SSH: Add ssh-askpass implementation

There is no standard implementation for the ssh-askpass tool on any
platform, so we currently can't find one on our own. In particular, this
means that the RemoteLinux device test will always fail for a newly
added device, which is not acceptable.
So we just add our own askpass implementation and point the SSH settings
to it.

Change-Id: I7ca18725e63f591ef9defdf13768a21cc3de4a54
Reviewed-by: hjk <hjk@qt.io>

src/libs/ssh/sshprocess.cpp

@@ -40,8 +40,13 @@ namespace Internal {
 SshProcess::SshProcess()
 {
     Utils::Environment env = Utils::Environment::systemEnvironment();
-    if (SshSettings::askpassFilePath().exists())
+    if (SshSettings::askpassFilePath().exists()) {
         env.set("SSH_ASKPASS", SshSettings::askpassFilePath().toUserOutput());
+
+        // OpenSSH only uses the askpass program if DISPLAY is set, regardless of the platform.
+        if (!env.hasKey("DISPLAY"))
+            env.set("DISPLAY", ":0");
+    }
     setProcessEnvironment(env.toProcessEnvironment());
 }
 

src/libs/ssh/sshsettings.cpp

@@ -113,12 +113,23 @@ int SshSettings::connectionSharingTimeout()
     return sshSettings->connectionSharingTimeOutInMinutes;
 }
 
-static FileName filePathValue(const FileName &value, const QString &defaultFileName)
+static FileName filePathValue(const FileName &value, const QStringList &candidateFileNames)
 {
-    return !value.isEmpty()
+    if (!value.isEmpty())
-            ? value
+        return value;
-            : Environment::systemEnvironment().searchInPath(defaultFileName,
+    const QList<FileName> additionalSearchPaths = sshSettings->searchPathRetriever();
-                                                            sshSettings->searchPathRetriever());
+    for (const QString &candidate : candidateFileNames) {
+        const FileName filePath = Environment::systemEnvironment()
+                .searchInPath(candidate, additionalSearchPaths);
+        if (!filePath.isEmpty())
+            return filePath;
+    }
+    return FileName();
+}
+
+static FileName filePathValue(const FileName &value, const QString &candidateFileName)
+{
+    return filePathValue(value, QStringList(candidateFileName));
 }
 
 void SshSettings::setSshFilePath(const FileName &ssh) { sshSettings->sshFilePath = ssh; }
@@ -138,7 +149,7 @@ FileName SshSettings::askpassFilePath()
     candidate = sshSettings->askpassFilePath;
     if (candidate.isEmpty())
         candidate = FileName::fromString(Environment::systemEnvironment().value("SSH_ASKPASS"));
-    return filePathValue(candidate, "ssh-askpass");
+    return filePathValue(candidate, QStringList{"qtc-askpass", "ssh-askpass"});
 }
 
 void SshSettings::setKeygenFilePath(const FileName &keygen)

src/plugins/projectexplorer/projectexplorer.cpp

@@ -1723,8 +1723,10 @@ void ProjectExplorerPlugin::extensionsInitialized()
     DeviceManager::instance()->addDevice(IDevice::Ptr(new DesktopDevice));
 
     QSsh::SshSettings::loadSettings(Core::ICore::settings());
-    if (Utils::HostOsInfo::isWindowsHost()) {
+    const auto searchPathRetriever = [] {
-        const auto searchPathRetriever = [] {
+        Utils::FileNameList searchPaths;
+        searchPaths << Utils::FileName::fromString(Core::ICore::libexecPath());
+        if (Utils::HostOsInfo::isWindowsHost()) {
             const QString gitBinary = Core::ICore::settings()->value("Git/BinaryPath", "git")
                     .toString();
             const QStringList rawGitSearchPaths = Core::ICore::settings()->value("Git/Path")
@@ -1733,15 +1735,14 @@ void ProjectExplorerPlugin::extensionsInitialized()
                     [](const QString &rawPath) { return Utils::FileName::fromString(rawPath); });
             const Utils::FileName fullGitPath = Utils::Environment::systemEnvironment()
                     .searchInPath(gitBinary, gitSearchPaths);
-            if (fullGitPath.isEmpty())
+            if (!fullGitPath.isEmpty()) {
-                return Utils::FileNameList();
+                searchPaths << fullGitPath.parentDir()
-            return Utils::FileNameList{
+                            << fullGitPath.parentDir().parentDir() + "/usr/bin";
-                fullGitPath.parentDir(),
+            }
-                fullGitPath.parentDir().parentDir() + "/usr/bin"
+        }
-            };
+        return searchPaths;
-        };
+    };
-        QSsh::SshSettings::setExtraSearchPathRetriever(searchPathRetriever);
+    QSsh::SshSettings::setExtraSearchPathRetriever(searchPathRetriever);
-    }
 
     // delay restoring kits until UI is shown for improved perceived startup performance
     QTimer::singleShot(0, this, &ProjectExplorerPlugin::restoreKits);

src/tools/qtc-askpass/qtc-askpass-main.cpp

@@ -0,0 +1,47 @@
+/****************************************************************************
+**
+** Copyright (C) 2018 The Qt Company Ltd.
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of Qt Creator.
+**
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3 as published by the Free Software
+** Foundation with exceptions as appearing in the file LICENSE.GPL3-EXCEPT
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-3.0.html.
+**
+****************************************************************************/
+
+#include <QApplication>
+#include <QInputDialog>
+#include <QTimer>
+#include <iostream>
+
+int main(int argc, char *argv[])
+{
+    QApplication app(argc, argv);
+    QTimer::singleShot(0, [] {
+        QInputDialog dlg;
+        const QStringList appArgs = qApp->arguments();
+        QString labelText = QCoreApplication::translate("qtc-askpass",
+                                                        "Password required for SSH login.");
+        if (appArgs.count() > 1)
+            labelText.append('\n').append(appArgs.at(1));
+        dlg.setLabelText(labelText);
+        dlg.setTextEchoMode(QLineEdit::Password);
+        if (dlg.exec() == QDialog::Accepted)
+            std::cout << qPrintable(dlg.textValue()) << std::endl;
+    });
+    return app.exec();
+}

src/tools/qtc-askpass/qtc-askpass.pro

@@ -0,0 +1,5 @@
+include(../../qtcreatortool.pri)
+
+TARGET = qtc-askpass
+
+SOURCES = qtc-askpass-main.cpp

src/tools/qtc-askpass/qtc-askpass.qbs

@@ -0,0 +1,9 @@
+import qbs
+
+QtcTool {
+    name: "qtc-askpass"
+    Depends { name: "Qt.widgets" }
+    files: [
+        "qtc-askpass-main.cpp",
+    ]
+}

src/tools/tools.pro

@@ -6,7 +6,8 @@ SUBDIRS = qtpromaker \
      ../plugins/cpaster/frontend \
      valgrindfake \
      3rdparty \
-     buildoutputparser
+     buildoutputparser \
+     qtc-askpass
 
 isEmpty(QTC_SKIP_SDKTOOL): SUBDIRS += sdktool
 

src/tools/tools.qbs

@@ -12,6 +12,7 @@ Project {
         "qml2puppet/qml2puppet.qbs",
         "qtcdebugger/qtcdebugger.qbs",
         "qtcreatorcrashhandler/qtcreatorcrashhandler.qbs",
+        "qtc-askpass/qtc-askpass.qbs",
         "qtpromaker/qtpromaker.qbs",
         "sdktool/sdktool.qbs",
         "valgrindfake/valgrindfake.qbs",