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 __author__ = 'Ka-Ping Yee <ping@zesty.ca>'

    48 

    49 RESERVED_NCS, RFC_4122, RESERVED_MICROSOFT, RESERVED_FUTURE = [

    50     'reserved for NCS compatibility', 'specified in RFC 4122',

    51     'reserved for Microsoft compatibility', 'reserved for future definition']

    52 

    53 class UUID(object):

    54     """Instances of the UUID class represent UUIDs as specified in RFC 4122.

    55     UUID objects are immutable, hashable, and usable as dictionary keys.

    56     Converting a UUID to a string with str() yields something in the form

    57     '12345678-1234-1234-1234-123456789abc'.  The UUID constructor accepts

    58     five possible forms: a similar string of hexadecimal digits, or a tuple

    59     of six integer fields (with 32-bit, 16-bit, 16-bit, 8-bit, 8-bit, and

    60     48-bit values respectively) as an argument named 'fields', or a string

    61     of 16 bytes (with all the integer fields in big-endian order) as an

    62     argument named 'bytes', or a string of 16 bytes (with the first three

    63     fields in little-endian order) as an argument named 'bytes_le', or a

    64     single 128-bit integer as an argument named 'int'.

    65 

    66     UUIDs have these read-only attributes:

    67 

    68         bytes       the UUID as a 16-byte string (containing the six

    69                     integer fields in big-endian byte order)

    70 

    71         bytes_le    the UUID as a 16-byte string (with time_low, time_mid,

    72                     and time_hi_version in little-endian byte order)

    73 

    74         fields      a tuple of the six integer fields of the UUID,

    75                     which are also available as six individual attributes

    76                     and two derived attributes:

    77 

    78             time_low                the first 32 bits of the UUID

    79             time_mid                the next 16 bits of the UUID

    80             time_hi_version         the next 16 bits of the UUID

    81             clock_seq_hi_variant    the next 8 bits of the UUID

    82             clock_seq_low           the next 8 bits of the UUID

    83             node                    the last 48 bits of the UUID

    84 

    85             time                    the 60-bit timestamp

    86             clock_seq               the 14-bit sequence number

    87 

    88         hex         the UUID as a 32-character hexadecimal string

    89 

    90         int         the UUID as a 128-bit integer

    91 

    92         urn         the UUID as a URN as specified in RFC 4122

    93 

    94         variant     the UUID variant (one of the constants RESERVED_NCS,

    95                     RFC_4122, RESERVED_MICROSOFT, or RESERVED_FUTURE)

    96 

    97         version     the UUID version number (1 through 5, meaningful only

    98                     when the variant is RFC_4122)

    99     """

   100 

   101     def __init__(self, hex=None, bytes=None, bytes_le=None, fields=None,

   102                        int=None, version=None):

   103         r"""Create a UUID from either a string of 32 hexadecimal digits,

   104         a string of 16 bytes as the 'bytes' argument, a string of 16 bytes

   105         in little-endian order as the 'bytes_le' argument, a tuple of six

   106         integers (32-bit time_low, 16-bit time_mid, 16-bit time_hi_version,

   107         8-bit clock_seq_hi_variant, 8-bit clock_seq_low, 48-bit node) as

   108         the 'fields' argument, or a single 128-bit integer as the 'int'

   109         argument.  When a string of hex digits is given, curly braces,

   110         hyphens, and a URN prefix are all optional.  For example, these

   111         expressions all yield the same UUID:

   112 

   113         UUID('{12345678-1234-5678-1234-567812345678}')

   114         UUID('12345678123456781234567812345678')

   115         UUID('urn:uuid:12345678-1234-5678-1234-567812345678')

   116         UUID(bytes='\x12\x34\x56\x78'*4)

   117         UUID(bytes_le='\x78\x56\x34\x12\x34\x12\x78\x56' +

   118                       '\x12\x34\x56\x78\x12\x34\x56\x78')

   119         UUID(fields=(0x12345678, 0x1234, 0x5678, 0x12, 0x34, 0x567812345678))

   120         UUID(int=0x12345678123456781234567812345678)

   121 

   122         Exactly one of 'hex', 'bytes', 'bytes_le', 'fields', or 'int' must

   123         be given.  The 'version' argument is optional; if given, the resulting

   124         UUID will have its variant and version set according to RFC 4122,

   125         overriding the given 'hex', 'bytes', 'bytes_le', 'fields', or 'int'.

   126         """

   127 

   128         if [hex, bytes, bytes_le, fields, int].count(None) != 4:

   129             raise TypeError('need one of hex, bytes, bytes_le, fields, or int')

   130         if hex is not None:

   131             hex = hex.replace('urn:', '').replace('uuid:', '')

   132             hex = hex.strip('{}').replace('-', '')

   133             if len(hex) != 32:

   134                 raise ValueError('badly formed hexadecimal UUID string')

   135             int = long(hex, 16)

   136         if bytes_le is not None:

   137             if len(bytes_le) != 16:

   138                 raise ValueError('bytes_le is not a 16-char string')

   139             bytes = (bytes_le[3] + bytes_le[2] + bytes_le[1] + bytes_le[0] +

   140                      bytes_le[5] + bytes_le[4] + bytes_le[7] + bytes_le[6] +

   141                      bytes_le[8:])

   142         if bytes is not None:

   143             if len(bytes) != 16:

   144                 raise ValueError('bytes is not a 16-char string')

   145             int = long(('%02x'*16) % tuple(map(ord, bytes)), 16)

   146         if fields is not None:

   147             if len(fields) != 6:

   148                 raise ValueError('fields is not a 6-tuple')

   149             (time_low, time_mid, time_hi_version,

   150              clock_seq_hi_variant, clock_seq_low, node) = fields

   151             if not 0 <= time_low < 1<<32L:

   152                 raise ValueError('field 1 out of range (need a 32-bit value)')

   153             if not 0 <= time_mid < 1<<16L:

   154                 raise ValueError('field 2 out of range (need a 16-bit value)')

   155             if not 0 <= time_hi_version < 1<<16L:

   156                 raise ValueError('field 3 out of range (need a 16-bit value)')

   157             if not 0 <= clock_seq_hi_variant < 1<<8L:

   158                 raise ValueError('field 4 out of range (need an 8-bit value)')

   159             if not 0 <= clock_seq_low < 1<<8L:

   160                 raise ValueError('field 5 out of range (need an 8-bit value)')

   161             if not 0 <= node < 1<<48L:

   162                 raise ValueError('field 6 out of range (need a 48-bit value)')

   163             clock_seq = (clock_seq_hi_variant << 8L) | clock_seq_low

   164             int = ((time_low << 96L) | (time_mid << 80L) |

   165                    (time_hi_version << 64L) | (clock_seq << 48L) | node)

   166         if int is not None:

   167             if not 0 <= int < 1<<128L:

   168                 raise ValueError('int is out of range (need a 128-bit value)')

   169         if version is not None:

   170             if not 1 <= version <= 5:

   171                 raise ValueError('illegal version number')

   172             # Set the variant to RFC 4122.

   173             int &= ~(0xc000 << 48L)

   174             int |= 0x8000 << 48L

   175             # Set the version number.

   176             int &= ~(0xf000 << 64L)

   177             int |= version << 76L

   178         self.__dict__['int'] = int

   179 

   180     def __cmp__(self, other):

   181         if isinstance(other, UUID):

   182             return cmp(self.int, other.int)

   183         return NotImplemented

   184 

   185     def __hash__(self):

   186         return hash(self.int)

   187 

   188     def __int__(self):

   189         return self.int

   190 

   191     def __repr__(self):

   192         return 'UUID(%r)' % str(self)

   193 

   194     def __setattr__(self, name, value):

   195         raise TypeError('UUID objects are immutable')

   196 

   197     def __str__(self):

   198         hex = '%032x' % self.int

   199         return '%s-%s-%s-%s-%s' % (

   200             hex[:8], hex[8:12], hex[12:16], hex[16:20], hex[20:])

   201 

   202     def get_bytes(self):

   203         bytes = ''

   204         for shift in range(0, 128, 8):

   205             bytes = chr((self.int >> shift) & 0xff) + bytes

   206         return bytes

   207 

   208     bytes = property(get_bytes)

   209 

   210     def get_bytes_le(self):

   211         bytes = self.bytes

   212         return (bytes[3] + bytes[2] + bytes[1] + bytes[0] +

   213                 bytes[5] + bytes[4] + bytes[7] + bytes[6] + bytes[8:])

   214 

   215     bytes_le = property(get_bytes_le)

   216 

   217     def get_fields(self):

   218         return (self.time_low, self.time_mid, self.time_hi_version,

   219                 self.clock_seq_hi_variant, self.clock_seq_low, self.node)

   220 

   221     fields = property(get_fields)

   222 

   223     def get_time_low(self):

   224         return self.int >> 96L

   225 

   226     time_low = property(get_time_low)

   227 

   228     def get_time_mid(self):

   229         return (self.int >> 80L) & 0xffff

   230 

   231     time_mid = property(get_time_mid)

   232 

   233     def get_time_hi_version(self):

   234         return (self.int >> 64L) & 0xffff

   235 

   236     time_hi_version = property(get_time_hi_version)

   237 

   238     def get_clock_seq_hi_variant(self):

   239         return (self.int >> 56L) & 0xff

   240 

   241     clock_seq_hi_variant = property(get_clock_seq_hi_variant)

   242 

   243     def get_clock_seq_low(self):

   244         return (self.int >> 48L) & 0xff

   245 

   246     clock_seq_low = property(get_clock_seq_low)

   247 

   248     def get_time(self):

   249         return (((self.time_hi_version & 0x0fffL) << 48L) |

   250                 (self.time_mid << 32L) | self.time_low)

   251 

   252     time = property(get_time)

   253 

   254     def get_clock_seq(self):

   255         return (((self.clock_seq_hi_variant & 0x3fL) << 8L) |

   256                 self.clock_seq_low)

   257 

   258     clock_seq = property(get_clock_seq)

   259 

   260     def get_node(self):

   261         return self.int & 0xffffffffffff

   262 

   263     node = property(get_node)

   264 

   265     def get_hex(self):

   266         return '%032x' % self.int

   267 

   268     hex = property(get_hex)

   269 

   270     def get_urn(self):

   271         return 'urn:uuid:' + str(self)

   272 

   273     urn = property(get_urn)

   274 

   275     def get_variant(self):

   276         if not self.int & (0x8000 << 48L):

   277             return RESERVED_NCS

   278         elif not self.int & (0x4000 << 48L):

   279             return RFC_4122

   280         elif not self.int & (0x2000 << 48L):

   281             return RESERVED_MICROSOFT

   282         else:

   283             return RESERVED_FUTURE

   284 

   285     variant = property(get_variant)

   286 

   287     def get_version(self):

   288         # The version bits are only meaningful for RFC 4122 UUIDs.

   289         if self.variant == RFC_4122:

   290             return int((self.int >> 76L) & 0xf)

   291 

   292     version = property(get_version)

   293 

   294 def _find_mac(command, args, hw_identifiers, get_index):

   295     import os

   296     for dir in ['', '/sbin/', '/usr/sbin']:

   297         executable = os.path.join(dir, command)

   298         if not os.path.exists(executable):

   299             continue

   300 

   301         try:

   302             # LC_ALL to get English output, 2>/dev/null to

   303             # prevent output on stderr

   304             cmd = 'LC_ALL=C %s %s 2>/dev/null' % (executable, args)

   305             pipe = os.popen(cmd)

   306         except IOError:

   307             continue

   308 

   309         for line in pipe:

   310             words = line.lower().split()

   311             for i in range(len(words)):

   312                 if words[i] in hw_identifiers:

   313                     return int(words[get_index(i)].replace(':', ''), 16)

   314     return None

   315 

   316 def _ifconfig_getnode():

   317     """Get the hardware address on Unix by running ifconfig."""

   318 

   319     # This works on Linux ('' or '-a'), Tru64 ('-av'), but not all Unixes.

   320     for args in ('', '-a', '-av'):

   321         mac = _find_mac('ifconfig', args, ['hwaddr', 'ether'], lambda i: i+1)

   322         if mac:

   323             return mac

   324 

   325     import socket

   326     ip_addr = socket.gethostbyname(socket.gethostname())

   327 

   328     # Try getting the MAC addr from arp based on our IP address (Solaris).

   329     mac = _find_mac('arp', '-an', [ip_addr], lambda i: -1)

   330     if mac:

   331         return mac

   332 

   333     # This might work on HP-UX.

   334     mac = _find_mac('lanscan', '-ai', ['lan0'], lambda i: 0)

   335     if mac:

   336         return mac

   337 

   338     return None

   339 

   340 def _ipconfig_getnode():

   341     """Get the hardware address on Windows by running ipconfig.exe."""

   342     import os, re

   343     dirs = ['', r'c:\windows\system32', r'c:\winnt\system32']

   344     try:

   345         import ctypes

   346         buffer = ctypes.create_string_buffer(300)

   347         ctypes.windll.kernel32.GetSystemDirectoryA(buffer, 300)

   348         dirs.insert(0, buffer.value.decode('mbcs'))

   349     except:

   350         pass

   351     for dir in dirs:

   352         try:

   353             pipe = os.popen(os.path.join(dir, 'ipconfig') + ' /all')

   354         except IOError:

   355             continue

   356         for line in pipe:

   357             value = line.split(':')[-1].strip().lower()

   358             if re.match('([0-9a-f][0-9a-f]-){5}[0-9a-f][0-9a-f]', value):

   359                 return int(value.replace('-', ''), 16)

   360 

   361 def _netbios_getnode():

   362     """Get the hardware address on Windows using NetBIOS calls.

   363     See http://support.microsoft.com/kb/118623 for details."""

   364     import win32wnet, netbios

   365     ncb = netbios.NCB()

   366     ncb.Command = netbios.NCBENUM

   367     ncb.Buffer = adapters = netbios.LANA_ENUM()

   368     adapters._pack()

   369     if win32wnet.Netbios(ncb) != 0:

   370         return

   371     adapters._unpack()

   372     for i in range(adapters.length):

   373         ncb.Reset()

   374         ncb.Command = netbios.NCBRESET

   375         ncb.Lana_num = ord(adapters.lana[i])

   376         if win32wnet.Netbios(ncb) != 0:

   377             continue

   378         ncb.Reset()

   379         ncb.Command = netbios.NCBASTAT

   380         ncb.Lana_num = ord(adapters.lana[i])

   381         ncb.Callname = '*'.ljust(16)

   382         ncb.Buffer = status = netbios.ADAPTER_STATUS()

   383         if win32wnet.Netbios(ncb) != 0:

   384             continue

   385         status._unpack()

   386         bytes = map(ord, status.adapter_address)

   387         return ((bytes[0]<<40L) + (bytes[1]<<32L) + (bytes[2]<<24L) +

   388                 (bytes[3]<<16L) + (bytes[4]<<8L) + bytes[5])

   389 

   390 # Thanks to Thomas Heller for ctypes and for his help with its use here.

   391 

   392 # If ctypes is available, use it to find system routines for UUID generation.

   393 _uuid_generate_random = _uuid_generate_time = _UuidCreate = None

   394 try:

   395     import ctypes, ctypes.util

   396     _buffer = ctypes.create_string_buffer(16)

   397 

   398     # The uuid_generate_* routines are provided by libuuid on at least

   399     # Linux and FreeBSD, and provided by libc on Mac OS X.

   400     for libname in ['uuid', 'c']:

   401         try:

   402             lib = ctypes.CDLL(ctypes.util.find_library(libname))

   403         except:

   404             continue

   405         if hasattr(lib, 'uuid_generate_random'):

   406             _uuid_generate_random = lib.uuid_generate_random

   407         if hasattr(lib, 'uuid_generate_time'):

   408             _uuid_generate_time = lib.uuid_generate_time

   409 

   410     # On Windows prior to 2000, UuidCreate gives a UUID containing the

   411     # hardware address.  On Windows 2000 and later, UuidCreate makes a

   412     # random UUID and UuidCreateSequential gives a UUID containing the

   413     # hardware address.  These routines are provided by the RPC runtime.

   414     # NOTE:  at least on Tim's WinXP Pro SP2 desktop box, while the last

   415     # 6 bytes returned by UuidCreateSequential are fixed, they don't appear

   416     # to bear any relationship to the MAC address of any network device

   417     # on the box.

   418     try:

   419         lib = ctypes.windll.rpcrt4

   420     except:

   421         lib = None

   422     _UuidCreate = getattr(lib, 'UuidCreateSequential',

   423                           getattr(lib, 'UuidCreate', None))

   424 except:

   425     pass

   426 

   427 def _unixdll_getnode():

   428     """Get the hardware address on Unix using ctypes."""

   429     _uuid_generate_time(_buffer)

   430     return UUID(bytes=_buffer.raw).node

   431 

   432 def _windll_getnode():

   433     """Get the hardware address on Windows using ctypes."""

   434     if _UuidCreate(_buffer) == 0:

   435         return UUID(bytes=_buffer.raw).node

   436 

   437 def _random_getnode():

   438     """Get a random node ID, with eighth bit set as suggested by RFC 4122."""

   439     import random

   440     return random.randrange(0, 1<<48L) | 0x010000000000L

   441 

   442 _node = None

   443 

   444 def getnode():

   445     """Get the hardware address as a 48-bit positive integer.

   446 

   447     The first time this runs, it may launch a separate program, which could

   448     be quite slow.  If all attempts to obtain the hardware address fail, we

   449     choose a random 48-bit number with its eighth bit set to 1 as recommended

   450     in RFC 4122.

   451     """

   452 

   453     global _node

   454     if _node is not None:

   455         return _node

   456 

   457     import sys

   458     if sys.platform == 'win32':

   459         getters = [_windll_getnode, _netbios_getnode, _ipconfig_getnode]

   460     else:

   461         getters = [_unixdll_getnode, _ifconfig_getnode]

   462 

   463     for getter in getters + [_random_getnode]:

   464         try:

   465             _node = getter()

   466         except:

   467             continue

   468         if _node is not None:

   469             return _node

   470 

   471 _last_timestamp = None

   472 

   473 def uuid1(node=None, clock_seq=None):

   474     """Generate a UUID from a host ID, sequence number, and the current time.

   475     If 'node' is not given, getnode() is used to obtain the hardware

   476     address.  If 'clock_seq' is given, it is used as the sequence number;

   477     otherwise a random 14-bit sequence number is chosen."""

   478 

   479     # When the system provides a version-1 UUID generator, use it (but don't

   480     # use UuidCreate here because its UUIDs don't conform to RFC 4122).

   481     if _uuid_generate_time and node is clock_seq is None:

   482         _uuid_generate_time(_buffer)

   483         return UUID(bytes=_buffer.raw)

   484 

   485     global _last_timestamp

   486     import time

   487     nanoseconds = int(time.time() * 1e9)

   488     # 0x01b21dd213814000 is the number of 100-ns intervals between the

   489     # UUID epoch 1582-10-15 00:00:00 and the Unix epoch 1970-01-01 00:00:00.

   490     timestamp = int(nanoseconds/100) + 0x01b21dd213814000L

   491     if timestamp <= _last_timestamp:

   492         timestamp = _last_timestamp + 1

   493     _last_timestamp = timestamp

   494     if clock_seq is None:

   495         import random

   496         clock_seq = random.randrange(1<<14L) # instead of stable storage

   497     time_low = timestamp & 0xffffffffL

   498     time_mid = (timestamp >> 32L) & 0xffffL

   499     time_hi_version = (timestamp >> 48L) & 0x0fffL

   500     clock_seq_low = clock_seq & 0xffL

   501     clock_seq_hi_variant = (clock_seq >> 8L) & 0x3fL

   502     if node is None:

   503         node = getnode()

   504     return UUID(fields=(time_low, time_mid, time_hi_version,

   505                         clock_seq_hi_variant, clock_seq_low, node), version=1)

   506 

   507 def uuid3(namespace, name):

   508     """Generate a UUID from the MD5 hash of a namespace UUID and a name."""

   509     import md5

   510     hash = md5.md5(namespace.bytes + name).digest()

   511     return UUID(bytes=hash[:16], version=3)

   512 

   513 def uuid4():

   514     """Generate a random UUID."""

   515 

   516     # When the system provides a version-4 UUID generator, use it.

   517     if _uuid_generate_random:

   518         _uuid_generate_random(_buffer)

   519         return UUID(bytes=_buffer.raw)

   520 

   521     # Otherwise, get randomness from urandom or the 'random' module.

   522     try:

   523         import os

   524         return UUID(bytes=os.urandom(16), version=4)

   525     except:

   526         import random

   527         bytes = [chr(random.randrange(256)) for i in range(16)]

   528         return UUID(bytes=bytes, version=4)

   529 

   530 def uuid5(namespace, name):

   531     """Generate a UUID from the SHA-1 hash of a namespace UUID and a name."""

   532     import sha

   533     hash = sha.sha(namespace.bytes + name).digest()

   534     return UUID(bytes=hash[:16], version=5)

   535 

   536 # The following standard UUIDs are for use with uuid3() or uuid5().

   537 

   538 NAMESPACE_DNS = UUID('6ba7b810-9dad-11d1-80b4-00c04fd430c8')

   539 NAMESPACE_URL = UUID('6ba7b811-9dad-11d1-80b4-00c04fd430c8')

   540 NAMESPACE_OID = UUID('6ba7b812-9dad-11d1-80b4-00c04fd430c8')

   541 NAMESPACE_X500 = UUID('6ba7b814-9dad-11d1-80b4-00c04fd430c8')