SSL: Add a feature for DTLS

For now the new feature depends on openssl as that is the only supported
implementation. Once we get an implementation for SecureTransport, we
can change the condition.

The feature needs to be public because qdtls.h is a public header.

Change-Id: Ie3e4acbeb2888f2fb13453b3ecdc19bacc83f6e6
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>

src/network/configure.json

@@ -216,6 +216,13 @@
             "condition": "config.winrt || features.securetransport || features.openssl",
             "output": [ "publicFeature", "feature" ]
         },
+        "dtls": {
+            "label": "DTLS",
+            "purpose": "Provides a DTLS implementation",
+            "section": "Networking",
+            "condition": "features.openssl",
+            "output": [ "publicFeature" ]
+        },
         "opensslv11": {
             "label": "OpenSSL 1.1",
             "condition": "features.openssl && tests.openssl11",

src/network/ssl/qdtls.h

@@ -48,6 +48,8 @@
 #include <QtCore/qcryptographichash.h>
 #include <QtCore/qobject.h>
 
+QT_REQUIRE_CONFIG(dtls);
+
 QT_BEGIN_NAMESPACE
 
 enum class QDtlsError : unsigned char

src/network/ssl/qdtls_openssl_p.h

@@ -44,8 +44,6 @@
 
 #include <QtCore/qglobal.h>
 
-QT_REQUIRE_CONFIG(openssl);
-
 #include <openssl/ossl_typ.h>
 
 #include "qdtls_p.h"
@@ -72,6 +70,9 @@ QT_REQUIRE_CONFIG(openssl);
 // We mean it.
 //
 
+QT_REQUIRE_CONFIG(openssl);
+QT_REQUIRE_CONFIG(dtls);
+
 QT_BEGIN_NAMESPACE
 
 class QDtlsPrivateOpenSSL;

src/network/ssl/qdtls_p.h

@@ -68,6 +68,8 @@
 // We mean it.
 //
 
+QT_REQUIRE_CONFIG(dtls);
+
 QT_BEGIN_NAMESPACE
 
 class QHostAddress;

src/network/ssl/ssl.pri

@@ -56,13 +56,17 @@ qtConfig(ssl) {
                    ssl/qsslellipticcurve_dummy.cpp
     }
 
+    qtConfig(dtls) {
+        HEADERS += ssl/qdtls.h \
+                   ssl/qdtls_p.h
+
+        SOURCES += ssl/qdtls.cpp
+    }
+
     qtConfig(openssl) {
         HEADERS += ssl/qsslcontext_openssl_p.h \
                    ssl/qsslsocket_openssl_p.h \
-                   ssl/qsslsocket_openssl_symbols_p.h \
-                   ssl/qdtls.h \
-                   ssl/qdtls_p.h \
-                   ssl/qdtls_openssl_p.h
+                   ssl/qsslsocket_openssl_symbols_p.h
         SOURCES += ssl/qsslsocket_openssl_symbols.cpp \
                    ssl/qssldiffiehellmanparameters_openssl.cpp \
                    ssl/qsslcertificate_openssl.cpp \
@@ -70,8 +74,11 @@ qtConfig(ssl) {
                    ssl/qsslkey_openssl.cpp \
                    ssl/qsslsocket_openssl.cpp \
                    ssl/qsslcontext_openssl.cpp \
-                   ssl/qdtls.cpp \
-                   ssl/qdtls_openssl.cpp
+
+        qtConfig(dtls) {
+            HEADERS += ssl/qdtls_openssl_p.h
+            SOURCES += ssl/qdtls_openssl.cpp
+        }
 
         qtConfig(opensslv11) {
             HEADERS += ssl/qsslsocket_openssl11_symbols_p.h