commit f5e6845453aa7fa760e815a10b3d82ea786cc9a8
author nharper <nharper@google.com> Wed May 29 17:24:18 2019 -0700
committer Copybara-Service <copybara-worker@google.com> Fri May 31 15:29:01 2019 -0700
tree 8b79dba1863638898c17c7890cb5705d54973ec5
parent 34df585a7623b4a12be892878aad44af594fa545

Refactor how TLS versions get enabled

This brings it closer in line to how QUIC_VERSION_99 is handled and sets up the
flag to be switched to a reloadable flag (blocked on being enabled). In particular,
AllSupportedVersions() now returns versions that include PROTOCOL_TLS1_3 for the
handshake_protocol.

When a TLS version is in use, it is safe to assume that
ParsedQuicVersion::KnowsWhichDecrypterToUse always returns true. This is because
KnowsWhichDecrypterToUse is enabled for QUIC_VERSION_47 and above, while TLS versions
only exist when CRYPTO frames are in use, which is currently only transport version 99.

gfe-relnote: refactor of TLS version code; protected by quic_supports_tls_handshake
PiperOrigin-RevId: 250599516
Change-Id: Ibfe68d74089ce29edeee219671c81e1643702000

quic/core/quic_versions.cc

diff --git a/quic/core/quic_versions.cc b/quic/core/quic_versions.cc
index 6873edd..9100f32 100644
--- a/quic/core/quic_versions.cc
+++ b/quic/core/quic_versions.cc
@@ -30,12 +30,7 @@
 ParsedQuicVersion::ParsedQuicVersion(HandshakeProtocol handshake_protocol,
                                      QuicTransportVersion transport_version)
     : handshake_protocol(handshake_protocol),
-      transport_version(transport_version) {
-  if (handshake_protocol == PROTOCOL_TLS1_3 &&
-      !GetQuicFlag(FLAGS_quic_supports_tls_handshake)) {
-    QUIC_BUG << "TLS use attempted when not enabled";
-  }
-}
+      transport_version(transport_version) {}
 
 bool ParsedQuicVersion::KnowsWhichDecrypterToUse() const {
   return transport_version >= QUIC_VERSION_47 ||
@@ -120,10 +115,8 @@
 }
 
 ParsedQuicVersion ParseQuicVersionLabel(QuicVersionLabel version_label) {
-  std::vector<HandshakeProtocol> protocols = {PROTOCOL_QUIC_CRYPTO};
-  if (GetQuicFlag(FLAGS_quic_supports_tls_handshake)) {
-    protocols.push_back(PROTOCOL_TLS1_3);
-  }
+  std::vector<HandshakeProtocol> protocols = {PROTOCOL_QUIC_CRYPTO,
+                                              PROTOCOL_TLS1_3};
   for (QuicTransportVersion version : kSupportedTransportVersions) {
     for (HandshakeProtocol handshake : protocols) {
       if (version_label ==
@@ -185,10 +178,6 @@
 ParsedQuicVersionVector AllSupportedVersions() {
   ParsedQuicVersionVector supported_versions;
   for (HandshakeProtocol protocol : kSupportedHandshakeProtocols) {
-    if (protocol == PROTOCOL_TLS1_3 &&
-        !GetQuicFlag(FLAGS_quic_supports_tls_handshake)) {
-      continue;
-    }
     for (QuicTransportVersion version : kSupportedTransportVersions) {
       if (protocol == PROTOCOL_TLS1_3 &&
           !QuicVersionUsesCryptoFrames(version)) {
@@ -232,6 +221,10 @@
   ParsedQuicVersionVector filtered_versions;
   filtered_versions.reserve(versions.size());
   for (ParsedQuicVersion version : versions) {
+    if (version.handshake_protocol == PROTOCOL_TLS1_3 &&
+        !GetQuicFlag(FLAGS_quic_supports_tls_handshake)) {
+      continue;
+    }
     if (version.transport_version == QUIC_VERSION_99) {
       if (GetQuicReloadableFlag(quic_enable_version_99) &&
           GetQuicReloadableFlag(quic_enable_version_47) &&