Merge #14451: Add BIP70 deprecation warning and allow building GUI without BIP70 support

48439b3c10391e5f5555c7d98e1a99706b77eaf7 Don't link SSL_LIBS with GUI unless BIP70 is enabled (James Hilliard)
fbb643d2a55ade3c06593a7490601acd2e36dce8 Add BIP70 deprecation warning (James Hilliard)
38b98507cdda02ff02a524d41bcc3427ca9e4fd9 qt: cleanup: Move BIP70 functions together in paymentserver (Wladimir J. van der Laan)
9dcf6c0dfec51f2a49edef537f377422d6dbdceb build: Add --disable-bip70 configure option (Wladimir J. van der Laan)

Pull request description:

  This is based off of #11622 and adds a deprecation warning when a BIP70 URL is used.

  Rational:

  - BIP70 increases attack surface in multiple ways and is difficult for third party wallets to implement in a secure manner
  - Very few merchants use the standard BIP70 variant supported by Bitcoin Core
  - The one major payment processor that doesn't support BIP21 and currently uses a customized non-standard version of BIP70 has indicated that "Unfortunately the original BIP70 is not useful for us."

Tree-SHA512: 1e16ee8d2cdac9499f751ee7b50d058278150f9e38a87a47ddb5105dd0353cdedabe462903f54ead6209b249b249fe5e6a10d29631531be27400f2f69c25b9b9

18 files changed, 305 insertions, 160 deletions

diff --git a/src/Makefile.am b/src/Makefile.am
index 7a2e9fa5e8..6141919007 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -587,9 +587,11 @@ if HARDEN
 	$(AM_V_at) READELF=$(READELF) OBJDUMP=$(OBJDUMP) $(top_srcdir)/contrib/devtools/security-check.py < $(bin_PROGRAMS)
 endif
 
+if ENABLE_BIP70
 %.pb.cc %.pb.h: %.proto
 	@test -f $(PROTOC)
 	$(AM_V_GEN) $(PROTOC) --cpp_out=$(@D) --proto_path=$(<D) $<
+endif
 
 if EMBEDDED_LEVELDB
 include Makefile.leveldb.include
diff --git a/src/Makefile.qt.include b/src/Makefile.qt.include
index 27a81ce4c8..8d25e83529 100644
--- a/src/Makefile.qt.include
+++ b/src/Makefile.qt.include
@@ -176,9 +176,15 @@ QT_QRC = qt/bitcoin.qrc
 QT_QRC_LOCALE_CPP = qt/qrc_bitcoin_locale.cpp
 QT_QRC_LOCALE = qt/bitcoin_locale.qrc
 
+if ENABLE_BIP70
 PROTOBUF_CC = qt/paymentrequest.pb.cc
 PROTOBUF_H = qt/paymentrequest.pb.h
 PROTOBUF_PROTO = qt/paymentrequest.proto
+else
+PROTOBUF_CC =
+PROTOBUF_H =
+PROTOBUF_PROTO =
+endif
 
 BITCOIN_QT_H = \
   qt/addressbookpage.h \
@@ -327,7 +333,6 @@ BITCOIN_QT_WALLET_CPP = \
   qt/editaddressdialog.cpp \
   qt/openuridialog.cpp \
   qt/overviewpage.cpp \
-  qt/paymentrequestplus.cpp \
   qt/paymentserver.cpp \
   qt/receivecoinsdialog.cpp \
   qt/receiverequestdialog.cpp \
@@ -346,13 +351,19 @@ BITCOIN_QT_WALLET_CPP = \
   qt/walletmodeltransaction.cpp \
   qt/walletview.cpp
 
+BITCOIN_QT_WALLET_BIP70_CPP = \
+  qt/paymentrequestplus.cpp
+
 BITCOIN_QT_CPP = $(BITCOIN_QT_BASE_CPP)
 if TARGET_WINDOWS
 BITCOIN_QT_CPP += $(BITCOIN_QT_WINDOWS_CPP)
 endif
 if ENABLE_WALLET
 BITCOIN_QT_CPP += $(BITCOIN_QT_WALLET_CPP)
-endif
+if ENABLE_BIP70
+BITCOIN_QT_CPP += $(BITCOIN_QT_WALLET_BIP70_CPP)
+endif # ENABLE_BIP70
+endif # ENABLE_WALLET
 
 RES_IMAGES =
 
@@ -405,8 +416,11 @@ endif
 if ENABLE_ZMQ
 qt_bitcoin_qt_LDADD += $(LIBBITCOIN_ZMQ) $(ZMQ_LIBS)
 endif
+if ENABLE_BIP70
+qt_bitcoin_qt_LDADD += $(SSL_LIBS)
+endif
 qt_bitcoin_qt_LDADD += $(LIBBITCOIN_CLI) $(LIBBITCOIN_COMMON) $(LIBBITCOIN_UTIL) $(LIBBITCOIN_CONSENSUS) $(LIBBITCOIN_CRYPTO) $(LIBUNIVALUE) $(LIBLEVELDB) $(LIBLEVELDB_SSE42) $(LIBMEMENV) \
-  $(BOOST_LIBS) $(QT_LIBS) $(QT_DBUS_LIBS) $(QR_LIBS) $(PROTOBUF_LIBS) $(BDB_LIBS) $(SSL_LIBS) $(CRYPTO_LIBS) $(MINIUPNPC_LIBS) $(LIBSECP256K1) \
+  $(BOOST_LIBS) $(QT_LIBS) $(QT_DBUS_LIBS) $(QR_LIBS) $(PROTOBUF_LIBS) $(BDB_LIBS) $(CRYPTO_LIBS) $(MINIUPNPC_LIBS) $(LIBSECP256K1) \
   $(EVENT_PTHREADS_LIBS) $(EVENT_LIBS)
 qt_bitcoin_qt_LDFLAGS = $(RELDFLAGS) $(AM_LDFLAGS) $(QT_LDFLAGS) $(LIBTOOL_APP_LDFLAGS)
 qt_bitcoin_qt_LIBTOOLFLAGS = $(AM_LIBTOOLFLAGS) --tag CXX
diff --git a/src/Makefile.qttest.include b/src/Makefile.qttest.include
index 4b14212b2e..db7873e8b7 100644
--- a/src/Makefile.qttest.include
+++ b/src/Makefile.qttest.include
@@ -13,9 +13,12 @@ TEST_QT_MOC_CPP = \
 if ENABLE_WALLET
 TEST_QT_MOC_CPP += \
   qt/test/moc_addressbooktests.cpp \
-  qt/test/moc_paymentservertests.cpp \
   qt/test/moc_wallettests.cpp
-endif
+if ENABLE_BIP70
+TEST_QT_MOC_CPP += \
+  qt/test/moc_paymentservertests.cpp
+endif # ENABLE_BIP70
+endif # ENABLE_WALLET
 
 TEST_QT_H = \
   qt/test/addressbooktests.h \
@@ -48,10 +51,13 @@ qt_test_test_bitcoin_qt_SOURCES = \
 if ENABLE_WALLET
 qt_test_test_bitcoin_qt_SOURCES += \
   qt/test/addressbooktests.cpp \
-  qt/test/paymentservertests.cpp \
   qt/test/wallettests.cpp \
   wallet/test/wallet_test_fixture.cpp
-endif
+if ENABLE_BIP70
+qt_test_test_bitcoin_qt_SOURCES += \
+  qt/test/paymentservertests.cpp
+endif # ENABLE_BIP70
+endif # ENABLE_WALLET
 
 nodist_qt_test_test_bitcoin_qt_SOURCES = $(TEST_QT_MOC_CPP)
 
diff --git a/src/qt/bitcoin.cpp b/src/qt/bitcoin.cpp
index a014ad4b28..c0f9b3d5d3 100644
--- a/src/qt/bitcoin.cpp
+++ b/src/qt/bitcoin.cpp
@@ -439,8 +439,10 @@ void BitcoinApplication::addWallet(WalletModel* walletModel)
         window->setCurrentWallet(walletModel->getWalletName());
     }
 
+#ifdef ENABLE_BIP70
     connect(walletModel, &WalletModel::coinsSent,
         paymentServer, &PaymentServer::fetchPaymentACK);
+#endif
     connect(walletModel, &WalletModel::unload, this, &BitcoinApplication::removeWallet);
 
     m_wallet_models.push_back(walletModel);
@@ -467,7 +469,9 @@ void BitcoinApplication::initializeResult(bool success)
         // Log this only after AppInitMain finishes, as then logging setup is guaranteed complete
         qWarning() << "Platform customization:" << platformStyle->getName();
 #ifdef ENABLE_WALLET
+#ifdef ENABLE_BIP70
         PaymentServer::LoadRootCAs();
+#endif
         paymentServer->setOptionsModel(optionsModel);
 #endif
 
@@ -536,7 +540,7 @@ WId BitcoinApplication::getMainWinId() const
 
 static void SetupUIArgs()
 {
-#ifdef ENABLE_WALLET
+#if defined(ENABLE_WALLET) && defined(ENABLE_BIP70)
     gArgs.AddArg("-allowselfsignedrootcertificates", strprintf("Allow self signed root certificates (default: %u)", DEFAULT_SELFSIGNED_ROOTCERTS), true, OptionsCategory::GUI);
 #endif
     gArgs.AddArg("-choosedatadir", strprintf("Choose data directory on startup (default: %u)", DEFAULT_CHOOSE_DATADIR), false, OptionsCategory::GUI);
diff --git a/src/qt/coincontroldialog.cpp b/src/qt/coincontroldialog.cpp
index 68330c51fa..ea970c0bc9 100644
--- a/src/qt/coincontroldialog.cpp
+++ b/src/qt/coincontroldialog.cpp
@@ -2,10 +2,15 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#if defined(HAVE_CONFIG_H)
+#include <config/bitcoin-config.h>
+#endif
+
 #include <qt/coincontroldialog.h>
 #include <qt/forms/ui_coincontroldialog.h>
 
 #include <qt/addresstablemodel.h>
+#include <base58.h>
 #include <qt/bitcoinunits.h>
 #include <qt/guiutil.h>
 #include <qt/optionsmodel.h>
diff --git a/src/qt/paymentserver.cpp b/src/qt/paymentserver.cpp
index bcafc8f859..3f118e37f1 100644
--- a/src/qt/paymentserver.cpp
+++ b/src/qt/paymentserver.cpp
@@ -2,6 +2,10 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#if defined(HAVE_CONFIG_H)
+#include <config/bitcoin-config.h>
+#endif
+
 #include <qt/paymentserver.h>
 
 #include <qt/bitcoinunits.h>
@@ -45,6 +49,7 @@
 
 const int BITCOIN_IPC_CONNECT_TIMEOUT = 1000; // milliseconds
 const QString BITCOIN_IPC_PREFIX("bitcoin:");
+#ifdef ENABLE_BIP70
 // BIP70 payment protocol messages
 const char* BIP70_MESSAGE_PAYMENTACK = "PaymentACK";
 const char* BIP70_MESSAGE_PAYMENTREQUEST = "PaymentRequest";
@@ -52,21 +57,7 @@ const char* BIP70_MESSAGE_PAYMENTREQUEST = "PaymentRequest";
 const char* BIP71_MIMETYPE_PAYMENT = "application/bitcoin-payment";
 const char* BIP71_MIMETYPE_PAYMENTACK = "application/bitcoin-paymentack";
 const char* BIP71_MIMETYPE_PAYMENTREQUEST = "application/bitcoin-paymentrequest";
-
-struct X509StoreDeleter {
-      void operator()(X509_STORE* b) {
-          X509_STORE_free(b);
-      }
-};
-
-struct X509Deleter {
-      void operator()(X509* b) { X509_free(b); }
-};
-
-namespace // Anon namespace
-{
-    std::unique_ptr<X509_STORE, X509StoreDeleter> certStore;
-}
+#endif
 
 //
 // Create a name that is unique for:
@@ -93,94 +84,6 @@ static QString ipcServerName()
 
 static QList<QString> savedPaymentRequests;
 
-static void ReportInvalidCertificate(const QSslCertificate& cert)
-{
-    qDebug() << QString("%1: Payment server found an invalid certificate: ").arg(__func__) << cert.serialNumber() << cert.subjectInfo(QSslCertificate::CommonName) << cert.subjectInfo(QSslCertificate::DistinguishedNameQualifier) << cert.subjectInfo(QSslCertificate::OrganizationalUnitName);
-}
-
-//
-// Load OpenSSL's list of root certificate authorities
-//
-void PaymentServer::LoadRootCAs(X509_STORE* _store)
-{
-    // Unit tests mostly use this, to pass in fake root CAs:
-    if (_store)
-    {
-        certStore.reset(_store);
-        return;
-    }
-
-    // Normal execution, use either -rootcertificates or system certs:
-    certStore.reset(X509_STORE_new());
-
-    // Note: use "-system-" default here so that users can pass -rootcertificates=""
-    // and get 'I don't like X.509 certificates, don't trust anybody' behavior:
-    QString certFile = QString::fromStdString(gArgs.GetArg("-rootcertificates", "-system-"));
-
-    // Empty store
-    if (certFile.isEmpty()) {
-        qDebug() << QString("PaymentServer::%1: Payment request authentication via X.509 certificates disabled.").arg(__func__);
-        return;
-    }
-
-    QList<QSslCertificate> certList;
-
-    if (certFile != "-system-") {
-            qDebug() << QString("PaymentServer::%1: Using \"%2\" as trusted root certificate.").arg(__func__).arg(certFile);
-
-        certList = QSslCertificate::fromPath(certFile);
-        // Use those certificates when fetching payment requests, too:
-        QSslSocket::setDefaultCaCertificates(certList);
-    } else
-        certList = QSslSocket::systemCaCertificates();
-
-    int nRootCerts = 0;
-    const QDateTime currentTime = QDateTime::currentDateTime();
-
-    for (const QSslCertificate& cert : certList) {
-        // Don't log NULL certificates
-        if (cert.isNull())
-            continue;
-
-        // Not yet active/valid, or expired certificate
-        if (currentTime < cert.effectiveDate() || currentTime > cert.expiryDate()) {
-            ReportInvalidCertificate(cert);
-            continue;
-        }
-
-        // Blacklisted certificate
-        if (cert.isBlacklisted()) {
-            ReportInvalidCertificate(cert);
-            continue;
-        }
-        QByteArray certData = cert.toDer();
-        const unsigned char *data = (const unsigned char *)certData.data();
-
-        std::unique_ptr<X509, X509Deleter> x509(d2i_X509(0, &data, certData.size()));
-        if (x509 && X509_STORE_add_cert(certStore.get(), x509.get()))
-        {
-            // Note: X509_STORE increases the reference count to the X509 object,
-            // we still have to release our reference to it.
-            ++nRootCerts;
-        }
-        else
-        {
-            ReportInvalidCertificate(cert);
-            continue;
-        }
-    }
-    qWarning() << "PaymentServer::LoadRootCAs: Loaded " << nRootCerts << " root certificates";
-
-    // Project for another day:
-    // Fetch certificate revocation lists, and add them to certStore.
-    // Issues to consider:
-    //   performance (start a thread to fetch in background?)
-    //   privacy (fetch through tor/proxy so IP address isn't revealed)
-    //   would it be easier to just use a compiled-in blacklist?
-    //    or use Qt's blacklist?
-    //   "certificate stapling" with server-side caching is more efficient
-}
-
 //
 // Sending to the server is done synchronously, at startup.
 // If the server isn't already running, startup continues,
@@ -221,6 +124,7 @@ void PaymentServer::ipcParseCommandLine(interfaces::Node& node, int argc, char*
                 }
             }
         }
+#ifdef ENABLE_BIP70
         else if (QFile::exists(arg)) // Filename
         {
             savedPaymentRequests.append(arg);
@@ -244,6 +148,7 @@ void PaymentServer::ipcParseCommandLine(interfaces::Node& node, int argc, char*
             // GUI hasn't started yet so we can't pop up a message box.
             qWarning() << "PaymentServer::ipcSendCommandLine: Payment request file does not exist: " << arg;
         }
+#endif
     }
 }
 
@@ -290,12 +195,16 @@ PaymentServer::PaymentServer(QObject* parent, bool startLocalServer) :
     QObject(parent),
     saveURIs(true),
     uriServer(0),
-    netManager(0),
     optionsModel(0)
+#ifdef ENABLE_BIP70
+    ,netManager(0)
+#endif
 {
+#ifdef ENABLE_BIP70
     // Verify that the version of the library that we linked against is
     // compatible with the version of the headers we compiled against.
     GOOGLE_PROTOBUF_VERIFY_VERSION;
+#endif
 
     // Install global event filter to catch QFileOpenEvents
     // on Mac: sent when you click bitcoin: links
@@ -319,14 +228,18 @@ PaymentServer::PaymentServer(QObject* parent, bool startLocalServer) :
         }
         else {
             connect(uriServer, &QLocalServer::newConnection, this, &PaymentServer::handleURIConnection);
+#ifdef ENABLE_BIP70
             connect(this, &PaymentServer::receivedPaymentACK, this, &PaymentServer::handlePaymentACK);
+#endif
         }
     }
 }
 
 PaymentServer::~PaymentServer()
 {
+#ifdef ENABLE_BIP70
     google::protobuf::ShutdownProtobufLibrary();
+#endif
 }
 
 //
@@ -349,33 +262,11 @@ bool PaymentServer::eventFilter(QObject *object, QEvent *event)
     return QObject::eventFilter(object, event);
 }
 
-void PaymentServer::initNetManager()
-{
-    if (!optionsModel)
-        return;
-    delete netManager;
-
-    // netManager is used to fetch paymentrequests given in bitcoin: URIs
-    netManager = new QNetworkAccessManager(this);
-
-    QNetworkProxy proxy;
-
-    // Query active SOCKS5 proxy
-    if (optionsModel->getProxySettings(proxy)) {
-        netManager->setProxy(proxy);
-
-        qDebug() << "PaymentServer::initNetManager: Using SOCKS5 proxy" << proxy.hostName() << ":" << proxy.port();
-    }
-    else
-        qDebug() << "PaymentServer::initNetManager: No active proxy server found.";
-
-    connect(netManager, &QNetworkAccessManager::finished, this, &PaymentServer::netRequestFinished);
-    connect(netManager, &QNetworkAccessManager::sslErrors, this, &PaymentServer::reportSslErrors);
-}
-
 void PaymentServer::uiReady()
 {
+#ifdef ENABLE_BIP70
     initNetManager();
+#endif
 
     saveURIs = false;
     for (const QString& s : savedPaymentRequests)
@@ -403,6 +294,10 @@ void PaymentServer::handleURIOrFile(const QString& s)
         QUrlQuery uri((QUrl(s)));
         if (uri.hasQueryItem("r")) // payment request URI
         {
+#ifdef ENABLE_BIP70
+            Q_EMIT message(tr("URI handling"),
+                tr("You are using a BIP70 URL which will be unsupported in the future."),
+                CClientUIInterface::ICON_WARNING);
             QByteArray temp;
             temp.append(uri.queryItemValue("r"));
             QString decoded = QUrl::fromPercentEncoding(temp);
@@ -420,7 +315,11 @@ void PaymentServer::handleURIOrFile(const QString& s)
                     tr("Payment request fetch URL is invalid: %1").arg(fetchUrl.toString()),
                     CClientUIInterface::ICON_WARNING);
             }
-
+#else
+            Q_EMIT message(tr("URI handling"),
+                tr("Cannot process payment request because BIP70 support was not compiled in."),
+                CClientUIInterface::ICON_WARNING);
+#endif
             return;
         }
         else // normal URI
@@ -444,6 +343,7 @@ void PaymentServer::handleURIOrFile(const QString& s)
         }
     }
 
+#ifdef ENABLE_BIP70
     if (QFile::exists(s)) // payment request file
     {
         PaymentRequestPlus request;
@@ -459,6 +359,7 @@ void PaymentServer::handleURIOrFile(const QString& s)
 
         return;
     }
+#endif
 }
 
 void PaymentServer::handleURIConnection()
@@ -481,6 +382,140 @@ void PaymentServer::handleURIConnection()
     handleURIOrFile(msg);
 }
 
+void PaymentServer::setOptionsModel(OptionsModel *_optionsModel)
+{
+    this->optionsModel = _optionsModel;
+}
+
+#ifdef ENABLE_BIP70
+struct X509StoreDeleter {
+      void operator()(X509_STORE* b) {
+          X509_STORE_free(b);
+      }
+};
+
+struct X509Deleter {
+      void operator()(X509* b) { X509_free(b); }
+};
+
+namespace // Anon namespace
+{
+    std::unique_ptr<X509_STORE, X509StoreDeleter> certStore;
+}
+
+static void ReportInvalidCertificate(const QSslCertificate& cert)
+{
+    qDebug() << QString("%1: Payment server found an invalid certificate: ").arg(__func__) << cert.serialNumber() << cert.subjectInfo(QSslCertificate::CommonName) << cert.subjectInfo(QSslCertificate::DistinguishedNameQualifier) << cert.subjectInfo(QSslCertificate::OrganizationalUnitName);
+}
+
+//
+// Load OpenSSL's list of root certificate authorities
+//
+void PaymentServer::LoadRootCAs(X509_STORE* _store)
+{
+    // Unit tests mostly use this, to pass in fake root CAs:
+    if (_store)
+    {
+        certStore.reset(_store);
+        return;
+    }
+
+    // Normal execution, use either -rootcertificates or system certs:
+    certStore.reset(X509_STORE_new());
+
+    // Note: use "-system-" default here so that users can pass -rootcertificates=""
+    // and get 'I don't like X.509 certificates, don't trust anybody' behavior:
+    QString certFile = QString::fromStdString(gArgs.GetArg("-rootcertificates", "-system-"));
+
+    // Empty store
+    if (certFile.isEmpty()) {
+        qDebug() << QString("PaymentServer::%1: Payment request authentication via X.509 certificates disabled.").arg(__func__);
+        return;
+    }
+
+    QList<QSslCertificate> certList;
+
+    if (certFile != "-system-") {
+            qDebug() << QString("PaymentServer::%1: Using \"%2\" as trusted root certificate.").arg(__func__).arg(certFile);
+
+        certList = QSslCertificate::fromPath(certFile);
+        // Use those certificates when fetching payment requests, too:
+        QSslSocket::setDefaultCaCertificates(certList);
+    } else
+        certList = QSslSocket::systemCaCertificates();
+
+    int nRootCerts = 0;
+    const QDateTime currentTime = QDateTime::currentDateTime();
+
+    for (const QSslCertificate& cert : certList) {
+        // Don't log NULL certificates
+        if (cert.isNull())
+            continue;
+
+        // Not yet active/valid, or expired certificate
+        if (currentTime < cert.effectiveDate() || currentTime > cert.expiryDate()) {
+            ReportInvalidCertificate(cert);
+            continue;
+        }
+
+        // Blacklisted certificate
+        if (cert.isBlacklisted()) {
+            ReportInvalidCertificate(cert);
+            continue;
+        }
+
+        QByteArray certData = cert.toDer();
+        const unsigned char *data = (const unsigned char *)certData.data();
+
+        std::unique_ptr<X509, X509Deleter> x509(d2i_X509(0, &data, certData.size()));
+        if (x509 && X509_STORE_add_cert(certStore.get(), x509.get()))
+        {
+            // Note: X509_STORE increases the reference count to the X509 object,
+            // we still have to release our reference to it.
+            ++nRootCerts;
+        }
+        else
+        {
+            ReportInvalidCertificate(cert);
+            continue;
+        }
+    }
+    qWarning() << "PaymentServer::LoadRootCAs: Loaded " << nRootCerts << " root certificates";
+
+    // Project for another day:
+    // Fetch certificate revocation lists, and add them to certStore.
+    // Issues to consider:
+    //   performance (start a thread to fetch in background?)
+    //   privacy (fetch through tor/proxy so IP address isn't revealed)
+    //   would it be easier to just use a compiled-in blacklist?
+    //    or use Qt's blacklist?
+    //   "certificate stapling" with server-side caching is more efficient
+}
+
+void PaymentServer::initNetManager()
+{
+    if (!optionsModel)
+        return;
+    delete netManager;
+
+    // netManager is used to fetch paymentrequests given in bitcoin: URIs
+    netManager = new QNetworkAccessManager(this);
+
+    QNetworkProxy proxy;
+
+    // Query active SOCKS5 proxy
+    if (optionsModel->getProxySettings(proxy)) {
+        netManager->setProxy(proxy);
+
+        qDebug() << "PaymentServer::initNetManager: Using SOCKS5 proxy" << proxy.hostName() << ":" << proxy.port();
+    }
+    else
+        qDebug() << "PaymentServer::initNetManager: No active proxy server found.";
+
+    connect(netManager, &QNetworkAccessManager::finished, this, &PaymentServer::netRequestFinished);
+    connect(netManager, &QNetworkAccessManager::sslErrors, this, &PaymentServer::reportSslErrors);
+}
+
 //
 // Warning: readPaymentRequestFromFile() is used in ipcSendCommandLine()
 // so don't use "Q_EMIT message()", but "QMessageBox::"!
@@ -731,11 +766,6 @@ void PaymentServer::reportSslErrors(QNetworkReply* reply, const QList<QSslError>
     Q_EMIT message(tr("Network request error"), errString, CClientUIInterface::MSG_ERROR);
 }
 
-void PaymentServer::setOptionsModel(OptionsModel *_optionsModel)
-{
-    this->optionsModel = _optionsModel;
-}
-
 void PaymentServer::handlePaymentACK(const QString& paymentACKMsg)
 {
     // currently we don't further process or store the paymentACK message
@@ -794,3 +824,4 @@ X509_STORE* PaymentServer::getCertStore()
 {
     return certStore.get();
 }
+#endif
diff --git a/src/qt/paymentserver.h b/src/qt/paymentserver.h
index d335db9c85..30b5bc3b6d 100644
--- a/src/qt/paymentserver.h
+++ b/src/qt/paymentserver.h
@@ -32,7 +32,13 @@
 // sends them to the server.
 //
 
+#if defined(HAVE_CONFIG_H)
+#include <config/bitcoin-config.h>
+#endif
+
+#ifdef ENABLE_BIP70
 #include <qt/paymentrequestplus.h>
+#endif
 #include <qt/walletmodel.h>
 
 #include <QObject>
@@ -73,6 +79,10 @@ public:
     explicit PaymentServer(QObject* parent, bool startLocalServer = true);
     ~PaymentServer();
 
+    // OptionsModel is used for getting proxy settings and display unit
+    void setOptionsModel(OptionsModel *optionsModel);
+
+#ifdef ENABLE_BIP70
     // Load root certificate authorities. Pass nullptr (default)
     // to read from the file specified in the -rootcertificates setting,
     // or, if that's not set, to use the system default root certificates.
@@ -83,9 +93,6 @@ public:
     // Return certificate store
     static X509_STORE* getCertStore();
 
-    // OptionsModel is used for getting proxy settings and display unit
-    void setOptionsModel(OptionsModel *optionsModel);
-
     // Verify that the payment request network matches the client network
     static bool verifyNetwork(interfaces::Node& node, const payments::PaymentDetails& requestDetails);
     // Verify if the payment request is expired
@@ -94,33 +101,40 @@ public:
     static bool verifySize(qint64 requestSize);
     // Verify the payment request amount is valid
     static bool verifyAmount(const CAmount& requestAmount);
+#endif
 
 Q_SIGNALS:
     // Fired when a valid payment request is received
     void receivedPaymentRequest(SendCoinsRecipient);
 
-    // Fired when a valid PaymentACK is received
-    void receivedPaymentACK(const QString &paymentACKMsg);
-
     // Fired when a message should be reported to the user
     void message(const QString &title, const QString &message, unsigned int style);
 
+#ifdef ENABLE_BIP70
+    // Fired when a valid PaymentACK is received
+    void receivedPaymentACK(const QString &paymentACKMsg);
+#endif
+
 public Q_SLOTS:
     // Signal this when the main window's UI is ready
     // to display payment requests to the user
     void uiReady();
 
-    // Submit Payment message to a merchant, get back PaymentACK:
-    void fetchPaymentACK(WalletModel* walletModel, const SendCoinsRecipient& recipient, QByteArray transaction);
-
     // Handle an incoming URI, URI with local file scheme or file
     void handleURIOrFile(const QString& s);
 
+#ifdef ENABLE_BIP70
+    // Submit Payment message to a merchant, get back PaymentACK:
+    void fetchPaymentACK(WalletModel* walletModel, const SendCoinsRecipient& recipient, QByteArray transaction);
+#endif
+
 private Q_SLOTS:
     void handleURIConnection();
+#ifdef ENABLE_BIP70
     void netRequestFinished(QNetworkReply*);
     void reportSslErrors(QNetworkReply*, const QList<QSslError> &);
     void handlePaymentACK(const QString& paymentACKMsg);
+#endif
 
 protected:
     // Constructor registers this on the parent QApplication to
@@ -128,19 +142,19 @@ protected:
     bool eventFilter(QObject *object, QEvent *event);
 
 private:
+    bool saveURIs;                      // true during startup
+    QLocalServer* uriServer;
+    OptionsModel *optionsModel;
+
+#ifdef ENABLE_BIP70
     static bool readPaymentRequestFromFile(const QString& filename, PaymentRequestPlus& request);
     bool processPaymentRequest(const PaymentRequestPlus& request, SendCoinsRecipient& recipient);
     void fetchRequest(const QUrl& url);
 
     // Setup networking
     void initNetManager();
-
-    bool saveURIs;                      // true during startup
-    QLocalServer* uriServer;
-
     QNetworkAccessManager* netManager;  // Used to fetch payment requests
-
-    OptionsModel *optionsModel;
+#endif
 };
 
 #endif // BITCOIN_QT_PAYMENTSERVER_H
diff --git a/src/qt/sendcoinsdialog.cpp b/src/qt/sendcoinsdialog.cpp
index 6f66bc19e1..858128f9f9 100644
--- a/src/qt/sendcoinsdialog.cpp
+++ b/src/qt/sendcoinsdialog.cpp
@@ -2,6 +2,10 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#if defined(HAVE_CONFIG_H)
+#include <config/bitcoin-config.h>
+#endif
+
 #include <qt/sendcoinsdialog.h>
 #include <qt/forms/ui_sendcoinsdialog.h>
 
@@ -290,7 +294,9 @@ void SendCoinsDialog::on_sendButton_clicked()
         QString recipientElement;
         recipientElement = "<br />";
 
+#ifdef ENABLE_BIP70
         if (!rcp.paymentRequest.IsInitialized()) // normal payment
+#endif
         {
             if(rcp.label.length() > 0) // label with address
             {
@@ -302,6 +308,7 @@ void SendCoinsDialog::on_sendButton_clicked()
                 recipientElement.append(tr("%1 to %2").arg(amount, address));
             }
         }
+#ifdef ENABLE_BIP70
         else if(!rcp.authenticatedMerchant.isEmpty()) // authenticated payment request
         {
             recipientElement.append(tr("%1 to %2").arg(amount, GUIUtil::HtmlEscape(rcp.authenticatedMerchant)));
@@ -310,6 +317,7 @@ void SendCoinsDialog::on_sendButton_clicked()
         {
             recipientElement.append(tr("%1 to %2").arg(amount, address));
         }
+#endif
 
         formatted.append(recipientElement);
     }
diff --git a/src/qt/sendcoinsentry.cpp b/src/qt/sendcoinsentry.cpp
index b394ff3150..76c942c8b9 100644
--- a/src/qt/sendcoinsentry.cpp
+++ b/src/qt/sendcoinsentry.cpp
@@ -2,6 +2,10 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#if defined(HAVE_CONFIG_H)
+#include <config/bitcoin-config.h>
+#endif
+
 #include <qt/sendcoinsentry.h>
 #include <qt/forms/ui_sendcoinsentry.h>
 
@@ -133,9 +137,11 @@ bool SendCoinsEntry::validate(interfaces::Node& node)
     // Check input validity
     bool retval = true;
 
+#ifdef ENABLE_BIP70
     // Skip checks for payment request
     if (recipient.paymentRequest.IsInitialized())
         return retval;
+#endif
 
     if (!model->validateAddress(ui->payTo->text()))
     {
@@ -166,9 +172,11 @@ bool SendCoinsEntry::validate(interfaces::Node& node)
 
 SendCoinsRecipient SendCoinsEntry::getValue()
 {
+#ifdef ENABLE_BIP70
     // Payment request
     if (recipient.paymentRequest.IsInitialized())
         return recipient;
+#endif
 
     // Normal payment
     recipient.address = ui->payTo->text();
@@ -196,6 +204,7 @@ void SendCoinsEntry::setValue(const SendCoinsRecipient &value)
 {
     recipient = value;
 
+#ifdef ENABLE_BIP70
     if (recipient.paymentRequest.IsInitialized()) // payment request
     {
         if (recipient.authenticatedMerchant.isEmpty()) // unauthenticated
@@ -216,6 +225,7 @@ void SendCoinsEntry::setValue(const SendCoinsRecipient &value)
         }
     }
     else // normal payment
+#endif
     {
         // message
         ui->messageTextLabel->setText(recipient.message);
diff --git a/src/qt/test/compattests.cpp b/src/qt/test/compattests.cpp
index af5c69ea9a..6750c543da 100644
--- a/src/qt/test/compattests.cpp
+++ b/src/qt/test/compattests.cpp
@@ -2,7 +2,13 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#if defined(HAVE_CONFIG_H)
+#include <config/bitcoin-config.h>
+#endif
+
+#if defined(ENABLE_WALLET) && defined(ENABLE_BIP70)
 #include <qt/paymentrequestplus.h> // this includes protobuf's port.h which defines its own bswap macos
+#endif
 
 #include <qt/test/compattests.h>
 
diff --git a/src/qt/test/test_main.cpp b/src/qt/test/test_main.cpp
index df65a85fb5..28df4ebf26 100644
--- a/src/qt/test/test_main.cpp
+++ b/src/qt/test/test_main.cpp
@@ -14,9 +14,11 @@
 
 #ifdef ENABLE_WALLET
 #include <qt/test/addressbooktests.h>
+#ifdef ENABLE_BIP70
 #include <qt/test/paymentservertests.h>
+#endif // ENABLE_BIP70
 #include <qt/test/wallettests.h>
-#endif
+#endif // ENABLE_WALLET
 
 #include <QApplication>
 #include <QObject>
@@ -74,7 +76,7 @@ int main(int argc, char *argv[])
     if (QTest::qExec(&test1) != 0) {
         fInvalid = true;
     }
-#ifdef ENABLE_WALLET
+#if defined(ENABLE_WALLET) && defined(ENABLE_BIP70)
     PaymentServerTests test2;
     if (QTest::qExec(&test2) != 0) {
         fInvalid = true;
diff --git a/src/qt/test/wallettests.cpp b/src/qt/test/wallettests.cpp
index 9ca0e7c67d..fcc5806b81 100644
--- a/src/qt/test/wallettests.cpp
+++ b/src/qt/test/wallettests.cpp
@@ -2,6 +2,7 @@
 #include <qt/test/util.h>
 
 #include <interfaces/node.h>
+#include <base58.h>
 #include <qt/bitcoinamountfield.h>
 #include <qt/optionsmodel.h>
 #include <qt/platformstyle.h>
diff --git a/src/qt/transactiondesc.cpp b/src/qt/transactiondesc.cpp
index 59332be754..3c5617bfa8 100644
--- a/src/qt/transactiondesc.cpp
+++ b/src/qt/transactiondesc.cpp
@@ -2,6 +2,10 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#ifdef HAVE_CONFIG_H
+#include <config/bitcoin-config.h>
+#endif
+
 #include <qt/transactiondesc.h>
 
 #include <qt/bitcoinunits.h>
@@ -257,6 +261,7 @@ QString TransactionDesc::toHTML(interfaces::Node& node, interfaces::Wallet& wall
         if (r.first == "Message")
             strHTML += "<br><b>" + tr("Message") + ":</b><br>" + GUIUtil::HtmlEscape(r.second, true) + "<br>";
 
+#ifdef ENABLE_BIP70
     //
     // PaymentRequest info:
     //
@@ -271,6 +276,7 @@ QString TransactionDesc::toHTML(interfaces::Node& node, interfaces::Wallet& wall
                 strHTML += "<b>" + tr("Merchant") + ":</b> " + GUIUtil::HtmlEscape(merchant) + "<br>";
         }
     }
+#endif
 
     if (wtx.is_coinbase)
     {
diff --git a/src/qt/utilitydialog.cpp b/src/qt/utilitydialog.cpp
index 7d903b3b1c..faeed87ec4 100644
--- a/src/qt/utilitydialog.cpp
+++ b/src/qt/utilitydialog.cpp
@@ -14,7 +14,9 @@
 #include <qt/clientmodel.h>
 #include <qt/guiconstants.h>
 #include <qt/intro.h>
+#ifdef ENABLE_BIP70
 #include <qt/paymentrequestplus.h>
+#endif
 #include <qt/guiutil.h>
 
 #include <clientversion.h>
diff --git a/src/qt/walletmodel.cpp b/src/qt/walletmodel.cpp
index f7cc94ae32..71b2d321e2 100644
--- a/src/qt/walletmodel.cpp
+++ b/src/qt/walletmodel.cpp
@@ -2,6 +2,10 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#if defined(HAVE_CONFIG_H)
+#include <config/bitcoin-config.h>
+#endif
+
 #include <qt/walletmodel.h>
 
 #include <qt/addresstablemodel.h>
@@ -142,6 +146,7 @@ WalletModel::SendCoinsReturn WalletModel::prepareTransaction(WalletModelTransact
         if (rcp.fSubtractFeeFromAmount)
             fSubtractFeeFromAmount = true;
 
+#ifdef ENABLE_BIP70
         if (rcp.paymentRequest.IsInitialized())
         {   // PaymentRequest...
             CAmount subtotal = 0;
@@ -164,6 +169,7 @@ WalletModel::SendCoinsReturn WalletModel::prepareTransaction(WalletModelTransact
             total += subtotal;
         }
         else
+#endif
         {   // User-entered bitcoin address / amount:
             if(!validateAddress(rcp.address))
             {
@@ -235,6 +241,7 @@ WalletModel::SendCoinsReturn WalletModel::sendCoins(WalletModelTransaction &tran
         std::vector<std::pair<std::string, std::string>> vOrderForm;
         for (const SendCoinsRecipient &rcp : transaction.getRecipients())
         {
+#ifdef ENABLE_BIP70
             if (rcp.paymentRequest.IsInitialized())
             {
                 // Make sure any payment requests involved are still valid.
@@ -247,7 +254,9 @@ WalletModel::SendCoinsReturn WalletModel::sendCoins(WalletModelTransaction &tran
                 rcp.paymentRequest.SerializeToString(&value);
                 vOrderForm.emplace_back("PaymentRequest", std::move(value));
             }
-            else if (!rcp.message.isEmpty()) // Message from normal bitcoin:URI (bitcoin:123...?message=example)
+            else
+#endif
+            if (!rcp.message.isEmpty()) // Message from normal bitcoin:URI (bitcoin:123...?message=example)
                 vOrderForm.emplace_back("Message", rcp.message.toStdString());
         }
 
@@ -266,7 +275,9 @@ WalletModel::SendCoinsReturn WalletModel::sendCoins(WalletModelTransaction &tran
     for (const SendCoinsRecipient &rcp : transaction.getRecipients())
     {
         // Don't touch the address book when we have a payment request
+#ifdef ENABLE_BIP70
         if (!rcp.paymentRequest.IsInitialized())
+#endif
         {
             std::string strAddress = rcp.address.toStdString();
             CTxDestination dest = DecodeDestination(strAddress);
diff --git a/src/qt/walletmodel.h b/src/qt/walletmodel.h
index b22728c69b..ec4c5a2a6c 100644
--- a/src/qt/walletmodel.h
+++ b/src/qt/walletmodel.h
@@ -10,7 +10,13 @@
 #include <serialize.h>
 #include <script/standard.h>
 
+#if defined(HAVE_CONFIG_H)
+#include <config/bitcoin-config.h>
+#endif
+
+#ifdef ENABLE_BIP70
 #include <qt/paymentrequestplus.h>
+#endif
 #include <qt/walletmodeltransaction.h>
 
 #include <interfaces/wallet.h>
@@ -63,8 +69,14 @@ public:
     // If from a payment request, this is used for storing the memo
     QString message;
 
+#ifdef ENABLE_BIP70
     // If from a payment request, paymentRequest.IsInitialized() will be true
     PaymentRequestPlus paymentRequest;
+#else
+    // If building with BIP70 is disabled, keep the payment request around as
+    // serialized string to ensure load/store is lossless
+    std::string sPaymentRequest;
+#endif
     // Empty if no authentication or invalid signature/cert/etc.
     QString authenticatedMerchant;
 
@@ -80,9 +92,11 @@ public:
         std::string sAddress = address.toStdString();
         std::string sLabel = label.toStdString();
         std::string sMessage = message.toStdString();
+#ifdef ENABLE_BIP70
         std::string sPaymentRequest;
         if (!ser_action.ForRead() && paymentRequest.IsInitialized())
             paymentRequest.SerializeToString(&sPaymentRequest);
+#endif
         std::string sAuthenticatedMerchant = authenticatedMerchant.toStdString();
 
         READWRITE(this->nVersion);
@@ -98,8 +112,10 @@ public:
             address = QString::fromStdString(sAddress);
             label = QString::fromStdString(sLabel);
             message = QString::fromStdString(sMessage);
+#ifdef ENABLE_BIP70
             if (!sPaymentRequest.empty())
                 paymentRequest.parse(QByteArray::fromRawData(sPaymentRequest.data(), sPaymentRequest.size()));
+#endif
             authenticatedMerchant = QString::fromStdString(sAuthenticatedMerchant);
         }
     }
diff --git a/src/qt/walletmodeltransaction.cpp b/src/qt/walletmodeltransaction.cpp
index de50616499..eb3b0baf08 100644
--- a/src/qt/walletmodeltransaction.cpp
+++ b/src/qt/walletmodeltransaction.cpp
@@ -2,6 +2,10 @@
 // Distributed under the MIT software license, see the accompanying
 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
 
+#ifdef HAVE_CONFIG_H
+#include <config/bitcoin-config.h>
+#endif
+
 #include <qt/walletmodeltransaction.h>
 
 #include <interfaces/node.h>
@@ -46,6 +50,7 @@ void WalletModelTransaction::reassignAmounts(int nChangePosRet)
     {
         SendCoinsRecipient& rcp = (*it);
 
+#ifdef ENABLE_BIP70
         if (rcp.paymentRequest.IsInitialized())
         {
             CAmount subtotal = 0;
@@ -62,6 +67,7 @@ void WalletModelTransaction::reassignAmounts(int nChangePosRet)
             rcp.amount = subtotal;
         }
         else // normal recipient (no payment request)
+#endif
         {
             if (i == nChangePosRet)
                 i++;
diff --git a/src/qt/walletmodeltransaction.h b/src/qt/walletmodeltransaction.h
index 75ede2e2a1..289aee847b 100644
--- a/src/qt/walletmodeltransaction.h
+++ b/src/qt/walletmodeltransaction.h
@@ -8,6 +8,7 @@
 #include <qt/walletmodel.h>
 
 #include <memory>
+#include <amount.h>
 
 #include <QObject>