1 r"""UUID objects (universally unique identifiers) according to RFC 4122. 2 3 This module provides immutable UUID objects (class UUID) and the functions 4 uuid1(), uuid3(), uuid4(), uuid5() for generating version 1, 3, 4, and 5 5 UUIDs as specified in RFC 4122. 6 7 If all you want is a unique ID, you should probably call uuid1() or uuid4(). 8 Note that uuid1() may compromise privacy since it creates a UUID containing 9 the computer's network address. uuid4() creates a random UUID. 10 11 Typical usage: 12 13 >>> import uuid 14 15 # make a UUID based on the host ID and current time 16 >>> uuid.uuid1() 17 UUID('a8098c1a-f86e-11da-bd1a-00112444be1e') 18 19 # make a UUID using an MD5 hash of a namespace UUID and a name 20 >>> uuid.uuid3(uuid.NAMESPACE_DNS, 'python.org') 21 UUID('6fa459ea-ee8a-3ca4-894e-db77e160355e') 22 23 # make a random UUID 24 >>> uuid.uuid4() 25 UUID('16fd2706-8baf-433b-82eb-8c7fada847da') 26 27 # make a UUID using a SHA-1 hash of a namespace UUID and a name 28 >>> uuid.uuid5(uuid.NAMESPACE_DNS, 'python.org') 29 UUID('886313e1-3b8a-5372-9b90-0c9aee199e5d') 30 31 # make a UUID from a string of hex digits (braces and hyphens ignored) 32 >>> x = uuid.UUID('{00010203-0405-0607-0809-0a0b0c0d0e0f}') 33 34 # convert a UUID to a string of hex digits in standard form 35 >>> str(x) 36 '00010203-0405-0607-0809-0a0b0c0d0e0f' 37 38 # get the raw 16 bytes of the UUID 39 >>> x.bytes 40 '\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f' 41 42 # make a UUID from a 16-byte string 43 >>> uuid.UUID(bytes=x.bytes) 44 UUID('00010203-0405-0607-0809-0a0b0c0d0e0f') 45 """ 46 47 import os 48 49 __author__ = 'Ka-Ping Yee <ping (at] zesty.ca>' 50 51 RESERVED_NCS, RFC_4122, RESERVED_MICROSOFT, RESERVED_FUTURE = [ 52 'reserved for NCS compatibility', 'specified in RFC 4122', 53 'reserved for Microsoft compatibility', 'reserved for future definition'] 54 55 class UUID(object): 56 """Instances of the UUID class represent UUIDs as specified in RFC 4122. 57 UUID objects are immutable, hashable, and usable as dictionary keys. 58 Converting a UUID to a string with str() yields something in the form 59 '12345678-1234-1234-1234-123456789abc'. The UUID constructor accepts 60 five possible forms: a similar string of hexadecimal digits, or a tuple 61 of six integer fields (with 32-bit, 16-bit, 16-bit, 8-bit, 8-bit, and 62 48-bit values respectively) as an argument named 'fields', or a string 63 of 16 bytes (with all the integer fields in big-endian order) as an 64 argument named 'bytes', or a string of 16 bytes (with the first three 65 fields in little-endian order) as an argument named 'bytes_le', or a 66 single 128-bit integer as an argument named 'int'. 67 68 UUIDs have these read-only attributes: 69 70 bytes the UUID as a 16-byte string (containing the six 71 integer fields in big-endian byte order) 72 73 bytes_le the UUID as a 16-byte string (with time_low, time_mid, 74 and time_hi_version in little-endian byte order) 75 76 fields a tuple of the six integer fields of the UUID, 77 which are also available as six individual attributes 78 and two derived attributes: 79 80 time_low the first 32 bits of the UUID 81 time_mid the next 16 bits of the UUID 82 time_hi_version the next 16 bits of the UUID 83 clock_seq_hi_variant the next 8 bits of the UUID 84 clock_seq_low the next 8 bits of the UUID 85 node the last 48 bits of the UUID 86 87 time the 60-bit timestamp 88 clock_seq the 14-bit sequence number 89 90 hex the UUID as a 32-character hexadecimal string 91 92 int the UUID as a 128-bit integer 93 94 urn the UUID as a URN as specified in RFC 4122 95 96 variant the UUID variant (one of the constants RESERVED_NCS, 97 RFC_4122, RESERVED_MICROSOFT, or RESERVED_FUTURE) 98 99 version the UUID version number (1 through 5, meaningful only 100 when the variant is RFC_4122) 101 """ 102 103 def __init__(self, hex=None, bytes=None, bytes_le=None, fields=None, 104 int=None, version=None): 105 r"""Create a UUID from either a string of 32 hexadecimal digits, 106 a string of 16 bytes as the 'bytes' argument, a string of 16 bytes 107 in little-endian order as the 'bytes_le' argument, a tuple of six 108 integers (32-bit time_low, 16-bit time_mid, 16-bit time_hi_version, 109 8-bit clock_seq_hi_variant, 8-bit clock_seq_low, 48-bit node) as 110 the 'fields' argument, or a single 128-bit integer as the 'int' 111 argument. When a string of hex digits is given, curly braces, 112 hyphens, and a URN prefix are all optional. For example, these 113 expressions all yield the same UUID: 114 115 UUID('{12345678-1234-5678-1234-567812345678}') 116 UUID('12345678123456781234567812345678') 117 UUID('urn:uuid:12345678-1234-5678-1234-567812345678') 118 UUID(bytes='\x12\x34\x56\x78'*4) 119 UUID(bytes_le='\x78\x56\x34\x12\x34\x12\x78\x56' + 120 '\x12\x34\x56\x78\x12\x34\x56\x78') 121 UUID(fields=(0x12345678, 0x1234, 0x5678, 0x12, 0x34, 0x567812345678)) 122 UUID(int=0x12345678123456781234567812345678) 123 124 Exactly one of 'hex', 'bytes', 'bytes_le', 'fields', or 'int' must 125 be given. The 'version' argument is optional; if given, the resulting 126 UUID will have its variant and version set according to RFC 4122, 127 overriding the given 'hex', 'bytes', 'bytes_le', 'fields', or 'int'. 128 """ 129 130 if [hex, bytes, bytes_le, fields, int].count(None) != 4: 131 raise TypeError('need one of hex, bytes, bytes_le, fields, or int') 132 if hex is not None: 133 hex = hex.replace('urn:', '').replace('uuid:', '') 134 hex = hex.strip('{}').replace('-', '') 135 if len(hex) != 32: 136 raise ValueError('badly formed hexadecimal UUID string') 137 int = long(hex, 16) 138 if bytes_le is not None: 139 if len(bytes_le) != 16: 140 raise ValueError('bytes_le is not a 16-char string') 141 bytes = (bytes_le[3] + bytes_le[2] + bytes_le[1] + bytes_le[0] + 142 bytes_le[5] + bytes_le[4] + bytes_le[7] + bytes_le[6] + 143 bytes_le[8:]) 144 if bytes is not None: 145 if len(bytes) != 16: 146 raise ValueError('bytes is not a 16-char string') 147 int = long(('%02x'*16) % tuple(map(ord, bytes)), 16) 148 if fields is not None: 149 if len(fields) != 6: 150 raise ValueError('fields is not a 6-tuple') 151 (time_low, time_mid, time_hi_version, 152 clock_seq_hi_variant, clock_seq_low, node) = fields 153 if not 0 <= time_low < 1<<32L: 154 raise ValueError('field 1 out of range (need a 32-bit value)') 155 if not 0 <= time_mid < 1<<16L: 156 raise ValueError('field 2 out of range (need a 16-bit value)') 157 if not 0 <= time_hi_version < 1<<16L: 158 raise ValueError('field 3 out of range (need a 16-bit value)') 159 if not 0 <= clock_seq_hi_variant < 1<<8L: 160 raise ValueError('field 4 out of range (need an 8-bit value)') 161 if not 0 <= clock_seq_low < 1<<8L: 162 raise ValueError('field 5 out of range (need an 8-bit value)') 163 if not 0 <= node < 1<<48L: 164 raise ValueError('field 6 out of range (need a 48-bit value)') 165 clock_seq = (clock_seq_hi_variant << 8L) | clock_seq_low 166 int = ((time_low << 96L) | (time_mid << 80L) | 167 (time_hi_version << 64L) | (clock_seq << 48L) | node) 168 if int is not None: 169 if not 0 <= int < 1<<128L: 170 raise ValueError('int is out of range (need a 128-bit value)') 171 if version is not None: 172 if not 1 <= version <= 5: 173 raise ValueError('illegal version number') 174 # Set the variant to RFC 4122. 175 int &= ~(0xc000 << 48L) 176 int |= 0x8000 << 48L 177 # Set the version number. 178 int &= ~(0xf000 << 64L) 179 int |= version << 76L 180 self.__dict__['int'] = int 181 182 def __cmp__(self, other): 183 if isinstance(other, UUID): 184 return cmp(self.int, other.int) 185 return NotImplemented 186 187 def __hash__(self): 188 return hash(self.int) 189 190 def __int__(self): 191 return self.int 192 193 def __repr__(self): 194 return 'UUID(%r)' % str(self) 195 196 def __setattr__(self, name, value): 197 raise TypeError('UUID objects are immutable') 198 199 def __str__(self): 200 hex = '%032x' % self.int 201 return '%s-%s-%s-%s-%s' % ( 202 hex[:8], hex[8:12], hex[12:16], hex[16:20], hex[20:]) 203 204 def get_bytes(self): 205 bytes = '' 206 for shift in range(0, 128, 8): 207 bytes = chr((self.int >> shift) & 0xff) + bytes 208 return bytes 209 210 bytes = property(get_bytes) 211 212 def get_bytes_le(self): 213 bytes = self.bytes 214 return (bytes[3] + bytes[2] + bytes[1] + bytes[0] + 215 bytes[5] + bytes[4] + bytes[7] + bytes[6] + bytes[8:]) 216 217 bytes_le = property(get_bytes_le) 218 219 def get_fields(self): 220 return (self.time_low, self.time_mid, self.time_hi_version, 221 self.clock_seq_hi_variant, self.clock_seq_low, self.node) 222 223 fields = property(get_fields) 224 225 def get_time_low(self): 226 return self.int >> 96L 227 228 time_low = property(get_time_low) 229 230 def get_time_mid(self): 231 return (self.int >> 80L) & 0xffff 232 233 time_mid = property(get_time_mid) 234 235 def get_time_hi_version(self): 236 return (self.int >> 64L) & 0xffff 237 238 time_hi_version = property(get_time_hi_version) 239 240 def get_clock_seq_hi_variant(self): 241 return (self.int >> 56L) & 0xff 242 243 clock_seq_hi_variant = property(get_clock_seq_hi_variant) 244 245 def get_clock_seq_low(self): 246 return (self.int >> 48L) & 0xff 247 248 clock_seq_low = property(get_clock_seq_low) 249 250 def get_time(self): 251 return (((self.time_hi_version & 0x0fffL) << 48L) | 252 (self.time_mid << 32L) | self.time_low) 253 254 time = property(get_time) 255 256 def get_clock_seq(self): 257 return (((self.clock_seq_hi_variant & 0x3fL) << 8L) | 258 self.clock_seq_low) 259 260 clock_seq = property(get_clock_seq) 261 262 def get_node(self): 263 return self.int & 0xffffffffffff 264 265 node = property(get_node) 266 267 def get_hex(self): 268 return '%032x' % self.int 269 270 hex = property(get_hex) 271 272 def get_urn(self): 273 return 'urn:uuid:' + str(self) 274 275 urn = property(get_urn) 276 277 def get_variant(self): 278 if not self.int & (0x8000 << 48L): 279 return RESERVED_NCS 280 elif not self.int & (0x4000 << 48L): 281 return RFC_4122 282 elif not self.int & (0x2000 << 48L): 283 return RESERVED_MICROSOFT 284 else: 285 return RESERVED_FUTURE 286 287 variant = property(get_variant) 288 289 def get_version(self): 290 # The version bits are only meaningful for RFC 4122 UUIDs. 291 if self.variant == RFC_4122: 292 return int((self.int >> 76L) & 0xf) 293 294 version = property(get_version) 295 296 def _popen(command, args): 297 import os 298 path = os.environ.get("PATH", os.defpath).split(os.pathsep) 299 path.extend(('/sbin', '/usr/sbin')) 300 for dir in path: 301 executable = os.path.join(dir, command) 302 if (os.path.exists(executable) and 303 os.access(executable, os.F_OK | os.X_OK) and 304 not os.path.isdir(executable)): 305 break 306 else: 307 return None 308 # LC_ALL to ensure English output, 2>/dev/null to prevent output on 309 # stderr (Note: we don't have an example where the words we search for 310 # are actually localized, but in theory some system could do so.) 311 cmd = 'LC_ALL=C %s %s 2>/dev/null' % (executable, args) 312 return os.popen(cmd) 313 314 def _find_mac(command, args, hw_identifiers, get_index): 315 try: 316 pipe = _popen(command, args) 317 if not pipe: 318 return 319 with pipe: 320 for line in pipe: 321 words = line.lower().rstrip().split() 322 for i in range(len(words)): 323 if words[i] in hw_identifiers: 324 try: 325 word = words[get_index(i)] 326 mac = int(word.replace(':', ''), 16) 327 if mac: 328 return mac 329 except (ValueError, IndexError): 330 # Virtual interfaces, such as those provided by 331 # VPNs, do not have a colon-delimited MAC address 332 # as expected, but a 16-byte HWAddr separated by 333 # dashes. These should be ignored in favor of a 334 # real MAC address 335 pass 336 except IOError: 337 pass 338 339 def _ifconfig_getnode(): 340 """Get the hardware address on Unix by running ifconfig.""" 341 # This works on Linux ('' or '-a'), Tru64 ('-av'), but not all Unixes. 342 for args in ('', '-a', '-av'): 343 mac = _find_mac('ifconfig', args, ['hwaddr', 'ether'], lambda i: i+1) 344 if mac: 345 return mac 346 347 def _arp_getnode(): 348 """Get the hardware address on Unix by running arp.""" 349 import os, socket 350 try: 351 ip_addr = socket.gethostbyname(socket.gethostname()) 352 except EnvironmentError: 353 return None 354 355 # Try getting the MAC addr from arp based on our IP address (Solaris). 356 return _find_mac('arp', '-an', [ip_addr], lambda i: -1) 357 358 def _lanscan_getnode(): 359 """Get the hardware address on Unix by running lanscan.""" 360 # This might work on HP-UX. 361 return _find_mac('lanscan', '-ai', ['lan0'], lambda i: 0) 362 363 def _netstat_getnode(): 364 """Get the hardware address on Unix by running netstat.""" 365 # This might work on AIX, Tru64 UNIX and presumably on IRIX. 366 try: 367 pipe = _popen('netstat', '-ia') 368 if not pipe: 369 return 370 with pipe: 371 words = pipe.readline().rstrip().split() 372 try: 373 i = words.index('Address') 374 except ValueError: 375 return 376 for line in pipe: 377 try: 378 words = line.rstrip().split() 379 word = words[i] 380 if len(word) == 17 and word.count(':') == 5: 381 mac = int(word.replace(':', ''), 16) 382 if mac: 383 return mac 384 except (ValueError, IndexError): 385 pass 386 except OSError: 387 pass 388 389 def _ipconfig_getnode(): 390 """Get the hardware address on Windows by running ipconfig.exe.""" 391 import os, re 392 dirs = ['', r'c:\windows\system32', r'c:\winnt\system32'] 393 try: 394 import ctypes 395 buffer = ctypes.create_string_buffer(300) 396 ctypes.windll.kernel32.GetSystemDirectoryA(buffer, 300) 397 dirs.insert(0, buffer.value.decode('mbcs')) 398 except: 399 pass 400 for dir in dirs: 401 try: 402 pipe = os.popen(os.path.join(dir, 'ipconfig') + ' /all') 403 except IOError: 404 continue 405 with pipe: 406 for line in pipe: 407 value = line.split(':')[-1].strip().lower() 408 if re.match('([0-9a-f][0-9a-f]-){5}[0-9a-f][0-9a-f]', value): 409 return int(value.replace('-', ''), 16) 410 411 def _netbios_getnode(): 412 """Get the hardware address on Windows using NetBIOS calls. 413 See http://support.microsoft.com/kb/118623 for details.""" 414 import win32wnet, netbios 415 ncb = netbios.NCB() 416 ncb.Command = netbios.NCBENUM 417 ncb.Buffer = adapters = netbios.LANA_ENUM() 418 adapters._pack() 419 if win32wnet.Netbios(ncb) != 0: 420 return 421 adapters._unpack() 422 for i in range(adapters.length): 423 ncb.Reset() 424 ncb.Command = netbios.NCBRESET 425 ncb.Lana_num = ord(adapters.lana[i]) 426 if win32wnet.Netbios(ncb) != 0: 427 continue 428 ncb.Reset() 429 ncb.Command = netbios.NCBASTAT 430 ncb.Lana_num = ord(adapters.lana[i]) 431 ncb.Callname = '*'.ljust(16) 432 ncb.Buffer = status = netbios.ADAPTER_STATUS() 433 if win32wnet.Netbios(ncb) != 0: 434 continue 435 status._unpack() 436 bytes = map(ord, status.adapter_address) 437 return ((bytes[0]<<40L) + (bytes[1]<<32L) + (bytes[2]<<24L) + 438 (bytes[3]<<16L) + (bytes[4]<<8L) + bytes[5]) 439 440 # Thanks to Thomas Heller for ctypes and for his help with its use here. 441 442 # If ctypes is available, use it to find system routines for UUID generation. 443 _uuid_generate_time = _UuidCreate = None 444 try: 445 import ctypes, ctypes.util 446 import sys 447 448 # The uuid_generate_* routines are provided by libuuid on at least 449 # Linux and FreeBSD, and provided by libc on Mac OS X. 450 _libnames = ['uuid'] 451 if not sys.platform.startswith('win'): 452 _libnames.append('c') 453 for libname in _libnames: 454 try: 455 lib = ctypes.CDLL(ctypes.util.find_library(libname)) 456 except: 457 continue 458 if hasattr(lib, 'uuid_generate_time'): 459 _uuid_generate_time = lib.uuid_generate_time 460 break 461 del _libnames 462 463 # The uuid_generate_* functions are broken on MacOS X 10.5, as noted 464 # in issue #8621 the function generates the same sequence of values 465 # in the parent process and all children created using fork (unless 466 # those children use exec as well). 467 # 468 # Assume that the uuid_generate functions are broken from 10.5 onward, 469 # the test can be adjusted when a later version is fixed. 470 if sys.platform == 'darwin': 471 import os 472 if int(os.uname()[2].split('.')[0]) >= 9: 473 _uuid_generate_time = None 474 475 # On Windows prior to 2000, UuidCreate gives a UUID containing the 476 # hardware address. On Windows 2000 and later, UuidCreate makes a 477 # random UUID and UuidCreateSequential gives a UUID containing the 478 # hardware address. These routines are provided by the RPC runtime. 479 # NOTE: at least on Tim's WinXP Pro SP2 desktop box, while the last 480 # 6 bytes returned by UuidCreateSequential are fixed, they don't appear 481 # to bear any relationship to the MAC address of any network device 482 # on the box. 483 try: 484 lib = ctypes.windll.rpcrt4 485 except: 486 lib = None 487 _UuidCreate = getattr(lib, 'UuidCreateSequential', 488 getattr(lib, 'UuidCreate', None)) 489 except: 490 pass 491 492 def _unixdll_getnode(): 493 """Get the hardware address on Unix using ctypes.""" 494 _buffer = ctypes.create_string_buffer(16) 495 _uuid_generate_time(_buffer) 496 return UUID(bytes=_buffer.raw).node 497 498 def _windll_getnode(): 499 """Get the hardware address on Windows using ctypes.""" 500 _buffer = ctypes.create_string_buffer(16) 501 if _UuidCreate(_buffer) == 0: 502 return UUID(bytes=_buffer.raw).node 503 504 def _random_getnode(): 505 """Get a random node ID, with eighth bit set as suggested by RFC 4122.""" 506 import random 507 return random.randrange(0, 1<<48L) | 0x010000000000L 508 509 _node = None 510 511 def getnode(): 512 """Get the hardware address as a 48-bit positive integer. 513 514 The first time this runs, it may launch a separate program, which could 515 be quite slow. If all attempts to obtain the hardware address fail, we 516 choose a random 48-bit number with its eighth bit set to 1 as recommended 517 in RFC 4122. 518 """ 519 520 global _node 521 if _node is not None: 522 return _node 523 524 import sys 525 if sys.platform == 'win32': 526 getters = [_windll_getnode, _netbios_getnode, _ipconfig_getnode] 527 else: 528 getters = [_unixdll_getnode, _ifconfig_getnode, _arp_getnode, 529 _lanscan_getnode, _netstat_getnode] 530 531 for getter in getters + [_random_getnode]: 532 try: 533 _node = getter() 534 except: 535 continue 536 if _node is not None: 537 return _node 538 539 _last_timestamp = None 540 541 def uuid1(node=None, clock_seq=None): 542 """Generate a UUID from a host ID, sequence number, and the current time. 543 If 'node' is not given, getnode() is used to obtain the hardware 544 address. If 'clock_seq' is given, it is used as the sequence number; 545 otherwise a random 14-bit sequence number is chosen.""" 546 547 # When the system provides a version-1 UUID generator, use it (but don't 548 # use UuidCreate here because its UUIDs don't conform to RFC 4122). 549 if _uuid_generate_time and node is clock_seq is None: 550 _buffer = ctypes.create_string_buffer(16) 551 _uuid_generate_time(_buffer) 552 return UUID(bytes=_buffer.raw) 553 554 global _last_timestamp 555 import time 556 nanoseconds = int(time.time() * 1e9) 557 # 0x01b21dd213814000 is the number of 100-ns intervals between the 558 # UUID epoch 1582-10-15 00:00:00 and the Unix epoch 1970-01-01 00:00:00. 559 timestamp = int(nanoseconds//100) + 0x01b21dd213814000L 560 if _last_timestamp is not None and timestamp <= _last_timestamp: 561 timestamp = _last_timestamp + 1 562 _last_timestamp = timestamp 563 if clock_seq is None: 564 import random 565 clock_seq = random.randrange(1<<14L) # instead of stable storage 566 time_low = timestamp & 0xffffffffL 567 time_mid = (timestamp >> 32L) & 0xffffL 568 time_hi_version = (timestamp >> 48L) & 0x0fffL 569 clock_seq_low = clock_seq & 0xffL 570 clock_seq_hi_variant = (clock_seq >> 8L) & 0x3fL 571 if node is None: 572 node = getnode() 573 return UUID(fields=(time_low, time_mid, time_hi_version, 574 clock_seq_hi_variant, clock_seq_low, node), version=1) 575 576 def uuid3(namespace, name): 577 """Generate a UUID from the MD5 hash of a namespace UUID and a name.""" 578 from hashlib import md5 579 hash = md5(namespace.bytes + name).digest() 580 return UUID(bytes=hash[:16], version=3) 581 582 def uuid4(): 583 """Generate a random UUID.""" 584 return UUID(bytes=os.urandom(16), version=4) 585 586 def uuid5(namespace, name): 587 """Generate a UUID from the SHA-1 hash of a namespace UUID and a name.""" 588 from hashlib import sha1 589 hash = sha1(namespace.bytes + name).digest() 590 return UUID(bytes=hash[:16], version=5) 591 592 # The following standard UUIDs are for use with uuid3() or uuid5(). 593 594 NAMESPACE_DNS = UUID('6ba7b810-9dad-11d1-80b4-00c04fd430c8') 595 NAMESPACE_URL = UUID('6ba7b811-9dad-11d1-80b4-00c04fd430c8') 596 NAMESPACE_OID = UUID('6ba7b812-9dad-11d1-80b4-00c04fd430c8') 597 NAMESPACE_X500 = UUID('6ba7b814-9dad-11d1-80b4-00c04fd430c8') 598