// Copyright 2015 The Go Authors. All rights reserved. // Use of this source code is governed by a BSD-style // license that can be found in the LICENSE file. //go:build windows // Package registry provides access to the Windows registry. // // Here is a simple example, opening a registry key and reading a string value from it. // // k, err := registry.OpenKey(registry.LOCAL_MACHINE, `SOFTWARE\Microsoft\Windows NT\CurrentVersion`, registry.QUERY_VALUE) // if err != nil { // log.Fatal(err) // } // defer k.Close() // // s, _, err := k.GetStringValue("SystemRoot") // if err != nil { // log.Fatal(err) // } // fmt.Printf("Windows system root is %q\n", s) // // NOTE: This package is a copy of golang.org/x/sys/windows/registry // with KeyInfo.ModTime removed to prevent dependency cycles. package registry import ( "runtime" "syscall" ) const ( // Registry key security and access rights. // See https://learn.microsoft.com/en-us/windows/win32/sysinfo/registry-key-security-and-access-rights // for details. ALL_ACCESS = 0xf003f CREATE_LINK = 0x00020 CREATE_SUB_KEY = 0x00004 ENUMERATE_SUB_KEYS = 0x00008 EXECUTE = 0x20019 NOTIFY = 0x00010 QUERY_VALUE = 0x00001 READ = 0x20019 SET_VALUE = 0x00002 WOW64_32KEY = 0x00200 WOW64_64KEY = 0x00100 WRITE = 0x20006 ) // Key is a handle to an open Windows registry key. // Keys can be obtained by calling OpenKey; there are // also some predefined root keys such as CURRENT_USER. // Keys can be used directly in the Windows API. type Key syscall.Handle const ( // Windows defines some predefined root keys that are always open. // An application can use these keys as entry points to the registry. // Normally these keys are used in OpenKey to open new keys, // but they can also be used anywhere a Key is required. CLASSES_ROOT = Key(syscall.HKEY_CLASSES_ROOT) CURRENT_USER = Key(syscall.HKEY_CURRENT_USER) LOCAL_MACHINE = Key(syscall.HKEY_LOCAL_MACHINE) USERS = Key(syscall.HKEY_USERS) CURRENT_CONFIG = Key(syscall.HKEY_CURRENT_CONFIG) ) // Close closes open key k. func (k Key) Close() error { return syscall.RegCloseKey(syscall.Handle(k)) } // OpenKey opens a new key with path name relative to key k. // It accepts any open key, including CURRENT_USER and others, // and returns the new key and an error. // The access parameter specifies desired access rights to the // key to be opened. func OpenKey(k Key, path string, access uint32) (Key, error) { p, err := syscall.UTF16PtrFromString(path) if err != nil { return 0, err } var subkey syscall.Handle err = syscall.RegOpenKeyEx(syscall.Handle(k), p, 0, access, &subkey) if err != nil { return 0, err } return Key(subkey), nil } // ReadSubKeyNames returns the names of subkeys of key k. func (k Key) ReadSubKeyNames() ([]string, error) { // RegEnumKeyEx must be called repeatedly and to completion. // During this time, this goroutine cannot migrate away from // its current thread. See #49320. runtime.LockOSThread() defer runtime.UnlockOSThread() names := make([]string, 0) // Registry key size limit is 255 bytes and described there: // https://learn.microsoft.com/en-us/windows/win32/sysinfo/registry-element-size-limits buf := make([]uint16, 256) //plus extra room for terminating zero byte loopItems: for i := uint32(0); ; i++ { l := uint32(len(buf)) for { err := syscall.RegEnumKeyEx(syscall.Handle(k), i, &buf[0], &l, nil, nil, nil, nil) if err == nil { break } if err == syscall.ERROR_MORE_DATA { // Double buffer size and try again. l = uint32(2 * len(buf)) buf = make([]uint16, l) continue } if err == _ERROR_NO_MORE_ITEMS { break loopItems } return names, err } names = append(names, syscall.UTF16ToString(buf[:l])) } return names, nil } // CreateKey creates a key named path under open key k. // CreateKey returns the new key and a boolean flag that reports // whether the key already existed. // The access parameter specifies the access rights for the key // to be created. func CreateKey(k Key, path string, access uint32) (newk Key, openedExisting bool, err error) { var h syscall.Handle var d uint32 err = regCreateKeyEx(syscall.Handle(k), syscall.StringToUTF16Ptr(path), 0, nil, _REG_OPTION_NON_VOLATILE, access, nil, &h, &d) if err != nil { return 0, false, err } return Key(h), d == _REG_OPENED_EXISTING_KEY, nil } // DeleteKey deletes the subkey path of key k and its values. func DeleteKey(k Key, path string) error { return regDeleteKey(syscall.Handle(k), syscall.StringToUTF16Ptr(path)) } // A KeyInfo describes the statistics of a key. It is returned by Stat. type KeyInfo struct { SubKeyCount uint32 MaxSubKeyLen uint32 // size of the key's subkey with the longest name, in Unicode characters, not including the terminating zero byte ValueCount uint32 MaxValueNameLen uint32 // size of the key's longest value name, in Unicode characters, not including the terminating zero byte MaxValueLen uint32 // longest data component among the key's values, in bytes lastWriteTime syscall.Filetime } // Stat retrieves information about the open key k. func (k Key) Stat() (*KeyInfo, error) { var ki KeyInfo err := syscall.RegQueryInfoKey(syscall.Handle(k), nil, nil, nil, &ki.SubKeyCount, &ki.MaxSubKeyLen, nil, &ki.ValueCount, &ki.MaxValueNameLen, &ki.MaxValueLen, nil, &ki.lastWriteTime) if err != nil { return nil, err } return &ki, nil }