Add missing protocol enumerators, report TLS 1.3 if negotiated

1. Remove the conditional inclusion of DTLS versions, they made difficult
and unnecessary ugly adding new protocols (something like TlsV1_2OrLater + 4).

2. OpenSSL 1.1.1 first introduced TLS 1.3 support. OpenSSL 1.1 back-end is
compatible with OpenSSL 1.1.1, but would fail to extract/report protocol
versions and set versions like 'TLS 1.3 only' or 'TLS 1.3 or better' on a
new context.  Given 1.1.1 is deployed/adapted fast by different distros,
and 5.12 is LTS, we fix this issue by introducing QSsl::Tls1_3 and
QSsl::Tls1_3OrLater.

SecureTransport, WinRT and OpenSSL below 1.1.1 will report an error in case
the application requests this protocol (SecureTransport in future will
probably enable TLS 1.3).

Saying all that, TLS 1.3 support is experimental in QSslSocket.

Done-by: Albert Astals Cid <albert.astals.cid@kdab.com>
Done-by: Timur Pocheptsov <timur.pocheptsov@qt.io>
Change-Id: I4a97cc789b62763763cf41c44157ef0a9fd6cbec
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

1 files changed, 12 insertions, 0 deletions

diff --git a/src/network/ssl/qsslsocket_mac.cpp b/src/network/ssl/qsslsocket_mac.cpp
index 9166e0ac29..65d98758ac 100644
--- a/src/network/ssl/qsslsocket_mac.cpp
+++ b/src/network/ssl/qsslsocket_mac.cpp
@@ -1110,6 +1110,18 @@ bool QSslSocketBackendPrivate::setSessionProtocol()
         return false;
     }
 
+    // SecureTransport has kTLSProtocol13 constant and also, kTLSProtocolMaxSupported.
+    // Calling SSLSetProtocolVersionMax/Min with any of these two constants results
+    // in errInvalidParam and a failure to set the protocol version. This means
+    // no TLS 1.3 on macOS and iOS.
+    switch (configuration.protocol) {
+    case QSsl::TlsV1_3:
+    case QSsl::TlsV1_3OrLater:
+        qCWarning(lcSsl) << plainSocket << "SecureTransport does not support TLS 1.3";
+        return false;
+    default:;
+    }
+
     OSStatus err = errSecSuccess;
 
     if (configuration.protocol == QSsl::SslV3) {