Do not use HTTP/2 without adequate security.

net/socket/ssl_client_socket_nss.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // This file includes code SSLClientSocketNSS::DoVerifyCertComplete() derived
 // from AuthCertificateCallback() in
 // mozilla/security/manager/ssl/src/nsNSSCallbacks.cpp.
 
 /* ***** BEGIN LICENSE BLOCK *****
  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
@@ skipping 955 matching lines @@
   DCHECK(OnNetworkTaskRunner());
   DCHECK(!nss_fd_);
   DCHECK(!nss_bufs_);
 
   nss_fd_ = socket;
   nss_bufs_ = buffers;
 
   SECStatus rv = SECSuccess;
 
   if (!ssl_config_.next_protos.empty()) {
-    std::vector<uint8_t> wire_protos =
-        SerializeNextProtos(ssl_config_.next_protos);
+    DCHECK(NSS_IsInitialized());
+    const std::vector<uint16> cipher_suites =
+        GetNSSDefaultEnabledCipherSuites();
+    std::vector<uint16> implemented_enabled_cipher_suites;
+    for (uint16 cipher : cipher_suites) {
+      PRBool enabled = PR_FALSE;
+      if (PK11_TokenExists(cipher) &&
+          SSL_CipherPrefGet(nss_fd_, cipher, &enabled) == SECSuccess &&
+          enabled) {
+        implemented_enabled_cipher_suites.push_back(cipher);
+      }
+    }
+    std::vector<uint8_t> wire_protos = SerializeNextProtos(
+        ssl_config_.next_protos,
+        IsSecurityAdequateForHTTP2(ssl_config_,
+                                   implemented_enabled_cipher_suites));
     rv = SSL_SetNextProtoNego(
         nss_fd_, wire_protos.empty() ? NULL : &wire_protos[0],
         wire_protos.size());
     if (rv != SECSuccess)
       LogFailedNSSFunction(*weak_net_log_, "SSL_SetNextProtoNego", "");
     rv = SSL_OptionSet(nss_fd_, SSL_ENABLE_ALPN, PR_TRUE);
     if (rv != SECSuccess)
       LogFailedNSSFunction(*weak_net_log_, "SSL_OptionSet", "SSL_ENABLE_ALPN");
     rv = SSL_OptionSet(nss_fd_, SSL_ENABLE_NPN, PR_TRUE);
     if (rv != SECSuccess)
@@ skipping 2630 matching lines @@
 scoped_refptr<X509Certificate>
 SSLClientSocketNSS::GetUnverifiedServerCertificateChain() const {
   return core_->state().server_cert.get();
 }
 
 ChannelIDService* SSLClientSocketNSS::GetChannelIDService() const {
   return channel_id_service_;
 }
 
 }  // namespace net