.captured(4);
        if (major < 2 || (major == 2 && (minor < 3 || (minor == 3 && patch < 11))) || (vendor == QLatin1String("-kolab-nocaps"))) {
            ksDebug << " kio_sieveProtocol::requestCapabilitiesAfterStartTLS : Enabling compat mode for Cyrus < 2.3.11 or Cyrus marked as \"kolab-nocaps\""
                    << returnEndLine();
            return true;
        }
    }
    return false;
}
#include "sieve.moc"