qt: Add job for refreshing OpenPGP keys via WKD

* lang/qt/src/wkdrefreshjob.cpp, lang/qt/src/wkdrefreshjob.h,
lang/qt/src/wkdrefreshjob_p.h, lang/qt/src/qgpgmewkdrefreshjob.cpp,
lang/qt/src/qgpgmewkdrefreshjob.h: New.
* lang/qt/src/protocol.h (class Protocol): Add pure virtual member
function wkdRefreshJob
* lang/qt/src/protocol_p.h (Protocol::wkdRefreshJob): ... and
implement it.
* lang/qt/src/Makefile.am: Update accordingly.

* lang/qt/tests/run-wkdrefreshjob.cpp: New.
* lang/qt/tests/Makefile.am: Add new test runner.
--

This job allows updating keys via WKD. Only user IDs that were
originally retrieved via WKD (i.e. which have origin WKD) are
considered.

GnuPG-bug-id: 6672

11 files changed, 545 insertions, 3 deletions

diff --git a/NEWS b/NEWS
index 60810787..7f38bee7 100644
--- a/NEWS
+++ b/NEWS
@@ -1,6 +1,12 @@
 Noteworthy changes in version 1.22.1 (unreleased)
 -------------------------------------------------
 
+ * qt: Support refreshing keys via WKD.  [T6672]
+
+ * Interface changes relative to the 1.22.0 release:
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+ qt: Protocol::wkdRefreshJob                NEW.
+ qt: WKDRefreshJob                          NEW.
 
 Noteworthy changes in version 1.22.0 (2023-08-21)
 -------------------------------------------------
diff --git a/lang/qt/src/Makefile.am b/lang/qt/src/Makefile.am
index 3b3f1e80..b6929f26 100644
--- a/lang/qt/src/Makefile.am
+++ b/lang/qt/src/Makefile.am
@@ -56,6 +56,7 @@ qgpgme_sources = \
     qgpgmesignencryptarchivejob.cpp \
     qgpgmesignjob.cpp qgpgmesignkeyjob.cpp qgpgmeverifydetachedjob.cpp \
     qgpgmeverifyopaquejob.cpp qgpgmewkdlookupjob.cpp threadedjobmixin.cpp \
+    qgpgmewkdrefreshjob.cpp \
     qgpgmekeyformailboxjob.cpp qgpgme_debug.cpp \
     qgpgmetofupolicyjob.cpp qgpgmequickjob.cpp \
     defaultkeygenerationjob.cpp qgpgmewkspublishjob.cpp \
@@ -64,7 +65,8 @@ qgpgme_sources = \
     signencryptjob.cpp \
     signencryptarchivejob.cpp \
     dn.cpp cryptoconfig.cpp wkdlookupresult.cpp \
-    util.cpp
+    util.cpp \
+    wkdrefreshjob.cpp
 
 # If you add one here make sure that you also add one in camelcase
 qgpgme_headers= \
@@ -115,6 +117,7 @@ qgpgme_headers= \
     tofupolicyjob.h \
     wkdlookupjob.h \
     wkdlookupresult.h \
+    wkdrefreshjob.h \
     wkspublishjob.h \
     gpgcardjob.h \
     dn.h
@@ -166,6 +169,7 @@ camelcase_headers= \
     DefaultKeyGenerationJob \
     WKDLookupJob \
     WKDLookupResult \
+    WKDRefreshJob \
     WKSPublishJob \
     TofuPolicyJob \
     GpgCardJob
@@ -211,6 +215,7 @@ private_qgpgme_headers = \
     qgpgmeverifydetachedjob.h \
     qgpgmeverifyopaquejob.h \
     qgpgmewkdlookupjob.h \
+    qgpgmewkdrefreshjob.h \
     qgpgmekeyformailboxjob.h \
     qgpgmewkspublishjob.h \
     qgpgmetofupolicyjob.h \
@@ -220,7 +225,8 @@ private_qgpgme_headers = \
     signencryptjob_p.h \
     signencryptarchivejob_p.h \
     threadedjobmixin.h \
-    util.h
+    util.h \
+    wkdrefreshjob_p.h
 
 qgpgme_moc_sources = \
     abstractimportjob.moc \
@@ -275,6 +281,7 @@ qgpgme_moc_sources = \
     qgpgmeverifydetachedjob.moc \
     qgpgmeverifyopaquejob.moc \
     qgpgmewkdlookupjob.moc \
+    qgpgmewkdrefreshjob.moc \
     qgpgmewkspublishjob.moc \
     tofupolicyjob.moc \
     qgpgmetofupolicyjob.moc \
@@ -291,6 +298,7 @@ qgpgme_moc_sources = \
     verifydetachedjob.moc \
     verifyopaquejob.moc \
     wkdlookupjob.moc \
+    wkdrefreshjob.moc \
     keyformailboxjob.moc \
     wkspublishjob.moc \
     qgpgmekeyformailboxjob.moc \
diff --git a/lang/qt/src/protocol.h b/lang/qt/src/protocol.h
index cbd93877..74fb921d 100644
--- a/lang/qt/src/protocol.h
+++ b/lang/qt/src/protocol.h
@@ -77,6 +77,7 @@ class GpgCardJob;
 class ReceiveKeysJob;
 class RevokeKeyJob;
 class SetPrimaryUserIDJob;
+class WKDRefreshJob;
 
 /** The main entry point for QGpgME Comes in OpenPGP and SMIME(CMS) flavors.
  *
@@ -198,6 +199,8 @@ public:
     virtual SignArchiveJob *signArchiveJob(bool armor = false) const = 0;
     virtual SignEncryptArchiveJob *signEncryptArchiveJob(bool armor = false) const = 0;
     virtual DecryptVerifyArchiveJob *decryptVerifyArchiveJob() const = 0;
+
+    virtual WKDRefreshJob *wkdRefreshJob() const = 0;
 };
 
 /** Obtain a reference to the OpenPGP Protocol.
diff --git a/lang/qt/src/protocol_p.h b/lang/qt/src/protocol_p.h
index fcb2b30a..b34b7a37 100644
--- a/lang/qt/src/protocol_p.h
+++ b/lang/qt/src/protocol_p.h
@@ -71,6 +71,7 @@
 #include "qgpgmereceivekeysjob.h"
 #include "qgpgmerevokekeyjob.h"
 #include "qgpgmesetprimaryuseridjob.h"
+#include "qgpgmewkdrefreshjob.h"
 
 namespace
 {
@@ -557,6 +558,17 @@ public:
         }
         return nullptr;
     }
+
+    QGpgME::WKDRefreshJob *wkdRefreshJob() const override
+    {
+        if (mProtocol != GpgME::OpenPGP) {
+            return nullptr;
+        }
+        if (auto context = GpgME::Context::createForProtocol(mProtocol)) {
+            return new QGpgME::QGpgMEWKDRefreshJob{context};
+        }
+        return nullptr;
+    }
 };
 
 }
diff --git a/lang/qt/src/qgpgmewkdrefreshjob.cpp b/lang/qt/src/qgpgmewkdrefreshjob.cpp
new file mode 100644
index 00000000..8bad1ef1
--- /dev/null
+++ b/lang/qt/src/qgpgmewkdrefreshjob.cpp
@@ -0,0 +1,147 @@
+/*
+    qgpgmewkdrefreshjob.cpp
+
+    This file is part of qgpgme, the Qt API binding for gpgme
+    Copyright (c) 2023 g10 Code GmbH
+    Software engineering by Ingo Klöcker <[email protected]>
+
+    QGpgME is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; either version 2 of the
+    License, or (at your option) any later version.
+
+    QGpgME is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+
+    In addition, as a special exception, the copyright holders give
+    permission to link the code of this program with any edition of
+    the Qt library by Trolltech AS, Norway (or with modified versions
+    of Qt that use the same license as Qt), and distribute linked
+    combinations including the two.  You must obey the GNU General
+    Public License in all respects for all of the code used other than
+    Qt.  If you modify this file, you may extend this exception to
+    your version of the file, but you are not obligated to do so.  If
+    you do not wish to do so, delete this exception statement from
+    your version.
+*/
+
+#ifdef HAVE_CONFIG_H
+ #include "config.h"
+#endif
+
+#include "qgpgmewkdrefreshjob.h"
+
+#include "debug.h"
+#include "qgpgme_debug.h"
+#include "qgpgmekeylistjob.h"
+#include "wkdrefreshjob_p.h"
+
+#include <context.h>
+
+#include <memory>
+
+using namespace QGpgME;
+using namespace GpgME;
+
+namespace
+{
+
+class QGpgMEWKDRefreshJobPrivate : public WKDRefreshJobPrivate
+{
+    QGpgMEWKDRefreshJob *q = nullptr;
+
+public:
+    QGpgMEWKDRefreshJobPrivate(QGpgMEWKDRefreshJob *qq)
+        : q{qq}
+    {
+    }
+
+    ~QGpgMEWKDRefreshJobPrivate() override = default;
+
+private:
+    GpgME::Error startIt() override;
+
+    void startNow() override
+    {
+        q->run();
+    }
+};
+
+static QStringList toEmailAddressesOriginatingFromWKD(const std::vector<GpgME::Key> &keys)
+{
+    const QStringList emails = std::accumulate(keys.begin(), keys.end(), QStringList{}, [](QStringList &emails, const Key &key) {
+        const auto userIDs = key.userIDs();
+        emails = std::accumulate(std::begin(userIDs), std::end(userIDs), emails, [](QStringList &emails, const UserID &userID) {
+            if (!userID.isRevoked() && !userID.addrSpec().empty() && userID.origin() == Key::OriginWKD) {
+                emails.push_back(QString::fromStdString(userID.addrSpec()));
+            }
+            return emails;
+        });
+        return emails;
+    });
+    return emails;
+}
+
+}
+
+QGpgMEWKDRefreshJob::QGpgMEWKDRefreshJob(Context *context)
+    : mixin_type{context}
+{
+    setJobPrivate(this, std::unique_ptr<QGpgMEWKDRefreshJobPrivate>{new QGpgMEWKDRefreshJobPrivate{this}});
+    lateInitialization();
+}
+
+QGpgMEWKDRefreshJob::~QGpgMEWKDRefreshJob() = default;
+
+static ImportResult locate_external_keys(Context *ctx, const std::vector<Key> &keys)
+{
+    const auto emails = toEmailAddressesOriginatingFromWKD(keys);
+    qCDebug(QGPGME_LOG) << __func__ << "locating external keys for" << emails;
+    if (emails.empty()) {
+        return ImportResult{};
+    }
+
+    Context::KeyListModeSaver saver{ctx};
+    ctx->setKeyListMode(GpgME::LocateExternal);
+    ctx->setFlag("auto-key-locate", "clear,wkd");
+    std::vector<Key> dummy;
+    auto job = std::unique_ptr<KeyListJob>{new QGpgMEKeyListJob{ctx}};
+    (void) job->exec(emails, false, dummy);
+    qCDebug(QGPGME_LOG) << __func__ << "number of keys:" << dummy.size();
+    std::for_each(dummy.cbegin(), dummy.cend(), [](const Key &k) {
+        qCDebug(QGPGME_LOG) << __func__ << toLogString(k).c_str();
+    });
+    const auto result = ctx->importResult();
+    qCDebug(QGPGME_LOG) << __func__ << "result:" << toLogString(result).c_str();
+    job.release();
+
+    return result;
+}
+
+static QGpgMEWKDRefreshJob::result_type refresh_keys(Context *ctx, const std::vector<Key> &keys)
+{
+    const auto result = locate_external_keys(ctx, keys);
+
+    return std::make_tuple(result, QString{}, Error{});
+}
+
+GpgME::Error QGpgMEWKDRefreshJobPrivate::startIt()
+{
+    if (m_keys.empty()) {
+        return Error::fromCode(GPG_ERR_INV_VALUE);
+    }
+
+    q->run([=](Context *ctx) {
+        return refresh_keys(ctx, m_keys);
+    });
+
+    return {};
+}
+
+#include "qgpgmewkdrefreshjob.moc"
diff --git a/lang/qt/src/qgpgmewkdrefreshjob.h b/lang/qt/src/qgpgmewkdrefreshjob.h
new file mode 100644
index 00000000..1b775aed
--- /dev/null
+++ b/lang/qt/src/qgpgmewkdrefreshjob.h
@@ -0,0 +1,64 @@
+/*
+    qgpgmewkdrefreshjob.h
+
+    This file is part of qgpgme, the Qt API binding for gpgme
+    Copyright (c) 2023 g10 Code GmbH
+    Software engineering by Ingo Klöcker <[email protected]>
+
+    QGpgME is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; either version 2 of the
+    License, or (at your option) any later version.
+
+    QGpgME is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+
+    In addition, as a special exception, the copyright holders give
+    permission to link the code of this program with any edition of
+    the Qt library by Trolltech AS, Norway (or with modified versions
+    of Qt that use the same license as Qt), and distribute linked
+    combinations including the two.  You must obey the GNU General
+    Public License in all respects for all of the code used other than
+    Qt.  If you modify this file, you may extend this exception to
+    your version of the file, but you are not obligated to do so.  If
+    you do not wish to do so, delete this exception statement from
+    your version.
+*/
+
+#ifndef __QGPGME_QGPGMEWKDREFRESHJOB_H__
+#define __QGPGME_QGPGMEWKDREFRESHJOB_H__
+
+#include "threadedjobmixin.h"
+#include "wkdrefreshjob.h"
+
+#include <importresult.h>
+
+namespace QGpgME
+{
+
+class QGpgMEWKDRefreshJob
+#ifdef Q_MOC_RUN
+    : public WKDRefreshJob
+#else
+    : public _detail::ThreadedJobMixin<WKDRefreshJob, std::tuple<GpgME::ImportResult, QString, GpgME::Error>>
+#endif
+{
+    Q_OBJECT
+#ifdef Q_MOC_RUN
+public Q_SLOTS:
+    void slotFinished();
+#endif
+public:
+    explicit QGpgMEWKDRefreshJob(GpgME::Context *context);
+    ~QGpgMEWKDRefreshJob() override;
+};
+
+}
+
+#endif // __QGPGME_QGPGMEWKDREFRESHJOB_H__
diff --git a/lang/qt/src/wkdrefreshjob.cpp b/lang/qt/src/wkdrefreshjob.cpp
new file mode 100644
index 00000000..37b990c8
--- /dev/null
+++ b/lang/qt/src/wkdrefreshjob.cpp
@@ -0,0 +1,57 @@
+/*
+    wkdrefreshjob.cpp
+
+    This file is part of qgpgme, the Qt API binding for gpgme
+    Copyright (c) 2023 g10 Code GmbH
+    Software engineering by Ingo Klöcker <[email protected]>
+
+    QGpgME is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; either version 2 of the
+    License, or (at your option) any later version.
+
+    QGpgME is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+
+    In addition, as a special exception, the copyright holders give
+    permission to link the code of this program with any edition of
+    the Qt library by Trolltech AS, Norway (or with modified versions
+    of Qt that use the same license as Qt), and distribute linked
+    combinations including the two.  You must obey the GNU General
+    Public License in all respects for all of the code used other than
+    Qt.  If you modify this file, you may extend this exception to
+    your version of the file, but you are not obligated to do so.  If
+    you do not wish to do so, delete this exception statement from
+    your version.
+*/
+
+#ifdef HAVE_CONFIG_H
+ #include "config.h"
+#endif
+
+#include "wkdrefreshjob.h"
+#include "wkdrefreshjob_p.h"
+
+using namespace QGpgME;
+
+WKDRefreshJob::WKDRefreshJob(QObject *parent)
+    : AbstractImportJob{parent}
+{
+}
+
+WKDRefreshJob::~WKDRefreshJob() = default;
+
+GpgME::Error WKDRefreshJob::start(const std::vector<GpgME::Key> &keys)
+{
+    auto d = jobPrivate<WKDRefreshJobPrivate>(this);
+    d->m_keys = keys;
+    return d->startIt();
+}
+
+#include "wkdrefreshjob.moc"
diff --git a/lang/qt/src/wkdrefreshjob.h b/lang/qt/src/wkdrefreshjob.h
new file mode 100644
index 00000000..c3aec65f
--- /dev/null
+++ b/lang/qt/src/wkdrefreshjob.h
@@ -0,0 +1,71 @@
+/*
+    wkdrefreshjob.h
+
+    This file is part of qgpgme, the Qt API binding for gpgme
+    Copyright (c) 2023 g10 Code GmbH
+    Software engineering by Ingo Klöcker <[email protected]>
+
+    QGpgME is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; either version 2 of the
+    License, or (at your option) any later version.
+
+    QGpgME is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+
+    In addition, as a special exception, the copyright holders give
+    permission to link the code of this program with any edition of
+    the Qt library by Trolltech AS, Norway (or with modified versions
+    of Qt that use the same license as Qt), and distribute linked
+    combinations including the two.  You must obey the GNU General
+    Public License in all respects for all of the code used other than
+    Qt.  If you modify this file, you may extend this exception to
+    your version of the file, but you are not obligated to do so.  If
+    you do not wish to do so, delete this exception statement from
+    your version.
+*/
+
+#ifndef __QGPGME_WKDREFRESHJOB_H__
+#define __QGPGME_WKDREFRESHJOB_H__
+
+#include "abstractimportjob.h"
+#include "qgpgme_export.h"
+
+#include <vector>
+
+namespace GpgME
+{
+class Error;
+class Key;
+}
+
+namespace QGpgME
+{
+
+/**
+ * This job refreshes OpenPGP keys via WKD. Only user IDs that have WKD set as
+ * origin are used for the WKD lookup. Revoked user IDs are ignored.
+ */
+class QGPGME_EXPORT WKDRefreshJob : public AbstractImportJob
+{
+    Q_OBJECT
+protected:
+    explicit WKDRefreshJob(QObject *parent);
+public:
+    ~WKDRefreshJob() override;
+
+    /**
+     * Starts a refresh of the \a keys.
+     */
+    GpgME::Error start(const std::vector<GpgME::Key> &keys);
+};
+
+}
+
+#endif // __QGPGME_WKDREFRESHJOB_H__
diff --git a/lang/qt/src/wkdrefreshjob_p.h b/lang/qt/src/wkdrefreshjob_p.h
new file mode 100644
index 00000000..377350f3
--- /dev/null
+++ b/lang/qt/src/wkdrefreshjob_p.h
@@ -0,0 +1,51 @@
+/*
+    wkdrefreshjob_p.h
+
+    This file is part of qgpgme, the Qt API binding for gpgme
+    Copyright (c) 2023 g10 Code GmbH
+    Software engineering by Ingo Klöcker <[email protected]>
+
+    QGpgME is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; either version 2 of the
+    License, or (at your option) any later version.
+
+    QGpgME is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+
+    In addition, as a special exception, the copyright holders give
+    permission to link the code of this program with any edition of
+    the Qt library by Trolltech AS, Norway (or with modified versions
+    of Qt that use the same license as Qt), and distribute linked
+    combinations including the two.  You must obey the GNU General
+    Public License in all respects for all of the code used other than
+    Qt.  If you modify this file, you may extend this exception to
+    your version of the file, but you are not obligated to do so.  If
+    you do not wish to do so, delete this exception statement from
+    your version.
+*/
+
+#ifndef __QGPGME_WKDREFRESHJOB_P_H__
+#define __QGPGME_WKDREFRESHJOB_P_H__
+
+#include "job_p.h"
+
+#include <key.h>
+
+namespace QGpgME
+{
+
+struct WKDRefreshJobPrivate : public JobPrivate
+{
+    std::vector<GpgME::Key> m_keys;
+};
+
+}
+
+#endif // __QGPGME_WKDREFRESHJOB_P_H__
diff --git a/lang/qt/tests/Makefile.am b/lang/qt/tests/Makefile.am
index d9713d90..32ad6466 100644
--- a/lang/qt/tests/Makefile.am
+++ b/lang/qt/tests/Makefile.am
@@ -97,6 +97,7 @@ run_keyformailboxjob_SOURCES = run-keyformailboxjob.cpp
 run_receivekeysjob_SOURCES = run-receivekeysjob.cpp
 run_refreshkeysjob_SOURCES = run-refreshkeysjob.cpp
 run_signarchivejob_SOURCES = run-signarchivejob.cpp
+run_wkdrefreshjob_SOURCES = run-wkdrefreshjob.cpp
 
 nodist_t_keylist_SOURCES = $(moc_files)
 
@@ -112,7 +113,8 @@ noinst_PROGRAMS = \
 	run-decryptverifyarchivejob \
 	run-encryptarchivejob \
 	run-importjob run-exportjob run-receivekeysjob run-refreshkeysjob \
-	run-signarchivejob
+	run-signarchivejob \
+	run-wkdrefreshjob
 
 
 CLEANFILES = secring.gpg pubring.gpg pubring.kbx trustdb.gpg dirmngr.conf \
diff --git a/lang/qt/tests/run-wkdrefreshjob.cpp b/lang/qt/tests/run-wkdrefreshjob.cpp
new file mode 100644
index 00000000..757ee899
--- /dev/null
+++ b/lang/qt/tests/run-wkdrefreshjob.cpp
@@ -0,0 +1,121 @@
+/*
+    run-wkdrefreshjob.cpp
+
+    This file is part of QGpgME's test suite.
+    Copyright (c) 2023 g10 Code GmbH
+    Software engineering by Ingo Klöcker <[email protected]>
+
+    QGpgME is free software; you can redistribute it and/or
+    modify it under the terms of the GNU General Public License as
+    published by the Free Software Foundation; either version 2 of the
+    License, or (at your option) any later version.
+
+    QGpgME is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+    General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+
+    In addition, as a special exception, the copyright holders give
+    permission to link the code of this program with any edition of
+    the Qt library by Trolltech AS, Norway (or with modified versions
+    of Qt that use the same license as Qt), and distribute linked
+    combinations including the two.  You must obey the GNU General
+    Public License in all respects for all of the code used other than
+    Qt.  If you modify this file, you may extend this exception to
+    your version of the file, but you are not obligated to do so.  If
+    you do not wish to do so, delete this exception statement from
+    your version.
+*/
+
+#ifdef HAVE_CONFIG_H
+ #include "config.h"
+#endif
+
+#include <protocol.h>
+#include <wkdrefreshjob.h>
+
+#include <QCoreApplication>
+#include <QDebug>
+
+#include <context.h>
+#include <importresult.h>
+
+#include <iostream>
+
+using namespace GpgME;
+
+std::ostream &operator<<(std::ostream &os, const QString &s)
+{
+    return os << s.toLocal8Bit().constData();
+}
+
+Key getOpenPGPKey(const QString &keyId, Error &err)
+{
+    Key key;
+
+    auto ctx = Context::create(GpgME::OpenPGP);
+    if (!ctx) {
+        err = Error::fromCode(GPG_ERR_GENERAL);
+        return key;
+    }
+
+    key = ctx->key(keyId.toLatin1().constData(), err);
+    if (err.code() == GPG_ERR_EOF) {
+        err = Error{};
+    }
+    return key;
+}
+
+int main(int argc, char **argv)
+{
+    GpgME::initializeLibrary();
+
+    if (argc != 2) {
+        std::cerr << "Usage: " << argv[0] << " KEYID" << std::endl;
+        return 1;
+    }
+
+    QCoreApplication app{argc, argv};
+    const auto keyId = qApp->arguments().last();
+
+    Error err;
+    const auto key = getOpenPGPKey(keyId, err);
+    if (err.code() == GPG_ERR_AMBIGUOUS_NAME) {
+        std::cerr << "Error: Multiple OpenPGP keys matching '" << keyId << "' found" << std::endl;
+        return 1;
+    }
+    if (key.isNull()) {
+        std::cerr << "Error: No OpenPGP key matching '" << keyId << "' found" << std::endl;
+        return 1;
+    }
+    if (err) {
+        std::cerr << "Error while getting OpenPGP key: " << err.asString() << std::endl;
+        return 1;
+    }
+    std::cout << "Refreshing OpenPGP key " << key.userID(0).id() << std::endl;
+
+    auto job = QGpgME::openpgp()->wkdRefreshJob();
+    if (!job) {
+        std::cerr << "Error: Could not create job to refresh OpenPGP key" << std::endl;
+        return 1;
+    }
+    QObject::connect(job, &QGpgME::WKDRefreshJob::result, &app, [](const GpgME::ImportResult &result, const QString &, const GpgME::Error &) {
+        if (result.isNull()) {
+            std::cout << "Empty result. Lookup via WKD failed or no user ID was originally retrieved via WKD." << std::endl;
+        } else {
+            std::cout << "Result: " << result << std::endl;
+        }
+        qApp->quit();
+    });
+    err = job->start({key});
+    if (err) {
+        std::cerr << "Error: " << err.asString() << std::endl;
+        return 1;
+    }
+
+    return app.exec();
+}