GH-3392 dirty initial MSA support that shares logic with Mojang flows

Both act as the first step of AuthContext.

launcher/minecraft/auth/flows/Yggdrasil.h

@@ -0,0 +1,82 @@
+/* Copyright 2013-2021 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 "../AccountTask.h"
+
+#include <QString>
+#include <QJsonObject>
+#include <QTimer>
+#include <qsslerror.h>
+
+#include "../MinecraftAccount.h"
+
+class QNetworkReply;
+
+/**
+ * A Yggdrasil task is a task that performs an operation on a given mojang account.
+ */
+class Yggdrasil : public AccountTask
+{
+    Q_OBJECT
+public:
+    explicit Yggdrasil(AccountData * data, QObject *parent = 0);
+    virtual ~Yggdrasil() {};
+
+    void refresh();
+    void login(QString password);
+protected:
+    void executeTask() override;
+
+    /**
+     * Processes the response received from the server.
+     * If an error occurred, this should emit a failed signal.
+     * 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.
+     */
+    void processResponse(QJsonObject responseData);
+
+    /**
+     * 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);
+
+protected slots:
+    void processReply();
+    void refreshTimers(qint64, qint64);
+    void heartbeat();
+    void sslErrors(QList<QSslError>);
+    void abortByTimeout();
+
+public slots:
+    virtual bool abort() override;
+
+private:
+    void sendRequest(QUrl endpoint, QByteArray content);
+
+protected:
+    QNetworkReply *m_netReply = nullptr;
+    QTimer timeout_keeper;
+    QTimer counter;
+    int count = 0; // num msec since time reset
+
+    const int timeout_max = 30000;
+    const int time_step = 50;
+};