1 files changed, 20 insertions, 53 deletions

diff --git a/conf/dpapi/dpapi_windows.go b/conf/dpapi/dpapi_windows.go
index 851ec1ee..49a32915 100644
--- a/conf/dpapi/dpapi_windows.go
+++ b/conf/dpapi/dpapi_windows.go
@@ -1,86 +1,53 @@
 /* SPDX-License-Identifier: MIT
  *
- * Copyright (C) 2019 WireGuard LLC. All Rights Reserved.
+ * Copyright (C) 2019-2022 WireGuard LLC. All Rights Reserved.
  */
 
 package dpapi
 
 import (
 	"errors"
+	"fmt"
 	"runtime"
 	"unsafe"
 
 	"golang.org/x/sys/windows"
 )
 
-const (
-	dpCRYPTPROTECT_UI_FORBIDDEN      uint32 = 0x1
-	dpCRYPTPROTECT_LOCAL_MACHINE     uint32 = 0x4
-	dpCRYPTPROTECT_CRED_SYNC         uint32 = 0x8
-	dpCRYPTPROTECT_AUDIT             uint32 = 0x10
-	dpCRYPTPROTECT_NO_RECOVERY       uint32 = 0x20
-	dpCRYPTPROTECT_VERIFY_PROTECTION uint32 = 0x40
-	dpCRYPTPROTECT_CRED_REGENERATE   uint32 = 0x80
-)
-
-type dpBlob struct {
-	len  uint32
-	data uintptr
-}
-
-func bytesToBlob(bytes []byte) *dpBlob {
-	blob := &dpBlob{}
-	blob.len = uint32(len(bytes))
+func bytesToBlob(bytes []byte) *windows.DataBlob {
+	blob := &windows.DataBlob{Size: uint32(len(bytes))}
 	if len(bytes) > 0 {
-		blob.data = uintptr(unsafe.Pointer(&bytes[0]))
+		blob.Data = &bytes[0]
 	}
 	return blob
 }
 
-//sys	cryptProtectData(dataIn *dpBlob, name *uint16, optionalEntropy *dpBlob, reserved uintptr, promptStruct uintptr, flags uint32, dataOut *dpBlob) (err error) = crypt32.CryptProtectData
-
 func Encrypt(data []byte, name string) ([]byte, error) {
-	out := dpBlob{}
-	err := cryptProtectData(bytesToBlob(data), windows.StringToUTF16Ptr(name), nil, 0, 0, dpCRYPTPROTECT_UI_FORBIDDEN, &out)
+	out := windows.DataBlob{}
+	err := windows.CryptProtectData(bytesToBlob(data), windows.StringToUTF16Ptr(name), nil, 0, nil, windows.CRYPTPROTECT_UI_FORBIDDEN, &out)
 	if err != nil {
-		return nil, errors.New("Unable to encrypt DPAPI protected data: " + err.Error())
+		return nil, fmt.Errorf("unable to encrypt DPAPI protected data: %w", err)
 	}
-
-	outSlice := *(*[]byte)(unsafe.Pointer(&(struct {
-		addr uintptr
-		len  int
-		cap  int
-	}{out.data, int(out.len), int(out.len)})))
-	ret := make([]byte, len(outSlice))
-	copy(ret, outSlice)
-	windows.LocalFree(windows.Handle(out.data))
-
+	ret := make([]byte, out.Size)
+	copy(ret, unsafe.Slice(out.Data, out.Size))
+	windows.LocalFree(windows.Handle(unsafe.Pointer(out.Data)))
 	return ret, nil
 }
 
-//sys	cryptUnprotectData(dataIn *dpBlob, name **uint16, optionalEntropy *dpBlob, reserved uintptr, promptStruct uintptr, flags uint32, dataOut *dpBlob) (err error) = crypt32.CryptUnprotectData
-
 func Decrypt(data []byte, name string) ([]byte, error) {
-	out := dpBlob{}
+	out := windows.DataBlob{}
 	var outName *uint16
 	utf16Name, err := windows.UTF16PtrFromString(name)
 	if err != nil {
 		return nil, err
 	}
-
-	err = cryptUnprotectData(bytesToBlob(data), &outName, nil, 0, 0, dpCRYPTPROTECT_UI_FORBIDDEN, &out)
+	err = windows.CryptUnprotectData(bytesToBlob(data), &outName, nil, 0, nil, windows.CRYPTPROTECT_UI_FORBIDDEN, &out)
 	if err != nil {
-		return nil, errors.New("Unable to decrypt DPAPI protected data: " + err.Error())
+		return nil, fmt.Errorf("unable to decrypt DPAPI protected data: %w", err)
 	}
-
-	outSlice := *(*[]byte)(unsafe.Pointer(&(struct {
-		addr uintptr
-		len  int
-		cap  int
-	}{out.data, int(out.len), int(out.len)})))
-	ret := make([]byte, len(outSlice))
-	copy(ret, outSlice)
-	windows.LocalFree(windows.Handle(out.data))
+	ret := make([]byte, out.Size)
+	copy(ret, unsafe.Slice(out.Data, out.Size))
+	windows.LocalFree(windows.Handle(unsafe.Pointer(out.Data)))
 
 	// Note: this ridiculous open-coded strcmp is not constant time.
 	different := false
@@ -94,14 +61,14 @@ func Decrypt(data []byte, name string) ([]byte, error) {
 		if *a == 0 || *b == 0 {
 			break
 		}
-		a = (*uint16)(unsafe.Pointer(uintptr(unsafe.Pointer(a)) + 2))
-		b = (*uint16)(unsafe.Pointer(uintptr(unsafe.Pointer(b)) + 2))
+		a = (*uint16)(unsafe.Add(unsafe.Pointer(a), 2))
+		b = (*uint16)(unsafe.Add(unsafe.Pointer(b), 2))
 	}
 	runtime.KeepAlive(utf16Name)
 	windows.LocalFree(windows.Handle(unsafe.Pointer(outName)))
 
 	if different {
-		return nil, errors.New("The input name does not match the stored name")
+		return nil, errors.New("input name does not match the stored name")
 	}
 
 	return ret, nil