YggdrasilTask.h

/* Copyright 2013-2019 MultiMC Contributors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#pragma once

#include <tasks/Task.h>

#include <QString>
#include <QJsonObject>
#include <QTimer>
#include <qsslerror.h>

#include "MojangAccount.h"

class QNetworkReply;

/**
 * A Yggdrasil task is a task that performs an operation on a given mojang account.
 */
class YggdrasilTask : public Task
{
    Q_OBJECT
public:
    explicit YggdrasilTask(MojangAccount * account, QObject *parent = 0);
    virtual ~YggdrasilTask() {};

    /**
     * assign a session to this task. the session will be filled with required infomration
     * upon completion
     */
    void assignSession(AuthSessionPtr session)
    {
        m_session = session;
    }

    /// get the assigned session for filling with information.
    AuthSessionPtr getAssignedSession()
    {
        return m_session;
    }

    /**
     * Class describing a Yggdrasil error response.
     */
    struct Error
    {
        QString m_errorMessageShort;
        QString m_errorMessageVerbose;
        QString m_cause;
    };

    enum AbortedBy
    {
        BY_NOTHING,
        BY_USER,
        BY_TIMEOUT,
        BY_DETECTED_MITM_ATTACK
    } m_aborted = BY_NOTHING;

    /**
     * Enum for describing the state of the current task.
     * Used by the getStateMessage function to determine what the status message should be.
     */
    enum State
    {
        STATE_CREATED,
        STATE_SENDING_REQUEST,
        STATE_PROCESSING_RESPONSE,
        STATE_FAILED_SOFT, //!< soft failure. this generally means the user auth details haven't been invalidated
        STATE_FAILED_HARD, //!< hard failure. auth is invalid
        STATE_FAILED_SECURITY, //!< hard failure. auth is invalid
        STATE_SUCCEEDED
    } m_state = STATE_CREATED;

protected:

    virtual void executeTask() override;

    /**
     * Gets the JSON object that will be sent to the authentication server.
     * Should be overridden by subclasses.
     */
    virtual QJsonObject getRequestContent() const = 0;

    /**
     * Gets the endpoint to POST to.
     * No leading slash.
     */
    virtual QString getEndpoint() const = 0;

    /**
     * Processes the response received from the server.
     * If an error occurred, this should emit a failed signal and return false.
     * If Yggdrasil gave an error response, it should call setError() first, and then return false.
     * Otherwise, it should return true.
     * Note: If the response from the server was blank, and the HTTP code was 200, this function is called with
     * an empty QJsonObject.
     */
    virtual void processResponse(QJsonObject responseData) = 0;

    /**
     * Processes an error response received from the server.
     * The default implementation will read data from Yggdrasil's standard error response format and set it as this task's Error.
     * \returns a QString error message that will be passed to emitFailed.
     */
    virtual void processError(QJsonObject responseData);

    /**
     * Returns the state message for the given state.
     * Used to set the status message for the task.
     * Should be overridden by subclasses that want to change messages for a given state.
     */
    virtual QString getStateMessage() const;

protected
slots:
    void processReply();
    void refreshTimers(qint64, qint64);
    void heartbeat();
    void sslErrors(QList<QSslError>);

    void changeState(State newState, QString reason=QString());
public
slots:
    virtual bool abort() override;
    void abortByTimeout();
    void abortByCertPinning();
    State state();
protected:
    // FIXME: segfault disaster waiting to happen
    MojangAccount *m_account = nullptr;
    QNetworkReply *m_netReply = nullptr;
    std::shared_ptr<Error> m_error;
    QTimer timeout_keeper;
    QTimer counter;
    int count = 0; // num msec since time reset

    const int timeout_max = 30000;
    const int time_step = 50;

    AuthSessionPtr m_session;
};