1// Copyright 2015 The Go Authors. All rights reserved. 2// Use of this source code is governed by a BSD-style 3// license that can be found in the LICENSE file. 4 5// +build windows 6 7package registry 8 9import ( 10 "errors" 11 "io" 12 "syscall" 13 "unicode/utf16" 14 "unsafe" 15) 16 17const ( 18 // Registry value types. 19 NONE = 0 20 SZ = 1 21 EXPAND_SZ = 2 22 BINARY = 3 23 DWORD = 4 24 DWORD_BIG_ENDIAN = 5 25 LINK = 6 26 MULTI_SZ = 7 27 RESOURCE_LIST = 8 28 FULL_RESOURCE_DESCRIPTOR = 9 29 RESOURCE_REQUIREMENTS_LIST = 10 30 QWORD = 11 31) 32 33var ( 34 // ErrShortBuffer is returned when the buffer was too short for the operation. 35 ErrShortBuffer = syscall.ERROR_MORE_DATA 36 37 // ErrNotExist is returned when a registry key or value does not exist. 38 ErrNotExist = syscall.ERROR_FILE_NOT_FOUND 39 40 // ErrUnexpectedType is returned by Get*Value when the value's type was unexpected. 41 ErrUnexpectedType = errors.New("unexpected key value type") 42) 43 44// GetValue retrieves the type and data for the specified value associated 45// with an open key k. It fills up buffer buf and returns the retrieved 46// byte count n. If buf is too small to fit the stored value it returns 47// ErrShortBuffer error along with the required buffer size n. 48// If no buffer is provided, it returns true and actual buffer size n. 49// If no buffer is provided, GetValue returns the value's type only. 50// If the value does not exist, the error returned is ErrNotExist. 51// 52// GetValue is a low level function. If value's type is known, use the appropriate 53// Get*Value function instead. 54func (k Key) GetValue(name string, buf []byte) (n int, valtype uint32, err error) { 55 pname, err := syscall.UTF16PtrFromString(name) 56 if err != nil { 57 return 0, 0, err 58 } 59 var pbuf *byte 60 if len(buf) > 0 { 61 pbuf = (*byte)(unsafe.Pointer(&buf[0])) 62 } 63 l := uint32(len(buf)) 64 err = syscall.RegQueryValueEx(syscall.Handle(k), pname, nil, &valtype, pbuf, &l) 65 if err != nil { 66 return int(l), valtype, err 67 } 68 return int(l), valtype, nil 69} 70 71func (k Key) getValue(name string, buf []byte) (data []byte, valtype uint32, err error) { 72 p, err := syscall.UTF16PtrFromString(name) 73 if err != nil { 74 return nil, 0, err 75 } 76 var t uint32 77 n := uint32(len(buf)) 78 for { 79 err = syscall.RegQueryValueEx(syscall.Handle(k), p, nil, &t, (*byte)(unsafe.Pointer(&buf[0])), &n) 80 if err == nil { 81 return buf[:n], t, nil 82 } 83 if err != syscall.ERROR_MORE_DATA { 84 return nil, 0, err 85 } 86 if n <= uint32(len(buf)) { 87 return nil, 0, err 88 } 89 buf = make([]byte, n) 90 } 91} 92 93// GetStringValue retrieves the string value for the specified 94// value name associated with an open key k. It also returns the value's type. 95// If value does not exist, GetStringValue returns ErrNotExist. 96// If value is not SZ or EXPAND_SZ, it will return the correct value 97// type and ErrUnexpectedType. 98func (k Key) GetStringValue(name string) (val string, valtype uint32, err error) { 99 data, typ, err2 := k.getValue(name, make([]byte, 64)) 100 if err2 != nil { 101 return "", typ, err2 102 } 103 switch typ { 104 case SZ, EXPAND_SZ: 105 default: 106 return "", typ, ErrUnexpectedType 107 } 108 if len(data) == 0 { 109 return "", typ, nil 110 } 111 u := (*[1 << 29]uint16)(unsafe.Pointer(&data[0]))[: len(data)/2 : len(data)/2] 112 return syscall.UTF16ToString(u), typ, nil 113} 114 115// GetMUIStringValue retrieves the localized string value for 116// the specified value name associated with an open key k. 117// If the value name doesn't exist or the localized string value 118// can't be resolved, GetMUIStringValue returns ErrNotExist. 119// GetMUIStringValue panics if the system doesn't support 120// regLoadMUIString; use LoadRegLoadMUIString to check if 121// regLoadMUIString is supported before calling this function. 122func (k Key) GetMUIStringValue(name string) (string, error) { 123 pname, err := syscall.UTF16PtrFromString(name) 124 if err != nil { 125 return "", err 126 } 127 128 buf := make([]uint16, 1024) 129 var buflen uint32 130 var pdir *uint16 131 132 err = regLoadMUIString(syscall.Handle(k), pname, &buf[0], uint32(len(buf)), &buflen, 0, pdir) 133 if err == syscall.ERROR_FILE_NOT_FOUND { // Try fallback path 134 135 // Try to resolve the string value using the system directory as 136 // a DLL search path; this assumes the string value is of the form 137 // @[path]\dllname,-strID but with no path given, e.g. @tzres.dll,-320. 138 139 // This approach works with tzres.dll but may have to be revised 140 // in the future to allow callers to provide custom search paths. 141 142 var s string 143 s, err = ExpandString("%SystemRoot%\\system32\\") 144 if err != nil { 145 return "", err 146 } 147 pdir, err = syscall.UTF16PtrFromString(s) 148 if err != nil { 149 return "", err 150 } 151 152 err = regLoadMUIString(syscall.Handle(k), pname, &buf[0], uint32(len(buf)), &buflen, 0, pdir) 153 } 154 155 for err == syscall.ERROR_MORE_DATA { // Grow buffer if needed 156 if buflen <= uint32(len(buf)) { 157 break // Buffer not growing, assume race; break 158 } 159 buf = make([]uint16, buflen) 160 err = regLoadMUIString(syscall.Handle(k), pname, &buf[0], uint32(len(buf)), &buflen, 0, pdir) 161 } 162 163 if err != nil { 164 return "", err 165 } 166 167 return syscall.UTF16ToString(buf), nil 168} 169 170// ExpandString expands environment-variable strings and replaces 171// them with the values defined for the current user. 172// Use ExpandString to expand EXPAND_SZ strings. 173func ExpandString(value string) (string, error) { 174 if value == "" { 175 return "", nil 176 } 177 p, err := syscall.UTF16PtrFromString(value) 178 if err != nil { 179 return "", err 180 } 181 r := make([]uint16, 100) 182 for { 183 n, err := expandEnvironmentStrings(p, &r[0], uint32(len(r))) 184 if err != nil { 185 return "", err 186 } 187 if n <= uint32(len(r)) { 188 return syscall.UTF16ToString(r[:n]), nil 189 } 190 r = make([]uint16, n) 191 } 192} 193 194// GetStringsValue retrieves the []string value for the specified 195// value name associated with an open key k. It also returns the value's type. 196// If value does not exist, GetStringsValue returns ErrNotExist. 197// If value is not MULTI_SZ, it will return the correct value 198// type and ErrUnexpectedType. 199func (k Key) GetStringsValue(name string) (val []string, valtype uint32, err error) { 200 data, typ, err2 := k.getValue(name, make([]byte, 64)) 201 if err2 != nil { 202 return nil, typ, err2 203 } 204 if typ != MULTI_SZ { 205 return nil, typ, ErrUnexpectedType 206 } 207 if len(data) == 0 { 208 return nil, typ, nil 209 } 210 p := (*[1 << 29]uint16)(unsafe.Pointer(&data[0]))[: len(data)/2 : len(data)/2] 211 if len(p) == 0 { 212 return nil, typ, nil 213 } 214 if p[len(p)-1] == 0 { 215 p = p[:len(p)-1] // remove terminating null 216 } 217 val = make([]string, 0, 5) 218 from := 0 219 for i, c := range p { 220 if c == 0 { 221 val = append(val, string(utf16.Decode(p[from:i]))) 222 from = i + 1 223 } 224 } 225 return val, typ, nil 226} 227 228// GetIntegerValue retrieves the integer value for the specified 229// value name associated with an open key k. It also returns the value's type. 230// If value does not exist, GetIntegerValue returns ErrNotExist. 231// If value is not DWORD or QWORD, it will return the correct value 232// type and ErrUnexpectedType. 233func (k Key) GetIntegerValue(name string) (val uint64, valtype uint32, err error) { 234 data, typ, err2 := k.getValue(name, make([]byte, 8)) 235 if err2 != nil { 236 return 0, typ, err2 237 } 238 switch typ { 239 case DWORD: 240 if len(data) != 4 { 241 return 0, typ, errors.New("DWORD value is not 4 bytes long") 242 } 243 var val32 uint32 244 copy((*[4]byte)(unsafe.Pointer(&val32))[:], data) 245 return uint64(val32), DWORD, nil 246 case QWORD: 247 if len(data) != 8 { 248 return 0, typ, errors.New("QWORD value is not 8 bytes long") 249 } 250 copy((*[8]byte)(unsafe.Pointer(&val))[:], data) 251 return val, QWORD, nil 252 default: 253 return 0, typ, ErrUnexpectedType 254 } 255} 256 257// GetBinaryValue retrieves the binary value for the specified 258// value name associated with an open key k. It also returns the value's type. 259// If value does not exist, GetBinaryValue returns ErrNotExist. 260// If value is not BINARY, it will return the correct value 261// type and ErrUnexpectedType. 262func (k Key) GetBinaryValue(name string) (val []byte, valtype uint32, err error) { 263 data, typ, err2 := k.getValue(name, make([]byte, 64)) 264 if err2 != nil { 265 return nil, typ, err2 266 } 267 if typ != BINARY { 268 return nil, typ, ErrUnexpectedType 269 } 270 return data, typ, nil 271} 272 273func (k Key) setValue(name string, valtype uint32, data []byte) error { 274 p, err := syscall.UTF16PtrFromString(name) 275 if err != nil { 276 return err 277 } 278 if len(data) == 0 { 279 return regSetValueEx(syscall.Handle(k), p, 0, valtype, nil, 0) 280 } 281 return regSetValueEx(syscall.Handle(k), p, 0, valtype, &data[0], uint32(len(data))) 282} 283 284// SetDWordValue sets the data and type of a name value 285// under key k to value and DWORD. 286func (k Key) SetDWordValue(name string, value uint32) error { 287 return k.setValue(name, DWORD, (*[4]byte)(unsafe.Pointer(&value))[:]) 288} 289 290// SetQWordValue sets the data and type of a name value 291// under key k to value and QWORD. 292func (k Key) SetQWordValue(name string, value uint64) error { 293 return k.setValue(name, QWORD, (*[8]byte)(unsafe.Pointer(&value))[:]) 294} 295 296func (k Key) setStringValue(name string, valtype uint32, value string) error { 297 v, err := syscall.UTF16FromString(value) 298 if err != nil { 299 return err 300 } 301 buf := (*[1 << 29]byte)(unsafe.Pointer(&v[0]))[: len(v)*2 : len(v)*2] 302 return k.setValue(name, valtype, buf) 303} 304 305// SetStringValue sets the data and type of a name value 306// under key k to value and SZ. The value must not contain a zero byte. 307func (k Key) SetStringValue(name, value string) error { 308 return k.setStringValue(name, SZ, value) 309} 310 311// SetExpandStringValue sets the data and type of a name value 312// under key k to value and EXPAND_SZ. The value must not contain a zero byte. 313func (k Key) SetExpandStringValue(name, value string) error { 314 return k.setStringValue(name, EXPAND_SZ, value) 315} 316 317// SetStringsValue sets the data and type of a name value 318// under key k to value and MULTI_SZ. The value strings 319// must not contain a zero byte. 320func (k Key) SetStringsValue(name string, value []string) error { 321 ss := "" 322 for _, s := range value { 323 for i := 0; i < len(s); i++ { 324 if s[i] == 0 { 325 return errors.New("string cannot have 0 inside") 326 } 327 } 328 ss += s + "\x00" 329 } 330 v := utf16.Encode([]rune(ss + "\x00")) 331 buf := (*[1 << 29]byte)(unsafe.Pointer(&v[0]))[: len(v)*2 : len(v)*2] 332 return k.setValue(name, MULTI_SZ, buf) 333} 334 335// SetBinaryValue sets the data and type of a name value 336// under key k to value and BINARY. 337func (k Key) SetBinaryValue(name string, value []byte) error { 338 return k.setValue(name, BINARY, value) 339} 340 341// DeleteValue removes a named value from the key k. 342func (k Key) DeleteValue(name string) error { 343 return regDeleteValue(syscall.Handle(k), syscall.StringToUTF16Ptr(name)) 344} 345 346// ReadValueNames returns the value names of key k. 347// The parameter n controls the number of returned names, 348// analogous to the way os.File.Readdirnames works. 349func (k Key) ReadValueNames(n int) ([]string, error) { 350 ki, err := k.Stat() 351 if err != nil { 352 return nil, err 353 } 354 names := make([]string, 0, ki.ValueCount) 355 buf := make([]uint16, ki.MaxValueNameLen+1) // extra room for terminating null character 356loopItems: 357 for i := uint32(0); ; i++ { 358 if n > 0 { 359 if len(names) == n { 360 return names, nil 361 } 362 } 363 l := uint32(len(buf)) 364 for { 365 err := regEnumValue(syscall.Handle(k), i, &buf[0], &l, nil, nil, nil, nil) 366 if err == nil { 367 break 368 } 369 if err == syscall.ERROR_MORE_DATA { 370 // Double buffer size and try again. 371 l = uint32(2 * len(buf)) 372 buf = make([]uint16, l) 373 continue 374 } 375 if err == _ERROR_NO_MORE_ITEMS { 376 break loopItems 377 } 378 return names, err 379 } 380 names = append(names, syscall.UTF16ToString(buf[:l])) 381 } 382 if n > len(names) { 383 return names, io.EOF 384 } 385 return names, nil 386} 387