Specify SSL_CTX_set_max_early_data and add an option to change max value

gennghttpxfun.py

@@ -171,6 +171,7 @@ OPTIONS = [
     "verify-client-tolerate-expired",
     "ignore-per-pattern-mruby-error",
     "tls-postpone-early-data",
+    "tls-max-early-data",
 ]
 
 LOGVARS = [

src/shrpx.cc

@@ -1465,6 +1465,7 @@ void fill_default_config(Config *config) {
       tls::proto_version_from_string(DEFAULT_TLS_MIN_PROTO_VERSION);
   tlsconf.max_proto_version =
       tls::proto_version_from_string(DEFAULT_TLS_MAX_PROTO_VERSION);
+  tlsconf.max_early_data = 16_k;
 #if OPENSSL_1_1_API || defined(OPENSSL_IS_BORINGSSL)
   tlsconf.ecdh_curves = StringRef::from_lit("X25519:P-256:P-384:P-521");
 #else  // !OPENSSL_1_1_API && !defined(OPENSSL_IS_BORINGSSL)
@@ -2376,6 +2377,11 @@ SSL/TLS:
               handshake  finishes.   This  option   must  be  used  to
               mitigate  possible  replay  attack  unless  all  backend
               servers recognize "Early-Data" header field.
+  --tls-max-early-data=<SIZE>
+              Sets  the  maximum  amount  of 0-RTT  data  that  server
+              accepts.
+              Default: )"
+      << util::utos_unit(config->tls.max_early_data) << R"(
 
 HTTP/2:
   -c, --frontend-http2-max-concurrent-streams=<N>
@@ -3443,6 +3449,7 @@ int main(int argc, char **argv) {
         {SHRPX_OPT_IGNORE_PER_PATTERN_MRUBY_ERROR.c_str(), no_argument, &flag,
          161},
         {SHRPX_OPT_TLS_POSTPONE_EARLY_DATA.c_str(), no_argument, &flag, 162},
+        {SHRPX_OPT_TLS_MAX_EARLY_DATA.c_str(), required_argument, &flag, 163},
         {nullptr, 0, nullptr, 0}};
 
     int option_index = 0;
@@ -4219,6 +4226,10 @@ int main(int argc, char **argv) {
         cmdcfgs.emplace_back(SHRPX_OPT_TLS_POSTPONE_EARLY_DATA,
                              StringRef::from_lit("yes"));
         break;
+      case 163:
+        // --tls-max-early-data
+        cmdcfgs.emplace_back(SHRPX_OPT_TLS_MAX_EARLY_DATA, StringRef{optarg});
+        break;
       default:
         break;
       }

src/shrpx_config.cc

@@ -1883,6 +1883,11 @@ int option_lookup_token(const char *name, size_t namelen) {
     break;
   case 18:
     switch (name[17]) {
+    case 'a':
+      if (util::strieq_l("tls-max-early-dat", name, 17)) {
+        return SHRPX_OPTID_TLS_MAX_EARLY_DATA;
+      }
+      break;
     case 'r':
       if (util::strieq_l("add-request-heade", name, 17)) {
         return SHRPX_OPTID_ADD_REQUEST_HEADER;
@@ -3600,6 +3605,9 @@ int parse_config(Config *config, int optid, const StringRef &opt,
     config->tls.postpone_early_data = util::strieq_l("yes", optarg);
 
     return 0;
+  case SHRPX_OPTID_TLS_MAX_EARLY_DATA: {
+    return parse_uint_with_unit(&config->tls.max_early_data, opt, optarg);
+  }
   case SHRPX_OPTID_CONF:
     LOG(WARN) << "conf: ignored";
 

src/shrpx_config.h

@@ -349,6 +349,8 @@ constexpr auto SHRPX_OPT_IGNORE_PER_PATTERN_MRUBY_ERROR =
     StringRef::from_lit("ignore-per-pattern-mruby-error");
 constexpr auto SHRPX_OPT_TLS_POSTPONE_EARLY_DATA =
     StringRef::from_lit("tls-postpone-early-data");
+constexpr auto SHRPX_OPT_TLS_MAX_EARLY_DATA =
+    StringRef::from_lit("tls-max-early-data");
 
 constexpr size_t SHRPX_OBFUSCATED_NODE_LENGTH = 8;
 
@@ -652,6 +654,8 @@ struct TLSConfig {
   StringRef ciphers;
   StringRef ecdh_curves;
   StringRef cacert;
+  // The maximum amount of 0-RTT data that server accepts.
+  uint32_t max_early_data;
   // The minimum and maximum TLS version.  These values are defined in
   // OpenSSL header file.
   int min_proto_version;
@@ -1119,6 +1123,7 @@ enum {
   SHRPX_OPTID_SYSLOG_FACILITY,
   SHRPX_OPTID_TLS_DYN_REC_IDLE_TIMEOUT,
   SHRPX_OPTID_TLS_DYN_REC_WARMUP_THRESHOLD,
+  SHRPX_OPTID_TLS_MAX_EARLY_DATA,
   SHRPX_OPTID_TLS_MAX_PROTO_VERSION,
   SHRPX_OPTID_TLS_MIN_PROTO_VERSION,
   SHRPX_OPTID_TLS_POSTPONE_EARLY_DATA,

src/shrpx_tls.cc

@@ -973,6 +973,14 @@ SSL_CTX *create_ssl_context(const char *private_key_file, const char *cert_file,
   }
 #endif // !LIBRESSL_IN_USE && OPENSSL_VERSION_NUMBER >= 0x10002000L
 
+#if OPENSSL_1_1_1_API
+  if (SSL_CTX_set_max_early_data(ssl_ctx, tlsconf.max_early_data) != 1) {
+    LOG(FATAL) << "SSL_CTX_set_max_early_data failed: "
+               << ERR_error_string(ERR_get_error(), nullptr);
+    DIE();
+  }
+#endif // OPENSSL_1_1_1_API
+
 #ifndef OPENSSL_NO_PSK
   SSL_CTX_set_psk_server_callback(ssl_ctx, psk_server_cb);
 #endif // !LIBRESSL_NO_PSK