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 keywords = ('hwaddr', 'ether', 'address:', 'lladdr') 343 for args in ('', '-a', '-av'): 344 mac = _find_mac('ifconfig', args, keywords, lambda i: i+1) 345 if mac: 346 return mac 347 348 def _arp_getnode(): 349 """Get the hardware address on Unix by running arp.""" 350 import os, socket 351 try: 352 ip_addr = socket.gethostbyname(socket.gethostname()) 353 except EnvironmentError: 354 return None 355 356 # Try getting the MAC addr from arp based on our IP address (Solaris). 357 mac = _find_mac('arp', '-an', [ip_addr], lambda i: -1) 358 if mac: 359 return mac 360 361 # This works on OpenBSD 362 mac = _find_mac('arp', '-an', [ip_addr], lambda i: i+1) 363 if mac: 364 return mac 365 366 # This works on Linux, FreeBSD and NetBSD 367 mac = _find_mac('arp', '-an', ['(%s)' % ip_addr], 368 lambda i: i+2) 369 if mac: 370 return mac 371 372 def _lanscan_getnode(): 373 """Get the hardware address on Unix by running lanscan.""" 374 # This might work on HP-UX. 375 return _find_mac('lanscan', '-ai', ['lan0'], lambda i: 0) 376 377 def _netstat_getnode(): 378 """Get the hardware address on Unix by running netstat.""" 379 # This might work on AIX, Tru64 UNIX and presumably on IRIX. 380 try: 381 pipe = _popen('netstat', '-ia') 382 if not pipe: 383 return 384 with pipe: 385 words = pipe.readline().rstrip().split() 386 try: 387 i = words.index('Address') 388 except ValueError: 389 return 390 for line in pipe: 391 try: 392 words = line.rstrip().split() 393 word = words[i] 394 if len(word) == 17 and word.count(':') == 5: 395 mac = int(word.replace(':', ''), 16) 396 if mac: 397 return mac 398 except (ValueError, IndexError): 399 pass 400 except OSError: 401 pass 402 403 def _ipconfig_getnode(): 404 """Get the hardware address on Windows by running ipconfig.exe.""" 405 import os, re 406 dirs = ['', r'c:\windows\system32', r'c:\winnt\system32'] 407 try: 408 import ctypes 409 buffer = ctypes.create_string_buffer(300) 410 ctypes.windll.kernel32.GetSystemDirectoryA(buffer, 300) 411 dirs.insert(0, buffer.value.decode('mbcs')) 412 except: 413 pass 414 for dir in dirs: 415 try: 416 pipe = os.popen(os.path.join(dir, 'ipconfig') + ' /all') 417 except IOError: 418 continue 419 with pipe: 420 for line in pipe: 421 value = line.split(':')[-1].strip().lower() 422 if re.match('(?:[0-9a-f][0-9a-f]-){5}[0-9a-f][0-9a-f]$', value): 423 return int(value.replace('-', ''), 16) 424 425 def _netbios_getnode(): 426 """Get the hardware address on Windows using NetBIOS calls. 427 See http://support.microsoft.com/kb/118623 for details.""" 428 import win32wnet, netbios 429 ncb = netbios.NCB() 430 ncb.Command = netbios.NCBENUM 431 ncb.Buffer = adapters = netbios.LANA_ENUM() 432 adapters._pack() 433 if win32wnet.Netbios(ncb) != 0: 434 return 435 adapters._unpack() 436 for i in range(adapters.length): 437 ncb.Reset() 438 ncb.Command = netbios.NCBRESET 439 ncb.Lana_num = ord(adapters.lana[i]) 440 if win32wnet.Netbios(ncb) != 0: 441 continue 442 ncb.Reset() 443 ncb.Command = netbios.NCBASTAT 444 ncb.Lana_num = ord(adapters.lana[i]) 445 ncb.Callname = '*'.ljust(16) 446 ncb.Buffer = status = netbios.ADAPTER_STATUS() 447 if win32wnet.Netbios(ncb) != 0: 448 continue 449 status._unpack() 450 bytes = map(ord, status.adapter_address) 451 return ((bytes[0]<<40L) + (bytes[1]<<32L) + (bytes[2]<<24L) + 452 (bytes[3]<<16L) + (bytes[4]<<8L) + bytes[5]) 453 454 # Thanks to Thomas Heller for ctypes and for his help with its use here. 455 456 # If ctypes is available, use it to find system routines for UUID generation. 457 _uuid_generate_time = _UuidCreate = None 458 try: 459 import ctypes, ctypes.util 460 import sys 461 462 # The uuid_generate_* routines are provided by libuuid on at least 463 # Linux and FreeBSD, and provided by libc on Mac OS X. 464 _libnames = ['uuid'] 465 if not sys.platform.startswith('win'): 466 _libnames.append('c') 467 for libname in _libnames: 468 try: 469 lib = ctypes.CDLL(ctypes.util.find_library(libname)) 470 except: 471 continue 472 if hasattr(lib, 'uuid_generate_time'): 473 _uuid_generate_time = lib.uuid_generate_time 474 break 475 del _libnames 476 477 # The uuid_generate_* functions are broken on MacOS X 10.5, as noted 478 # in issue #8621 the function generates the same sequence of values 479 # in the parent process and all children created using fork (unless 480 # those children use exec as well). 481 # 482 # Assume that the uuid_generate functions are broken from 10.5 onward, 483 # the test can be adjusted when a later version is fixed. 484 if sys.platform == 'darwin': 485 import os 486 if int(os.uname()[2].split('.')[0]) >= 9: 487 _uuid_generate_time = None 488 489 # On Windows prior to 2000, UuidCreate gives a UUID containing the 490 # hardware address. On Windows 2000 and later, UuidCreate makes a 491 # random UUID and UuidCreateSequential gives a UUID containing the 492 # hardware address. These routines are provided by the RPC runtime. 493 # NOTE: at least on Tim's WinXP Pro SP2 desktop box, while the last 494 # 6 bytes returned by UuidCreateSequential are fixed, they don't appear 495 # to bear any relationship to the MAC address of any network device 496 # on the box. 497 try: 498 lib = ctypes.windll.rpcrt4 499 except: 500 lib = None 501 _UuidCreate = getattr(lib, 'UuidCreateSequential', 502 getattr(lib, 'UuidCreate', None)) 503 except: 504 pass 505 506 def _unixdll_getnode(): 507 """Get the hardware address on Unix using ctypes.""" 508 _buffer = ctypes.create_string_buffer(16) 509 _uuid_generate_time(_buffer) 510 return UUID(bytes=_buffer.raw).node 511 512 def _windll_getnode(): 513 """Get the hardware address on Windows using ctypes.""" 514 _buffer = ctypes.create_string_buffer(16) 515 if _UuidCreate(_buffer) == 0: 516 return UUID(bytes=_buffer.raw).node 517 518 def _random_getnode(): 519 """Get a random node ID, with eighth bit set as suggested by RFC 4122.""" 520 import random 521 return random.randrange(0, 1<<48L) | 0x010000000000L 522 523 _node = None 524 525 _NODE_GETTERS_WIN32 = [_windll_getnode, _netbios_getnode, _ipconfig_getnode] 526 527 _NODE_GETTERS_UNIX = [_unixdll_getnode, _ifconfig_getnode, _arp_getnode, 528 _lanscan_getnode, _netstat_getnode] 529 530 def getnode(): 531 """Get the hardware address as a 48-bit positive integer. 532 533 The first time this runs, it may launch a separate program, which could 534 be quite slow. If all attempts to obtain the hardware address fail, we 535 choose a random 48-bit number with its eighth bit set to 1 as recommended 536 in RFC 4122. 537 """ 538 539 global _node 540 if _node is not None: 541 return _node 542 543 import sys 544 if sys.platform == 'win32': 545 getters = _NODE_GETTERS_WIN32 546 else: 547 getters = _NODE_GETTERS_UNIX 548 549 for getter in getters + [_random_getnode]: 550 try: 551 _node = getter() 552 except: 553 continue 554 if (_node is not None) and (0 <= _node < (1 << 48)): 555 return _node 556 assert False, '_random_getnode() returned invalid value: {}'.format(_node) 557 558 559 _last_timestamp = None 560 561 def uuid1(node=None, clock_seq=None): 562 """Generate a UUID from a host ID, sequence number, and the current time. 563 If 'node' is not given, getnode() is used to obtain the hardware 564 address. If 'clock_seq' is given, it is used as the sequence number; 565 otherwise a random 14-bit sequence number is chosen.""" 566 567 # When the system provides a version-1 UUID generator, use it (but don't 568 # use UuidCreate here because its UUIDs don't conform to RFC 4122). 569 if _uuid_generate_time and node is clock_seq is None: 570 _buffer = ctypes.create_string_buffer(16) 571 _uuid_generate_time(_buffer) 572 return UUID(bytes=_buffer.raw) 573 574 global _last_timestamp 575 import time 576 nanoseconds = int(time.time() * 1e9) 577 # 0x01b21dd213814000 is the number of 100-ns intervals between the 578 # UUID epoch 1582-10-15 00:00:00 and the Unix epoch 1970-01-01 00:00:00. 579 timestamp = int(nanoseconds//100) + 0x01b21dd213814000L 580 if _last_timestamp is not None and timestamp <= _last_timestamp: 581 timestamp = _last_timestamp + 1 582 _last_timestamp = timestamp 583 if clock_seq is None: 584 import random 585 clock_seq = random.randrange(1<<14L) # instead of stable storage 586 time_low = timestamp & 0xffffffffL 587 time_mid = (timestamp >> 32L) & 0xffffL 588 time_hi_version = (timestamp >> 48L) & 0x0fffL 589 clock_seq_low = clock_seq & 0xffL 590 clock_seq_hi_variant = (clock_seq >> 8L) & 0x3fL 591 if node is None: 592 node = getnode() 593 return UUID(fields=(time_low, time_mid, time_hi_version, 594 clock_seq_hi_variant, clock_seq_low, node), version=1) 595 596 def uuid3(namespace, name): 597 """Generate a UUID from the MD5 hash of a namespace UUID and a name.""" 598 from hashlib import md5 599 hash = md5(namespace.bytes + name).digest() 600 return UUID(bytes=hash[:16], version=3) 601 602 def uuid4(): 603 """Generate a random UUID.""" 604 return UUID(bytes=os.urandom(16), version=4) 605 606 def uuid5(namespace, name): 607 """Generate a UUID from the SHA-1 hash of a namespace UUID and a name.""" 608 from hashlib import sha1 609 hash = sha1(namespace.bytes + name).digest() 610 return UUID(bytes=hash[:16], version=5) 611 612 # The following standard UUIDs are for use with uuid3() or uuid5(). 613 614 NAMESPACE_DNS = UUID('6ba7b810-9dad-11d1-80b4-00c04fd430c8') 615 NAMESPACE_URL = UUID('6ba7b811-9dad-11d1-80b4-00c04fd430c8') 616 NAMESPACE_OID = UUID('6ba7b812-9dad-11d1-80b4-00c04fd430c8') 617 NAMESPACE_X500 = UUID('6ba7b814-9dad-11d1-80b4-00c04fd430c8') 618
