Fix unloading ssh keys on database lock

* Fix #5928 - SSH Agent keys are properly removed on database lock. Also fixes crash when keys are still loaded on application close.
* Remove dependency on DatabaseWidget within SSH Agent.

src/gui/DatabaseWidget.cpp

@@ -214,13 +214,6 @@ DatabaseWidget::DatabaseWidget(QSharedPointer<Database> db, QWidget* parent)
     m_EntrySearcher = new EntrySearcher(false);
     m_searchLimitGroup = config()->get(Config::SearchLimitGroup).toBool();
 
-#ifdef WITH_XC_SSHAGENT
-    if (sshAgent()->isEnabled()) {
-        connect(this, SIGNAL(databaseLocked()), sshAgent(), SLOT(databaseLocked()));
-        connect(this, SIGNAL(databaseUnlocked()), sshAgent(), SLOT(databaseUnlocked()));
-    }
-#endif
-
 #ifdef WITH_XC_KEESHARE
     // We need to reregister the database to allow exports
     // from a newly created database
@@ -1089,6 +1082,9 @@ void DatabaseWidget::loadDatabase(bool accepted)
         m_entryBeforeLock = QUuid();
         m_saveAttempts = 0;
         emit databaseUnlocked();
+#ifdef WITH_XC_SSHAGENT
+        sshAgent()->databaseUnlocked(m_db);
+#endif
         if (config()->get(Config::MinimizeAfterUnlock).toBool()) {
             getMainWindow()->minimizeOrHide();
         }
@@ -1176,6 +1172,10 @@ void DatabaseWidget::unlockDatabase(bool accepted)
     processAutoOpen();
     emit databaseUnlocked();
 
+#ifdef WITH_XC_SSHAGENT
+    sshAgent()->databaseUnlocked(m_db);
+#endif
+
     if (senderDialog && senderDialog->intent() == DatabaseOpenDialog::Intent::AutoType) {
         QList<QSharedPointer<Database>> dbList;
         dbList.append(m_db);
@@ -1597,6 +1597,10 @@ bool DatabaseWidget::lock()
         m_entryBeforeLock = currentEntry->uuid();
     }
 
+#ifdef WITH_XC_SSHAGENT
+    sshAgent()->databaseLocked(m_db);
+#endif
+
     endSearch();
     clearAllWidgets();
     switchToOpenDatabase(m_db->filePath());

src/gui/MainWindow.cpp

@@ -601,6 +601,9 @@ MainWindow::MainWindow()
 
 MainWindow::~MainWindow()
 {
+#ifdef WITH_XC_SSHAGENT
+    sshAgent()->removeAllIdentities();
+#endif
 }
 
 QList<DatabaseWidget*> MainWindow::getOpenDatabases()

src/sshagent/SSHAgent.cpp

@@ -19,6 +19,9 @@
 #include "SSHAgent.h"
 
 #include "core/Config.h"
+#include "core/Database.h"
+#include "core/Group.h"
+#include "core/Metadata.h"
 #include "crypto/ssh/BinaryStream.h"
 #include "crypto/ssh/OpenSSHKey.h"
 #include "sshagent/KeeAgentSettings.h"
@@ -31,11 +34,6 @@
 
 Q_GLOBAL_STATIC(SSHAgent, s_sshAgent);
 
-SSHAgent::~SSHAgent()
-{
-    removeAllIdentities();
-}
-
 SSHAgent* SSHAgent::instance()
 {
     return s_sshAgent;
@@ -427,18 +425,15 @@ void SSHAgent::setAutoRemoveOnLock(const OpenSSHKey& key, bool autoRemove)
     }
 }
 
-void SSHAgent::databaseLocked()
+void SSHAgent::databaseLocked(QSharedPointer<Database> db)
 {
-    auto* widget = qobject_cast<DatabaseWidget*>(sender());
-    if (!widget) {
+    if (!db) {
         return;
     }
 
-    QUuid databaseUuid = widget->database()->uuid();
-
     auto it = m_addedKeys.begin();
     while (it != m_addedKeys.end()) {
-        if (it.value().first != databaseUuid) {
+        if (it.value().first != db->uuid()) {
             ++it;
             continue;
         }
@@ -452,16 +447,14 @@ void SSHAgent::databaseLocked()
     }
 }
 
-void SSHAgent::databaseUnlocked()
+void SSHAgent::databaseUnlocked(QSharedPointer<Database> db)
 {
-    auto* widget = qobject_cast<DatabaseWidget*>(sender());
-    if (!widget) {
+    if (!db || !isEnabled()) {
         return;
     }
 
-    for (Entry* e : widget->database()->rootGroup()->entriesRecursive()) {
-        if (widget->database()->metadata()->recycleBinEnabled()
-            && e->group() == widget->database()->metadata()->recycleBin()) {
+    for (Entry* e : db->rootGroup()->entriesRecursive()) {
+        if (db->metadata()->recycleBinEnabled() && e->group() == db->metadata()->recycleBin()) {
             continue;
         }
 
@@ -483,7 +476,7 @@ void SSHAgent::databaseUnlocked()
 
         // Add key to agent; ignore errors if we have previously added the key
         bool known_key = m_addedKeys.contains(key);
-        if (!addIdentity(key, settings, widget->database()->uuid()) && !known_key) {
+        if (!addIdentity(key, settings, db->uuid()) && !known_key) {
             emit error(m_error);
         }
     }

src/sshagent/SSHAgent.h

@@ -24,7 +24,6 @@
 #include <QtCore>
 
 #include "crypto/ssh/OpenSSHKey.h"
-#include "gui/DatabaseWidget.h"
 #include "sshagent/KeeAgentSettings.h"
 
 class SSHAgent : public QObject
@@ -32,7 +31,7 @@ class SSHAgent : public QObject
     Q_OBJECT
 
 public:
-    ~SSHAgent() override;
+    ~SSHAgent() override = default;
     static SSHAgent* instance();
 
     bool isEnabled() const;
@@ -59,8 +58,8 @@ signals:
     void enabledChanged(bool enabled);
 
 public slots:
-    void databaseLocked();
-    void databaseUnlocked();
+    void databaseLocked(QSharedPointer<Database> db);
+    void databaseUnlocked(QSharedPointer<Database> db);
 
 private:
     const quint8 SSH_AGENT_FAILURE = 5;