SsoSession and Connection::prepareForSso()

Final part of #388 backport.

4 files changed, 181 insertions, 0 deletions

diff --git a/lib/connection.cpp b/lib/connection.cpp
index 6da04118..647fc006 100644
--- a/lib/connection.cpp
+++ b/lib/connection.cpp
@@ -254,6 +254,12 @@ void Connection::doConnectToServer(const QString& user, const QString& password,
                      password, /*token*/ "", deviceId, initialDeviceName);
 }
 
+SsoSession* Connection::prepareForSso(const QString& initialDeviceName,
+                                      const QString& deviceId)
+{
+    return new SsoSession(this, initialDeviceName, deviceId);
+}
+
 void Connection::loginWithToken(const QByteArray& loginToken,
                                 const QString& initialDeviceName,
                                 const QString& deviceId)
diff --git a/lib/connection.h b/lib/connection.h
index 782ffd2c..33f9bfba 100644
--- a/lib/connection.h
+++ b/lib/connection.h
@@ -19,6 +19,7 @@
 #pragma once
 
 #include "csapi/login.h"
+#include "ssosession.h"
 #include "csapi/create_room.h"
 #include "joinstate.h"
 #include "events/accountdataevents.h"
@@ -415,6 +416,9 @@ namespace QMatrixClient
                                             std::forward<JobArgTs>(jobArgs)...);
             }
 
+            Q_INVOKABLE SsoSession* prepareForSso(
+                const QString& initialDeviceName, const QString& deviceId = {});
+
             /** Generate a new transaction id. Transaction id's are unique within
              * a single Connection object
              */
diff --git a/lib/ssosession.cpp b/lib/ssosession.cpp
new file mode 100644
index 00000000..6ea4a3f5
--- /dev/null
+++ b/lib/ssosession.cpp
@@ -0,0 +1,127 @@
+#include "ssosession.h"
+
+#include "connection.h"
+#include "csapi/sso_login_redirect.h"
+
+#include <QtNetwork/QTcpServer>
+#include <QtNetwork/QTcpSocket>
+#include <QtCore/QCoreApplication>
+#include <QtCore/QStringBuilder>
+
+using namespace QMatrixClient;
+
+struct SsoSession::Private {
+    Private(SsoSession* q, const QString& initialDeviceName = {},
+            const QString& deviceId = {}, Connection* connection = nullptr)
+        : initialDeviceName(initialDeviceName)
+        , deviceId(deviceId)
+        , connection(connection)
+    {
+        auto* server = new QTcpServer(q);
+        server->listen();
+        // The "/returnToApplication" part is just a hint for the end-user,
+        // the callback will work without it equally well.
+        callbackUrl = QStringLiteral("http://localhost:%1/returnToApplication")
+                          .arg(server->serverPort());
+        ssoUrl = connection->getUrlForApi<RedirectToSSOJob>(callbackUrl);
+
+        QObject::connect(server, &QTcpServer::newConnection, q, [this, server] {
+            qCDebug(MAIN) << "SSO callback initiated";
+            socket = server->nextPendingConnection();
+            server->close();
+            QObject::connect(socket, &QTcpSocket::readyRead, socket, [this] {
+                requestData.append(socket->readAll());
+                if (!socket->atEnd() && !requestData.endsWith("\r\n\r\n")) {
+                    qDebug(MAIN) << "Incomplete request, waiting for more data";
+                    return;
+                }
+                processCallback();
+            });
+            QObject::connect(socket, &QTcpSocket::disconnected, socket,
+                             [this] { socket->deleteLater(); });
+        });
+    }
+    void processCallback();
+    void sendHttpResponse(const QByteArray& code, const QByteArray& msg);
+    void onError(const QByteArray& code, const QString& errorMsg);
+
+    QString initialDeviceName;
+    QString deviceId;
+    Connection* connection;
+    QString callbackUrl {};
+    QUrl ssoUrl {};
+    QTcpSocket* socket = nullptr;
+    QByteArray requestData {};
+};
+
+SsoSession::SsoSession(Connection* connection, const QString& initialDeviceName,
+                       const QString& deviceId)
+    : QObject(connection)
+    , d(std::make_unique<Private>(this, initialDeviceName, deviceId, connection))
+{
+    qCDebug(MAIN) << "SSO session constructed";
+}
+
+SsoSession::~SsoSession()
+{
+    qCDebug(MAIN) << "SSO session deconstructed";
+}
+
+QUrl SsoSession::ssoUrl() const { return d->ssoUrl; }
+
+QUrl SsoSession::callbackUrl() const { return d->callbackUrl; }
+
+void SsoSession::Private::processCallback()
+{
+    // https://matrix.org/docs/guides/sso-for-client-developers
+    // Inspired by Clementine's src/internet/core/localredirectserver.cpp
+    // (see at https://github.com/clementine-player/Clementine/)
+    const auto& requestParts = requestData.split(' ');
+    if (requestParts.size() < 2 || requestParts[1].isEmpty()) {
+        onError("400 Bad Request", tr("No login token in SSO callback"));
+        return;
+    }
+    const auto& QueryItemName = QStringLiteral("loginToken");
+    QUrlQuery query { QUrl(requestParts[1]).query() };
+    if (!query.hasQueryItem(QueryItemName)) {
+        onError("400 Bad Request", tr("Malformed single sign-on callback"));
+    }
+    qCDebug(MAIN) << "Found the token in SSO callback, logging in";
+    connection->loginWithToken(query.queryItemValue(QueryItemName).toLatin1(),
+                               initialDeviceName, deviceId);
+    connect(connection, &Connection::connected, socket, [this] {
+        const QString msg =
+            "The application '" % QCoreApplication::applicationName()
+            % "' has successfully logged in as a user " % connection->userId()
+            % " with device id " % connection->deviceId()
+            % ". This window can be closed. Thank you.\r\n";
+        sendHttpResponse("200 OK", msg.toHtmlEscaped().toUtf8());
+        socket->disconnectFromHost();
+    });
+    connect(connection, &Connection::loginError, socket, [this] {
+        onError("401 Unauthorised", tr("Login failed"));
+        socket->disconnectFromHost();
+    });
+}
+
+void SsoSession::Private::sendHttpResponse(const QByteArray& code,
+                                           const QByteArray& msg)
+{
+    socket->write("HTTP/1.0 ");
+    socket->write(code);
+    socket->write("\r\n"
+                  "Content-type: text/html;charset=UTF-8\r\n"
+                  "\r\n\r\n");
+    socket->write(msg);
+    socket->write("\r\n");
+}
+
+void SsoSession::Private::onError(const QByteArray& code,
+                                  const QString& errorMsg)
+{
+    qCWarning(MAIN).nospace() << errorMsg;
+    sendHttpResponse(code, "<h3>" + errorMsg.toUtf8() + "</h3>");
+    // [kitsune] Yeah, I know, dirty. Maybe the "right" way would be to have
+    // an intermediate signal but that seems just a fight for purity.
+    emit connection->loginError(errorMsg, requestData);
+}
diff --git a/lib/ssosession.h b/lib/ssosession.h
new file mode 100644
index 00000000..af20c075
--- /dev/null
+++ b/lib/ssosession.h
@@ -0,0 +1,44 @@
+#pragma once
+
+#include <QtCore/QUrl>
+#include <QtCore/QObject>
+
+#include <memory>
+
+class QTcpServer;
+class QTcpSocket;
+
+namespace QMatrixClient {
+class Connection;
+
+/*! Single sign-on (SSO) session encapsulation
+ *
+ * This class is responsible for setting up of a new SSO session, providing
+ * a URL to be opened (usually, in a web browser) and handling the callback
+ * response after completing the single sign-on, all the way to actually
+ * logging the user in. It does NOT open and render the SSO URL, it only does
+ * the necessary backstage work.
+ *
+ * Clients only need to open the URL; the rest is done for them.
+ * Client code can look something like:
+ * \code
+ * QDesktopServices::openUrl(
+ *     connection->prepareForSso(initialDeviceName)->ssoUrl());
+ * \endcode
+ */
+class SsoSession : public QObject {
+    Q_OBJECT
+    Q_PROPERTY(QUrl ssoUrl READ ssoUrl CONSTANT)
+    Q_PROPERTY(QUrl callbackUrl READ callbackUrl CONSTANT)
+public:
+    SsoSession(Connection* connection, const QString& initialDeviceName,
+               const QString& deviceId = {});
+    ~SsoSession() override;
+    QUrl ssoUrl() const;
+    QUrl callbackUrl() const;
+
+private:
+    class Private;
+    std::unique_ptr<Private> d;
+};
+} // namespace QMatrixClient