nss: allow to enable/disable new AES GCM cipher-suites

... if built against a new enough version of NSS

lib/vtls/nss.c

@@ -165,6 +165,16 @@ static const cipher_s cipherlist[] = {
   {"ecdhe_ecdsa_aes_128_cbc_sha_256", TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256},
   {"ecdhe_rsa_aes_128_cbc_sha_256",   TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256},
 #endif
+#ifdef TLS_RSA_WITH_AES_128_GCM_SHA256
+  /* AES GCM cipher suites in RFC 5288 and RFC 5289 */
+  {"rsa_aes_128_gcm_sha_256",         TLS_RSA_WITH_AES_128_GCM_SHA256},
+  {"dhe_rsa_aes_128_gcm_sha_256",     TLS_DHE_RSA_WITH_AES_128_GCM_SHA256},
+  {"dhe_dss_aes_128_gcm_sha_256",     TLS_DHE_DSS_WITH_AES_128_GCM_SHA256},
+  {"ecdhe_ecdsa_aes_128_gcm_sha_256", TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256},
+  {"ecdh_ecdsa_aes_128_gcm_sha_256",  TLS_ECDH_ECDSA_WITH_AES_128_GCM_SHA256},
+  {"ecdhe_rsa_aes_128_gcm_sha_256",   TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256},
+  {"ecdh_rsa_aes_128_gcm_sha_256",    TLS_ECDH_RSA_WITH_AES_128_GCM_SHA256},
+#endif
 };
 
 static const char* pem_library = "libnsspem.so";