aboutsummaryrefslogtreecommitdiff
path: root/cryptech/libhal.py
blob: 102e663e46c2bd8596d1bc9c5d8a8e27d0b58fb1 (plain) (blame)
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
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
# Copyright (c) 2016, NORDUnet A/S
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions are
# met:
# - Redistributions of source code must retain the above copyright notice,
#   this list of conditions and the following disclaimer.
#
# - Redistributions in binary form must reproduce the above copyright
#   notice, this list of conditions and the following disclaimer in the
#   documentation and/or other materials provided with the distribution.
#
# - Neither the name of the NORDUnet nor the names of its contributors may
#   be used to endorse or promote products derived from this software
#   without specific prior written permission.
#
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
# IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
# TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
# PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
# HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
# TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
# PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
# LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
# NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
# SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

"""
A Python interface to the Cryptech libhal RPC API.
"""

# A lot of this is hand-generated XDR data structure encoding.  If and
# when we ever convert the C library to use data structures processed
# by rpcgen, we may want to rewrite this code to use the output of
# something like https://github.com/floodlight/xdr.git -- in either
# case the generated code would just be for the data structures, we're
# not likely to want to use the full ONC RPC mechanism.

import os
import sys
import uuid
import xdrlib
import socket
import logging
import binascii

logger = logging.getLogger(__name__)

if sys.version_info.major == 2:
    def colon_hex(raw):
        return ":".join("{:02x}".format(ord(b)) for b in raw)
else:
    def colon_hex(raw):
        return ":".join("{:02x}".format(b) for b in raw)


SLIP_END     = b"\300"          # indicates end of packet
SLIP_ESC     = b"\333"          # indicates byte stuffing
SLIP_ESC_END = b"\334"          # ESC ESC_END means END data byte
SLIP_ESC_ESC = b"\335"          # ESC ESC_ESC means ESC data byte


def slip_encode(buffer):
    return SLIP_END + buffer.replace(SLIP_ESC, SLIP_ESC + SLIP_ESC_ESC).replace(SLIP_END, SLIP_ESC + SLIP_ESC_END) + SLIP_END

def slip_decode(buffer):
    return buffer.strip(SLIP_END).replace(SLIP_ESC + SLIP_ESC_END, SLIP_END).replace(SLIP_ESC + SLIP_ESC_ESC, SLIP_ESC)


HAL_OK = 0

class HALError(Exception):
    "LibHAL error"

    table = [None]

    @classmethod
    def define(cls, **kw):
        assert len(kw) == 1
        name, text = list(kw.items())[0]
        e = type(name, (cls,), dict(__doc__ = text))
        cls.table.append(e)
        globals()[name] = e

HALError.define(HAL_ERROR_BAD_ARGUMENTS             = "Bad arguments given")
HALError.define(HAL_ERROR_UNSUPPORTED_KEY           = "Unsupported key type or key length")
HALError.define(HAL_ERROR_IO_SETUP_FAILED           = "Could not set up I/O with FPGA")
HALError.define(HAL_ERROR_IO_TIMEOUT                = "I/O with FPGA timed out")
HALError.define(HAL_ERROR_IO_UNEXPECTED             = "Unexpected response from FPGA")
HALError.define(HAL_ERROR_IO_OS_ERROR               = "Operating system error talking to FPGA")
HALError.define(HAL_ERROR_IO_BAD_COUNT              = "Bad byte count")
HALError.define(HAL_ERROR_CSPRNG_BROKEN             = "CSPRNG is returning nonsense")
HALError.define(HAL_ERROR_KEYWRAP_BAD_MAGIC         = "Bad magic number while unwrapping key")
HALError.define(HAL_ERROR_KEYWRAP_BAD_LENGTH        = "Length out of range while unwrapping key")
HALError.define(HAL_ERROR_KEYWRAP_BAD_PADDING       = "Non-zero padding detected unwrapping key")
HALError.define(HAL_ERROR_IMPOSSIBLE                = "\"Impossible\" error")
HALError.define(HAL_ERROR_ALLOCATION_FAILURE        = "Memory allocation failed")
HALError.define(HAL_ERROR_RESULT_TOO_LONG           = "Result too long for buffer")
HALError.define(HAL_ERROR_ASN1_PARSE_FAILED         = "ASN.1 parse failed")
HALError.define(HAL_ERROR_KEY_NOT_ON_CURVE          = "EC key is not on its purported curve")
HALError.define(HAL_ERROR_INVALID_SIGNATURE         = "Invalid signature")
HALError.define(HAL_ERROR_CORE_NOT_FOUND            = "Requested core not found")
HALError.define(HAL_ERROR_CORE_BUSY                 = "Requested core busy")
HALError.define(HAL_ERROR_KEYSTORE_ACCESS           = "Could not access keystore")
HALError.define(HAL_ERROR_KEY_NOT_FOUND             = "Key not found")
HALError.define(HAL_ERROR_KEY_NAME_IN_USE           = "Key name in use")
HALError.define(HAL_ERROR_NO_KEY_SLOTS_AVAILABLE    = "No key slots available")
HALError.define(HAL_ERROR_PIN_INCORRECT             = "PIN incorrect")
HALError.define(HAL_ERROR_NO_CLIENT_SLOTS_AVAILABLE = "No client slots available")
HALError.define(HAL_ERROR_FORBIDDEN                 = "Forbidden")
HALError.define(HAL_ERROR_XDR_BUFFER_OVERFLOW       = "XDR buffer overflow")
HALError.define(HAL_ERROR_RPC_TRANSPORT             = "RPC transport error")
HALError.define(HAL_ERROR_RPC_PACKET_OVERFLOW       = "RPC packet overflow")
HALError.define(HAL_ERROR_RPC_BAD_FUNCTION          = "Bad RPC function number")
HALError.define(HAL_ERROR_KEY_NAME_TOO_LONG         = "Key name too long")
HALError.define(HAL_ERROR_MASTERKEY_NOT_SET         = "Master key (Key Encryption Key) not set")
HALError.define(HAL_ERROR_MASTERKEY_FAIL            = "Master key generic failure")
HALError.define(HAL_ERROR_MASTERKEY_BAD_LENGTH      = "Master key of unacceptable length")
HALError.define(HAL_ERROR_KS_DRIVER_NOT_FOUND       = "Keystore driver not found")
HALError.define(HAL_ERROR_KEYSTORE_BAD_CRC          = "Bad CRC in keystore")
HALError.define(HAL_ERROR_KEYSTORE_BAD_BLOCK_TYPE   = "Unsupported keystore block type")
HALError.define(HAL_ERROR_KEYSTORE_LOST_DATA        = "Keystore appears to have lost data")
HALError.define(HAL_ERROR_BAD_ATTRIBUTE_LENGTH      = "Bad attribute length")
HALError.define(HAL_ERROR_ATTRIBUTE_NOT_FOUND       = "Attribute not found")
HALError.define(HAL_ERROR_NO_KEY_INDEX_SLOTS        = "No key index slots available")
HALError.define(HAL_ERROR_KS_INDEX_UUID_MISORDERED  = "Key index UUID misordered")
HALError.define(HAL_ERROR_KEYSTORE_WRONG_BLOCK_TYPE = "Wrong block type in keystore")
HALError.define(HAL_ERROR_RPC_PROTOCOL_ERROR        = "RPC protocol error")
HALError.define(HAL_ERROR_NOT_IMPLEMENTED           = "Not implemented")


# When we finally drop Python 2 support, this class should probably be
# replaced by enum.IntEnum from the Python 3 standard library.

class CEnum(int):

    def __new__(cls, name, value):
        self = int.__new__(cls, value)
        self._name = name
        setattr(self.__class__, name, self)
        return self

    def __str__(self):
        return self._name

    def __repr__(self):
        return "<CEnum:{0.__class__.__name__} {0._name}:{0:d}>".format(self)

    _counter = 0

    @classmethod
    def define(cls, names):
        symbols = []
        for name in names.split(","):
            if "=" in name:
                name, sep, expr = name.partition("=")
                cls._counter = eval(expr.strip())
            if not isinstance(cls._counter, int):
                raise TypeError
            symbols.append(cls(name.strip(), cls._counter))
            cls._counter += 1
        cls.index = dict((int(symbol),  symbol) for symbol in symbols)
        globals().update((symbol._name, symbol) for symbol in symbols)

    def xdr_packer(self, packer):
        packer.pack_uint(self)


class RPCFunc(CEnum): pass

RPCFunc.define('''
    RPC_FUNC_GET_VERSION,
    RPC_FUNC_GET_RANDOM,
    RPC_FUNC_SET_PIN,
    RPC_FUNC_LOGIN,
    RPC_FUNC_LOGOUT,
    RPC_FUNC_LOGOUT_ALL,
    RPC_FUNC_IS_LOGGED_IN,
    RPC_FUNC_HASH_GET_DIGEST_LEN,
    RPC_FUNC_HASH_GET_DIGEST_ALGORITHM_ID,
    RPC_FUNC_HASH_GET_ALGORITHM,
    RPC_FUNC_HASH_INITIALIZE,
    RPC_FUNC_HASH_UPDATE,
    RPC_FUNC_HASH_FINALIZE,
    RPC_FUNC_PKEY_LOAD,
    RPC_FUNC_PKEY_OPEN,
    RPC_FUNC_PKEY_GENERATE_RSA,
    RPC_FUNC_PKEY_GENERATE_EC,
    RPC_FUNC_PKEY_CLOSE,
    RPC_FUNC_PKEY_DELETE,
    RPC_FUNC_PKEY_GET_KEY_TYPE,
    RPC_FUNC_PKEY_GET_KEY_FLAGS,
    RPC_FUNC_PKEY_GET_PUBLIC_KEY_LEN,
    RPC_FUNC_PKEY_GET_PUBLIC_KEY,
    RPC_FUNC_PKEY_SIGN,
    RPC_FUNC_PKEY_VERIFY,
    RPC_FUNC_PKEY_MATCH,
    RPC_FUNC_PKEY_GET_KEY_CURVE,
    RPC_FUNC_PKEY_SET_ATTRIBUTES,
    RPC_FUNC_PKEY_GET_ATTRIBUTES,
    RPC_FUNC_PKEY_EXPORT,
    RPC_FUNC_PKEY_IMPORT,
    RPC_FUNC_PKEY_GENERATE_HASHSIG,
''')

class HALDigestAlgorithm(CEnum): pass

HALDigestAlgorithm.define('''
    HAL_DIGEST_ALGORITHM_NONE,
    HAL_DIGEST_ALGORITHM_SHA1,
    HAL_DIGEST_ALGORITHM_SHA224,
    HAL_DIGEST_ALGORITHM_SHA256,
    HAL_DIGEST_ALGORITHM_SHA512_224,
    HAL_DIGEST_ALGORITHM_SHA512_256,
    HAL_DIGEST_ALGORITHM_SHA384,
    HAL_DIGEST_ALGORITHM_SHA512
''')

class HALKeyType(CEnum): pass

HALKeyType.define('''
    HAL_KEY_TYPE_NONE,
    HAL_KEY_TYPE_RSA_PRIVATE,
    HAL_KEY_TYPE_RSA_PUBLIC,
    HAL_KEY_TYPE_EC_PRIVATE,
    HAL_KEY_TYPE_EC_PUBLIC,
    HAL_KEY_TYPE_HASHSIG_PRIVATE,
    HAL_KEY_TYPE_HASHSIG_PUBLIC,
    HAL_KEY_TYPE_HASHSIG_LMS,
    HAL_KEY_TYPE_HASHSIG_LMOTS
''')

class HALCurve(CEnum): pass

HALCurve.define('''
    HAL_CURVE_NONE,
    HAL_CURVE_P256,
    HAL_CURVE_P384,
    HAL_CURVE_P521
''')

class HALUser(CEnum): pass

HALUser.define('''
    HAL_USER_NONE,
    HAL_USER_NORMAL,
    HAL_USER_SO,
    HAL_USER_WHEEL
''')

class HALLmotsAlgorithm(CEnum): pass

HALLmotsAlgorithm.define('''
    HAL_LMOTS_RESERVED      = 0,
    HAL_LMOTS_SHA256_N32_W1 = 1,
    HAL_LMOTS_SHA256_N32_W2 = 2,
    HAL_LMOTS_SHA256_N32_W4 = 3,
    HAL_LMOTS_SHA256_N32_W8 = 4
''')

class HALLmsAlgorithm(CEnum): pass

HALLmsAlgorithm.define('''
    HAL_LMS_RESERVED        = 0,
    HAL_LMS_SHA256_N32_H5   = 5,
    HAL_LMS_SHA256_N32_H10  = 6,
    HAL_LMS_SHA256_N32_H15  = 7,
    HAL_LMS_SHA256_N32_H20  = 8,
    HAL_LMS_SHA256_N32_H25  = 9
''')


HAL_KEY_FLAG_USAGE_DIGITALSIGNATURE     = (1 << 0)
HAL_KEY_FLAG_USAGE_KEYENCIPHERMENT      = (1 << 1)
HAL_KEY_FLAG_USAGE_DATAENCIPHERMENT     = (1 << 2)
HAL_KEY_FLAG_TOKEN                      = (1 << 3)
HAL_KEY_FLAG_PUBLIC                     = (1 << 4)
HAL_KEY_FLAG_EXPORTABLE                 = (1 << 5)

HAL_PKEY_ATTRIBUTE_NIL                  = (0xFFFFFFFF)


class UUID(uuid.UUID):

    def xdr_packer(self, packer):
        packer.pack_bytes(self.bytes)


def cached_property(func):

    attr_name = "_" + func.__name__

    def wrapped(self):
        try:
            value = getattr(self, attr_name)
        except AttributeError:
            value = func(self)
            setattr(self, attr_name, value)
        return value

    wrapped.__name__ = func.__name__

    return property(wrapped)


class Handle(object):

    def __int__(self):
        return self.handle

    def __cmp__(self, other):
        return cmp(self.handle, int(other))

    def xdr_packer(self, packer):
        packer.pack_uint(self.handle)


class Digest(Handle):

    def __init__(self, hsm, handle, algorithm):
        self.hsm       = hsm
        self.handle    = handle
        self.algorithm = algorithm

    def update(self, data):
        self.hsm.hash_update(self, data)

    def finalize(self, length = None):
        return self.hsm.hash_finalize(self, length or self.digest_length)

    @cached_property
    def algorithm_id(self):
        return self.hsm.hash_get_digest_algorithm_id(self.algorithm)

    @cached_property
    def digest_length(self):
        return self.hsm.hash_get_digest_length(self.algorithm)


class LocalDigest(object):
    """
    Implements same interface as Digest class, but using PyCrypto, to
    support mixed-mode PKey operations.  This only supports algorithms
    that PyCrypto supports, so no SHA512/224 or SHA512/256, sorry.
    """

    def __init__(self, hsm, handle, algorithm, key):
        from Crypto.Hash import HMAC, SHA, SHA224, SHA256, SHA384, SHA512
        from struct import pack
        self.hsm       = hsm
        self.handle    = handle
        self.algorithm = algorithm
        try:
            h = self._algorithms[algorithm]
        except AttributeError:
            self._algorithms = {
                HAL_DIGEST_ALGORITHM_SHA1   : SHA.SHA1Hash,
                HAL_DIGEST_ALGORITHM_SHA224 : SHA224.SHA224Hash,
                HAL_DIGEST_ALGORITHM_SHA256 : SHA256.SHA256Hash,
                HAL_DIGEST_ALGORITHM_SHA384 : SHA384.SHA384Hash,
                HAL_DIGEST_ALGORITHM_SHA512 : SHA512.SHA512Hash
            }
            h = self._algorithms[algorithm]
        self.digest_length = h.digest_size
        self.algorithm_id  = pack("BB", 0x30, 2 + len(h.oid)) + h.oid
        self._context = HMAC.HMAC(key = key, digestmod = h) if key else h()

    def update(self, data):
        self._context.update(data)

    def finalize(self, length = None):
        return self._context.digest()

    def finalize_padded(self, pkey):
        if pkey.key_type not in (HAL_KEY_TYPE_RSA_PRIVATE, HAL_KEY_TYPE_RSA_PUBLIC):
            return self.finalize()
        # PKCS #1.5 requires the digest to be wrapped up in an ASN.1 DigestInfo object.
        from Crypto.Util.asn1 import DerSequence, DerNull, DerOctetString
        return DerSequence([DerSequence([self._context.oid, DerNull().encode()]).encode(),
                            DerOctetString(self.finalize()).encode()]).encode()


class PKey(Handle):

    def __init__(self, hsm, handle, uuid):
        self.hsm     = hsm
        self.handle  = handle
        self.uuid    = uuid
        self.deleted = False

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        if not self.deleted:
            self.close()

    def close(self):
        self.hsm.pkey_close(self)

    def delete(self):
        self.hsm.pkey_delete(self)
        self.deleted = True

    @cached_property
    def key_type(self):
        return self.hsm.pkey_get_key_type(self)

    @cached_property
    def key_curve(self):
        return self.hsm.pkey_get_key_curve(self)

    @cached_property
    def key_flags(self):
        return self.hsm.pkey_get_key_flags(self)

    @cached_property
    def public_key_len(self):
        return self.hsm.pkey_get_public_key_len(self)

    @cached_property
    def public_key(self):
        return self.hsm.pkey_get_public_key(self, self.public_key_len)

    def sign(self, hash = 0, data = b"", length = 1024):
        return self.hsm.pkey_sign(self, hash = hash, data = data, length = length)

    def verify(self, hash = 0, data = b"", signature = None):
        self.hsm.pkey_verify(self, hash = hash, data = data, signature = signature)

    def set_attributes(self, attributes = None, **kwargs):
        assert attributes is None or not kwargs
        self.hsm.pkey_set_attributes(self, attributes or kwargs)

    def get_attributes(self, attributes):
        attrs = self.hsm.pkey_get_attributes(self, attributes, 0)
        attrs = dict((k, v) for k, v in attrs.items() if v != HAL_PKEY_ATTRIBUTE_NIL)
        result = dict((a, None) for a in attributes)
        result.update(self.hsm.pkey_get_attributes(self, iter(attrs.keys()), sum(attrs.values())))
        return result

    def export_pkey(self, pkey):
        return self.hsm.pkey_export(pkey = pkey, kekek = self, pkcs8_max = 5480, kek_max = 512)

    def import_pkey(self, pkcs8, kek, flags = 0):
        return self.hsm.pkey_import(kekek = self, pkcs8 = pkcs8, kek = kek, flags = flags)

class ContextManagedUnpacker(xdrlib.Unpacker):

    def __enter__(self):
        return self

    def __exit__(self, exc_type, exc_val, exc_tb):
        self.done()


class HSM(object):

    mixed_mode = False
    debug_io = False

    def _raise_if_error(self, status):
        if status != 0:
            raise HALError.table[status]()

    def __init__(self, sockname = os.getenv("CRYPTECH_RPC_CLIENT_SOCKET_NAME",
                                            "/tmp/.cryptech_muxd.rpc")):
        self.socket = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
        self.socket.connect(sockname)
        self.sockfile = self.socket.makefile("rb")

    def _send(self, msg):       # Expects an xdrlib.Packer
        msg = slip_encode(msg.get_buffer())
        if self.debug_io:
            logger.debug("send: %s", colon_hex(msg))
        self.socket.sendall(msg)

    def _recv(self, code):      # Returns a ContextManagedUnpacker
        closed = False
        while True:
            msg = [self.sockfile.read(1)]
            while msg[-1] != SLIP_END:
                if msg[-1] == b"":
                    raise HAL_ERROR_RPC_TRANSPORT()
                msg.append(self.sockfile.read(1))
            if self.debug_io:
                logger.debug("recv: %s", colon_hex(msg))
            msg = slip_decode(b"".join(msg))
            if not msg:
                continue
            msg = ContextManagedUnpacker(msg)
            if msg.unpack_uint() != code:
                continue
            return msg

    _pack_builtin = ((int,                "_pack_uint"),
                     (bytes,              "_pack_bytes"),
                     (str,                "_pack_str"),
                     ((list, tuple, set), "_pack_array"),
                     (dict,               "_pack_items"))

    try:
        _pack_builtin += ((long, "_pack_uint"),)
    except NameError:           # "long" merged with "int" in Python 3
        pass

    def _pack_arg(self, packer, arg):
        if hasattr(arg, "xdr_packer"):
            return arg.xdr_packer(packer)
        for cls, method in self._pack_builtin:
            if isinstance(arg, cls):
                return getattr(self, method)(packer, arg)
        raise RuntimeError("Don't know how to pack {!r} ({!r})".format(arg, type(arg)))

    def _pack_args(self, packer, args):
        for arg in args:
            self._pack_arg(packer, arg)

    def _pack_uint(self, packer, arg):
        packer.pack_uint(arg)

    def _pack_bytes(self, packer, arg):
        packer.pack_bytes(arg)

    def _pack_str(self, packer, arg):
        packer.pack_bytes(arg.encode())

    def _pack_array(self, packer, arg):
        packer.pack_uint(len(arg))
        self._pack_args(packer, arg)

    def _pack_items(self, packer, arg):
        packer.pack_uint(len(arg))
        for name, value in arg.items():
            self._pack_arg(packer, name)
            self._pack_arg(packer, HAL_PKEY_ATTRIBUTE_NIL if value is None else value)

    def rpc(self, code, *args, **kwargs):
        client = kwargs.get("client", 0)
        packer = xdrlib.Packer()
        packer.pack_uint(code)
        packer.pack_uint(client)
        self._pack_args(packer, args)
        self._send(packer)
        unpacker = self._recv(code)
        client = unpacker.unpack_uint()
        self._raise_if_error(unpacker.unpack_uint())
        return unpacker

    def get_version(self):
        with self.rpc(RPC_FUNC_GET_VERSION) as r:
            return r.unpack_uint()

    def get_random(self, n):
        with self.rpc(RPC_FUNC_GET_RANDOM, n) as r:
            return r.unpack_bytes()

    def set_pin(self, user, pin, client = 0):
        with self.rpc(RPC_FUNC_SET_PIN, user, pin, client = client):
            return

    def login(self, user, pin, client = 0):
        with self.rpc(RPC_FUNC_LOGIN, user, pin, client = client):
            return

    def logout(self, client = 0):
        with self.rpc(RPC_FUNC_LOGOUT, client = client):
            return

    def logout_all(self):
        with self.rpc(RPC_FUNC_LOGOUT_ALL):
            return

    def is_logged_in(self, user, client = 0):
        with self.rpc(RPC_FUNC_IS_LOGGED_IN, user, client = client):
            return

    def hash_get_digest_length(self, alg):
        with self.rpc(RPC_FUNC_HASH_GET_DIGEST_LEN, alg) as r:
            return r.unpack_uint()

    def hash_get_digest_algorithm_id(self, alg, max_len = 256):
        with self.rpc(RPC_FUNC_HASH_GET_DIGEST_ALGORITHM_ID, alg, max_len) as r:
            return r.unpack_bytes()

    def hash_get_algorithm(self, handle):
        with self.rpc(RPC_FUNC_HASH_GET_ALGORITHM, handle) as r:
            return HALDigestAlgorithm.index[r.unpack_uint()]

    def hash_initialize(self, alg, key = None, client = 0, session = 0, mixed_mode = None):
        if key is None:
            key = b""
        if mixed_mode is None:
            mixed_mode = self.mixed_mode
        if mixed_mode:
            return LocalDigest(self, 0, alg, key)
        else:
            with self.rpc(RPC_FUNC_HASH_INITIALIZE, session, alg, key, client = client) as r:
                return Digest(self, r.unpack_uint(), alg)

    def hash_update(self, handle, data):
        with self.rpc(RPC_FUNC_HASH_UPDATE, handle, data):
            return

    def hash_finalize(self, handle, length = None):
        if length is None:
            length = self.hash_get_digest_length(self.hash_get_algorithm(handle))
        with self.rpc(RPC_FUNC_HASH_FINALIZE, handle, length) as r:
            return r.unpack_bytes()

    def pkey_load(self, der, flags = 0, client = 0, session = 0):
        with self.rpc(RPC_FUNC_PKEY_LOAD, session, der, flags, client = client) as r:
            pkey = PKey(self, r.unpack_uint(), UUID(bytes = r.unpack_bytes()))
            logger.debug("Loaded pkey %s", pkey.uuid)
            return pkey

    def pkey_open(self, uuid, client = 0, session = 0):
        with self.rpc(RPC_FUNC_PKEY_OPEN, session, uuid, client = client) as r:
            pkey = PKey(self, r.unpack_uint(), uuid)
            logger.debug("Opened pkey %s", pkey.uuid)
            return pkey

    def pkey_generate_rsa(self, keylen, flags = 0, exponent = b"\x01\x00\x01", client = 0, session = 0):
        with self.rpc(RPC_FUNC_PKEY_GENERATE_RSA, session, keylen, exponent, flags, client = client) as r:
            pkey = PKey(self, r.unpack_uint(), UUID(bytes = r.unpack_bytes()))
            logger.debug("Generated RSA pkey %s", pkey.uuid)
            return pkey

    def pkey_generate_ec(self, curve, flags = 0, client = 0, session = 0):
        with self.rpc(RPC_FUNC_PKEY_GENERATE_EC, session, curve, flags, client = client) as r:
            pkey = PKey(self, r.unpack_uint(), UUID(bytes = r.unpack_bytes()))
            logger.debug("Generated EC pkey %s", pkey.uuid)
            return pkey

    def pkey_generate_hashsig(self, L, lms, lmots, flags = 0, client = 0, session = 0):
        with self.rpc(RPC_FUNC_PKEY_GENERATE_HASHSIG, session, L, lms, lmots, flags, client = client) as r:
            pkey = PKey(self, r.unpack_uint(), UUID(bytes = r.unpack_bytes()))
            logger.debug("Generated hashsig pkey %s", pkey.uuid)
            return pkey

    def pkey_close(self, pkey):
        try:
            logger.debug("Closing pkey %s", pkey.uuid)
        except AttributeError:
            pass
        with self.rpc(RPC_FUNC_PKEY_CLOSE, pkey):
            return

    def pkey_delete(self, pkey):
        try:
            logger.debug("Deleting pkey %s", pkey.uuid)
        except AttributeError:
            pass
        with self.rpc(RPC_FUNC_PKEY_DELETE, pkey):
            return

    def pkey_get_key_type(self, pkey):
        with self.rpc(RPC_FUNC_PKEY_GET_KEY_TYPE, pkey) as r:
            return HALKeyType.index[r.unpack_uint()]

    def pkey_get_key_curve(self, pkey):
        with self.rpc(RPC_FUNC_PKEY_GET_KEY_CURVE, pkey) as r:
            return HALCurve.index[r.unpack_uint()]

    def pkey_get_key_flags(self, pkey):
        with self.rpc(RPC_FUNC_PKEY_GET_KEY_FLAGS, pkey) as r:
            return r.unpack_uint()

    def pkey_get_public_key_len(self, pkey):
        with self.rpc(RPC_FUNC_PKEY_GET_PUBLIC_KEY_LEN, pkey) as r:
            return r.unpack_uint()

    def pkey_get_public_key(self, pkey, length = None):
        if length is None:
            length = self.pkey_get_public_key_len(pkey)
        with self.rpc(RPC_FUNC_PKEY_GET_PUBLIC_KEY, pkey, length) as r:
            return r.unpack_bytes()

    def pkey_sign(self, pkey, hash = 0, data = b"", length = 1024):
        assert not hash or not data
        if isinstance(hash, LocalDigest):
            hash, data = 0, hash.finalize_padded(pkey)
        with self.rpc(RPC_FUNC_PKEY_SIGN, pkey, hash, data, length) as r:
            return r.unpack_bytes()

    def pkey_verify(self, pkey, hash = 0, data = b"", signature = None):
        assert not hash or not data
        if isinstance(hash, LocalDigest):
            hash, data = 0, hash.finalize_padded(pkey)
        with self.rpc(RPC_FUNC_PKEY_VERIFY, pkey, hash, data, signature):
            return

    def pkey_match(self, type = 0, curve = 0, mask = 0, flags = 0,
                   attributes = {}, length = 64, client = 0, session = 0):
        u = UUID(int = 0)
        n = length
        s = 0
        while n == length:
            r = self.rpc(RPC_FUNC_PKEY_MATCH, session, type, curve, mask, flags,
                         attributes, s, length, u, client = client)
            s = r.unpack_uint()
            n = r.unpack_uint()
            for i in range(n):
                u = UUID(bytes = r.unpack_bytes())
                yield u
            r.done()

    def pkey_set_attributes(self, pkey, attributes):
        with self.rpc(RPC_FUNC_PKEY_SET_ATTRIBUTES, pkey, attributes):
            return

    def pkey_get_attributes(self, pkey, attributes, attributes_buffer_len = 2048):
        attributes = tuple(attributes)
        with self.rpc(RPC_FUNC_PKEY_GET_ATTRIBUTES, pkey, attributes, attributes_buffer_len) as r:
            n = r.unpack_uint()
            if n != len(attributes):
                raise HAL_ERROR_RPC_PROTOCOL_ERROR
            if attributes_buffer_len > 0:
                return dict((r.unpack_uint(), r.unpack_bytes()) for i in range(n))
            else:
                return dict((r.unpack_uint(), r.unpack_uint()) for i in range(n))

    def pkey_export(self, pkey, kekek, pkcs8_max = 2560, kek_max = 512):
        with self.rpc(RPC_FUNC_PKEY_EXPORT, pkey, kekek, pkcs8_max, kek_max) as r:
            pkcs8, kek = r.unpack_bytes(), r.unpack_bytes()
            logger.debug("Exported pkey %s", pkey.uuid)
            return pkcs8, kek

    def pkey_import(self, kekek, pkcs8, kek, flags = 0, client = 0, session = 0):
        with self.rpc(RPC_FUNC_PKEY_IMPORT, session, kekek, pkcs8, kek, flags, client = client) as r:
            pkey = PKey(self, r.unpack_uint(), UUID(bytes = r.unpack_bytes()))
            logger.debug("Imported pkey %s", pkey.uuid)
            return pkey