summaryrefslogtreecommitdiffstats
path: root/Lib/uuid.py
blob: 029df518a3d1c33c4ec17d67a5b33d419b1910ec (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
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
r"""UUID objects (universally unique identifiers) according to RFC 4122.

This module provides immutable UUID objects (class UUID) and the functions
uuid1(), uuid3(), uuid4(), uuid5() for generating version 1, 3, 4, and 5
UUIDs as specified in RFC 4122.

If all you want is a unique ID, you should probably call uuid1() or uuid4().
Note that uuid1() may compromise privacy since it creates a UUID containing
the computer's network address.  uuid4() creates a random UUID.

Typical usage:

    >>> import uuid

    # make a UUID based on the host ID and current time
    >>> uuid.uuid1()
    UUID('a8098c1a-f86e-11da-bd1a-00112444be1e')

    # make a UUID using an MD5 hash of a namespace UUID and a name
    >>> uuid.uuid3(uuid.NAMESPACE_DNS, 'python.org')
    UUID('6fa459ea-ee8a-3ca4-894e-db77e160355e')

    # make a random UUID
    >>> uuid.uuid4()
    UUID('16fd2706-8baf-433b-82eb-8c7fada847da')

    # make a UUID using a SHA-1 hash of a namespace UUID and a name
    >>> uuid.uuid5(uuid.NAMESPACE_DNS, 'python.org')
    UUID('886313e1-3b8a-5372-9b90-0c9aee199e5d')

    # make a UUID from a string of hex digits (braces and hyphens ignored)
    >>> x = uuid.UUID('{00010203-0405-0607-0809-0a0b0c0d0e0f}')

    # convert a UUID to a string of hex digits in standard form
    >>> str(x)
    '00010203-0405-0607-0809-0a0b0c0d0e0f'

    # get the raw 16 bytes of the UUID
    >>> x.bytes
    '\x00\x01\x02\x03\x04\x05\x06\x07\x08\t\n\x0b\x0c\r\x0e\x0f'

    # make a UUID from a 16-byte string
    >>> uuid.UUID(bytes=x.bytes)
    UUID('00010203-0405-0607-0809-0a0b0c0d0e0f')
"""

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

RESERVED_NCS, RFC_4122, RESERVED_MICROSOFT, RESERVED_FUTURE = [
    'reserved for NCS compatibility', 'specified in RFC 4122',
    'reserved for Microsoft compatibility', 'reserved for future definition']

int_ = int # The built-in int function

class UUID(object):
    """Instances of the UUID class represent UUIDs as specified in RFC 4122.
    UUID objects are immutable, hashable, and usable as dictionary keys.
    Converting a UUID to a string with str() yields something in the form
    '12345678-1234-1234-1234-123456789abc'.  The UUID constructor accepts
    five possible forms: a similar string of hexadecimal digits, or a tuple
    of six integer fields (with 32-bit, 16-bit, 16-bit, 8-bit, 8-bit, and
    48-bit values respectively) as an argument named 'fields', or a string
    of 16 bytes (with all the integer fields in big-endian order) as an
    argument named 'bytes', or a string of 16 bytes (with the first three
    fields in little-endian order) as an argument named 'bytes_le', or a
    single 128-bit integer as an argument named 'int'.

    UUIDs have these read-only attributes:

        bytes       the UUID as a 16-byte string (containing the six
                    integer fields in big-endian byte order)

        bytes_le    the UUID as a 16-byte string (with time_low, time_mid,
                    and time_hi_version in little-endian byte order)

        fields      a tuple of the six integer fields of the UUID,
                    which are also available as six individual attributes
                    and two derived attributes:

            time_low                the first 32 bits of the UUID
            time_mid                the next 16 bits of the UUID
            time_hi_version         the next 16 bits of the UUID
            clock_seq_hi_variant    the next 8 bits of the UUID
            clock_seq_low           the next 8 bits of the UUID
            node                    the last 48 bits of the UUID

            time                    the 60-bit timestamp
            clock_seq               the 14-bit sequence number

        hex         the UUID as a 32-character hexadecimal string

        int         the UUID as a 128-bit integer

        urn         the UUID as a URN as specified in RFC 4122

        variant     the UUID variant (one of the constants RESERVED_NCS,
                    RFC_4122, RESERVED_MICROSOFT, or RESERVED_FUTURE)

        version     the UUID version number (1 through 5, meaningful only
                    when the variant is RFC_4122)
    """

    def __init__(self, hex=None, bytes=None, bytes_le=None, fields=None,
                       int=None, version=None):
        r"""Create a UUID from either a string of 32 hexadecimal digits,
        a string of 16 bytes as the 'bytes' argument, a string of 16 bytes
        in little-endian order as the 'bytes_le' argument, a tuple of six
        integers (32-bit time_low, 16-bit time_mid, 16-bit time_hi_version,
        8-bit clock_seq_hi_variant, 8-bit clock_seq_low, 48-bit node) as
        the 'fields' argument, or a single 128-bit integer as the 'int'
        argument.  When a string of hex digits is given, curly braces,
        hyphens, and a URN prefix are all optional.  For example, these
        expressions all yield the same UUID:

        UUID('{12345678-1234-5678-1234-567812345678}')
        UUID('12345678123456781234567812345678')
        UUID('urn:uuid:12345678-1234-5678-1234-567812345678')
        UUID(bytes='\x12\x34\x56\x78'*4)
        UUID(bytes_le='\x78\x56\x34\x12\x34\x12\x78\x56' +
                      '\x12\x34\x56\x78\x12\x34\x56\x78')
        UUID(fields=(0x12345678, 0x1234, 0x5678, 0x12, 0x34, 0x567812345678))
        UUID(int=0x12345678123456781234567812345678)

        Exactly one of 'hex', 'bytes', 'bytes_le', 'fields', or 'int' must
        be given.  The 'version' argument is optional; if given, the resulting
        UUID will have its variant and version set according to RFC 4122,
        overriding the given 'hex', 'bytes', 'bytes_le', 'fields', or 'int'.
        """

        if [hex, bytes, bytes_le, fields, int].count(None) != 4:
            raise TypeError('need one of hex, bytes, bytes_le, fields, or int')
        if hex is not None:
            hex = hex.replace('urn:', '').replace('uuid:', '')
            hex = hex.strip('{}').replace('-', '')
            if len(hex) != 32:
                raise ValueError('badly formed hexadecimal UUID string')
            int = int_(hex, 16)
        if bytes_le is not None:
            if len(bytes_le) != 16:
                raise ValueError('bytes_le is not a 16-char string')
            bytes = (bytes_le[3] + bytes_le[2] + bytes_le[1] + bytes_le[0] +
                     bytes_le[5] + bytes_le[4] + bytes_le[7] + bytes_le[6] +
                     bytes_le[8:])
        if bytes is not None:
            if len(bytes) != 16:
                raise ValueError('bytes is not a 16-char string')
            int = int_(('%02x'*16) % tuple(map(ord, bytes)), 16)
        if fields is not None:
            if len(fields) != 6:
                raise ValueError('fields is not a 6-tuple')
            (time_low, time_mid, time_hi_version,
             clock_seq_hi_variant, clock_seq_low, node) = fields
            if not 0 <= time_low < 1<<32:
                raise ValueError('field 1 out of range (need a 32-bit value)')
            if not 0 <= time_mid < 1<<16:
                raise ValueError('field 2 out of range (need a 16-bit value)')
            if not 0 <= time_hi_version < 1<<16:
                raise ValueError('field 3 out of range (need a 16-bit value)')
            if not 0 <= clock_seq_hi_variant < 1<<8:
                raise ValueError('field 4 out of range (need an 8-bit value)')
            if not 0 <= clock_seq_low < 1<<8:
                raise ValueError('field 5 out of range (need an 8-bit value)')
            if not 0 <= node < 1<<48:
                raise ValueError('field 6 out of range (need a 48-bit value)')
            clock_seq = (clock_seq_hi_variant << 8) | clock_seq_low
            int = ((time_low << 96) | (time_mid << 80) |
                   (time_hi_version << 64) | (clock_seq << 48) | node)
        if int is not None:
            if not 0 <= int < 1<<128:
                raise ValueError('int is out of range (need a 128-bit value)')
        if version is not None:
            if not 1 <= version <= 5:
                raise ValueError('illegal version number')
            # Set the variant to RFC 4122.
            int &= ~(0xc000 << 48)
            int |= 0x8000 << 48
            # Set the version number.
            int &= ~(0xf000 << 64)
            int |= version << 76
        self.__dict__['int'] = int

    def __eq__(self, other):
        if isinstance(other, UUID):
            return self.int == other.int
        return NotImplemented

    def __ne__(self, other):
        if isinstance(other, UUID):
            return self.int != other.int
        return NotImplemented

    # XXX What's the value of being able to sort UUIDs?

    def __lt__(self, other):
        if isinstance(other, UUID):
            return self.int < other.int
        return NotImplemented

    def __gt__(self, other):
        if isinstance(other, UUID):
            return self.int > other.int
        return NotImplemented

    def __le__(self, other):
        if isinstance(other, UUID):
            return self.int <= other.int
        return NotImplemented

    def __ge__(self, other):
        if isinstance(other, UUID):
            return self.int >= other.int
        return NotImplemented

    def __hash__(self):
        return hash(self.int)

    def __int__(self):
        return self.int

    def __repr__(self):
        return 'UUID(%r)' % str(self)

    def __setattr__(self, name, value):
        raise TypeError('UUID objects are immutable')

    def __str__(self):
        hex = '%032x' % self.int
        return '%s-%s-%s-%s-%s' % (
            hex[:8], hex[8:12], hex[12:16], hex[16:20], hex[20:])

    def get_bytes(self):
        bytes = ''
        for shift in range(0, 128, 8):
            bytes = chr((self.int >> shift) & 0xff) + bytes
        return bytes

    bytes = property(get_bytes)

    def get_bytes_le(self):
        bytes = self.bytes
        return (bytes[3] + bytes[2] + bytes[1] + bytes[0] +
                bytes[5] + bytes[4] + bytes[7] + bytes[6] + bytes[8:])

    bytes_le = property(get_bytes_le)

    def get_fields(self):
        return (self.time_low, self.time_mid, self.time_hi_version,
                self.clock_seq_hi_variant, self.clock_seq_low, self.node)

    fields = property(get_fields)

    def get_time_low(self):
        return self.int >> 96

    time_low = property(get_time_low)

    def get_time_mid(self):
        return (self.int >> 80) & 0xffff

    time_mid = property(get_time_mid)

    def get_time_hi_version(self):
        return (self.int >> 64) & 0xffff

    time_hi_version = property(get_time_hi_version)

    def get_clock_seq_hi_variant(self):
        return (self.int >> 56) & 0xff

    clock_seq_hi_variant = property(get_clock_seq_hi_variant)

    def get_clock_seq_low(self):
        return (self.int >> 48) & 0xff

    clock_seq_low = property(get_clock_seq_low)

    def get_time(self):
        return (((self.time_hi_version & 0x0fff) << 48) |
                (self.time_mid << 32) | self.time_low)

    time = property(get_time)

    def get_clock_seq(self):
        return (((self.clock_seq_hi_variant & 0x3f) << 8) |
                self.clock_seq_low)

    clock_seq = property(get_clock_seq)

    def get_node(self):
        return self.int & 0xffffffffffff

    node = property(get_node)

    def get_hex(self):
        return '%032x' % self.int

    hex = property(get_hex)

    def get_urn(self):
        return 'urn:uuid:' + str(self)

    urn = property(get_urn)

    def get_variant(self):
        if not self.int & (0x8000 << 48):
            return RESERVED_NCS
        elif not self.int & (0x4000 << 48):
            return RFC_4122
        elif not self.int & (0x2000 << 48):
            return RESERVED_MICROSOFT
        else:
            return RESERVED_FUTURE

    variant = property(get_variant)

    def get_version(self):
        # The version bits are only meaningful for RFC 4122 UUIDs.
        if self.variant == RFC_4122:
            return int((self.int >> 76) & 0xf)

    version = property(get_version)

def _find_mac(command, args, hw_identifiers, get_index):
    import os
    for dir in ['', '/sbin/', '/usr/sbin']:
        executable = os.path.join(dir, command)
        if not os.path.exists(executable):
            continue

        try:
            # LC_ALL to get English output, 2>/dev/null to
            # prevent output on stderr
            cmd = 'LC_ALL=C %s %s 2>/dev/null' % (executable, args)
            pipe = os.popen(cmd)
        except IOError:
            continue

        for line in pipe:
            words = line.lower().split()
            for i in range(len(words)):
                if words[i] in hw_identifiers:
                    return int(words[get_index(i)].replace(':', ''), 16)
    return None

def _ifconfig_getnode():
    """Get the hardware address on Unix by running ifconfig."""

    # This works on Linux ('' or '-a'), Tru64 ('-av'), but not all Unixes.
    for args in ('', '-a', '-av'):
        mac = _find_mac('ifconfig', args, ['hwaddr', 'ether'], lambda i: i+1)
        if mac:
            return mac

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

    # Try getting the MAC addr from arp based on our IP address (Solaris).
    mac = _find_mac('arp', '-an', [ip_addr], lambda i: -1)
    if mac:
        return mac

    # This might work on HP-UX.
    mac = _find_mac('lanscan', '-ai', ['lan0'], lambda i: 0)
    if mac:
        return mac

    return None

def _ipconfig_getnode():
    """Get the hardware address on Windows by running ipconfig.exe."""
    import os, re
    dirs = ['', r'c:\windows\system32', r'c:\winnt\system32']
    try:
        import ctypes
        buffer = ctypes.create_string_buffer(300)
        ctypes.windll.kernel32.GetSystemDirectoryA(buffer, 300)
        dirs.insert(0, buffer.value.decode('mbcs'))
    except:
        pass
    for dir in dirs:
        try:
            pipe = os.popen(os.path.join(dir, 'ipconfig') + ' /all')
        except IOError:
            continue
        for line in pipe:
            value = line.split(':')[-1].strip().lower()
            if re.match('([0-9a-f][0-9a-f]-){5}[0-9a-f][0-9a-f]', value):
                return int(value.replace('-', ''), 16)

def _netbios_getnode():
    """Get the hardware address on Windows using NetBIOS calls.
    See http://support.microsoft.com/kb/118623 for details."""
    import win32wnet, netbios
    ncb = netbios.NCB()
    ncb.Command = netbios.NCBENUM
    ncb.Buffer = adapters = netbios.LANA_ENUM()
    adapters._pack()
    if win32wnet.Netbios(ncb) != 0:
        return
    adapters._unpack()
    for i in range(adapters.length):
        ncb.Reset()
        ncb.Command = netbios.NCBRESET
        ncb.Lana_num = ord(adapters.lana[i])
        if win32wnet.Netbios(ncb) != 0:
            continue
        ncb.Reset()
        ncb.Command = netbios.NCBASTAT
        ncb.Lana_num = ord(adapters.lana[i])
        ncb.Callname = '*'.ljust(16)
        ncb.Buffer = status = netbios.ADAPTER_STATUS()
        if win32wnet.Netbios(ncb) != 0:
            continue
        status._unpack()
        bytes = map(ord, status.adapter_address)
        return ((bytes[0]<<40) + (bytes[1]<<32) + (bytes[2]<<24) +
                (bytes[3]<<16) + (bytes[4]<<8) + bytes[5])

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

# If ctypes is available, use it to find system routines for UUID generation.
_uuid_generate_random = _uuid_generate_time = _UuidCreate = None
try:
    import ctypes, ctypes.util
    _buffer = ctypes.create_string_buffer(16)

    # The uuid_generate_* routines are provided by libuuid on at least
    # Linux and FreeBSD, and provided by libc on Mac OS X.
    for libname in ['uuid', 'c']:
        try:
            lib = ctypes.CDLL(ctypes.util.find_library(libname))
        except:
            continue
        if hasattr(lib, 'uuid_generate_random'):
            _uuid_generate_random = lib.uuid_generate_random
        if hasattr(lib, 'uuid_generate_time'):
            _uuid_generate_time = lib.uuid_generate_time

    # On Windows prior to 2000, UuidCreate gives a UUID containing the
    # hardware address.  On Windows 2000 and later, UuidCreate makes a
    # random UUID and UuidCreateSequential gives a UUID containing the
    # hardware address.  These routines are provided by the RPC runtime.
    # NOTE:  at least on Tim's WinXP Pro SP2 desktop box, while the last
    # 6 bytes returned by UuidCreateSequential are fixed, they don't appear
    # to bear any relationship to the MAC address of any network device
    # on the box.
    try:
        lib = ctypes.windll.rpcrt4
    except:
        lib = None
    _UuidCreate = getattr(lib, 'UuidCreateSequential',
                          getattr(lib, 'UuidCreate', None))
except:
    pass

def _unixdll_getnode():
    """Get the hardware address on Unix using ctypes."""
    _uuid_generate_time(_buffer)
    return UUID(bytes=_buffer.raw).node

def _windll_getnode():
    """Get the hardware address on Windows using ctypes."""
    if _UuidCreate(_buffer) == 0:
        return UUID(bytes=_buffer.raw).node

def _random_getnode():
    """Get a random node ID, with eighth bit set as suggested by RFC 4122."""
    import random
    return random.randrange(0, 1<<48) | 0x010000000000

_node = None

def getnode():
    """Get the hardware address as a 48-bit positive integer.

    The first time this runs, it may launch a separate program, which could
    be quite slow.  If all attempts to obtain the hardware address fail, we
    choose a random 48-bit number with its eighth bit set to 1 as recommended
    in RFC 4122.
    """

    global _node
    if _node is not None:
        return _node

    import sys
    if sys.platform == 'win32':
        getters = [_windll_getnode, _netbios_getnode, _ipconfig_getnode]
    else:
        getters = [_unixdll_getnode, _ifconfig_getnode]

    for getter in getters + [_random_getnode]:
        try:
            _node = getter()
        except:
            continue
        if _node is not None:
            return _node

_last_timestamp = None

def uuid1(node=None, clock_seq=None):
    """Generate a UUID from a host ID, sequence number, and the current time.
    If 'node' is not given, getnode() is used to obtain the hardware
    address.  If 'clock_seq' is given, it is used as the sequence number;
    otherwise a random 14-bit sequence number is chosen."""

    # When the system provides a version-1 UUID generator, use it (but don't
    # use UuidCreate here because its UUIDs don't conform to RFC 4122).
    if _uuid_generate_time and node is clock_seq is None:
        _uuid_generate_time(_buffer)
        return UUID(bytes=_buffer.raw)

    global _last_timestamp
    import time
    nanoseconds = int(time.time() * 1e9)
    # 0x01b21dd213814000 is the number of 100-ns intervals between the
    # UUID epoch 1582-10-15 00:00:00 and the Unix epoch 1970-01-01 00:00:00.
    timestamp = int(nanoseconds/100) + 0x01b21dd213814000
    if _last_timestamp is not None and timestamp <= _last_timestamp:
        timestamp = _last_timestamp + 1
    _last_timestamp = timestamp
    if clock_seq is None:
        import random
        clock_seq = random.randrange(1<<14) # instead of stable storage
    time_low = timestamp & 0xffffffff
    time_mid = (timestamp >> 32) & 0xffff
    time_hi_version = (timestamp >> 48) & 0x0fff
    clock_seq_low = clock_seq & 0xff
    clock_seq_hi_variant = (clock_seq >> 8) & 0x3f
    if node is None:
        node = getnode()
    return UUID(fields=(time_low, time_mid, time_hi_version,
                        clock_seq_hi_variant, clock_seq_low, node), version=1)

def uuid3(namespace, name):
    """Generate a UUID from the MD5 hash of a namespace UUID and a name."""
    import hashlib
    hash = hashlib.md5(namespace.bytes + name).digest()
    return UUID(bytes=hash[:16], version=3)

def uuid4():
    """Generate a random UUID."""

    # When the system provides a version-4 UUID generator, use it.
    if _uuid_generate_random:
        _uuid_generate_random(_buffer)
        return UUID(bytes=_buffer.raw)

    # Otherwise, get randomness from urandom or the 'random' module.
    try:
        import os
        return UUID(bytes=os.urandom(16), version=4)
    except:
        import random
        bytes = [chr(random.randrange(256)) for i in range(16)]
        return UUID(bytes=bytes, version=4)

def uuid5(namespace, name):
    """Generate a UUID from the SHA-1 hash of a namespace UUID and a name."""
    import sha
    hash = sha.sha(namespace.bytes + name).digest()
    return UUID(bytes=hash[:16], version=5)

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

NAMESPACE_DNS = UUID('6ba7b810-9dad-11d1-80b4-00c04fd430c8')
NAMESPACE_URL = UUID('6ba7b811-9dad-11d1-80b4-00c04fd430c8')
NAMESPACE_OID = UUID('6ba7b812-9dad-11d1-80b4-00c04fd430c8')
NAMESPACE_X500 = UUID('6ba7b814-9dad-11d1-80b4-00c04fd430c8')