1 files changed, 157 insertions, 0 deletions
diff --git a/updater/winhttp/winhttp.go b/updater/winhttp/winhttp.go
new file mode 100644
index 00000000..c75b5b57
--- /dev/null
+++ b/updater/winhttp/winhttp.go
@@ -0,0 +1,157 @@
+/* SPDX-License-Identifier: MIT
+ *
+ * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
+ */
+
+package winhttp
+
+import (
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+	"syscall"
+	"unsafe"
+
+	"golang.org/x/sys/windows"
+)
+
+type Response struct {
+	session    _HINTERNET
+	connection _HINTERNET
+	request    _HINTERNET
+}
+
+func convertError(err *error) {
+	if *err == nil {
+		return
+	}
+	if se, ok := (*err).(syscall.Errno); ok {
+		if se > _WINHTTP_ERROR_BASE && se <= _WINHTTP_ERROR_LAST {
+			*err = Error(se)
+		}
+	}
+}
+
+func Get(userAgent string, url string) (response *Response, err error) {
+	response = new(Response)
+	defer convertError(&err)
+	defer func() {
+		if err != nil {
+			response.Close()
+			response = nil
+		}
+	}()
+	userAgent16, err := windows.UTF16PtrFromString(userAgent)
+	if err != nil {
+		return
+	}
+	url16, err := windows.UTF16PtrFromString(url)
+	if err != nil {
+		return
+	}
+	components := _URL_COMPONENTS{
+		structSize:     uint32(unsafe.Sizeof(_URL_COMPONENTS{})),
+		hostName:       &make([]uint16, 512)[0],
+		hostNameLength: 512,
+		urlPath:        &make([]uint16, 512)[0],
+		urlPathLength:  512,
+	}
+	err = winHttpCrackUrl(url16, 0, _ICU_REJECT_USERPWD, &components)
+	if err != nil {
+		return
+	}
+	if components.schemeType != _INTERNET_SCHEME_HTTP && components.schemeType != _INTERNET_SCHEME_HTTPS {
+		err = _ERROR_WINHTTP_INVALID_URL
+		return
+	}
+	response.session, err = winHttpOpen(userAgent16, _WINHTTP_ACCESS_TYPE_NO_PROXY, nil, nil, 0)
+	if err != nil {
+		return
+	}
+	response.connection, err = winHttpConnect(response.session, components.hostName, components.port, 0)
+	if err != nil {
+		return
+	}
+	flags := uint32(_WINHTTP_FLAG_REFRESH)
+	if components.schemeType == _INTERNET_SCHEME_HTTPS {
+		flags |= _WINHTTP_FLAG_SECURE
+	}
+	response.request, err = winHttpOpenRequest(response.connection, windows.StringToUTF16Ptr("GET"), components.urlPath, nil, nil, nil, flags)
+	if err != nil {
+		return
+	}
+	err = winHttpSendRequest(response.request, nil, 0, nil, 0, 0, 0)
+	if err != nil {
+		return
+	}
+	err = winHttpReceiveResponse(response.request, 0)
+	if err != nil {
+		return
+	}
+	return
+}
+
+func (response *Response) Length() (length uint64, err error) {
+	defer convertError(&err)
+	numBuf := make([]uint16, 22)
+	numLen := uint32(len(numBuf) * 2)
+	err = winHttpQueryHeaders(response.request, _WINHTTP_QUERY_CONTENT_LENGTH, nil, unsafe.Pointer(&numBuf[0]), &numLen, nil)
+	if err != nil {
+		return
+	}
+	length, err = strconv.ParseUint(windows.UTF16ToString(numBuf[:numLen]), 10, 64)
+	if err != nil {
+		return
+	}
+	return
+}
+
+func (response *Response) Read(p []byte) (n int, err error) {
+	defer convertError(&err)
+	if len(p) == 0 {
+		return 0, nil
+	}
+	var bytesRead uint32
+	err = winHttpReadData(response.request, &p[0], uint32(len(p)), &bytesRead)
+	if err != nil {
+		return 0, nil
+	}
+	if bytesRead == 0 || int(bytesRead) < 0 {
+		return 0, io.EOF
+	}
+	return int(bytesRead), nil
+}
+
+func (response *Response) Close() (err error) {
+	defer convertError(&err)
+	var err1, err2, err3 error
+	if response.request != 0 {
+		err1 = winHttpCloseHandle(response.request)
+	}
+	if response.connection != 0 {
+		err2 = winHttpCloseHandle(response.connection)
+	}
+	if response.session != 0 {
+		err3 = winHttpCloseHandle(response.session)
+	}
+	switch {
+	case err1 != nil:
+		return err1
+	case err2 != nil:
+		return err2
+	case err3 != nil:
+		return err3
+	}
+	return nil
+}
+
+func (error Error) Error() string {
+	var message [2048]uint16
+	n, err := windows.FormatMessage(windows.FORMAT_MESSAGE_FROM_HMODULE|windows.FORMAT_MESSAGE_IGNORE_INSERTS|windows.FORMAT_MESSAGE_MAX_WIDTH_MASK,
+		modwinhttp.Handle(), uint32(error), 0, message[:], nil)
+	if err != nil {
+		return fmt.Sprintf("WinHTTP error #%d", error)
+	}
+	return strings.TrimSpace(windows.UTF16ToString(message[:n]))
+}