From 871332ecf0603c46c020482553c6420e1c18943f Mon Sep 17 00:00:00 2001
From: Janek Bevendorff <janek@jbev.net>
Date: Wed, 27 Dec 2017 14:20:28 +0100
Subject: [PATCH] Add warning when using legacy key file formats.

---
 src/cli/Extract.cpp               |  7 +++++++
 src/gui/ChangeMasterKeyWidget.cpp |  8 ++++++++
 src/gui/DatabaseOpenWidget.cpp    | 17 +++++++++++++++++
 src/keys/FileKey.cpp              | 21 +++++++++++++++++++--
 src/keys/FileKey.h                | 10 ++++++++++
 5 files changed, 61 insertions(+), 2 deletions(-)

diff --git a/src/cli/Extract.cpp b/src/cli/Extract.cpp
index 54c8a45ee..477f2b0e2 100644
--- a/src/cli/Extract.cpp
+++ b/src/cli/Extract.cpp
@@ -82,6 +82,13 @@ int Extract::execute(QStringList arguments)
             return EXIT_FAILURE;
         }
 
+        if (fileKey.type() != FileKey::Hashed) {
+            errorTextStream << QObject::tr("WARNING: You are using a legacy key file format which may become\n"
+                                               "unsupported in the future.\n\n"
+                                               "Please consider generating a new key file.");
+            errorTextStream << endl;
+        }
+
         compositeKey.addKey(fileKey);
     }
 
diff --git a/src/gui/ChangeMasterKeyWidget.cpp b/src/gui/ChangeMasterKeyWidget.cpp
index ef4b61ef2..28a0991db 100644
--- a/src/gui/ChangeMasterKeyWidget.cpp
+++ b/src/gui/ChangeMasterKeyWidget.cpp
@@ -162,6 +162,14 @@ void ChangeMasterKeyWidget::generateKey()
                tr("Failed to set %1 as the Key file:\n%2").arg(fileKeyName, errorMsg), MessageWidget::Error);
             return;
         }
+        if (fileKey.type() != FileKey::Hashed) {
+            QMessageBox::warning(this,
+                                 tr("Legacy key file format"),
+                                 tr("You are using a legacy key file format which may become\n"
+                                        "unsupported in the future.\n\n"
+                                        "Please consider generating a new key file."),
+                                 QMessageBox::Ok);
+        }
         m_key.addKey(fileKey);
     }
 
diff --git a/src/gui/DatabaseOpenWidget.cpp b/src/gui/DatabaseOpenWidget.cpp
index 451dc597a..3af0c6e8f 100644
--- a/src/gui/DatabaseOpenWidget.cpp
+++ b/src/gui/DatabaseOpenWidget.cpp
@@ -218,6 +218,23 @@ QSharedPointer<CompositeKey> DatabaseOpenWidget::databaseKey()
                                              MessageWidget::Error);
             return QSharedPointer<CompositeKey>();
         }
+        if (key.type() != FileKey::Hashed && !config()->get("Messages/NoLegacyKeyFileWarning").toBool()) {
+            QMessageBox legacyWarning;
+            legacyWarning.setWindowTitle(tr("Legacy key file format"));
+            legacyWarning.setText(tr("You are using a legacy key file format which may become\n"
+                                         "unsupported in the future.\n\n"
+                                         "Please consider generating a new key file."));
+            legacyWarning.setIcon(QMessageBox::Icon::Warning);
+            legacyWarning.addButton(QMessageBox::Ok);
+            legacyWarning.setDefaultButton(QMessageBox::Ok);
+            legacyWarning.setCheckBox(new QCheckBox(tr("Don't show this warning again")));
+
+            connect(legacyWarning.checkBox(), &QCheckBox::stateChanged, [](int state){
+                config()->set("Messages/NoLegacyKeyFileWarning", state == Qt::CheckState::Checked);
+            });
+
+            legacyWarning.exec();
+        }
         masterKey->addKey(key);
         lastKeyFiles[m_filename] = keyFilename;
     } else {
diff --git a/src/keys/FileKey.cpp b/src/keys/FileKey.cpp
index 7f2f8a6ea..26db40d85 100644
--- a/src/keys/FileKey.cpp
+++ b/src/keys/FileKey.cpp
@@ -45,6 +45,8 @@
  */
 bool FileKey::load(QIODevice* device)
 {
+    m_type = None;
+
     // we may need to read the file multiple times
     if (device->isSequential()) {
         return false;
@@ -59,6 +61,7 @@ bool FileKey::load(QIODevice* device)
         return false;
     }
     if (loadXml(device)) {
+        m_type = KeePass2XML;
         return true;
     }
 
@@ -66,6 +69,7 @@ bool FileKey::load(QIODevice* device)
         return false;
     }
     if (loadBinary(device)) {
+        m_type = FixedBinary;
         return true;
     }
 
@@ -73,15 +77,20 @@ bool FileKey::load(QIODevice* device)
         return false;
     }
     if (loadHex(device)) {
+        m_type = FixedBinaryHex;
         return true;
     }
 
+    // if no legacy format was detected, generate SHA-256 hash of key file
     if (!device->reset()) {
         return false;
     }
+    if (loadHashed(device)) {
+        m_type = Hashed;
+        return true;
+    }
 
-    // if no legacy format was detected, generate SHA-256 hash of key file
-    return loadHashed(device);
+    return false;
 }
 
 /**
@@ -345,3 +354,11 @@ bool FileKey::loadHashed(QIODevice* device)
 
     return true;
 }
+
+/**
+ * @return type of loaded key file
+ */
+FileKey::Type FileKey::type() const
+{
+    return m_type;
+}
diff --git a/src/keys/FileKey.h b/src/keys/FileKey.h
index af324e530..2aa48909b 100644
--- a/src/keys/FileKey.h
+++ b/src/keys/FileKey.h
@@ -28,10 +28,19 @@ class QIODevice;
 class FileKey: public Key
 {
 public:
+    enum Type {
+        None,
+        Hashed,
+        KeePass2XML,
+        FixedBinary,
+        FixedBinaryHex
+    };
+
     bool load(QIODevice* device);
     bool load(const QString& fileName, QString* errorMsg = nullptr);
     QByteArray rawKey() const override;
     FileKey* clone() const override;
+    Type type() const;
     static void create(QIODevice* device, int size = 128);
     static bool create(const QString& fileName, QString* errorMsg = nullptr, int size = 128);
 
@@ -44,6 +53,7 @@ private:
     bool loadHashed(QIODevice* device);
 
     QByteArray m_key;
+    Type m_type = None;
 };
 
 #endif // KEEPASSX_FILEKEY_H