src: Support ALPN

Requires unreleased OpenSSL >= 1.0.2

src/HttpServer.cc

@@ -196,6 +196,7 @@ Http2Handler::~Http2Handler()
     SSL_shutdown(ssl_);
   }
   if(bev_) {
+    bufferevent_disable(bev_, EV_READ | EV_WRITE);
     bufferevent_free(bev_);
   }
   if(ssl_) {
@@ -398,19 +399,30 @@ int Http2Handler::verify_npn_result()
 {
   const unsigned char *next_proto = nullptr;
   unsigned int next_proto_len;
+  // Check the negotiated protocol in NPN or ALPN
   SSL_get0_next_proto_negotiated(ssl_, &next_proto, &next_proto_len);
-  if(next_proto) {
-    std::string proto(next_proto, next_proto+next_proto_len);
-    if(sessions_->get_config()->verbose) {
-      std::cout << "The negotiated next protocol: " << proto << std::endl;
-    }
-    if(proto == NGHTTP2_PROTO_VERSION_ID) {
-      return 0;
+  for(int i = 0; i < 2; ++i) {
+    if(next_proto) {
+      std::string proto(next_proto, next_proto+next_proto_len);
+      if(sessions_->get_config()->verbose) {
+        std::cout << "The negotiated protocol: " << proto << std::endl;
+      }
+      if(proto == NGHTTP2_PROTO_VERSION_ID) {
+        return 0;
+      }
+      break;
+    } else {
+#if OPENSSL_VERSION_NUMBER >= 0x10002000L
+      SSL_get0_alpn_selected(ssl_, &next_proto, &next_proto_len);
+#else // OPENSSL_VERSION_NUMBER < 0x10002000L
+      break;
+#endif // OPENSSL_VERSION_NUMBER < 0x10002000L
     }
   }
-  std::cerr << "The negotiated next protocol is not supported."
+  std::cerr << "Client did not advertise HTTP/2.0 protocol."
+            << " (nghttp2 expects " << NGHTTP2_PROTO_VERSION_ID << ")"
             << std::endl;
-  return 0;
+  return -1;
 }
 
 int Http2Handler::sendcb(const uint8_t *data, size_t len)
@@ -1094,6 +1106,33 @@ int start_listen(event_base *evbase, Sessions *sessions,
 }
 } // namespace
 
+#if OPENSSL_VERSION_NUMBER >= 0x10002000L
+namespace {
+int alpn_select_proto_cb(SSL* ssl,
+                         const unsigned char **out, unsigned char *outlen,
+                         const unsigned char *in, unsigned int inlen,
+                         void *arg)
+{
+  auto config = reinterpret_cast<HttpServer*>(arg)->get_config();
+  if(config->verbose) {
+    std::cout << "[ALPN] client offers:" << std::endl;
+  }
+  if(config->verbose) {
+    for(unsigned int i = 0; i < inlen; i += in[i]+1) {
+      std::cout << " * ";
+      std::cout.write(reinterpret_cast<const char*>(&in[i+1]), in[i]);
+      std::cout << std::endl;
+    }
+  }
+  if(nghttp2_select_next_protocol(const_cast<unsigned char**>(out), outlen,
+                                  in, inlen) <= 0) {
+    return SSL_TLSEXT_ERR_NOACK;
+  }
+  return SSL_TLSEXT_ERR_OK;
+}
+} // namespace
+#endif // OPENSSL_VERSION_NUMBER >= 0x10002000L
+
 int HttpServer::run()
 {
   SSL_CTX *ssl_ctx = nullptr;
@@ -1138,6 +1177,10 @@ int HttpServer::run()
     next_proto.second = proto_list[0] + 1;
 
     SSL_CTX_set_next_protos_advertised_cb(ssl_ctx, next_proto_cb, &next_proto);
+#if OPENSSL_VERSION_NUMBER >= 0x10002000L
+    // ALPN selection callback
+    SSL_CTX_set_alpn_select_cb(ssl_ctx, alpn_select_proto_cb, this);
+#endif // OPENSSL_VERSION_NUMBER >= 0x10002000L
   }
 
   auto evbase = event_base_new();
@@ -1152,4 +1195,9 @@ int HttpServer::run()
   return 0;
 }
 
+const Config* HttpServer::get_config() const
+{
+  return config_;
+}
+
 } // namespace nghttp2

src/HttpServer.h

@@ -137,6 +137,7 @@ public:
   HttpServer(const Config* config);
   int listen();
   int run();
+  const Config* get_config() const;
 private:
   const Config *config_;
 };

src/nghttp.cc

@@ -1223,6 +1223,15 @@ void print_stats(const HttpClient& client)
 }
 } // namespace
 
+namespace {
+void print_protocol_nego_error()
+{
+  std::cerr << "Server did not select HTTP/2.0 protocol."
+            << " (nghttp2 expects " << NGHTTP2_PROTO_VERSION_ID << ")"
+            << std::endl;
+}
+} // namespace
+
 namespace {
 int client_select_next_proto_cb(SSL* ssl,
                                 unsigned char **out, unsigned char *outlen,
@@ -1231,8 +1240,7 @@ int client_select_next_proto_cb(SSL* ssl,
 {
   if(config.verbose) {
     print_timer();
-    std::cout << " NPN select next protocol: the remote server offers:"
-              << std::endl;
+    std::cout << "[NPN] server offers:" << std::endl;
   }
   for(unsigned int i = 0; i < inlen; i += in[i]+1) {
     if(config.verbose) {
@@ -1242,15 +1250,8 @@ int client_select_next_proto_cb(SSL* ssl,
     }
   }
   if(nghttp2_select_next_protocol(out, outlen, in, inlen) <= 0) {
-    std::cerr << "Server did not advertise HTTP/2.0 protocol."
-              << " (nghttp2 expects " << NGHTTP2_PROTO_VERSION_ID << ")"
-              << std::endl;
-  } else {
-    if(config.verbose) {
-      std::cout << "          NPN selected the protocol: ";
-      std::cout.write(reinterpret_cast<const char*>(*out), (size_t)*outlen);
-      std::cout << std::endl;
-    }
+    print_protocol_nego_error();
+    return SSL_TLSEXT_ERR_NOACK;
   }
   return SSL_TLSEXT_ERR_OK;
 }
@@ -1312,7 +1313,37 @@ void eventcb(bufferevent *bev, short events, void *ptr)
     if(client->need_upgrade()) {
       rv = client->on_upgrade_connect();
     } else {
-      // TODO Check NPN result and fail fast?
+      // Check NPN or ALPN result
+      const unsigned char *next_proto = nullptr;
+      unsigned int next_proto_len;
+      SSL_get0_next_proto_negotiated(client->ssl,
+                                     &next_proto, &next_proto_len);
+      for(int i = 0; i < 2; ++i) {
+        if(next_proto) {
+          if(config.verbose) {
+            std::cout << "The negotiated protocol: ";
+            std::cout.write(reinterpret_cast<const char*>(next_proto),
+                            next_proto_len);
+            std::cout << std::endl;
+          }
+          if(NGHTTP2_PROTO_VERSION_ID_LEN != next_proto_len ||
+             memcmp(NGHTTP2_PROTO_VERSION_ID, next_proto,
+                    NGHTTP2_PROTO_VERSION_ID_LEN) != 0) {
+            next_proto = nullptr;
+          }
+          break;
+        }
+#if OPENSSL_VERSION_NUMBER >= 0x10002000L
+        SSL_get0_alpn_selected(client->ssl, &next_proto, &next_proto_len);
+#else // OPENSSL_VERSION_NUMBER < 0x10002000L
+        break;
+#endif // OPENSSL_VERSION_NUMBER < 0x10002000L
+      }
+      if(!next_proto) {
+        print_protocol_nego_error();
+        client->disconnect();
+        return;
+      }
       rv = client->on_connect();
     }
     if(rv != 0) {
@@ -1404,6 +1435,14 @@ int communicate(const std::string& scheme, const std::string& host,
     }
     SSL_CTX_set_next_proto_select_cb(ssl_ctx,
                                      client_select_next_proto_cb, nullptr);
+
+#if OPENSSL_VERSION_NUMBER >= 0x10002000L
+    unsigned char proto_list[255];
+    proto_list[0] = NGHTTP2_PROTO_VERSION_ID_LEN;
+    memcpy(&proto_list[1], NGHTTP2_PROTO_VERSION_ID,
+           NGHTTP2_PROTO_VERSION_ID_LEN);
+    SSL_CTX_set_alpn_protos(ssl_ctx, proto_list, proto_list[0] + 1);
+#endif // OPENSSL_VERSION_NUMBER >= 0x10002000L
   }
   {
     HttpClient client{callbacks, evbase, ssl_ctx};

src/shrpx_client_handler.cc

@@ -299,26 +299,37 @@ int ClientHandler::validate_next_proto()
   // First set callback for catch all cases
   set_bev_cb(upstream_readcb, upstream_writecb, upstream_eventcb);
   SSL_get0_next_proto_negotiated(ssl_, &next_proto, &next_proto_len);
-  if(next_proto) {
-    std::string proto(next_proto, next_proto+next_proto_len);
-    if(LOG_ENABLED(INFO)) {
-      CLOG(INFO, this) << "The negotiated next protocol: " << proto;
-    }
-    if(proto == NGHTTP2_PROTO_VERSION_ID) {
-      set_bev_cb(upstream_http2_connhd_readcb, upstream_writecb,
-                 upstream_eventcb);
-      upstream_ = util::make_unique<Http2Upstream>(this);
-      return 0;
-    } else {
-#ifdef HAVE_SPDYLAY
-      uint16_t version = spdylay_npn_get_version(next_proto, next_proto_len);
-      if(version) {
-        upstream_ = util::make_unique<SpdyUpstream>(version, this);
-        return 0;
+  for(int i = 0; i < 2; ++i) {
+    if(next_proto) {
+      if(LOG_ENABLED(INFO)) {
+        std::string proto(next_proto, next_proto+next_proto_len);
+        CLOG(INFO, this) << "The negotiated next protocol: " << proto;
       }
+      if(next_proto_len == NGHTTP2_PROTO_VERSION_ID_LEN &&
+         memcmp(NGHTTP2_PROTO_VERSION_ID, next_proto,
+                NGHTTP2_PROTO_VERSION_ID_LEN) == 0) {
+        set_bev_cb(upstream_http2_connhd_readcb, upstream_writecb,
+                   upstream_eventcb);
+        upstream_ = util::make_unique<Http2Upstream>(this);
+        return 0;
+      } else {
+#ifdef HAVE_SPDYLAY
+        uint16_t version = spdylay_npn_get_version(next_proto, next_proto_len);
+        if(version) {
+          upstream_ = util::make_unique<SpdyUpstream>(version, this);
+          return 0;
+        }
 #endif // HAVE_SPDYLAY
+      }
+      break;
     }
-  } else {
+#if OPENSSL_VERSION_NUMBER >= 0x10002000L
+    SSL_get0_alpn_selected(ssl_, &next_proto, &next_proto_len);
+#else // OPENSSL_VERSION_NUMBER < 0x10002000L
+    break;
+#endif // OPENSSL_VERSION_NUMBER < 0x10002000L
+  }
+  if(!next_proto) {
     if(LOG_ENABLED(INFO)) {
       CLOG(INFO, this) << "No proto negotiated.";
     }

src/shrpx_http2_session.cc

@@ -1120,15 +1120,30 @@ int on_unknown_frame_recv_callback(nghttp2_session *session,
 int Http2Session::on_connect()
 {
   int rv;
-  const unsigned char *next_proto = nullptr;
-  unsigned int next_proto_len;
   if(ssl_ctx_) {
+    const unsigned char *next_proto = nullptr;
+    unsigned int next_proto_len;
     SSL_get0_next_proto_negotiated(ssl_, &next_proto, &next_proto_len);
-    std::string proto(next_proto, next_proto+next_proto_len);
-    if(LOG_ENABLED(INFO)) {
-      SSLOG(INFO, this) << "Negotiated next protocol: " << proto;
+    for(int i = 0; i < 2; ++i) {
+      if(next_proto) {
+        if(LOG_ENABLED(INFO)) {
+          std::string proto(next_proto, next_proto+next_proto_len);
+          SSLOG(INFO, this) << "Negotiated next protocol: " << proto;
+        }
+        if(next_proto_len != NGHTTP2_PROTO_VERSION_ID_LEN ||
+           memcmp(NGHTTP2_PROTO_VERSION_ID, next_proto,
+                  NGHTTP2_PROTO_VERSION_ID_LEN) != 0) {
+          return -1;
+        }
+        break;
+      }
+#if OPENSSL_VERSION_NUMBER >= 0x10002000L
+      SSL_get0_alpn_selected(ssl_, &next_proto, &next_proto_len);
+#else // OPENSSL_VERSION_NUMBER < 0x10002000L
+      break;
+#endif // OPENSSL_VERSION_NUMBER < 0x10002000L
     }
-    if(proto != NGHTTP2_PROTO_VERSION_ID) {
+    if(!next_proto) {
       return -1;
     }
   }

src/shrpx_ssl.cc

@@ -132,6 +132,23 @@ int servername_callback(SSL *ssl, int *al, void *arg)
 }
 } // namespace
 
+#if OPENSSL_VERSION_NUMBER >= 0x10002000L
+namespace {
+int alpn_select_proto_cb(SSL* ssl,
+                         const unsigned char **out,
+                         unsigned char *outlen,
+                         const unsigned char *in, unsigned int inlen,
+                         void *arg)
+{
+  if(nghttp2_select_next_protocol
+     (const_cast<unsigned char**>(out), outlen, in, inlen) == -1) {
+    return SSL_TLSEXT_ERR_NOACK;
+  }
+  return SSL_TLSEXT_ERR_OK;
+}
+} // namespace
+#endif // OPENSSL_VERSION_NUMBER >= 0x10002000L
+
 SSL_CTX* create_ssl_context(const char *private_key_file,
                             const char *cert_file)
 {
@@ -241,11 +258,16 @@ SSL_CTX* create_ssl_context(const char *private_key_file,
   }
   SSL_CTX_set_tlsext_servername_callback(ssl_ctx, servername_callback);
 
+  // NPN advertisement
   auto proto_list_len = set_npn_prefs(proto_list, get_config()->npn_list,
                                       get_config()->npn_list_len);
   next_proto.first = proto_list;
   next_proto.second = proto_list_len;
   SSL_CTX_set_next_protos_advertised_cb(ssl_ctx, next_proto_cb, &next_proto);
+#if OPENSSL_VERSION_NUMBER >= 0x10002000L
+  // ALPN selection callback
+  SSL_CTX_set_alpn_select_cb(ssl_ctx, alpn_select_proto_cb, nullptr);
+#endif // OPENSSL_VERSION_NUMBER >= 0x10002000L
   return ssl_ctx;
 }
 
@@ -322,8 +344,18 @@ SSL_CTX* create_ssl_client_context()
       DIE();
     }
   }
-
+  // NPN selection callback
   SSL_CTX_set_next_proto_select_cb(ssl_ctx, select_next_proto_cb, nullptr);
+
+#if OPENSSL_VERSION_NUMBER >= 0x10002000L
+  // ALPN advertisement
+  auto proto_list_len = set_npn_prefs(proto_list, get_config()->npn_list,
+                                      get_config()->npn_list_len);
+  next_proto.first = proto_list;
+  next_proto.second = proto_list_len;
+  SSL_CTX_set_alpn_protos(ssl_ctx, proto_list, proto_list[0] + 1);
+#endif // OPENSSL_VERSION_NUMBER >= 0x10002000L
+
   return ssl_ctx;
 }