Merge tag 'block-6.1-2022-10-20' of git://git.kernel.dk/linux
[linux-block.git] / tools / testing / selftests / tpm2 / tpm2.py
1 # SPDX-License-Identifier: (GPL-2.0 OR BSD-3-Clause)
2
3 import hashlib
4 import os
5 import socket
6 import struct
7 import sys
8 import unittest
9 import fcntl
10 import select
11
12 TPM2_ST_NO_SESSIONS = 0x8001
13 TPM2_ST_SESSIONS = 0x8002
14
15 TPM2_CC_FIRST = 0x01FF
16
17 TPM2_CC_CREATE_PRIMARY = 0x0131
18 TPM2_CC_DICTIONARY_ATTACK_LOCK_RESET = 0x0139
19 TPM2_CC_CREATE = 0x0153
20 TPM2_CC_LOAD = 0x0157
21 TPM2_CC_UNSEAL = 0x015E
22 TPM2_CC_FLUSH_CONTEXT = 0x0165
23 TPM2_CC_START_AUTH_SESSION = 0x0176
24 TPM2_CC_GET_CAPABILITY  = 0x017A
25 TPM2_CC_GET_RANDOM = 0x017B
26 TPM2_CC_PCR_READ = 0x017E
27 TPM2_CC_POLICY_PCR = 0x017F
28 TPM2_CC_PCR_EXTEND = 0x0182
29 TPM2_CC_POLICY_PASSWORD = 0x018C
30 TPM2_CC_POLICY_GET_DIGEST = 0x0189
31
32 TPM2_SE_POLICY = 0x01
33 TPM2_SE_TRIAL = 0x03
34
35 TPM2_ALG_RSA = 0x0001
36 TPM2_ALG_SHA1 = 0x0004
37 TPM2_ALG_AES = 0x0006
38 TPM2_ALG_KEYEDHASH = 0x0008
39 TPM2_ALG_SHA256 = 0x000B
40 TPM2_ALG_NULL = 0x0010
41 TPM2_ALG_CBC = 0x0042
42 TPM2_ALG_CFB = 0x0043
43
44 TPM2_RH_OWNER = 0x40000001
45 TPM2_RH_NULL = 0x40000007
46 TPM2_RH_LOCKOUT = 0x4000000A
47 TPM2_RS_PW = 0x40000009
48
49 TPM2_RC_SIZE            = 0x01D5
50 TPM2_RC_AUTH_FAIL       = 0x098E
51 TPM2_RC_POLICY_FAIL     = 0x099D
52 TPM2_RC_COMMAND_CODE    = 0x0143
53
54 TSS2_RC_LAYER_SHIFT = 16
55 TSS2_RESMGR_TPM_RC_LAYER = (11 << TSS2_RC_LAYER_SHIFT)
56
57 TPM2_CAP_HANDLES = 0x00000001
58 TPM2_CAP_COMMANDS = 0x00000002
59 TPM2_CAP_PCRS = 0x00000005
60 TPM2_CAP_TPM_PROPERTIES = 0x00000006
61
62 TPM2_PT_FIXED = 0x100
63 TPM2_PT_TOTAL_COMMANDS = TPM2_PT_FIXED + 41
64
65 HR_SHIFT = 24
66 HR_LOADED_SESSION = 0x02000000
67 HR_TRANSIENT = 0x80000000
68
69 SHA1_DIGEST_SIZE = 20
70 SHA256_DIGEST_SIZE = 32
71
72 TPM2_VER0_ERRORS = {
73     0x000: "TPM_RC_SUCCESS",
74     0x030: "TPM_RC_BAD_TAG",
75 }
76
77 TPM2_VER1_ERRORS = {
78     0x000: "TPM_RC_FAILURE",
79     0x001: "TPM_RC_FAILURE",
80     0x003: "TPM_RC_SEQUENCE",
81     0x00B: "TPM_RC_PRIVATE",
82     0x019: "TPM_RC_HMAC",
83     0x020: "TPM_RC_DISABLED",
84     0x021: "TPM_RC_EXCLUSIVE",
85     0x024: "TPM_RC_AUTH_TYPE",
86     0x025: "TPM_RC_AUTH_MISSING",
87     0x026: "TPM_RC_POLICY",
88     0x027: "TPM_RC_PCR",
89     0x028: "TPM_RC_PCR_CHANGED",
90     0x02D: "TPM_RC_UPGRADE",
91     0x02E: "TPM_RC_TOO_MANY_CONTEXTS",
92     0x02F: "TPM_RC_AUTH_UNAVAILABLE",
93     0x030: "TPM_RC_REBOOT",
94     0x031: "TPM_RC_UNBALANCED",
95     0x042: "TPM_RC_COMMAND_SIZE",
96     0x043: "TPM_RC_COMMAND_CODE",
97     0x044: "TPM_RC_AUTHSIZE",
98     0x045: "TPM_RC_AUTH_CONTEXT",
99     0x046: "TPM_RC_NV_RANGE",
100     0x047: "TPM_RC_NV_SIZE",
101     0x048: "TPM_RC_NV_LOCKED",
102     0x049: "TPM_RC_NV_AUTHORIZATION",
103     0x04A: "TPM_RC_NV_UNINITIALIZED",
104     0x04B: "TPM_RC_NV_SPACE",
105     0x04C: "TPM_RC_NV_DEFINED",
106     0x050: "TPM_RC_BAD_CONTEXT",
107     0x051: "TPM_RC_CPHASH",
108     0x052: "TPM_RC_PARENT",
109     0x053: "TPM_RC_NEEDS_TEST",
110     0x054: "TPM_RC_NO_RESULT",
111     0x055: "TPM_RC_SENSITIVE",
112     0x07F: "RC_MAX_FM0",
113 }
114
115 TPM2_FMT1_ERRORS = {
116     0x001: "TPM_RC_ASYMMETRIC",
117     0x002: "TPM_RC_ATTRIBUTES",
118     0x003: "TPM_RC_HASH",
119     0x004: "TPM_RC_VALUE",
120     0x005: "TPM_RC_HIERARCHY",
121     0x007: "TPM_RC_KEY_SIZE",
122     0x008: "TPM_RC_MGF",
123     0x009: "TPM_RC_MODE",
124     0x00A: "TPM_RC_TYPE",
125     0x00B: "TPM_RC_HANDLE",
126     0x00C: "TPM_RC_KDF",
127     0x00D: "TPM_RC_RANGE",
128     0x00E: "TPM_RC_AUTH_FAIL",
129     0x00F: "TPM_RC_NONCE",
130     0x010: "TPM_RC_PP",
131     0x012: "TPM_RC_SCHEME",
132     0x015: "TPM_RC_SIZE",
133     0x016: "TPM_RC_SYMMETRIC",
134     0x017: "TPM_RC_TAG",
135     0x018: "TPM_RC_SELECTOR",
136     0x01A: "TPM_RC_INSUFFICIENT",
137     0x01B: "TPM_RC_SIGNATURE",
138     0x01C: "TPM_RC_KEY",
139     0x01D: "TPM_RC_POLICY_FAIL",
140     0x01F: "TPM_RC_INTEGRITY",
141     0x020: "TPM_RC_TICKET",
142     0x021: "TPM_RC_RESERVED_BITS",
143     0x022: "TPM_RC_BAD_AUTH",
144     0x023: "TPM_RC_EXPIRED",
145     0x024: "TPM_RC_POLICY_CC",
146     0x025: "TPM_RC_BINDING",
147     0x026: "TPM_RC_CURVE",
148     0x027: "TPM_RC_ECC_POINT",
149 }
150
151 TPM2_WARN_ERRORS = {
152     0x001: "TPM_RC_CONTEXT_GAP",
153     0x002: "TPM_RC_OBJECT_MEMORY",
154     0x003: "TPM_RC_SESSION_MEMORY",
155     0x004: "TPM_RC_MEMORY",
156     0x005: "TPM_RC_SESSION_HANDLES",
157     0x006: "TPM_RC_OBJECT_HANDLES",
158     0x007: "TPM_RC_LOCALITY",
159     0x008: "TPM_RC_YIELDED",
160     0x009: "TPM_RC_CANCELED",
161     0x00A: "TPM_RC_TESTING",
162     0x010: "TPM_RC_REFERENCE_H0",
163     0x011: "TPM_RC_REFERENCE_H1",
164     0x012: "TPM_RC_REFERENCE_H2",
165     0x013: "TPM_RC_REFERENCE_H3",
166     0x014: "TPM_RC_REFERENCE_H4",
167     0x015: "TPM_RC_REFERENCE_H5",
168     0x016: "TPM_RC_REFERENCE_H6",
169     0x018: "TPM_RC_REFERENCE_S0",
170     0x019: "TPM_RC_REFERENCE_S1",
171     0x01A: "TPM_RC_REFERENCE_S2",
172     0x01B: "TPM_RC_REFERENCE_S3",
173     0x01C: "TPM_RC_REFERENCE_S4",
174     0x01D: "TPM_RC_REFERENCE_S5",
175     0x01E: "TPM_RC_REFERENCE_S6",
176     0x020: "TPM_RC_NV_RATE",
177     0x021: "TPM_RC_LOCKOUT",
178     0x022: "TPM_RC_RETRY",
179     0x023: "TPM_RC_NV_UNAVAILABLE",
180     0x7F: "TPM_RC_NOT_USED",
181 }
182
183 RC_VER1 = 0x100
184 RC_FMT1 = 0x080
185 RC_WARN = 0x900
186
187 ALG_DIGEST_SIZE_MAP = {
188     TPM2_ALG_SHA1: SHA1_DIGEST_SIZE,
189     TPM2_ALG_SHA256: SHA256_DIGEST_SIZE,
190 }
191
192 ALG_HASH_FUNCTION_MAP = {
193     TPM2_ALG_SHA1: hashlib.sha1,
194     TPM2_ALG_SHA256: hashlib.sha256
195 }
196
197 NAME_ALG_MAP = {
198     "sha1": TPM2_ALG_SHA1,
199     "sha256": TPM2_ALG_SHA256,
200 }
201
202
203 class UnknownAlgorithmIdError(Exception):
204     def __init__(self, alg):
205         self.alg = alg
206
207     def __str__(self):
208         return '0x%0x' % (alg)
209
210
211 class UnknownAlgorithmNameError(Exception):
212     def __init__(self, name):
213         self.name = name
214
215     def __str__(self):
216         return name
217
218
219 class UnknownPCRBankError(Exception):
220     def __init__(self, alg):
221         self.alg = alg
222
223     def __str__(self):
224         return '0x%0x' % (alg)
225
226
227 class ProtocolError(Exception):
228     def __init__(self, cc, rc):
229         self.cc = cc
230         self.rc = rc
231
232         if (rc & RC_FMT1) == RC_FMT1:
233             self.name = TPM2_FMT1_ERRORS.get(rc & 0x3f, "TPM_RC_UNKNOWN")
234         elif (rc & RC_WARN) == RC_WARN:
235             self.name = TPM2_WARN_ERRORS.get(rc & 0x7f, "TPM_RC_UNKNOWN")
236         elif (rc & RC_VER1) == RC_VER1:
237             self.name = TPM2_VER1_ERRORS.get(rc & 0x7f, "TPM_RC_UNKNOWN")
238         else:
239             self.name = TPM2_VER0_ERRORS.get(rc & 0x7f, "TPM_RC_UNKNOWN")
240
241     def __str__(self):
242         if self.cc:
243             return '%s: cc=0x%08x, rc=0x%08x' % (self.name, self.cc, self.rc)
244         else:
245             return '%s: rc=0x%08x' % (self.name, self.rc)
246
247
248 class AuthCommand(object):
249     """TPMS_AUTH_COMMAND"""
250
251     def __init__(self, session_handle=TPM2_RS_PW, nonce=bytes(),
252                  session_attributes=0, hmac=bytes()):
253         self.session_handle = session_handle
254         self.nonce = nonce
255         self.session_attributes = session_attributes
256         self.hmac = hmac
257
258     def __bytes__(self):
259         fmt = '>I H%us B H%us' % (len(self.nonce), len(self.hmac))
260         return struct.pack(fmt, self.session_handle, len(self.nonce),
261                            self.nonce, self.session_attributes, len(self.hmac),
262                            self.hmac)
263
264     def __len__(self):
265         fmt = '>I H%us B H%us' % (len(self.nonce), len(self.hmac))
266         return struct.calcsize(fmt)
267
268
269 class SensitiveCreate(object):
270     """TPMS_SENSITIVE_CREATE"""
271
272     def __init__(self, user_auth=bytes(), data=bytes()):
273         self.user_auth = user_auth
274         self.data = data
275
276     def __bytes__(self):
277         fmt = '>H%us H%us' % (len(self.user_auth), len(self.data))
278         return struct.pack(fmt, len(self.user_auth), self.user_auth,
279                            len(self.data), self.data)
280
281     def __len__(self):
282         fmt = '>H%us H%us' % (len(self.user_auth), len(self.data))
283         return struct.calcsize(fmt)
284
285
286 class Public(object):
287     """TPMT_PUBLIC"""
288
289     FIXED_TPM = (1 << 1)
290     FIXED_PARENT = (1 << 4)
291     SENSITIVE_DATA_ORIGIN = (1 << 5)
292     USER_WITH_AUTH = (1 << 6)
293     RESTRICTED = (1 << 16)
294     DECRYPT = (1 << 17)
295
296     def __fmt(self):
297         return '>HHIH%us%usH%us' % \
298             (len(self.auth_policy), len(self.parameters), len(self.unique))
299
300     def __init__(self, object_type, name_alg, object_attributes,
301                  auth_policy=bytes(), parameters=bytes(),
302                  unique=bytes()):
303         self.object_type = object_type
304         self.name_alg = name_alg
305         self.object_attributes = object_attributes
306         self.auth_policy = auth_policy
307         self.parameters = parameters
308         self.unique = unique
309
310     def __bytes__(self):
311         return struct.pack(self.__fmt(),
312                            self.object_type,
313                            self.name_alg,
314                            self.object_attributes,
315                            len(self.auth_policy),
316                            self.auth_policy,
317                            self.parameters,
318                            len(self.unique),
319                            self.unique)
320
321     def __len__(self):
322         return struct.calcsize(self.__fmt())
323
324
325 def get_digest_size(alg):
326     ds = ALG_DIGEST_SIZE_MAP.get(alg)
327     if not ds:
328         raise UnknownAlgorithmIdError(alg)
329     return ds
330
331
332 def get_hash_function(alg):
333     f = ALG_HASH_FUNCTION_MAP.get(alg)
334     if not f:
335         raise UnknownAlgorithmIdError(alg)
336     return f
337
338
339 def get_algorithm(name):
340     alg = NAME_ALG_MAP.get(name)
341     if not alg:
342         raise UnknownAlgorithmNameError(name)
343     return alg
344
345
346 def hex_dump(d):
347     d = [format(ord(x), '02x') for x in d]
348     d = [d[i: i + 16] for i in range(0, len(d), 16)]
349     d = [' '.join(x) for x in d]
350     d = os.linesep.join(d)
351
352     return d
353
354 class Client:
355     FLAG_DEBUG = 0x01
356     FLAG_SPACE = 0x02
357     FLAG_NONBLOCK = 0x04
358     TPM_IOC_NEW_SPACE = 0xa200
359
360     def __init__(self, flags = 0):
361         self.flags = flags
362
363         if (self.flags & Client.FLAG_SPACE) == 0:
364             self.tpm = open('/dev/tpm0', 'r+b', buffering=0)
365         else:
366             self.tpm = open('/dev/tpmrm0', 'r+b', buffering=0)
367
368         if (self.flags & Client.FLAG_NONBLOCK):
369             flags = fcntl.fcntl(self.tpm, fcntl.F_GETFL)
370             flags |= os.O_NONBLOCK
371             fcntl.fcntl(self.tpm, fcntl.F_SETFL, flags)
372             self.tpm_poll = select.poll()
373
374     def __del__(self):
375         if self.tpm:
376             self.tpm.close()
377
378     def close(self):
379         self.tpm.close()
380
381     def send_cmd(self, cmd):
382         self.tpm.write(cmd)
383
384         if (self.flags & Client.FLAG_NONBLOCK):
385             self.tpm_poll.register(self.tpm, select.POLLIN)
386             self.tpm_poll.poll(10000)
387
388         rsp = self.tpm.read()
389
390         if (self.flags & Client.FLAG_NONBLOCK):
391             self.tpm_poll.unregister(self.tpm)
392
393         if (self.flags & Client.FLAG_DEBUG) != 0:
394             sys.stderr.write('cmd' + os.linesep)
395             sys.stderr.write(hex_dump(cmd) + os.linesep)
396             sys.stderr.write('rsp' + os.linesep)
397             sys.stderr.write(hex_dump(rsp) + os.linesep)
398
399         rc = struct.unpack('>I', rsp[6:10])[0]
400         if rc != 0:
401             cc = struct.unpack('>I', cmd[6:10])[0]
402             raise ProtocolError(cc, rc)
403
404         return rsp
405
406     def read_pcr(self, i, bank_alg = TPM2_ALG_SHA1):
407         pcrsel_len = max((i >> 3) + 1, 3)
408         pcrsel = [0] * pcrsel_len
409         pcrsel[i >> 3] = 1 << (i & 7)
410         pcrsel = ''.join(map(chr, pcrsel)).encode()
411
412         fmt = '>HII IHB%us' % (pcrsel_len)
413         cmd = struct.pack(fmt,
414                           TPM2_ST_NO_SESSIONS,
415                           struct.calcsize(fmt),
416                           TPM2_CC_PCR_READ,
417                           1,
418                           bank_alg,
419                           pcrsel_len, pcrsel)
420
421         rsp = self.send_cmd(cmd)
422
423         pcr_update_cnt, pcr_select_cnt = struct.unpack('>II', rsp[10:18])
424         assert pcr_select_cnt == 1
425         rsp = rsp[18:]
426
427         alg2, pcrsel_len2 = struct.unpack('>HB', rsp[:3])
428         assert bank_alg == alg2 and pcrsel_len == pcrsel_len2
429         rsp = rsp[3 + pcrsel_len:]
430
431         digest_cnt = struct.unpack('>I', rsp[:4])[0]
432         if digest_cnt == 0:
433             return None
434         rsp = rsp[6:]
435
436         return rsp
437
438     def extend_pcr(self, i, dig, bank_alg = TPM2_ALG_SHA1):
439         ds = get_digest_size(bank_alg)
440         assert(ds == len(dig))
441
442         auth_cmd = AuthCommand()
443
444         fmt = '>HII I I%us IH%us' % (len(auth_cmd), ds)
445         cmd = struct.pack(
446             fmt,
447             TPM2_ST_SESSIONS,
448             struct.calcsize(fmt),
449             TPM2_CC_PCR_EXTEND,
450             i,
451             len(auth_cmd),
452             bytes(auth_cmd),
453             1, bank_alg, dig)
454
455         self.send_cmd(cmd)
456
457     def start_auth_session(self, session_type, name_alg = TPM2_ALG_SHA1):
458         fmt = '>HII IIH16sHBHH'
459         cmd = struct.pack(fmt,
460                           TPM2_ST_NO_SESSIONS,
461                           struct.calcsize(fmt),
462                           TPM2_CC_START_AUTH_SESSION,
463                           TPM2_RH_NULL,
464                           TPM2_RH_NULL,
465                           16,
466                           ('\0' * 16).encode(),
467                           0,
468                           session_type,
469                           TPM2_ALG_NULL,
470                           name_alg)
471
472         return struct.unpack('>I', self.send_cmd(cmd)[10:14])[0]
473
474     def __calc_pcr_digest(self, pcrs, bank_alg = TPM2_ALG_SHA1,
475                           digest_alg = TPM2_ALG_SHA1):
476         x = []
477         f = get_hash_function(digest_alg)
478
479         for i in pcrs:
480             pcr = self.read_pcr(i, bank_alg)
481             if pcr is None:
482                 return None
483             x += pcr
484
485         return f(bytearray(x)).digest()
486
487     def policy_pcr(self, handle, pcrs, bank_alg = TPM2_ALG_SHA1,
488                    name_alg = TPM2_ALG_SHA1):
489         ds = get_digest_size(name_alg)
490         dig = self.__calc_pcr_digest(pcrs, bank_alg, name_alg)
491         if not dig:
492             raise UnknownPCRBankError(bank_alg)
493
494         pcrsel_len = max((max(pcrs) >> 3) + 1, 3)
495         pcrsel = [0] * pcrsel_len
496         for i in pcrs:
497             pcrsel[i >> 3] |= 1 << (i & 7)
498         pcrsel = ''.join(map(chr, pcrsel)).encode()
499
500         fmt = '>HII IH%usIHB3s' % ds
501         cmd = struct.pack(fmt,
502                           TPM2_ST_NO_SESSIONS,
503                           struct.calcsize(fmt),
504                           TPM2_CC_POLICY_PCR,
505                           handle,
506                           len(dig),
507                           bytes(dig),
508                           1,
509                           bank_alg,
510                           pcrsel_len, pcrsel)
511
512         self.send_cmd(cmd)
513
514     def policy_password(self, handle):
515         fmt = '>HII I'
516         cmd = struct.pack(fmt,
517                           TPM2_ST_NO_SESSIONS,
518                           struct.calcsize(fmt),
519                           TPM2_CC_POLICY_PASSWORD,
520                           handle)
521
522         self.send_cmd(cmd)
523
524     def get_policy_digest(self, handle):
525         fmt = '>HII I'
526         cmd = struct.pack(fmt,
527                           TPM2_ST_NO_SESSIONS,
528                           struct.calcsize(fmt),
529                           TPM2_CC_POLICY_GET_DIGEST,
530                           handle)
531
532         return self.send_cmd(cmd)[12:]
533
534     def flush_context(self, handle):
535         fmt = '>HIII'
536         cmd = struct.pack(fmt,
537                           TPM2_ST_NO_SESSIONS,
538                           struct.calcsize(fmt),
539                           TPM2_CC_FLUSH_CONTEXT,
540                           handle)
541
542         self.send_cmd(cmd)
543
544     def create_root_key(self, auth_value = bytes()):
545         attributes = \
546             Public.FIXED_TPM | \
547             Public.FIXED_PARENT | \
548             Public.SENSITIVE_DATA_ORIGIN | \
549             Public.USER_WITH_AUTH | \
550             Public.RESTRICTED | \
551             Public.DECRYPT
552
553         auth_cmd = AuthCommand()
554         sensitive = SensitiveCreate(user_auth=auth_value)
555
556         public_parms = struct.pack(
557             '>HHHHHI',
558             TPM2_ALG_AES,
559             128,
560             TPM2_ALG_CFB,
561             TPM2_ALG_NULL,
562             2048,
563             0)
564
565         public = Public(
566             object_type=TPM2_ALG_RSA,
567             name_alg=TPM2_ALG_SHA1,
568             object_attributes=attributes,
569             parameters=public_parms)
570
571         fmt = '>HIII I%us H%us H%us HI' % \
572             (len(auth_cmd), len(sensitive), len(public))
573         cmd = struct.pack(
574             fmt,
575             TPM2_ST_SESSIONS,
576             struct.calcsize(fmt),
577             TPM2_CC_CREATE_PRIMARY,
578             TPM2_RH_OWNER,
579             len(auth_cmd),
580             bytes(auth_cmd),
581             len(sensitive),
582             bytes(sensitive),
583             len(public),
584             bytes(public),
585             0, 0)
586
587         return struct.unpack('>I', self.send_cmd(cmd)[10:14])[0]
588
589     def seal(self, parent_key, data, auth_value, policy_dig,
590              name_alg = TPM2_ALG_SHA1):
591         ds = get_digest_size(name_alg)
592         assert(not policy_dig or ds == len(policy_dig))
593
594         attributes = 0
595         if not policy_dig:
596             attributes |= Public.USER_WITH_AUTH
597             policy_dig = bytes()
598
599         auth_cmd =  AuthCommand()
600         sensitive = SensitiveCreate(user_auth=auth_value, data=data)
601
602         public = Public(
603             object_type=TPM2_ALG_KEYEDHASH,
604             name_alg=name_alg,
605             object_attributes=attributes,
606             auth_policy=policy_dig,
607             parameters=struct.pack('>H', TPM2_ALG_NULL))
608
609         fmt = '>HIII I%us H%us H%us HI' % \
610             (len(auth_cmd), len(sensitive), len(public))
611         cmd = struct.pack(
612             fmt,
613             TPM2_ST_SESSIONS,
614             struct.calcsize(fmt),
615             TPM2_CC_CREATE,
616             parent_key,
617             len(auth_cmd),
618             bytes(auth_cmd),
619             len(sensitive),
620             bytes(sensitive),
621             len(public),
622             bytes(public),
623             0, 0)
624
625         rsp = self.send_cmd(cmd)
626
627         return rsp[14:]
628
629     def unseal(self, parent_key, blob, auth_value, policy_handle):
630         private_len = struct.unpack('>H', blob[0:2])[0]
631         public_start = private_len + 2
632         public_len = struct.unpack('>H', blob[public_start:public_start + 2])[0]
633         blob = blob[:private_len + public_len + 4]
634
635         auth_cmd = AuthCommand()
636
637         fmt = '>HII I I%us %us' % (len(auth_cmd), len(blob))
638         cmd = struct.pack(
639             fmt,
640             TPM2_ST_SESSIONS,
641             struct.calcsize(fmt),
642             TPM2_CC_LOAD,
643             parent_key,
644             len(auth_cmd),
645             bytes(auth_cmd),
646             blob)
647
648         data_handle = struct.unpack('>I', self.send_cmd(cmd)[10:14])[0]
649
650         if policy_handle:
651             auth_cmd = AuthCommand(session_handle=policy_handle, hmac=auth_value)
652         else:
653             auth_cmd = AuthCommand(hmac=auth_value)
654
655         fmt = '>HII I I%us' % (len(auth_cmd))
656         cmd = struct.pack(
657             fmt,
658             TPM2_ST_SESSIONS,
659             struct.calcsize(fmt),
660             TPM2_CC_UNSEAL,
661             data_handle,
662             len(auth_cmd),
663             bytes(auth_cmd))
664
665         try:
666             rsp = self.send_cmd(cmd)
667         finally:
668             self.flush_context(data_handle)
669
670         data_len = struct.unpack('>I', rsp[10:14])[0] - 2
671
672         return rsp[16:16 + data_len]
673
674     def reset_da_lock(self):
675         auth_cmd = AuthCommand()
676
677         fmt = '>HII I I%us' % (len(auth_cmd))
678         cmd = struct.pack(
679             fmt,
680             TPM2_ST_SESSIONS,
681             struct.calcsize(fmt),
682             TPM2_CC_DICTIONARY_ATTACK_LOCK_RESET,
683             TPM2_RH_LOCKOUT,
684             len(auth_cmd),
685             bytes(auth_cmd))
686
687         self.send_cmd(cmd)
688
689     def __get_cap_cnt(self, cap, pt, cnt):
690         handles = []
691         fmt = '>HII III'
692
693         cmd = struct.pack(fmt,
694                           TPM2_ST_NO_SESSIONS,
695                           struct.calcsize(fmt),
696                           TPM2_CC_GET_CAPABILITY,
697                           cap, pt, cnt)
698
699         rsp = self.send_cmd(cmd)[10:]
700         more_data, cap, cnt = struct.unpack('>BII', rsp[:9])
701         rsp = rsp[9:]
702
703         for i in range(0, cnt):
704             handle = struct.unpack('>I', rsp[:4])[0]
705             handles.append(handle)
706             rsp = rsp[4:]
707
708         return handles, more_data
709
710     def get_cap(self, cap, pt):
711         handles = []
712
713         more_data = True
714         while more_data:
715             next_handles, more_data = self.__get_cap_cnt(cap, pt, 1)
716             handles += next_handles
717             pt += 1
718
719         return handles
720
721     def get_cap_pcrs(self):
722         pcr_banks = {}
723
724         fmt = '>HII III'
725
726         cmd = struct.pack(fmt,
727                           TPM2_ST_NO_SESSIONS,
728                           struct.calcsize(fmt),
729                           TPM2_CC_GET_CAPABILITY,
730                           TPM2_CAP_PCRS, 0, 1)
731         rsp = self.send_cmd(cmd)[10:]
732         _, _, cnt = struct.unpack('>BII', rsp[:9])
733         rsp = rsp[9:]
734
735         # items are TPMS_PCR_SELECTION's
736         for i in range(0, cnt):
737               hash, sizeOfSelect = struct.unpack('>HB', rsp[:3])
738               rsp = rsp[3:]
739
740               pcrSelect = 0
741               if sizeOfSelect > 0:
742                   pcrSelect, = struct.unpack('%ds' % sizeOfSelect,
743                                              rsp[:sizeOfSelect])
744                   rsp = rsp[sizeOfSelect:]
745                   pcrSelect = int.from_bytes(pcrSelect, byteorder='big')
746
747               pcr_banks[hash] = pcrSelect
748
749         return pcr_banks