feat: encrypt saved server profile tokens

src/qEmbyCore/models/sync/configbundle.cpp

@@ -1,6 +1,7 @@
 #include "configbundle.h"
 
 #include "../../config/configstore.h"
+#include "../../utils/serverprofilecrypto.h"
 
 #include <QCoreApplication>
 #include <QDateTime>
@@ -304,7 +305,9 @@ ConfigBundle ConfigBundle::collectFromLocal()
             f.close();
             const QJsonDocument doc = QJsonDocument::fromJson(bytes);
             if (doc.isArray()) {
-                b.servers = doc.array();
+                bool migrated = false;
+                b.servers =
+                    ServerProfileCrypto::decryptServerArray(doc.array(), &migrated);
             } else {
                 qWarning() << "[ConfigBundle] servers.json is not array, skipped";
             }

src/qEmbyCore/services/manager/servermanager.cpp

@@ -1,11 +1,25 @@
 #include "servermanager.h"
 #include "../../api/embywebsocket.h"
+#include "../../utils/serverprofilecrypto.h"
+#include <QDebug>
 #include <QJsonArray>
 #include <QJsonDocument>
 #include <QFile>
+#include <QFileInfo>
 #include <QStandardPaths>
 #include <QDir>
 
+namespace
+{
+
+QString serversJsonPath()
+{
+    const QString dir = QStandardPaths::writableLocation(QStandardPaths::AppDataLocation);
+    return QDir(dir).filePath(QStringLiteral("servers.json"));
+}
+
+} // namespace
+
 ServerManager::ServerManager(NetworkManager* nm, QObject* parent)
     : QObject(parent), m_network(nm) {
     loadSettings();
@@ -181,20 +195,55 @@ void ServerManager::saveSettings() {
         array.append(obj);
     }
 
-    QString path = QStandardPaths::writableLocation(QStandardPaths::AppDataLocation);
-    QDir().mkpath(path);
-    QFile file(path + "/servers.json");
-    if (file.open(QIODevice::WriteOnly)) {
-        file.write(QJsonDocument(array).toJson());
+    const QString filePath = serversJsonPath();
+    const QString dirPath = QFileInfo(filePath).absolutePath();
+    if (!QDir().mkpath(dirPath)) {
+        qWarning() << "[ServerManager] failed to create server config dir:"
+                   << dirPath;
+        return;
     }
+
+    bool encrypted = true;
+    const QJsonArray encryptedArray =
+        ServerProfileCrypto::encryptServerArray(array, &encrypted);
+    if (!encrypted) {
+        qWarning() << "[ServerManager] refusing to save server config because token encryption failed";
+        return;
+    }
+    const QByteArray payload = QJsonDocument(encryptedArray).toJson();
+    const QString tmpPath = filePath + QStringLiteral(".tmp");
+    QFile file(tmpPath);
+    if (!file.open(QIODevice::WriteOnly | QIODevice::Truncate)) {
+        qWarning() << "[ServerManager] failed to open server config for write:"
+                   << tmpPath << "|" << file.errorString();
+        return;
+    }
+    if (file.write(payload) != payload.size()) {
+        qWarning() << "[ServerManager] failed to write complete server config:"
+                   << tmpPath;
+        file.close();
+        QFile::remove(tmpPath);
+        return;
+    }
+    file.close();
+
+    QFile::remove(filePath);
+    if (!QFile::rename(tmpPath, filePath)) {
+        qWarning() << "[ServerManager] failed to replace server config:"
+                   << filePath;
+        QFile::remove(tmpPath);
+        return;
+    }
+    ServerProfileCrypto::setOwnerOnlyPermissions(filePath);
 }
 
 void ServerManager::loadSettings() {
-    QString path = QStandardPaths::writableLocation(QStandardPaths::AppDataLocation);
-    QFile file(path + "/servers.json");
+    QFile file(serversJsonPath());
     if (!file.open(QIODevice::ReadOnly)) return;
 
-    QJsonArray array = QJsonDocument::fromJson(file.readAll()).array();
+    bool shouldResave = false;
+    QJsonArray array = ServerProfileCrypto::decryptServerArray(
+        QJsonDocument::fromJson(file.readAll()).array(), &shouldResave);
     m_servers.clear();
     for (auto val : array) {
         QJsonObject obj = val.toObject();
@@ -220,6 +269,11 @@ void ServerManager::loadSettings() {
     if (!m_servers.isEmpty()) {
         setActiveServer(m_servers.first().id);
     }
+
+    if (shouldResave) {
+        qInfo() << "[ServerManager] migrating plaintext server tokens to encrypted storage";
+        saveSettings();
+    }
 }
 
 void ServerManager::clearActiveSession()
@@ -229,4 +283,3 @@ void ServerManager::clearActiveSession()
     m_activeClient.reset();
     Q_EMIT activeServerChanged(m_activeProfile);
 }
-

src/qEmbyCore/services/sync/webdavsyncservice.cpp

@@ -2,6 +2,7 @@
 
 #include "../../api/webdav/webdavclient.h"
 #include "../../config/configstore.h"
+#include "../../utils/serverprofilecrypto.h"
 #include "../../utils/securesecretbox.h"
 
 #include <QDateTime>
@@ -81,7 +82,8 @@ QJsonArray readServersJson()
     }
     const QByteArray bytes = f.readAll();
     f.close();
-    return QJsonDocument::fromJson(bytes).array();
+    return ServerProfileCrypto::decryptServerArray(
+        QJsonDocument::fromJson(bytes).array());
 }
 
 bool writeServersJson(const QJsonArray &arr)
@@ -94,7 +96,16 @@ bool writeServersJson(const QJsonArray &arr)
         return false;
     }
 
-    const QByteArray payload = QJsonDocument(arr).toJson(QJsonDocument::Indented);
+    bool encryptedOk = true;
+    const QJsonArray encrypted =
+        ServerProfileCrypto::encryptServerArray(arr, &encryptedOk);
+    if (!encryptedOk)
+    {
+        qWarning() << "[WebdavSyncService] refusing to write servers.json because token encryption failed";
+        return false;
+    }
+    const QByteArray payload =
+        QJsonDocument(encrypted).toJson(QJsonDocument::Indented);
 
     const QString tmpPath = path + QStringLiteral(".tmp");
     {
@@ -124,6 +135,7 @@ bool writeServersJson(const QJsonArray &arr)
         }
         QFile::remove(tmpPath);
     }
+    ServerProfileCrypto::setOwnerOnlyPermissions(path);
     return true;
 }
 

src/qEmbyCore/utils/serverprofilecrypto.cpp

@@ -0,0 +1,201 @@
+#include "serverprofilecrypto.h"
+
+#include "securesecretbox.h"
+
+#include <QByteArray>
+#include <QDebug>
+#include <QFile>
+#include <QJsonValue>
+
+namespace
+{
+
+constexpr char kAccessToken[] = "accessToken";
+constexpr char kAccessTokenEncrypted[] = "accessTokenEncrypted";
+
+QString encryptToken(const QString &plainToken)
+{
+    if (plainToken.isEmpty())
+    {
+        return QString();
+    }
+
+    QByteArray tokenBytes = plainToken.toUtf8();
+    const QByteArray cipher = SecureSecretBox::encryptLocalSecret(tokenBytes);
+    SecureSecretBox::secureZero(tokenBytes);
+    if (cipher.isEmpty())
+    {
+        return QString();
+    }
+
+    return QString::fromLatin1(cipher.toBase64(QByteArray::Base64Encoding));
+}
+
+QString decryptToken(const QString &cipherBase64)
+{
+    if (cipherBase64.isEmpty())
+    {
+        return QString();
+    }
+
+    const QByteArray cipher = QByteArray::fromBase64(
+        cipherBase64.toLatin1(), QByteArray::Base64Encoding);
+    if (cipher.isEmpty())
+    {
+        return QString();
+    }
+
+    auto plain = SecureSecretBox::decryptLocalSecret(cipher);
+    if (!plain.has_value())
+    {
+        return QString();
+    }
+
+    QString token = QString::fromUtf8(plain->constData(), plain->size());
+    SecureSecretBox::secureZero(*plain);
+    return token;
+}
+
+} // namespace
+
+QJsonObject ServerProfileCrypto::encryptServerObject(QJsonObject obj, bool *ok)
+{
+    if (ok)
+    {
+        *ok = true;
+    }
+
+    const QString token =
+        obj.value(QString::fromLatin1(kAccessToken)).toString();
+    if (token.isEmpty())
+    {
+        obj.remove(QString::fromLatin1(kAccessToken));
+        obj.remove(QString::fromLatin1(kAccessTokenEncrypted));
+        return obj;
+    }
+
+    const QString cipher = encryptToken(token);
+    if (cipher.isEmpty())
+    {
+        qWarning() << "[ServerProfileCrypto] failed to encrypt access token"
+                   << "| serverId:" << obj.value(QStringLiteral("id")).toString();
+        if (ok)
+        {
+            *ok = false;
+        }
+        return obj;
+    }
+
+    obj.insert(QString::fromLatin1(kAccessToken), cipher);
+    obj.insert(QString::fromLatin1(kAccessTokenEncrypted), true);
+    return obj;
+}
+
+QJsonArray ServerProfileCrypto::encryptServerArray(const QJsonArray &array,
+                                                   bool *ok)
+{
+    bool allOk = true;
+    QJsonArray encrypted;
+    for (const QJsonValue &value : array)
+    {
+        if (value.isObject())
+        {
+            bool objectOk = true;
+            encrypted.append(encryptServerObject(value.toObject(), &objectOk));
+            allOk = allOk && objectOk;
+        }
+        else
+        {
+            encrypted.append(value);
+        }
+    }
+    if (ok)
+    {
+        *ok = allOk;
+    }
+    return encrypted;
+}
+
+QJsonObject ServerProfileCrypto::decryptServerObject(QJsonObject obj,
+                                                     bool *migrated)
+{
+    if (migrated)
+    {
+        *migrated = false;
+    }
+
+    const QString token =
+        obj.value(QString::fromLatin1(kAccessToken)).toString();
+    if (token.isEmpty())
+    {
+        obj.remove(QString::fromLatin1(kAccessTokenEncrypted));
+        return obj;
+    }
+
+    const bool encrypted =
+        obj.value(QString::fromLatin1(kAccessTokenEncrypted)).toBool(false);
+    if (!encrypted)
+    {
+        if (migrated)
+        {
+            *migrated = true;
+        }
+        return obj;
+    }
+
+    const QString plain = decryptToken(token);
+    if (plain.isEmpty())
+    {
+        qWarning() << "[ServerProfileCrypto] failed to decrypt access token"
+                   << "| serverId:" << obj.value(QStringLiteral("id")).toString();
+        obj.remove(QString::fromLatin1(kAccessToken));
+        obj.remove(QString::fromLatin1(kAccessTokenEncrypted));
+        return obj;
+    }
+
+    obj.insert(QString::fromLatin1(kAccessToken), plain);
+    obj.remove(QString::fromLatin1(kAccessTokenEncrypted));
+    return obj;
+}
+
+QJsonArray ServerProfileCrypto::decryptServerArray(const QJsonArray &array,
+                                                   bool *migrated)
+{
+    bool anyMigrated = false;
+    QJsonArray decrypted;
+    for (const QJsonValue &value : array)
+    {
+        if (!value.isObject())
+        {
+            decrypted.append(value);
+            continue;
+        }
+
+        bool objectMigrated = false;
+        decrypted.append(decryptServerObject(value.toObject(), &objectMigrated));
+        anyMigrated = anyMigrated || objectMigrated;
+    }
+
+    if (migrated)
+    {
+        *migrated = anyMigrated;
+    }
+    return decrypted;
+}
+
+bool ServerProfileCrypto::setOwnerOnlyPermissions(const QString &path)
+{
+    if (path.isEmpty())
+    {
+        return false;
+    }
+
+    const bool ok = QFile::setPermissions(
+        path, QFileDevice::ReadOwner | QFileDevice::WriteOwner);
+    if (!ok)
+    {
+        qWarning() << "[ServerProfileCrypto] failed to set owner-only permissions:"
+                   << path;
+    }
+    return ok;
+}

src/qEmbyCore/utils/serverprofilecrypto.h

@@ -0,0 +1,25 @@
+#ifndef SERVERPROFILECRYPTO_H
+#define SERVERPROFILECRYPTO_H
+
+#include "../qEmbyCore_global.h"
+
+#include <QJsonArray>
+#include <QJsonObject>
+#include <QString>
+
+class QEMBYCORE_EXPORT ServerProfileCrypto
+{
+public:
+    static QJsonObject encryptServerObject(QJsonObject obj, bool *ok = nullptr);
+    static QJsonArray encryptServerArray(const QJsonArray &array, bool *ok = nullptr);
+
+    static QJsonObject decryptServerObject(QJsonObject obj, bool *migrated = nullptr);
+    static QJsonArray decryptServerArray(const QJsonArray &array, bool *migrated = nullptr);
+
+    static bool setOwnerOnlyPermissions(const QString &path);
+
+private:
+    ServerProfileCrypto() = delete;
+};
+
+#endif