Update NSS to 3.38

- Added HACL*Poly1305 32-bit (INRIA/Microsoft)
- Updated to final TLS 1.3 draft version (28)
- Removed TLS 1.3 prerelease draft limit check
- Removed NPN code
- Enabled dev/urandom-only RNG on Linux with NSS_SEED_ONLY_DEV_URANDOM for non-standard environments
- Fixed several bugs with TLS 1.3 negotiation
- Updated internal certificate store
- Added support for the TLS Record Size Limit Extension.
- Fixed CVE-2018-0495
- Various security fixes in the ASN.1 code.

security/nss/fuzz/tls_client_target.cc

@@ -87,15 +87,12 @@ static void SetupCallbacks(PRFileDesc* fd, ClientConfig* config) {
 }
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t len) {
-  static std::unique_ptr<NSSDatabase> db(new NSSDatabase());
+  std::unique_ptr<NSSDatabase> db(new NSSDatabase());
   assert(db != nullptr);
 
   EnableAllProtocolVersions();
   std::unique_ptr<ClientConfig> config(new ClientConfig(data, len));
 
-  // Clear the cache. We never want to resume as we couldn't reproduce that.
-  SSL_ClearSessionCache();
-
   // Reset the RNG state.
   assert(RNG_RandomUpdate(NULL, 0) == SECSuccess);
 
@@ -114,6 +111,9 @@ extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t len) {
   SetupCallbacks(ssl_fd, config.get());
   DoHandshake(ssl_fd, false);
 
+  // Release all SIDs.
+  SSL_ClearSessionCache();
+
   return 0;
 }