Merge tag 'tpmdd-next-20190625' of git://git.infradead.org/users/jjs/linux-tpmdd
[muen/linux.git] / drivers / char / tpm / tpm2-cmd.c
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2014, 2015 Intel Corporation
4  *
5  * Authors:
6  * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
7  *
8  * Maintained by: <tpmdd-devel@lists.sourceforge.net>
9  *
10  * This file contains TPM2 protocol implementations of the commands
11  * used by the kernel internally.
12  */
13
14 #include "tpm.h"
15 #include <crypto/hash_info.h>
16 #include <keys/trusted-type.h>
17
18 enum tpm2_object_attributes {
19         TPM2_OA_USER_WITH_AUTH          = BIT(6),
20 };
21
22 enum tpm2_session_attributes {
23         TPM2_SA_CONTINUE_SESSION        = BIT(0),
24 };
25
26 struct tpm2_hash {
27         unsigned int crypto_id;
28         unsigned int tpm_id;
29 };
30
31 static struct tpm2_hash tpm2_hash_map[] = {
32         {HASH_ALGO_SHA1, TPM_ALG_SHA1},
33         {HASH_ALGO_SHA256, TPM_ALG_SHA256},
34         {HASH_ALGO_SHA384, TPM_ALG_SHA384},
35         {HASH_ALGO_SHA512, TPM_ALG_SHA512},
36         {HASH_ALGO_SM3_256, TPM_ALG_SM3_256},
37 };
38
39 int tpm2_get_timeouts(struct tpm_chip *chip)
40 {
41         /* Fixed timeouts for TPM2 */
42         chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
43         chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
44         chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
45         chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
46
47         /* PTP spec timeouts */
48         chip->duration[TPM_SHORT] = msecs_to_jiffies(TPM2_DURATION_SHORT);
49         chip->duration[TPM_MEDIUM] = msecs_to_jiffies(TPM2_DURATION_MEDIUM);
50         chip->duration[TPM_LONG] = msecs_to_jiffies(TPM2_DURATION_LONG);
51
52         /* Key creation commands long timeouts */
53         chip->duration[TPM_LONG_LONG] =
54                 msecs_to_jiffies(TPM2_DURATION_LONG_LONG);
55
56         chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
57
58         return 0;
59 }
60
61 /**
62  * tpm2_ordinal_duration_index() - returns an index to the chip duration table
63  * @ordinal: TPM command ordinal.
64  *
65  * The function returns an index to the chip duration table
66  * (enum tpm_duration), that describes the maximum amount of
67  * time the chip could take to return the result for a  particular ordinal.
68  *
69  * The values of the MEDIUM, and LONG durations are taken
70  * from the PC Client Profile (PTP) specification (750, 2000 msec)
71  *
72  * LONG_LONG is for commands that generates keys which empirically takes
73  * a longer time on some systems.
74  *
75  * Return:
76  * * TPM_MEDIUM
77  * * TPM_LONG
78  * * TPM_LONG_LONG
79  * * TPM_UNDEFINED
80  */
81 static u8 tpm2_ordinal_duration_index(u32 ordinal)
82 {
83         switch (ordinal) {
84         /* Startup */
85         case TPM2_CC_STARTUP:                 /* 144 */
86                 return TPM_MEDIUM;
87
88         case TPM2_CC_SELF_TEST:               /* 143 */
89                 return TPM_LONG;
90
91         case TPM2_CC_GET_RANDOM:              /* 17B */
92                 return TPM_LONG;
93
94         case TPM2_CC_SEQUENCE_UPDATE:         /* 15C */
95                 return TPM_MEDIUM;
96         case TPM2_CC_SEQUENCE_COMPLETE:       /* 13E */
97                 return TPM_MEDIUM;
98         case TPM2_CC_EVENT_SEQUENCE_COMPLETE: /* 185 */
99                 return TPM_MEDIUM;
100         case TPM2_CC_HASH_SEQUENCE_START:     /* 186 */
101                 return TPM_MEDIUM;
102
103         case TPM2_CC_VERIFY_SIGNATURE:        /* 177 */
104                 return TPM_LONG;
105
106         case TPM2_CC_PCR_EXTEND:              /* 182 */
107                 return TPM_MEDIUM;
108
109         case TPM2_CC_HIERARCHY_CONTROL:       /* 121 */
110                 return TPM_LONG;
111         case TPM2_CC_HIERARCHY_CHANGE_AUTH:   /* 129 */
112                 return TPM_LONG;
113
114         case TPM2_CC_GET_CAPABILITY:          /* 17A */
115                 return TPM_MEDIUM;
116
117         case TPM2_CC_NV_READ:                 /* 14E */
118                 return TPM_LONG;
119
120         case TPM2_CC_CREATE_PRIMARY:          /* 131 */
121                 return TPM_LONG_LONG;
122         case TPM2_CC_CREATE:                  /* 153 */
123                 return TPM_LONG_LONG;
124         case TPM2_CC_CREATE_LOADED:           /* 191 */
125                 return TPM_LONG_LONG;
126
127         default:
128                 return TPM_UNDEFINED;
129         }
130 }
131
132 /**
133  * tpm2_calc_ordinal_duration() - calculate the maximum command duration
134  * @chip:    TPM chip to use.
135  * @ordinal: TPM command ordinal.
136  *
137  * The function returns the maximum amount of time the chip could take
138  * to return the result for a particular ordinal in jiffies.
139  *
140  * Return: A maximal duration time for an ordinal in jiffies.
141  */
142 unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
143 {
144         unsigned int index;
145
146         index = tpm2_ordinal_duration_index(ordinal);
147
148         if (index != TPM_UNDEFINED)
149                 return chip->duration[index];
150         else
151                 return msecs_to_jiffies(TPM2_DURATION_DEFAULT);
152 }
153
154
155 struct tpm2_pcr_read_out {
156         __be32  update_cnt;
157         __be32  pcr_selects_cnt;
158         __be16  hash_alg;
159         u8      pcr_select_size;
160         u8      pcr_select[TPM2_PCR_SELECT_MIN];
161         __be32  digests_cnt;
162         __be16  digest_size;
163         u8      digest[];
164 } __packed;
165
166 /**
167  * tpm2_pcr_read() - read a PCR value
168  * @chip:       TPM chip to use.
169  * @pcr_idx:    index of the PCR to read.
170  * @digest:     PCR bank and buffer current PCR value is written to.
171  * @digest_size_ptr:    pointer to variable that stores the digest size.
172  *
173  * Return: Same as with tpm_transmit_cmd.
174  */
175 int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
176                   struct tpm_digest *digest, u16 *digest_size_ptr)
177 {
178         int i;
179         int rc;
180         struct tpm_buf buf;
181         struct tpm2_pcr_read_out *out;
182         u8 pcr_select[TPM2_PCR_SELECT_MIN] = {0};
183         u16 digest_size;
184         u16 expected_digest_size = 0;
185
186         if (pcr_idx >= TPM2_PLATFORM_PCR)
187                 return -EINVAL;
188
189         if (!digest_size_ptr) {
190                 for (i = 0; i < chip->nr_allocated_banks &&
191                      chip->allocated_banks[i].alg_id != digest->alg_id; i++)
192                         ;
193
194                 if (i == chip->nr_allocated_banks)
195                         return -EINVAL;
196
197                 expected_digest_size = chip->allocated_banks[i].digest_size;
198         }
199
200         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_PCR_READ);
201         if (rc)
202                 return rc;
203
204         pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7);
205
206         tpm_buf_append_u32(&buf, 1);
207         tpm_buf_append_u16(&buf, digest->alg_id);
208         tpm_buf_append_u8(&buf, TPM2_PCR_SELECT_MIN);
209         tpm_buf_append(&buf, (const unsigned char *)pcr_select,
210                        sizeof(pcr_select));
211
212         rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to read a pcr value");
213         if (rc)
214                 goto out;
215
216         out = (struct tpm2_pcr_read_out *)&buf.data[TPM_HEADER_SIZE];
217         digest_size = be16_to_cpu(out->digest_size);
218         if (digest_size > sizeof(digest->digest) ||
219             (!digest_size_ptr && digest_size != expected_digest_size)) {
220                 rc = -EINVAL;
221                 goto out;
222         }
223
224         if (digest_size_ptr)
225                 *digest_size_ptr = digest_size;
226
227         memcpy(digest->digest, out->digest, digest_size);
228 out:
229         tpm_buf_destroy(&buf);
230         return rc;
231 }
232
233 struct tpm2_null_auth_area {
234         __be32  handle;
235         __be16  nonce_size;
236         u8  attributes;
237         __be16  auth_size;
238 } __packed;
239
240 /**
241  * tpm2_pcr_extend() - extend a PCR value
242  *
243  * @chip:       TPM chip to use.
244  * @pcr_idx:    index of the PCR.
245  * @digests:    list of pcr banks and corresponding digest values to extend.
246  *
247  * Return: Same as with tpm_transmit_cmd.
248  */
249 int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
250                     struct tpm_digest *digests)
251 {
252         struct tpm_buf buf;
253         struct tpm2_null_auth_area auth_area;
254         int rc;
255         int i;
256
257         rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND);
258         if (rc)
259                 return rc;
260
261         tpm_buf_append_u32(&buf, pcr_idx);
262
263         auth_area.handle = cpu_to_be32(TPM2_RS_PW);
264         auth_area.nonce_size = 0;
265         auth_area.attributes = 0;
266         auth_area.auth_size = 0;
267
268         tpm_buf_append_u32(&buf, sizeof(struct tpm2_null_auth_area));
269         tpm_buf_append(&buf, (const unsigned char *)&auth_area,
270                        sizeof(auth_area));
271         tpm_buf_append_u32(&buf, chip->nr_allocated_banks);
272
273         for (i = 0; i < chip->nr_allocated_banks; i++) {
274                 tpm_buf_append_u16(&buf, digests[i].alg_id);
275                 tpm_buf_append(&buf, (const unsigned char *)&digests[i].digest,
276                                chip->allocated_banks[i].digest_size);
277         }
278
279         rc = tpm_transmit_cmd(chip, &buf, 0, "attempting extend a PCR value");
280
281         tpm_buf_destroy(&buf);
282
283         return rc;
284 }
285
286 struct tpm2_get_random_out {
287         __be16 size;
288         u8 buffer[TPM_MAX_RNG_DATA];
289 } __packed;
290
291 /**
292  * tpm2_get_random() - get random bytes from the TPM RNG
293  *
294  * @chip:       a &tpm_chip instance
295  * @dest:       destination buffer
296  * @max:        the max number of random bytes to pull
297  *
298  * Return:
299  *   size of the buffer on success,
300  *   -errno otherwise (positive TPM return codes are masked to -EIO)
301  */
302 int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
303 {
304         struct tpm2_get_random_out *out;
305         struct tpm_buf buf;
306         u32 recd;
307         u32 num_bytes = max;
308         int err;
309         int total = 0;
310         int retries = 5;
311         u8 *dest_ptr = dest;
312
313         if (!num_bytes || max > TPM_MAX_RNG_DATA)
314                 return -EINVAL;
315
316         err = tpm_buf_init(&buf, 0, 0);
317         if (err)
318                 return err;
319
320         do {
321                 tpm_buf_reset(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_RANDOM);
322                 tpm_buf_append_u16(&buf, num_bytes);
323                 err = tpm_transmit_cmd(chip, &buf,
324                                        offsetof(struct tpm2_get_random_out,
325                                                 buffer),
326                                        "attempting get random");
327                 if (err) {
328                         if (err > 0)
329                                 err = -EIO;
330                         goto out;
331                 }
332
333                 out = (struct tpm2_get_random_out *)
334                         &buf.data[TPM_HEADER_SIZE];
335                 recd = min_t(u32, be16_to_cpu(out->size), num_bytes);
336                 if (tpm_buf_length(&buf) <
337                     TPM_HEADER_SIZE +
338                     offsetof(struct tpm2_get_random_out, buffer) +
339                     recd) {
340                         err = -EFAULT;
341                         goto out;
342                 }
343                 memcpy(dest_ptr, out->buffer, recd);
344
345                 dest_ptr += recd;
346                 total += recd;
347                 num_bytes -= recd;
348         } while (retries-- && total < max);
349
350         tpm_buf_destroy(&buf);
351         return total ? total : -EIO;
352 out:
353         tpm_buf_destroy(&buf);
354         return err;
355 }
356
357 /**
358  * tpm2_flush_context() - execute a TPM2_FlushContext command
359  * @chip:       TPM chip to use
360  * @handle:     context handle
361  */
362 void tpm2_flush_context(struct tpm_chip *chip, u32 handle)
363 {
364         struct tpm_buf buf;
365         int rc;
366
367         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_FLUSH_CONTEXT);
368         if (rc) {
369                 dev_warn(&chip->dev, "0x%08x was not flushed, out of memory\n",
370                          handle);
371                 return;
372         }
373
374         tpm_buf_append_u32(&buf, handle);
375
376         tpm_transmit_cmd(chip, &buf, 0, "flushing context");
377         tpm_buf_destroy(&buf);
378 }
379
380 /**
381  * tpm_buf_append_auth() - append TPMS_AUTH_COMMAND to the buffer.
382  *
383  * @buf: an allocated tpm_buf instance
384  * @session_handle: session handle
385  * @nonce: the session nonce, may be NULL if not used
386  * @nonce_len: the session nonce length, may be 0 if not used
387  * @attributes: the session attributes
388  * @hmac: the session HMAC or password, may be NULL if not used
389  * @hmac_len: the session HMAC or password length, maybe 0 if not used
390  */
391 static void tpm2_buf_append_auth(struct tpm_buf *buf, u32 session_handle,
392                                  const u8 *nonce, u16 nonce_len,
393                                  u8 attributes,
394                                  const u8 *hmac, u16 hmac_len)
395 {
396         tpm_buf_append_u32(buf, 9 + nonce_len + hmac_len);
397         tpm_buf_append_u32(buf, session_handle);
398         tpm_buf_append_u16(buf, nonce_len);
399
400         if (nonce && nonce_len)
401                 tpm_buf_append(buf, nonce, nonce_len);
402
403         tpm_buf_append_u8(buf, attributes);
404         tpm_buf_append_u16(buf, hmac_len);
405
406         if (hmac && hmac_len)
407                 tpm_buf_append(buf, hmac, hmac_len);
408 }
409
410 /**
411  * tpm2_seal_trusted() - seal the payload of a trusted key
412  *
413  * @chip: TPM chip to use
414  * @payload: the key data in clear and encrypted form
415  * @options: authentication values and other options
416  *
417  * Return: < 0 on error and 0 on success.
418  */
419 int tpm2_seal_trusted(struct tpm_chip *chip,
420                       struct trusted_key_payload *payload,
421                       struct trusted_key_options *options)
422 {
423         unsigned int blob_len;
424         struct tpm_buf buf;
425         u32 hash;
426         int i;
427         int rc;
428
429         for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
430                 if (options->hash == tpm2_hash_map[i].crypto_id) {
431                         hash = tpm2_hash_map[i].tpm_id;
432                         break;
433                 }
434         }
435
436         if (i == ARRAY_SIZE(tpm2_hash_map))
437                 return -EINVAL;
438
439         rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE);
440         if (rc)
441                 return rc;
442
443         tpm_buf_append_u32(&buf, options->keyhandle);
444         tpm2_buf_append_auth(&buf, TPM2_RS_PW,
445                              NULL /* nonce */, 0,
446                              0 /* session_attributes */,
447                              options->keyauth /* hmac */,
448                              TPM_DIGEST_SIZE);
449
450         /* sensitive */
451         tpm_buf_append_u16(&buf, 4 + TPM_DIGEST_SIZE + payload->key_len + 1);
452
453         tpm_buf_append_u16(&buf, TPM_DIGEST_SIZE);
454         tpm_buf_append(&buf, options->blobauth, TPM_DIGEST_SIZE);
455         tpm_buf_append_u16(&buf, payload->key_len + 1);
456         tpm_buf_append(&buf, payload->key, payload->key_len);
457         tpm_buf_append_u8(&buf, payload->migratable);
458
459         /* public */
460         tpm_buf_append_u16(&buf, 14 + options->policydigest_len);
461         tpm_buf_append_u16(&buf, TPM_ALG_KEYEDHASH);
462         tpm_buf_append_u16(&buf, hash);
463
464         /* policy */
465         if (options->policydigest_len) {
466                 tpm_buf_append_u32(&buf, 0);
467                 tpm_buf_append_u16(&buf, options->policydigest_len);
468                 tpm_buf_append(&buf, options->policydigest,
469                                options->policydigest_len);
470         } else {
471                 tpm_buf_append_u32(&buf, TPM2_OA_USER_WITH_AUTH);
472                 tpm_buf_append_u16(&buf, 0);
473         }
474
475         /* public parameters */
476         tpm_buf_append_u16(&buf, TPM_ALG_NULL);
477         tpm_buf_append_u16(&buf, 0);
478
479         /* outside info */
480         tpm_buf_append_u16(&buf, 0);
481
482         /* creation PCR */
483         tpm_buf_append_u32(&buf, 0);
484
485         if (buf.flags & TPM_BUF_OVERFLOW) {
486                 rc = -E2BIG;
487                 goto out;
488         }
489
490         rc = tpm_transmit_cmd(chip, &buf, 4, "sealing data");
491         if (rc)
492                 goto out;
493
494         blob_len = be32_to_cpup((__be32 *) &buf.data[TPM_HEADER_SIZE]);
495         if (blob_len > MAX_BLOB_SIZE) {
496                 rc = -E2BIG;
497                 goto out;
498         }
499         if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 4 + blob_len) {
500                 rc = -EFAULT;
501                 goto out;
502         }
503
504         memcpy(payload->blob, &buf.data[TPM_HEADER_SIZE + 4], blob_len);
505         payload->blob_len = blob_len;
506
507 out:
508         tpm_buf_destroy(&buf);
509
510         if (rc > 0) {
511                 if (tpm2_rc_value(rc) == TPM2_RC_HASH)
512                         rc = -EINVAL;
513                 else
514                         rc = -EPERM;
515         }
516
517         return rc;
518 }
519
520 /**
521  * tpm2_load_cmd() - execute a TPM2_Load command
522  *
523  * @chip: TPM chip to use
524  * @payload: the key data in clear and encrypted form
525  * @options: authentication values and other options
526  * @blob_handle: returned blob handle
527  *
528  * Return: 0 on success.
529  *        -E2BIG on wrong payload size.
530  *        -EPERM on tpm error status.
531  *        < 0 error from tpm_transmit_cmd.
532  */
533 static int tpm2_load_cmd(struct tpm_chip *chip,
534                          struct trusted_key_payload *payload,
535                          struct trusted_key_options *options,
536                          u32 *blob_handle)
537 {
538         struct tpm_buf buf;
539         unsigned int private_len;
540         unsigned int public_len;
541         unsigned int blob_len;
542         int rc;
543
544         private_len = be16_to_cpup((__be16 *) &payload->blob[0]);
545         if (private_len > (payload->blob_len - 2))
546                 return -E2BIG;
547
548         public_len = be16_to_cpup((__be16 *) &payload->blob[2 + private_len]);
549         blob_len = private_len + public_len + 4;
550         if (blob_len > payload->blob_len)
551                 return -E2BIG;
552
553         rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
554         if (rc)
555                 return rc;
556
557         tpm_buf_append_u32(&buf, options->keyhandle);
558         tpm2_buf_append_auth(&buf, TPM2_RS_PW,
559                              NULL /* nonce */, 0,
560                              0 /* session_attributes */,
561                              options->keyauth /* hmac */,
562                              TPM_DIGEST_SIZE);
563
564         tpm_buf_append(&buf, payload->blob, blob_len);
565
566         if (buf.flags & TPM_BUF_OVERFLOW) {
567                 rc = -E2BIG;
568                 goto out;
569         }
570
571         rc = tpm_transmit_cmd(chip, &buf, 4, "loading blob");
572         if (!rc)
573                 *blob_handle = be32_to_cpup(
574                         (__be32 *) &buf.data[TPM_HEADER_SIZE]);
575
576 out:
577         tpm_buf_destroy(&buf);
578
579         if (rc > 0)
580                 rc = -EPERM;
581
582         return rc;
583 }
584
585 /**
586  * tpm2_unseal_cmd() - execute a TPM2_Unload command
587  *
588  * @chip: TPM chip to use
589  * @payload: the key data in clear and encrypted form
590  * @options: authentication values and other options
591  * @blob_handle: blob handle
592  *
593  * Return: 0 on success
594  *         -EPERM on tpm error status
595  *         < 0 error from tpm_transmit_cmd
596  */
597 static int tpm2_unseal_cmd(struct tpm_chip *chip,
598                            struct trusted_key_payload *payload,
599                            struct trusted_key_options *options,
600                            u32 blob_handle)
601 {
602         struct tpm_buf buf;
603         u16 data_len;
604         u8 *data;
605         int rc;
606
607         rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL);
608         if (rc)
609                 return rc;
610
611         tpm_buf_append_u32(&buf, blob_handle);
612         tpm2_buf_append_auth(&buf,
613                              options->policyhandle ?
614                              options->policyhandle : TPM2_RS_PW,
615                              NULL /* nonce */, 0,
616                              TPM2_SA_CONTINUE_SESSION,
617                              options->blobauth /* hmac */,
618                              TPM_DIGEST_SIZE);
619
620         rc = tpm_transmit_cmd(chip, &buf, 6, "unsealing");
621         if (rc > 0)
622                 rc = -EPERM;
623
624         if (!rc) {
625                 data_len = be16_to_cpup(
626                         (__be16 *) &buf.data[TPM_HEADER_SIZE + 4]);
627                 if (data_len < MIN_KEY_SIZE ||  data_len > MAX_KEY_SIZE + 1) {
628                         rc = -EFAULT;
629                         goto out;
630                 }
631
632                 if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 6 + data_len) {
633                         rc = -EFAULT;
634                         goto out;
635                 }
636                 data = &buf.data[TPM_HEADER_SIZE + 6];
637
638                 memcpy(payload->key, data, data_len - 1);
639                 payload->key_len = data_len - 1;
640                 payload->migratable = data[data_len - 1];
641         }
642
643 out:
644         tpm_buf_destroy(&buf);
645         return rc;
646 }
647
648 /**
649  * tpm2_unseal_trusted() - unseal the payload of a trusted key
650  *
651  * @chip: TPM chip to use
652  * @payload: the key data in clear and encrypted form
653  * @options: authentication values and other options
654  *
655  * Return: Same as with tpm_transmit_cmd.
656  */
657 int tpm2_unseal_trusted(struct tpm_chip *chip,
658                         struct trusted_key_payload *payload,
659                         struct trusted_key_options *options)
660 {
661         u32 blob_handle;
662         int rc;
663
664         rc = tpm2_load_cmd(chip, payload, options, &blob_handle);
665         if (rc)
666                 return rc;
667
668         rc = tpm2_unseal_cmd(chip, payload, options, blob_handle);
669         tpm2_flush_context(chip, blob_handle);
670         return rc;
671 }
672
673 struct tpm2_get_cap_out {
674         u8 more_data;
675         __be32 subcap_id;
676         __be32 property_cnt;
677         __be32 property_id;
678         __be32 value;
679 } __packed;
680
681 /**
682  * tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property
683  * @chip:               a &tpm_chip instance
684  * @property_id:        property ID.
685  * @value:              output variable.
686  * @desc:               passed to tpm_transmit_cmd()
687  *
688  * Return:
689  *   0 on success,
690  *   -errno or a TPM return code otherwise
691  */
692 ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,  u32 *value,
693                         const char *desc)
694 {
695         struct tpm2_get_cap_out *out;
696         struct tpm_buf buf;
697         int rc;
698
699         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
700         if (rc)
701                 return rc;
702         tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
703         tpm_buf_append_u32(&buf, property_id);
704         tpm_buf_append_u32(&buf, 1);
705         rc = tpm_transmit_cmd(chip, &buf, 0, NULL);
706         if (!rc) {
707                 out = (struct tpm2_get_cap_out *)
708                         &buf.data[TPM_HEADER_SIZE];
709                 *value = be32_to_cpu(out->value);
710         }
711         tpm_buf_destroy(&buf);
712         return rc;
713 }
714 EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt);
715
716 /**
717  * tpm2_shutdown() - send a TPM shutdown command
718  *
719  * Sends a TPM shutdown command. The shutdown command is used in call
720  * sites where the system is going down. If it fails, there is not much
721  * that can be done except print an error message.
722  *
723  * @chip:               a &tpm_chip instance
724  * @shutdown_type:      TPM_SU_CLEAR or TPM_SU_STATE.
725  */
726 void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
727 {
728         struct tpm_buf buf;
729         int rc;
730
731         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SHUTDOWN);
732         if (rc)
733                 return;
734         tpm_buf_append_u16(&buf, shutdown_type);
735         tpm_transmit_cmd(chip, &buf, 0, "stopping the TPM");
736         tpm_buf_destroy(&buf);
737 }
738
739 /**
740  * tpm2_do_selftest() - ensure that all self tests have passed
741  *
742  * @chip: TPM chip to use
743  *
744  * Return: Same as with tpm_transmit_cmd.
745  *
746  * The TPM can either run all self tests synchronously and then return
747  * RC_SUCCESS once all tests were successful. Or it can choose to run the tests
748  * asynchronously and return RC_TESTING immediately while the self tests still
749  * execute in the background. This function handles both cases and waits until
750  * all tests have completed.
751  */
752 static int tpm2_do_selftest(struct tpm_chip *chip)
753 {
754         struct tpm_buf buf;
755         int full;
756         int rc;
757
758         for (full = 0; full < 2; full++) {
759                 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SELF_TEST);
760                 if (rc)
761                         return rc;
762
763                 tpm_buf_append_u8(&buf, full);
764                 rc = tpm_transmit_cmd(chip, &buf, 0,
765                                       "attempting the self test");
766                 tpm_buf_destroy(&buf);
767
768                 if (rc == TPM2_RC_TESTING)
769                         rc = TPM2_RC_SUCCESS;
770                 if (rc == TPM2_RC_INITIALIZE || rc == TPM2_RC_SUCCESS)
771                         return rc;
772         }
773
774         return rc;
775 }
776
777 /**
778  * tpm2_probe() - probe for the TPM 2.0 protocol
779  * @chip:       a &tpm_chip instance
780  *
781  * Send an idempotent TPM 2.0 command and see whether there is TPM2 chip in the
782  * other end based on the response tag. The flag TPM_CHIP_FLAG_TPM2 is set by
783  * this function if this is the case.
784  *
785  * Return:
786  *   0 on success,
787  *   -errno otherwise
788  */
789 int tpm2_probe(struct tpm_chip *chip)
790 {
791         struct tpm_header *out;
792         struct tpm_buf buf;
793         int rc;
794
795         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
796         if (rc)
797                 return rc;
798         tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
799         tpm_buf_append_u32(&buf, TPM_PT_TOTAL_COMMANDS);
800         tpm_buf_append_u32(&buf, 1);
801         rc = tpm_transmit_cmd(chip, &buf, 0, NULL);
802         /* We ignore TPM return codes on purpose. */
803         if (rc >=  0) {
804                 out = (struct tpm_header *)buf.data;
805                 if (be16_to_cpu(out->tag) == TPM2_ST_NO_SESSIONS)
806                         chip->flags |= TPM_CHIP_FLAG_TPM2;
807         }
808         tpm_buf_destroy(&buf);
809         return 0;
810 }
811 EXPORT_SYMBOL_GPL(tpm2_probe);
812
813 static int tpm2_init_bank_info(struct tpm_chip *chip, u32 bank_index)
814 {
815         struct tpm_bank_info *bank = chip->allocated_banks + bank_index;
816         struct tpm_digest digest = { .alg_id = bank->alg_id };
817         int i;
818
819         /*
820          * Avoid unnecessary PCR read operations to reduce overhead
821          * and obtain identifiers of the crypto subsystem.
822          */
823         for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
824                 enum hash_algo crypto_algo = tpm2_hash_map[i].crypto_id;
825
826                 if (bank->alg_id != tpm2_hash_map[i].tpm_id)
827                         continue;
828
829                 bank->digest_size = hash_digest_size[crypto_algo];
830                 bank->crypto_id = crypto_algo;
831                 return 0;
832         }
833
834         return tpm2_pcr_read(chip, 0, &digest, &bank->digest_size);
835 }
836
837 struct tpm2_pcr_selection {
838         __be16  hash_alg;
839         u8  size_of_select;
840         u8  pcr_select[3];
841 } __packed;
842
843 static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
844 {
845         struct tpm2_pcr_selection pcr_selection;
846         struct tpm_buf buf;
847         void *marker;
848         void *end;
849         void *pcr_select_offset;
850         u32 sizeof_pcr_selection;
851         u32 nr_possible_banks;
852         u32 nr_alloc_banks = 0;
853         u16 hash_alg;
854         u32 rsp_len;
855         int rc;
856         int i = 0;
857
858         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
859         if (rc)
860                 return rc;
861
862         tpm_buf_append_u32(&buf, TPM2_CAP_PCRS);
863         tpm_buf_append_u32(&buf, 0);
864         tpm_buf_append_u32(&buf, 1);
865
866         rc = tpm_transmit_cmd(chip, &buf, 9, "get tpm pcr allocation");
867         if (rc)
868                 goto out;
869
870         nr_possible_banks = be32_to_cpup(
871                 (__be32 *)&buf.data[TPM_HEADER_SIZE + 5]);
872
873         chip->allocated_banks = kcalloc(nr_possible_banks,
874                                         sizeof(*chip->allocated_banks),
875                                         GFP_KERNEL);
876         if (!chip->allocated_banks) {
877                 rc = -ENOMEM;
878                 goto out;
879         }
880
881         marker = &buf.data[TPM_HEADER_SIZE + 9];
882
883         rsp_len = be32_to_cpup((__be32 *)&buf.data[2]);
884         end = &buf.data[rsp_len];
885
886         for (i = 0; i < nr_possible_banks; i++) {
887                 pcr_select_offset = marker +
888                         offsetof(struct tpm2_pcr_selection, size_of_select);
889                 if (pcr_select_offset >= end) {
890                         rc = -EFAULT;
891                         break;
892                 }
893
894                 memcpy(&pcr_selection, marker, sizeof(pcr_selection));
895                 hash_alg = be16_to_cpu(pcr_selection.hash_alg);
896
897                 pcr_select_offset = memchr_inv(pcr_selection.pcr_select, 0,
898                                                pcr_selection.size_of_select);
899                 if (pcr_select_offset) {
900                         chip->allocated_banks[nr_alloc_banks].alg_id = hash_alg;
901
902                         rc = tpm2_init_bank_info(chip, nr_alloc_banks);
903                         if (rc < 0)
904                                 break;
905
906                         nr_alloc_banks++;
907                 }
908
909                 sizeof_pcr_selection = sizeof(pcr_selection.hash_alg) +
910                         sizeof(pcr_selection.size_of_select) +
911                         pcr_selection.size_of_select;
912                 marker = marker + sizeof_pcr_selection;
913         }
914
915         chip->nr_allocated_banks = nr_alloc_banks;
916 out:
917         tpm_buf_destroy(&buf);
918
919         return rc;
920 }
921
922 static int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip)
923 {
924         struct tpm_buf buf;
925         u32 nr_commands;
926         __be32 *attrs;
927         u32 cc;
928         int i;
929         int rc;
930
931         rc = tpm2_get_tpm_pt(chip, TPM_PT_TOTAL_COMMANDS, &nr_commands, NULL);
932         if (rc)
933                 goto out;
934
935         if (nr_commands > 0xFFFFF) {
936                 rc = -EFAULT;
937                 goto out;
938         }
939
940         chip->cc_attrs_tbl = devm_kcalloc(&chip->dev, 4, nr_commands,
941                                           GFP_KERNEL);
942
943         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
944         if (rc)
945                 goto out;
946
947         tpm_buf_append_u32(&buf, TPM2_CAP_COMMANDS);
948         tpm_buf_append_u32(&buf, TPM2_CC_FIRST);
949         tpm_buf_append_u32(&buf, nr_commands);
950
951         rc = tpm_transmit_cmd(chip, &buf, 9 + 4 * nr_commands, NULL);
952         if (rc) {
953                 tpm_buf_destroy(&buf);
954                 goto out;
955         }
956
957         if (nr_commands !=
958             be32_to_cpup((__be32 *)&buf.data[TPM_HEADER_SIZE + 5])) {
959                 tpm_buf_destroy(&buf);
960                 goto out;
961         }
962
963         chip->nr_commands = nr_commands;
964
965         attrs = (__be32 *)&buf.data[TPM_HEADER_SIZE + 9];
966         for (i = 0; i < nr_commands; i++, attrs++) {
967                 chip->cc_attrs_tbl[i] = be32_to_cpup(attrs);
968                 cc = chip->cc_attrs_tbl[i] & 0xFFFF;
969
970                 if (cc == TPM2_CC_CONTEXT_SAVE || cc == TPM2_CC_FLUSH_CONTEXT) {
971                         chip->cc_attrs_tbl[i] &=
972                                 ~(GENMASK(2, 0) << TPM2_CC_ATTR_CHANDLES);
973                         chip->cc_attrs_tbl[i] |= 1 << TPM2_CC_ATTR_CHANDLES;
974                 }
975         }
976
977         tpm_buf_destroy(&buf);
978
979 out:
980         if (rc > 0)
981                 rc = -ENODEV;
982         return rc;
983 }
984
985 /**
986  * tpm2_startup - turn on the TPM
987  * @chip: TPM chip to use
988  *
989  * Normally the firmware should start the TPM. This function is provided as a
990  * workaround if this does not happen. A legal case for this could be for
991  * example when a TPM emulator is used.
992  *
993  * Return: same as tpm_transmit_cmd()
994  */
995
996 static int tpm2_startup(struct tpm_chip *chip)
997 {
998         struct tpm_buf buf;
999         int rc;
1000
1001         dev_info(&chip->dev, "starting up the TPM manually\n");
1002
1003         rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP);
1004         if (rc < 0)
1005                 return rc;
1006
1007         tpm_buf_append_u16(&buf, TPM2_SU_CLEAR);
1008         rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to start the TPM");
1009         tpm_buf_destroy(&buf);
1010
1011         return rc;
1012 }
1013
1014 /**
1015  * tpm2_auto_startup - Perform the standard automatic TPM initialization
1016  *                     sequence
1017  * @chip: TPM chip to use
1018  *
1019  * Returns 0 on success, < 0 in case of fatal error.
1020  */
1021 int tpm2_auto_startup(struct tpm_chip *chip)
1022 {
1023         int rc;
1024
1025         rc = tpm2_get_timeouts(chip);
1026         if (rc)
1027                 goto out;
1028
1029         rc = tpm2_do_selftest(chip);
1030         if (rc && rc != TPM2_RC_INITIALIZE)
1031                 goto out;
1032
1033         if (rc == TPM2_RC_INITIALIZE) {
1034                 rc = tpm2_startup(chip);
1035                 if (rc)
1036                         goto out;
1037
1038                 rc = tpm2_do_selftest(chip);
1039                 if (rc)
1040                         goto out;
1041         }
1042
1043         rc = tpm2_get_pcr_allocation(chip);
1044         if (rc)
1045                 goto out;
1046
1047         rc = tpm2_get_cc_attrs_tbl(chip);
1048
1049 out:
1050         if (rc > 0)
1051                 rc = -ENODEV;
1052         return rc;
1053 }
1054
1055 int tpm2_find_cc(struct tpm_chip *chip, u32 cc)
1056 {
1057         int i;
1058
1059         for (i = 0; i < chip->nr_commands; i++)
1060                 if (cc == (chip->cc_attrs_tbl[i] & GENMASK(15, 0)))
1061                         return i;
1062
1063         return -1;
1064 }