inspector: check Host header

Backport-PR-URL: https://github.com/nodejs-private/node-private/pull/108
PR-URL: https://github.com/nodejs-private/node-private/pull/102/
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>

src/inspector_socket.cc

@@ -394,12 +394,7 @@ static int header_value_cb(http_parser* parser, const char* at, size_t length) {
   auto inspector = static_cast<InspectorSocket*>(parser->data);
   auto state = inspector->http_parsing_state;
   state->parsing_value = true;
-  if (state->current_header.size() == sizeof(SEC_WEBSOCKET_KEY_HEADER) - 1 &&
-      node::StringEqualNoCaseN(state->current_header.data(),
-                               SEC_WEBSOCKET_KEY_HEADER,
-                               sizeof(SEC_WEBSOCKET_KEY_HEADER) - 1)) {
-    state->ws_key.append(at, length);
-  }
+  state->headers[state->current_header].append(at, length);
   return 0;
 }
 
@@ -472,10 +467,59 @@ static void handshake_failed(InspectorSocket* inspector) {
 // init_handshake references message_complete_cb
 static void init_handshake(InspectorSocket* inspector);
 
+static std::string TrimPort(const std::string& host) {
+  size_t last_colon_pos = host.rfind(":");
+  if (last_colon_pos == std::string::npos)
+    return host;
+  size_t bracket = host.rfind("]");
+  if (bracket == std::string::npos || last_colon_pos > bracket)
+    return host.substr(0, last_colon_pos);
+  return host;
+}
+
+static bool IsIPAddress(const std::string& host) {
+  if (host.length() >= 4 && host.front() == '[' && host.back() == ']')
+    return true;
+  int quads = 0;
+  for (char c : host) {
+    if (c == '.')
+      quads++;
+    else if (!isdigit(c))
+      return false;
+  }
+  return quads == 3;
+}
+
+static std::string HeaderValue(const struct http_parsing_state_s* state,
+                               const std::string& header) {
+  bool header_found = false;
+  std::string value;
+  for (const auto& header_value : state->headers) {
+    if (node::StringEqualNoCaseN(header_value.first.data(), header.data(),
+                                 header.length())) {
+      if (header_found)
+        return "";
+      value = header_value.second;
+      header_found = true;
+    }
+  }
+  return value;
+}
+
+static bool IsAllowedHost(const std::string& host_with_port) {
+  std::string host = TrimPort(host_with_port);
+  return host.empty() || IsIPAddress(host)
+         || node::StringEqualNoCase(host.data(), "localhost")
+         || node::StringEqualNoCase(host.data(), "localhost6");
+}
+
 static int message_complete_cb(http_parser* parser) {
   InspectorSocket* inspector = static_cast<InspectorSocket*>(parser->data);
   struct http_parsing_state_s* state = inspector->http_parsing_state;
-  if (parser->method != HTTP_GET) {
+  state->ws_key = HeaderValue(state, "Sec-WebSocket-Key");
+
+  if (!IsAllowedHost(HeaderValue(state, "Host")) ||
+      parser->method != HTTP_GET) {
     handshake_failed(inspector);
   } else if (!parser->upgrade) {
     if (state->callback(inspector, kInspectorHandshakeHttpGet, state->path)) {

src/inspector_socket.h

@@ -6,6 +6,7 @@
 #include "util-inl.h"
 #include "uv.h"
 
+#include <map>
 #include <string>
 #include <vector>
 
@@ -38,6 +39,7 @@ struct http_parsing_state_s {
   std::string ws_key;
   std::string path;
   std::string current_header;
+  std::map<std::string, std::string> headers;
 };
 
 struct ws_state_s {

test/cctest/test_inspector_socket.cc

@@ -906,4 +906,35 @@ TEST_F(InspectorSocketTest, ErrorCleansUpTheSocket) {
   EXPECT_EQ(UV_EPROTO, err);
 }
 
+static void HostCheckedForGet_handshake(enum inspector_handshake_event state,
+                                        const std::string &path, bool *cont) {
+  EXPECT_EQ(kInspectorHandshakeFailed, state);
+  EXPECT_TRUE(path.empty());
+  *cont = false;
+}
+
+TEST_F(InspectorSocketTest, HostCheckedForGet) {
+  handshake_delegate = HostCheckedForGet_handshake;
+  const char WRITE_REQUEST[] = "GET /respond/withtext HTTP/1.1\r\n"
+                               "Host: notlocalhost:9222\r\n\r\n";
+  send_in_chunks(WRITE_REQUEST, sizeof(WRITE_REQUEST) - 1);
+
+  expect_handshake_failure();
+  assert_both_sockets_closed();
+}
+
+TEST_F(InspectorSocketTest, HostCheckedForUpgrade) {
+  handshake_delegate = HostCheckedForGet_handshake;
+  const char UPGRADE_REQUEST[] = "GET /ws/path HTTP/1.1\r\n"
+                                 "Host: nonlocalhost:9229\r\n"
+                                 "Upgrade: websocket\r\n"
+                                 "Connection: Upgrade\r\n"
+                                 "Sec-WebSocket-Key: aaa==\r\n"
+                                 "Sec-WebSocket-Version: 13\r\n\r\n";
+  send_in_chunks(UPGRADE_REQUEST, sizeof(UPGRADE_REQUEST) - 1);
+
+  expect_handshake_failure();
+  assert_both_sockets_closed();
+}
+
 }  // anonymous namespace