Fix connect-time username prompt never reaching SSH/RDP authentication

The username entered at the connect-time prompt (added for issue #21)
was updating SessionTab's own in-memory Profile copy, but
SshSessionBackend/RdpSessionBackend are constructed with -- and only
ever read from -- their own separate Profile copy on a worker thread,
which never saw that edit. Authentication was still built from the
original (blank) username regardless of what was typed into the
prompt.

SessionConnectOptions gains a username field, populated by SessionTab
on every connect attempt and threaded through the same way password
already is; both backends now prefer options.username over
profile().username. Covered by a new SSH regression test using an
exact-match fixture host that only succeeds for a specific
user@host target.

Bump version to v2026.9.16.5.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

CMakeLists.txt

@@ -1,6 +1,6 @@
 cmake_minimum_required(VERSION 3.21)
 
-project(OrbitHub VERSION 2026.9.16 LANGUAGES CXX)
+project(OrbitHub VERSION 2026.9.16.5 LANGUAGES CXX)
 
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)

docs/PROGRESS.md

@@ -157,6 +157,58 @@ Delivered:
   gets its own prompt, with an empty password allowed through (unlike
   RDP's hard requirement) since some VNC servers are no-auth and there's
   no way to know that before the server's security-type negotiation
+- Profiles can now leave the username blank for every protocol (issue
+  #21): SSH/RDP previously hard-required one at profile-save time; that
+  validation is gone, and `SessionTab` now asks for it at connect time
+  instead (reusing the existing password-prompt bar in unmasked mode),
+  same as it already does for a blank password. VNC's username is only
+  ever asked for if the server's negotiated auth method actually needs
+  one -- plain VNC Authentication and no-auth never do, only the two
+  Apple schemes (30/33) do -- which happens *mid-connection*, after the
+  backend has already picked a security type, not before connecting like
+  SSH/RDP. This needed a new async request/response pair on
+  `SessionBackend` (`usernameRequested()` / `provideUsername()`,
+  mirroring the existing SSH host-key-confirmation pattern):
+  `VncSessionBackend` pauses its state machine mid-parse (without
+  consuming the already-buffered response bytes) and emits the request,
+  resuming once `SessionTab` answers; cancelling fails the connection
+  cleanly rather than sending Apple auth a blank username. The value is
+  kept on the tab's in-memory profile copy for its lifetime, not written
+  back to the saved profile
+- The blank-username relaxation above initially only covered
+  `ProfileDialog`'s own save-time validation; `ProfileRepository::
+  isProfileValid()` had the identical "username required for SSH/RDP"
+  check independently, called directly by `insertProfile()`/
+  `updateProfile()` -- which is exactly the path mRemoteNG import uses
+  (it builds `Profile` objects and inserts them directly, never going
+  through the dialog), so importing any SSH/RDP entry without a
+  username still failed outright until this second check was found and
+  removed too
+- A third, independent username check was still live even after the two
+  above were removed: `SessionTab::validateProfileForConnect()` (run at
+  the very top of `connectSession()`/`reconnectSession()`, before
+  `requestConnectOptions()` ever gets a chance to run its async prompt)
+  had its own hard-fail "SSH/RDP username is required" `QMessageBox`,
+  so a blank-username profile still couldn't connect at all -- it just
+  told the user to go edit the profile instead of ever prompting inline.
+  Removed; connect-time prompting is now the only username gate for
+  SSH/RDP
+- Even with the three checks above gone, a username entered at the
+  connect-time prompt still never actually reached SSH or RDP
+  authentication: `SshSessionBackend`/`RdpSessionBackend` are constructed
+  with their own `Profile` copy up front (moved to a worker thread) and
+  read `profile().username` directly, which never sees `SessionTab`'s
+  later edit to its own in-memory profile once the user answers the
+  prompt. `SessionConnectOptions` (which already carries `password` the
+  same way) gained a `username` field, populated by `SessionTab` from
+  its profile copy on every connect attempt; both backends now prefer
+  `options.username` over `profile().username` when building the actual
+  connect target/auth call. Covered by a new SSH regression test
+  (`tests/fixtures/fake_ssh.sh`'s `requireuser` host only accepts an
+  exact `prompted-user@requireuser` target, so the test fails unless the
+  option, not the stale profile copy, is actually used) -- RDP has no
+  equivalent fake-server test harness, so that side relies on mirroring
+  the already-tested `m_activeOptions.password` pattern exactly
 - Robustness fix: an unrecognized `FramebufferUpdate` rectangle encoding
   used to abort the connection generically; `kAnnouncedEncodings` is now
   the single source of truth for what `SetEncodings` announces and what

src/profile_dialog.cpp

@@ -257,13 +257,6 @@ void ProfileDialog::accept()
     }
 
     const QString protocol = m_protocolInput->currentText();
-    if ((protocol == QStringLiteral("SSH") || protocol == QStringLiteral("RDP"))
-        && m_usernameInput->text().trimmed().isEmpty()) {
-        QMessageBox::warning(this,
-                             QStringLiteral("Validation Error"),
-                             QStringLiteral("Username is required for %1 profiles.").arg(protocol));
-        return;
-    }
 
     if (protocol == QStringLiteral("SSH")
         && m_authModeInput->currentText() == QStringLiteral("Private Key")) {
@@ -310,12 +303,14 @@ void ProfileDialog::refreshAuthFields()
 
     if (isSsh) {
         m_usernameInput->setPlaceholderText(QStringLiteral("deploy"));
-        m_protocolHint->setText(
+        m_protocolHint->setText(QStringLiteral(
-            QStringLiteral("SSH: username is required. Choose Password or Private Key auth."));
+            "SSH: you'll be asked for a username at connect time if left blank here. "
+            "Choose Password or Private Key auth."));
     } else if (isRdp) {
         m_usernameInput->setPlaceholderText(QStringLiteral("Administrator"));
-        m_protocolHint->setText(
+        m_protocolHint->setText(QStringLiteral(
-            QStringLiteral("RDP: username and password are required. Domain is optional."));
+            "RDP: you'll be asked for a username at connect time if left blank here. "
+            "Domain is optional."));
     } else if (isVnc) {
         m_usernameInput->setPlaceholderText(QStringLiteral("optional"));
         m_protocolHint->setText(QStringLiteral(

src/profile_repository.cpp

@@ -235,13 +235,6 @@ bool isProfileValid(const Profile& profile, QString* error)
     }
 
     const QString protocol = normalizedProtocol(profile.protocol);
-    if ((protocol == QStringLiteral("SSH") || protocol == QStringLiteral("RDP"))
-        && profile.username.trimmed().isEmpty()) {
-        if (error != nullptr) {
-            *error = QStringLiteral("Username is required for %1 profiles.").arg(protocol);
-        }
-        return false;
-    }
 
     const QString authMode = normalizedAuthMode(protocol, profile.authMode);
     if (protocol == QStringLiteral("SSH") && authMode == QStringLiteral("Private Key")

src/rdp_session_backend.cpp

@@ -1640,7 +1640,13 @@ void RdpSessionBackend::workerMain()
     const Profile& p = profile();
 
     const QString host = p.host.trimmed();
-    QString username = p.username.trimmed();
+    // m_activeOptions.username carries a value prompted for at connect time
+    // (see SessionTab::requestConnectOptions()) when the saved profile's
+    // own username was blank; profile().username never sees that edit
+    // since this backend's Profile copy was captured at construction time.
+    QString username = m_activeOptions.username.trimmed().isEmpty()
+        ? p.username.trimmed()
+        : m_activeOptions.username.trimmed();
     QString domain = p.domain.trimmed();
     if (domain.isEmpty()) {
         const int domainSeparator = username.indexOf(QLatin1Char('\\'));

src/session_backend.h

@@ -12,6 +12,12 @@
 class SessionConnectOptions
 {
 public:
+    // Only set when the profile's own username was blank and SessionTab
+    // prompted for one inline at connect time (see issue #21); empty means
+    // "use the backend's own profile().username" as before. SSH/RDP need
+    // this up front, unlike VNC's Apple auth which discovers the need for
+    // one mid-connection via usernameRequested()/provideUsername() instead.
+    QString username;
     QString password;
     QString privateKeyPath;
     QString knownHostsPolicy;
@@ -55,6 +61,16 @@ public slots:
     {
         Q_UNUSED(text);
     }
+    // Response to usernameRequested(), for backends that discover mid-
+    // connection (not before connectSession() is even called) that they
+    // need one -- currently only VNC's Apple authentication schemes,
+    // which only require a username for security types 30/33, not for
+    // plain VNC Authentication or no-auth. An empty username is treated
+    // the same as the prompt being cancelled.
+    virtual void provideUsername(const QString& username)
+    {
+        Q_UNUSED(username);
+    }
     virtual void sendKeyEvent(int key,
                               quint32 nativeScanCode,
                               const QString& text,
@@ -93,6 +109,10 @@ signals:
     void connectionError(const QString& displayMessage, const QString& rawMessage);
     void outputReceived(const QString& text);
     void hostKeyConfirmationRequested(const QString& prompt);
+    // Mirrors hostKeyConfirmationRequested()'s request/response shape, for
+    // a backend that discovers mid-connection it needs a username it
+    // wasn't given -- see provideUsername().
+    void usernameRequested(const QString& prompt);
     void frameUpdated(const QImage& frame);
     void remoteDesktopSizeChanged(int width, int height);
     void remoteClipboardTextChanged(const QString& text);

src/session_tab.cpp

@@ -215,6 +215,11 @@ SessionTab::SessionTab(const Profile& profile,
                 m_backend,
                 &SessionBackend::setClipboardText,
                 Qt::QueuedConnection);
+        connect(this,
+                &SessionTab::requestProvideUsername,
+                m_backend,
+                &SessionBackend::provideUsername,
+                Qt::QueuedConnection);
 
         connect(m_backend,
                 &SessionBackend::stateChanged,
@@ -241,6 +246,11 @@ SessionTab::SessionTab(const Profile& profile,
                 this,
                 &SessionTab::onBackendHostKeyConfirmationRequested,
                 Qt::QueuedConnection);
+        connect(m_backend,
+                &SessionBackend::usernameRequested,
+                this,
+                &SessionTab::onBackendUsernameRequested,
+                Qt::QueuedConnection);
         connect(m_backend,
                 &SessionBackend::frameUpdated,
                 this,
@@ -714,6 +724,16 @@ void SessionTab::onBackendHostKeyConfirmationRequested(const QString& prompt)
     emit requestHostKeyConfirmation(reply == QMessageBox::Yes);
 }
 
+void SessionTab::onBackendUsernameRequested(const QString& prompt)
+{
+    showPasswordPrompt(
+        prompt.isEmpty() ? QStringLiteral("Username for %1:").arg(m_profile.host) : prompt,
+        [this](std::optional<QString> username) {
+            emit requestProvideUsername(username.value_or(QString()).trimmed());
+        },
+        false);
+}
+
 void SessionTab::onBackendRemoteClipboardTextChanged(const QString& text)
 {
     if (text == m_lastSyncedClipboardText) {
@@ -978,11 +998,35 @@ void SessionTab::requestConnectOptions(
 {
     SessionConnectOptions baseOptions;
     baseOptions.knownHostsPolicy = m_profile.knownHostsPolicy;
+    // The backend's own Profile copy was captured when it was constructed
+    // and never sees later edits to m_profile (e.g. the username prompt
+    // below) -- it has to travel through here instead.
+    baseOptions.username = m_profile.username.trimmed();
 
     const bool isSsh = m_profile.protocol.compare(QStringLiteral("SSH"), Qt::CaseInsensitive) == 0;
     const bool isRdp = m_profile.protocol.compare(QStringLiteral("RDP"), Qt::CaseInsensitive) == 0;
     const bool isVnc = m_profile.protocol.compare(QStringLiteral("VNC"), Qt::CaseInsensitive) == 0;
 
+    // SSH and RDP always need a username; a profile is now allowed to
+    // leave it blank (see profile_dialog.cpp) and get asked here instead,
+    // the same way a blank password is already handled below. The value
+    // is kept on this in-memory m_profile copy for the rest of the tab's
+    // lifetime, not written back to the saved profile.
+    if ((isSsh || isRdp) && m_profile.username.trimmed().isEmpty()) {
+        showPasswordPrompt(
+            QStringLiteral("%1 username for %2:").arg(m_profile.protocol, m_profile.host),
+            [this, callback](std::optional<QString> username) {
+                if (!username.has_value() || username->trimmed().isEmpty()) {
+                    callback(std::nullopt);
+                    return;
+                }
+                m_profile.username = username->trimmed();
+                requestConnectOptions(callback);
+            },
+            false);
+        return;
+    }
+
     if (isVnc) {
         // Unlike RDP, an empty password is allowed through: some VNC
         // servers (no-auth) don't need one at all, and there's no
@@ -1102,7 +1146,8 @@ void SessionTab::requestConnectOptions(
 }
 
 void SessionTab::showPasswordPrompt(const QString& labelText,
-                                    std::function<void(std::optional<QString>)> callback)
+                                    std::function<void(std::optional<QString>)> callback,
+                                    bool maskInput)
 {
     if (m_passwordPromptCallback) {
         const auto previousCallback = m_passwordPromptCallback;
@@ -1113,6 +1158,7 @@ void SessionTab::showPasswordPrompt(const QString& labelText,
     m_passwordPromptCallback = std::move(callback);
     m_passwordPromptLabel->setText(labelText);
     m_passwordPromptInput->clear();
+    m_passwordPromptInput->setEchoMode(maskInput ? QLineEdit::Password : QLineEdit::Normal);
     m_passwordPromptBar->setVisible(true);
     m_passwordPromptInput->setFocus();
 }
@@ -1139,14 +1185,10 @@ bool SessionTab::validateProfileForConnect()
         return false;
     }
 
-    if ((m_profile.protocol.compare(QStringLiteral("SSH"), Qt::CaseInsensitive) == 0
+    // SSH/RDP no longer hard-require a username here -- a blank one is
-         || m_profile.protocol.compare(QStringLiteral("RDP"), Qt::CaseInsensitive) == 0)
+    // handled by requestConnectOptions() prompting for it inline at connect
-        && m_profile.username.trimmed().isEmpty()) {
+    // time (see issue #21). Do not re-add a check here without also
-        QMessageBox::warning(this,
+    // updating that flow.
-                             QStringLiteral("Connect"),
-                             QStringLiteral("%1 username is required.").arg(m_profile.protocol));
-        return false;
-    }
 
     return true;
 }

src/session_tab.h

@@ -91,6 +91,7 @@ signals:
     void requestMouseButtonEvent(int x, int y, int button, bool pressed);
     void requestMouseWheelEvent(int x, int y, int deltaX, int deltaY);
     void requestSetClipboardText(const QString& text);
+    void requestProvideUsername(const QString& username);
 
 private slots:
     void onBackendStateChanged(SessionState state, const QString& message);
@@ -98,6 +99,7 @@ private slots:
     void onBackendConnectionError(const QString& displayMessage, const QString& rawMessage);
     void onBackendOutputReceived(const QString& text);
     void onBackendHostKeyConfirmationRequested(const QString& prompt);
+    void onBackendUsernameRequested(const QString& prompt);
     void onBackendRemoteClipboardTextChanged(const QString& text);
     void onSystemClipboardChanged();
 
@@ -149,7 +151,8 @@ private:
     void setupUi();
     void requestConnectOptions(std::function<void(std::optional<SessionConnectOptions>)> callback);
     void showPasswordPrompt(const QString& labelText,
-                            std::function<void(std::optional<QString>)> callback);
+                            std::function<void(std::optional<QString>)> callback,
+                            bool maskInput = true);
     void hidePasswordPrompt();
     bool validateProfileForConnect();
     void appendEvent(const QString& message);

src/ssh_session_backend.cpp

@@ -388,9 +388,16 @@ bool SshSessionBackend::startSshProcess(const SessionConnectOptions& options)
              << QStringLiteral("PasswordAuthentication=no");
     }
 
-    const QString target = p.username.trimmed().isEmpty()
+    // options.username carries a value prompted for at connect time (see
+    // SessionTab::requestConnectOptions()) when the saved profile's own
+    // username was blank; profile().username never sees that edit since
+    // the backend's Profile copy was captured at construction time.
+    const QString username = options.username.trimmed().isEmpty()
+        ? p.username.trimmed()
+        : options.username.trimmed();
+    const QString target = username.isEmpty()
         ? p.host.trimmed()
-        : QStringLiteral("%1@%2").arg(p.username.trimmed(), p.host.trimmed());
+        : QStringLiteral("%1@%2").arg(username, p.host.trimmed());
     args << target;
 
     m_process->setProcessEnvironment(environment);

src/vnc_session_backend.cpp

@@ -196,7 +196,8 @@ VncSessionBackend::VncSessionBackend(const Profile& profile, QObject* parent)
       m_tightCompressionMode(0),
       m_tightFilterId(0),
       m_tightLengthByteIndex(0),
-      m_appleAuthKeyLength(0)
+      m_appleAuthKeyLength(0),
+      m_waitingForUsername(false)
 {
     std::memset(m_zrleInflateStream, 0, sizeof(z_stream_s));
     for (z_stream_s* stream : m_tightInflateStreams) {
@@ -531,6 +532,8 @@ void VncSessionBackend::resetProtocolState()
     }
     m_appleAuthGenerator.clear();
     m_appleAuthKeyLength = 0;
+    m_waitingForUsername = false;
+    m_promptedUsername.clear();
 }
 
 bool VncSessionBackend::haveBytes(int count) const
@@ -671,6 +674,47 @@ void VncSessionBackend::sendAppleRsaHostKeyRequest()
     m_socket->write(msg);
 }
 
+QString VncSessionBackend::effectiveUsername() const
+{
+    const QString profileUsername = profile().username.trimmed();
+    return profileUsername.isEmpty() ? m_promptedUsername : profileUsername;
+}
+
+bool VncSessionBackend::ensureUsernameAvailable()
+{
+    if (!effectiveUsername().isEmpty()) {
+        return true;
+    }
+    if (!m_waitingForUsername) {
+        m_waitingForUsername = true;
+        emit usernameRequested(
+            QStringLiteral("A username is required for %1's authentication method:")
+                .arg(profile().host));
+    }
+    return false;
+}
+
+void VncSessionBackend::provideUsername(const QString& username)
+{
+    if (!m_waitingForUsername) {
+        return;
+    }
+    m_waitingForUsername = false;
+    if (m_state != SessionState::Connecting) {
+        // The connection already failed or was torn down while the
+        // prompt was pending -- nothing left to resume.
+        return;
+    }
+    m_promptedUsername = username.trimmed();
+    if (m_promptedUsername.isEmpty()) {
+        failConnection(
+            QStringLiteral("A username is required for this VNC server's authentication method."),
+            QStringLiteral("Username prompt was cancelled or left empty"));
+        return;
+    }
+    processReceiveBuffer();
+}
+
 void VncSessionBackend::finishHandshakeIntoRunningState()
 {
     emit remoteDesktopSizeChanged(m_framebuffer.width(), m_framebuffer.height());
@@ -963,13 +1007,20 @@ void VncSessionBackend::processReceiveBuffer()
             if (!haveBytes(static_cast<int>(m_pendingLength))) {
                 return;
             }
+            // Checked before consuming any bytes: if a username is needed
+            // and not yet available, pause here (leaving m_recvBuffer
+            // untouched) until provideUsername() resumes us and this same
+            // case re-parses identically.
+            if (!ensureUsernameAvailable()) {
+                return;
+            }
             const int keyLength = static_cast<int>(m_appleAuthKeyLength);
             const QByteArray prime = m_recvBuffer.left(keyLength);
             const QByteArray serverPublicKey = m_recvBuffer.mid(keyLength, keyLength);
             m_recvBuffer.remove(0, static_cast<int>(m_pendingLength));
 
             const VncAppleDhAuth::Response response = VncAppleDhAuth::computeResponse(
-                m_appleAuthGenerator, prime, serverPublicKey, profile().username,
+                m_appleAuthGenerator, prime, serverPublicKey, effectiveUsername(),
                 m_activeOptions.password);
             if (response.clientPublicKey.isEmpty()) {
                 failConnection(
@@ -1020,11 +1071,15 @@ void VncSessionBackend::processReceiveBuffer()
             if (!haveBytes(totalBytes)) {
                 return;
             }
+            // See the matching comment in WaitingAppleAuthPrimeAndServerKey.
+            if (!ensureUsernameAvailable()) {
+                return;
+            }
             const QByteArray hostKeyDer = m_recvBuffer.left(static_cast<int>(m_pendingLength));
             m_recvBuffer.remove(0, totalBytes);
 
             const VncAppleRsaAuth::Response response = VncAppleRsaAuth::computeResponse(
-                hostKeyDer, profile().username, m_activeOptions.password);
+                hostKeyDer, effectiveUsername(), m_activeOptions.password);
             if (response.encryptedCredentials.isEmpty() || response.encryptedAesKey.isEmpty()) {
                 failConnection(
                     QStringLiteral(

src/vnc_session_backend.h

@@ -84,6 +84,7 @@ public slots:
     void sendMouseButtonEvent(int x, int y, int button, bool pressed) override;
     void sendMouseWheelEvent(int x, int y, int deltaX, int deltaY) override;
     void setClipboardText(const QString& text) override;
+    void provideUsername(const QString& username) override;
 
 private slots:
     void onSocketConnected();
@@ -209,6 +210,16 @@ private:
     QByteArray m_appleAuthGenerator;
     quint32 m_appleAuthKeyLength;
 
+    // Apple auth (types 30 and 33) is the only case where VNC ever needs a
+    // username -- plain VNC Authentication and no-auth never do, so this
+    // isn't asked for upfront. If profile().username is empty when an
+    // Apple-auth response is about to be computed, processReceiveBuffer()
+    // pauses (leaving the already-buffered bytes untouched so re-entry
+    // re-parses them identically) and emits usernameRequested(); resumed
+    // by provideUsername() once SessionTab answers.
+    bool m_waitingForUsername;
+    QString m_promptedUsername;
+
     void setState(SessionState state, const QString& message);
     void resetProtocolState();
     void processReceiveBuffer();
@@ -227,6 +238,12 @@ private:
     QRect currentHextileTileRect() const;
     void advanceHextileTile();
     bool inflateTightStream(int streamIndex, const QByteArray& compressed, QByteArray* decompressed);
+    QString effectiveUsername() const;
+    // Returns false (and pauses, emitting usernameRequested() at most once
+    // until provideUsername() resumes processing) if a username is needed
+    // but not yet available. Callers must return from processReceiveBuffer()
+    // immediately when this returns false, without consuming any bytes.
+    bool ensureUsernameAvailable();
 };
 
 #endif

tests/fixtures/fake_ssh.sh

@@ -6,6 +6,22 @@
 # host, optionally as user@host, as the final argument).
 for arg in "$@"; do
     case "$arg" in
+        prompted-user@requireuser)
+            # Only the exact user@host below is accepted -- used to prove a
+            # username supplied via SessionConnectOptions (prompted for at
+            # connect time because the saved profile's own username was
+            # blank) actually reaches the ssh command line, not just that
+            # *some* connection to this host succeeds.
+            echo "Welcome to the fake host."
+            while IFS= read -r line; do
+                echo "$line"
+            done
+            exit 0
+            ;;
+        *@requireuser|requireuser)
+            echo "Permission denied (publickey,password)." >&2
+            exit 255
+            ;;
         *@succeed|succeed)
             echo "Welcome to the fake host."
             # Stay alive echoing stdin back (simulates an interactive

tests/test_profile_repository.cpp

@@ -48,7 +48,7 @@ private slots:
     void createProfileRejectsMissingName();
     void createProfileRejectsMissingHost();
     void createProfileRejectsInvalidPort();
-    void createProfileRejectsMissingUsernameForSsh();
+    void createProfileAllowsMissingUsernameForSsh();
     void createProfileRejectsMissingPrivateKeyForKeyAuth();
     void createProfileRejectsDuplicateName();
     void updateProfilePersistsChanges();
@@ -156,11 +156,17 @@ void TestProfileRepository::createProfileRejectsInvalidPort()
     QVERIFY(!m_repo->createProfile(profile).has_value());
 }
 
-void TestProfileRepository::createProfileRejectsMissingUsernameForSsh()
+void TestProfileRepository::createProfileAllowsMissingUsernameForSsh()
 {
+    // SSH/RDP no longer require a username at save time (issue #21) --
+    // among other things, this unblocks importing mRemoteNG entries that
+    // don't have one recorded, which used to fail outright. The user is
+    // asked for it at connect time instead (see SessionTab).
     Profile profile = makeSshProfile();
     profile.username.clear();
-    QVERIFY(!m_repo->createProfile(profile).has_value());
+    const auto created = m_repo->createProfile(profile);
+    QVERIFY(created.has_value());
+    QVERIFY(created->username.isEmpty());
 }
 
 void TestProfileRepository::createProfileRejectsMissingPrivateKeyForKeyAuth()

tests/test_ssh_session_backend.cpp

@@ -21,6 +21,13 @@ Profile makeProfile(const QString& fixtureHost)
     return profile;
 }
 
+Profile makeBlankUsernameProfile(const QString& fixtureHost)
+{
+    Profile profile = makeProfile(fixtureHost);
+    profile.username.clear();
+    return profile;
+}
+
 SessionConnectOptions makeOptions()
 {
     SessionConnectOptions options;
@@ -50,10 +57,12 @@ private slots:
     void connectionRefusedReachesFailedState();
     void sendInputEchoesThroughOutputReceived();
     void reconnectRestartsAndReachesConnectedAgain();
+    void connectOptionsUsernameReachesProcessWhenProfileUsernameIsBlank();
 
 private:
     QString fixturePath() const;
     void createBackend(const QString& fixtureHost);
+    void createBackend(const Profile& profile);
 
     std::unique_ptr<SshSessionBackend> m_backend;
     SessionState m_lastState = SessionState::Disconnected;
@@ -69,8 +78,12 @@ QString TestSshSessionBackend::fixturePath() const
 
 void TestSshSessionBackend::createBackend(const QString& fixtureHost)
 {
-    m_backend =
+    createBackend(makeProfile(fixtureHost));
-        std::make_unique<SshSessionBackend>(makeProfile(fixtureHost), fixturePath(), nullptr);
+}
+
+void TestSshSessionBackend::createBackend(const Profile& profile)
+{
+    m_backend = std::make_unique<SshSessionBackend>(profile, fixturePath(), nullptr);
     connect(m_backend.get(),
             &SessionBackend::stateChanged,
             this,
@@ -232,5 +245,24 @@ void TestSshSessionBackend::reconnectRestartsAndReachesConnectedAgain()
     QTRY_COMPARE(m_lastState, SessionState::Connected);
 }
 
+void TestSshSessionBackend::connectOptionsUsernameReachesProcessWhenProfileUsernameIsBlank()
+{
+    // Regression test for a bug where a username entered at the
+    // connect-time prompt (SessionTab::requestConnectOptions(), for a
+    // profile with no saved username -- issue #21) never actually reached
+    // the ssh process: SshSessionBackend built its target purely from
+    // profile().username, which is a separate copy captured when the
+    // backend was constructed and never sees SessionTab's later edit.
+    // fixtures/fake_ssh.sh's "requireuser" host only accepts the exact
+    // target "prompted-user@requireuser", so this fails unless
+    // SessionConnectOptions::username is actually used.
+    createBackend(makeBlankUsernameProfile(QStringLiteral("requireuser")));
+
+    SessionConnectOptions options = makeOptions();
+    options.username = QStringLiteral("prompted-user");
+    m_backend->connectSession(options);
+    QTRY_COMPARE(m_lastState, SessionState::Connected);
+}
+
 QTEST_GUILESS_MAIN(TestSshSessionBackend)
 #include "test_ssh_session_backend.moc"

tests/test_vnc_session_backend.cpp

@@ -420,6 +420,7 @@ private slots:
     void connectsWithAppleDhAuthenticationRfb38();
     void appleDhAuthIsPreferredOverVncAuthWhenBothOffered();
     void appleDhAuthAcceptsRealCapturedMacOsServerParameters();
+    void cancellingUsernamePromptFailsConnectionCleanly();
 
 private:
     std::unique_ptr<FakeVncServer> m_server;
@@ -2036,8 +2037,20 @@ void TestVncSessionBackend::connectsWithAppleDhAuthenticationRfb38()
         }
     });
 
+    // makeVncProfile() sets no username, and Apple DH is the one VNC auth
+    // method that needs one -- expect the backend to pause and ask,
+    // exactly like a real profile with a blank username would hit at
+    // connect time (see issue #21 / SessionBackend::usernameRequested).
+    QString requestedPrompt;
+    connect(m_backend.get(), &SessionBackend::usernameRequested, this,
+            [this, &requestedPrompt](const QString& prompt) {
+                requestedPrompt = prompt;
+                m_backend->provideUsername(QStringLiteral("tester"));
+            });
+
     m_backend->connectSession(makeOptions(password));
     QTRY_COMPARE(m_lastState, SessionState::Connected);
+    QVERIFY(!requestedPrompt.isEmpty());
 
     // Verify wire order: encrypted credentials (128 bytes) MUST come
     // before the client's public key, per neatvnc's authoritative
@@ -2085,7 +2098,9 @@ void TestVncSessionBackend::connectsWithAppleDhAuthenticationRfb38()
     EVP_CIPHER_CTX_free(decCtx);
 
     QByteArray expected(128, char(0));
+    const QByteArray userBytes = QByteArrayLiteral("tester").left(64);
     const QByteArray passBytes = password.toLatin1().left(64);
+    std::memcpy(expected.data(), userBytes.constData(), static_cast<size_t>(userBytes.size()));
     std::memcpy(expected.data() + 64, passBytes.constData(), static_cast<size_t>(passBytes.size()));
     QCOMPARE(plain, expected);
 
@@ -2172,5 +2187,51 @@ void TestVncSessionBackend::appleDhAuthAcceptsRealCapturedMacOsServerParameters(
     QCOMPARE(response.encryptedCredentials.size(), 128);
 }
 
+void TestVncSessionBackend::cancellingUsernamePromptFailsConnectionCleanly()
+{
+    ToyDhKeypair serverKeypair = generateToyDhKeypair();
+    const QByteArray authMessage = appleDhAuthServerMessage(
+        serverKeypair.generatorBytes, serverKeypair.primeBytes, serverKeypair.publicKeyBytes);
+
+    bool gotUsernameRequest = false;
+    connect(m_backend.get(), &SessionBackend::usernameRequested, this,
+            [this, &gotUsernameRequest](const QString&) {
+                gotUsernameRequest = true;
+                // An empty response mirrors the prompt being cancelled
+                // (see SessionTab::onBackendUsernameRequested).
+                m_backend->provideUsername(QString());
+            });
+
+    connect(m_server.get(), &FakeVncServer::clientConnected, this, [this]() {
+        m_server->sendWhenConnected(QByteArray("RFB 003.008\n"));
+    });
+    connect(m_server.get(), &FakeVncServer::dataReceived, this, [this, authMessage]() {
+        switch (m_server->nextStep()) {
+        case 0: {
+            QByteArray securityTypes;
+            securityTypes.append(char(1));
+            securityTypes.append(char(30)); // Apple's scheme -- no other option offered
+            m_server->sendWhenConnected(securityTypes);
+            break;
+        }
+        case 1:
+            m_server->sendWhenConnected(authMessage);
+            break;
+        default:
+            break;
+        }
+    });
+
+    // No username in the profile (makeVncProfile() sets none) and no
+    // other security type to fall back to.
+    m_backend->connectSession(makeOptions(QStringLiteral("s3cret-pass")));
+    QTRY_COMPARE(m_lastState, SessionState::Failed);
+    QVERIFY(gotUsernameRequest);
+    QVERIFY(m_lastErrorDisplay.contains(QStringLiteral("username"), Qt::CaseInsensitive));
+
+    BN_free(serverKeypair.privateExponent);
+    BN_free(serverKeypair.prime);
+}
+
 QTEST_GUILESS_MAIN(TestVncSessionBackend)
 #include "test_vnc_session_backend.moc"