summaryrefslogtreecommitdiff
path: root/vendor/golang.org/x/sys/windows/registry/key.go
blob: c256483434f0cd43372ecfdf03a45f3111347e23 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
// 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.

// +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)
//
package registry

import (
	"io"
	"syscall"
	"time"
)

const (
	// Registry key security and access rights.
	// See https://msdn.microsoft.com/en-us/library/windows/desktop/ms724878.aspx
	// 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)
	PERFORMANCE_DATA = Key(syscall.HKEY_PERFORMANCE_DATA)
)

// 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
}

// OpenRemoteKey opens a predefined registry key on another
// computer pcname. The key to be opened is specified by k, but
// can only be one of LOCAL_MACHINE, PERFORMANCE_DATA or USERS.
// If pcname is "", OpenRemoteKey returns local computer key.
func OpenRemoteKey(pcname string, k Key) (Key, error) {
	var err error
	var p *uint16
	if pcname != "" {
		p, err = syscall.UTF16PtrFromString(`\\` + pcname)
		if err != nil {
			return 0, err
		}
	}
	var remoteKey syscall.Handle
	err = regConnectRegistry(p, syscall.Handle(k), &remoteKey)
	if err != nil {
		return 0, err
	}
	return Key(remoteKey), nil
}

// ReadSubKeyNames returns the names of subkeys of key k.
// The parameter n controls the number of returned names,
// analogous to the way os.File.Readdirnames works.
func (k Key) ReadSubKeyNames(n int) ([]string, error) {
	names := make([]string, 0)
	// Registry key size limit is 255 bytes and described there:
	// https://msdn.microsoft.com/library/windows/desktop/ms724872.aspx
	buf := make([]uint16, 256) //plus extra room for terminating zero byte
loopItems:
	for i := uint32(0); ; i++ {
		if n > 0 {
			if len(names) == n {
				return names, nil
			}
		}
		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]))
	}
	if n > len(names) {
		return names, io.EOF
	}
	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
}

// ModTime returns the key's last write time.
func (ki *KeyInfo) ModTime() time.Time {
	return time.Unix(0, ki.lastWriteTime.Nanoseconds())
}

// 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
}