1 /*
2 * Copyright (C) 2014, 2015 Intel Corporation
3 *
4 * Authors:
5 * Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
6 *
7 * Maintained by: <tpmdd-devel@lists.sourceforge.net>
8 *
9 * This file contains TPM2 protocol implementations of the commands
10 * used by the kernel internally.
11 *
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License
14 * as published by the Free Software Foundation; version 2
15 * of the License.
16 */
17
18 #include "tpm.h"
19 #include <crypto/hash_info.h>
20 #include <keys/trusted-type.h>
21
22 enum tpm2_object_attributes {
23 TPM2_OA_USER_WITH_AUTH = BIT(6),
24 };
25
26 enum tpm2_session_attributes {
27 TPM2_SA_CONTINUE_SESSION = BIT(0),
28 };
29
30 struct tpm2_startup_in {
31 __be16 startup_type;
32 } __packed;
33
34 struct tpm2_self_test_in {
35 u8 full_test;
36 } __packed;
37
38 struct tpm2_pcr_read_in {
39 __be32 pcr_selects_cnt;
40 __be16 hash_alg;
41 u8 pcr_select_size;
42 u8 pcr_select[TPM2_PCR_SELECT_MIN];
43 } __packed;
44
45 struct tpm2_pcr_read_out {
46 __be32 update_cnt;
47 __be32 pcr_selects_cnt;
48 __be16 hash_alg;
49 u8 pcr_select_size;
50 u8 pcr_select[TPM2_PCR_SELECT_MIN];
51 __be32 digests_cnt;
52 __be16 digest_size;
53 u8 digest[TPM_DIGEST_SIZE];
54 } __packed;
55
56 struct tpm2_null_auth_area {
57 __be32 handle;
58 __be16 nonce_size;
59 u8 attributes;
60 __be16 auth_size;
61 } __packed;
62
63 struct tpm2_pcr_extend_in {
64 __be32 pcr_idx;
65 __be32 auth_area_size;
66 struct tpm2_null_auth_area auth_area;
67 __be32 digest_cnt;
68 __be16 hash_alg;
69 u8 digest[TPM_DIGEST_SIZE];
70 } __packed;
71
72 struct tpm2_get_tpm_pt_in {
73 __be32 cap_id;
74 __be32 property_id;
75 __be32 property_cnt;
76 } __packed;
77
78 struct tpm2_get_tpm_pt_out {
79 u8 more_data;
80 __be32 subcap_id;
81 __be32 property_cnt;
82 __be32 property_id;
83 __be32 value;
84 } __packed;
85
86 struct tpm2_get_random_in {
87 __be16 size;
88 } __packed;
89
90 struct tpm2_get_random_out {
91 __be16 size;
92 u8 buffer[TPM_MAX_RNG_DATA];
93 } __packed;
94
95 union tpm2_cmd_params {
96 struct tpm2_startup_in startup_in;
97 struct tpm2_self_test_in selftest_in;
98 struct tpm2_pcr_read_in pcrread_in;
99 struct tpm2_pcr_read_out pcrread_out;
100 struct tpm2_pcr_extend_in pcrextend_in;
101 struct tpm2_get_tpm_pt_in get_tpm_pt_in;
102 struct tpm2_get_tpm_pt_out get_tpm_pt_out;
103 struct tpm2_get_random_in getrandom_in;
104 struct tpm2_get_random_out getrandom_out;
105 };
106
107 struct tpm2_cmd {
108 tpm_cmd_header header;
109 union tpm2_cmd_params params;
110 } __packed;
111
112 struct tpm2_hash {
113 unsigned int crypto_id;
114 unsigned int tpm_id;
115 };
116
117 static struct tpm2_hash tpm2_hash_map[] = {
118 {HASH_ALGO_SHA1, TPM2_ALG_SHA1},
119 {HASH_ALGO_SHA256, TPM2_ALG_SHA256},
120 {HASH_ALGO_SHA384, TPM2_ALG_SHA384},
121 {HASH_ALGO_SHA512, TPM2_ALG_SHA512},
122 {HASH_ALGO_SM3_256, TPM2_ALG_SM3_256},
123 };
124
125 /*
126 * Array with one entry per ordinal defining the maximum amount
127 * of time the chip could take to return the result. The values
128 * of the SHORT, MEDIUM, and LONG durations are taken from the
129 * PC Client Profile (PTP) specification.
130 */
131 static const u8 tpm2_ordinal_duration[TPM2_CC_LAST - TPM2_CC_FIRST + 1] = {
132 TPM_UNDEFINED, /* 11F */
133 TPM_UNDEFINED, /* 120 */
134 TPM_LONG, /* 121 */
135 TPM_UNDEFINED, /* 122 */
136 TPM_UNDEFINED, /* 123 */
137 TPM_UNDEFINED, /* 124 */
138 TPM_UNDEFINED, /* 125 */
139 TPM_UNDEFINED, /* 126 */
140 TPM_UNDEFINED, /* 127 */
141 TPM_UNDEFINED, /* 128 */
142 TPM_LONG, /* 129 */
143 TPM_UNDEFINED, /* 12a */
144 TPM_UNDEFINED, /* 12b */
145 TPM_UNDEFINED, /* 12c */
146 TPM_UNDEFINED, /* 12d */
147 TPM_UNDEFINED, /* 12e */
148 TPM_UNDEFINED, /* 12f */
149 TPM_UNDEFINED, /* 130 */
150 TPM_UNDEFINED, /* 131 */
151 TPM_UNDEFINED, /* 132 */
152 TPM_UNDEFINED, /* 133 */
153 TPM_UNDEFINED, /* 134 */
154 TPM_UNDEFINED, /* 135 */
155 TPM_UNDEFINED, /* 136 */
156 TPM_UNDEFINED, /* 137 */
157 TPM_UNDEFINED, /* 138 */
158 TPM_UNDEFINED, /* 139 */
159 TPM_UNDEFINED, /* 13a */
160 TPM_UNDEFINED, /* 13b */
161 TPM_UNDEFINED, /* 13c */
162 TPM_UNDEFINED, /* 13d */
163 TPM_MEDIUM, /* 13e */
164 TPM_UNDEFINED, /* 13f */
165 TPM_UNDEFINED, /* 140 */
166 TPM_UNDEFINED, /* 141 */
167 TPM_UNDEFINED, /* 142 */
168 TPM_LONG, /* 143 */
169 TPM_MEDIUM, /* 144 */
170 TPM_UNDEFINED, /* 145 */
171 TPM_UNDEFINED, /* 146 */
172 TPM_UNDEFINED, /* 147 */
173 TPM_UNDEFINED, /* 148 */
174 TPM_UNDEFINED, /* 149 */
175 TPM_UNDEFINED, /* 14a */
176 TPM_UNDEFINED, /* 14b */
177 TPM_UNDEFINED, /* 14c */
178 TPM_UNDEFINED, /* 14d */
179 TPM_LONG, /* 14e */
180 TPM_UNDEFINED, /* 14f */
181 TPM_UNDEFINED, /* 150 */
182 TPM_UNDEFINED, /* 151 */
183 TPM_UNDEFINED, /* 152 */
184 TPM_UNDEFINED, /* 153 */
185 TPM_UNDEFINED, /* 154 */
186 TPM_UNDEFINED, /* 155 */
187 TPM_UNDEFINED, /* 156 */
188 TPM_UNDEFINED, /* 157 */
189 TPM_UNDEFINED, /* 158 */
190 TPM_UNDEFINED, /* 159 */
191 TPM_UNDEFINED, /* 15a */
192 TPM_UNDEFINED, /* 15b */
193 TPM_MEDIUM, /* 15c */
194 TPM_UNDEFINED, /* 15d */
195 TPM_UNDEFINED, /* 15e */
196 TPM_UNDEFINED, /* 15f */
197 TPM_UNDEFINED, /* 160 */
198 TPM_UNDEFINED, /* 161 */
199 TPM_UNDEFINED, /* 162 */
200 TPM_UNDEFINED, /* 163 */
201 TPM_UNDEFINED, /* 164 */
202 TPM_UNDEFINED, /* 165 */
203 TPM_UNDEFINED, /* 166 */
204 TPM_UNDEFINED, /* 167 */
205 TPM_UNDEFINED, /* 168 */
206 TPM_UNDEFINED, /* 169 */
207 TPM_UNDEFINED, /* 16a */
208 TPM_UNDEFINED, /* 16b */
209 TPM_UNDEFINED, /* 16c */
210 TPM_UNDEFINED, /* 16d */
211 TPM_UNDEFINED, /* 16e */
212 TPM_UNDEFINED, /* 16f */
213 TPM_UNDEFINED, /* 170 */
214 TPM_UNDEFINED, /* 171 */
215 TPM_UNDEFINED, /* 172 */
216 TPM_UNDEFINED, /* 173 */
217 TPM_UNDEFINED, /* 174 */
218 TPM_UNDEFINED, /* 175 */
219 TPM_UNDEFINED, /* 176 */
220 TPM_LONG, /* 177 */
221 TPM_UNDEFINED, /* 178 */
222 TPM_UNDEFINED, /* 179 */
223 TPM_MEDIUM, /* 17a */
224 TPM_LONG, /* 17b */
225 TPM_UNDEFINED, /* 17c */
226 TPM_UNDEFINED, /* 17d */
227 TPM_UNDEFINED, /* 17e */
228 TPM_UNDEFINED, /* 17f */
229 TPM_UNDEFINED, /* 180 */
230 TPM_UNDEFINED, /* 181 */
231 TPM_MEDIUM, /* 182 */
232 TPM_UNDEFINED, /* 183 */
233 TPM_UNDEFINED, /* 184 */
234 TPM_MEDIUM, /* 185 */
235 TPM_MEDIUM, /* 186 */
236 TPM_UNDEFINED, /* 187 */
237 TPM_UNDEFINED, /* 188 */
238 TPM_UNDEFINED, /* 189 */
239 TPM_UNDEFINED, /* 18a */
240 TPM_UNDEFINED, /* 18b */
241 TPM_UNDEFINED, /* 18c */
242 TPM_UNDEFINED, /* 18d */
243 TPM_UNDEFINED, /* 18e */
244 TPM_UNDEFINED /* 18f */
245 };
246
247 #define TPM2_PCR_READ_IN_SIZE \
248 (sizeof(struct tpm_input_header) + \
249 sizeof(struct tpm2_pcr_read_in))
250
251 static const struct tpm_input_header tpm2_pcrread_header = {
252 .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
253 .length = cpu_to_be32(TPM2_PCR_READ_IN_SIZE),
254 .ordinal = cpu_to_be32(TPM2_CC_PCR_READ)
255 };
256
257 /**
258 * tpm2_pcr_read() - read a PCR value
259 * @chip: TPM chip to use.
260 * @pcr_idx: index of the PCR to read.
261 * @ref_buf: buffer to store the resulting hash,
262 *
263 * 0 is returned when the operation is successful. If a negative number is
264 * returned it remarks a POSIX error code. If a positive number is returned
265 * it remarks a TPM error.
266 */
tpm2_pcr_read(struct tpm_chip * chip,int pcr_idx,u8 * res_buf)267 int tpm2_pcr_read(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)
268 {
269 int rc;
270 struct tpm2_cmd cmd;
271 u8 *buf;
272
273 if (pcr_idx >= TPM2_PLATFORM_PCR)
274 return -EINVAL;
275
276 cmd.header.in = tpm2_pcrread_header;
277 cmd.params.pcrread_in.pcr_selects_cnt = cpu_to_be32(1);
278 cmd.params.pcrread_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
279 cmd.params.pcrread_in.pcr_select_size = TPM2_PCR_SELECT_MIN;
280
281 memset(cmd.params.pcrread_in.pcr_select, 0,
282 sizeof(cmd.params.pcrread_in.pcr_select));
283 cmd.params.pcrread_in.pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7);
284
285 rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0,
286 "attempting to read a pcr value");
287 if (rc == 0) {
288 buf = cmd.params.pcrread_out.digest;
289 memcpy(res_buf, buf, TPM_DIGEST_SIZE);
290 }
291
292 return rc;
293 }
294
295 #define TPM2_GET_PCREXTEND_IN_SIZE \
296 (sizeof(struct tpm_input_header) + \
297 sizeof(struct tpm2_pcr_extend_in))
298
299 static const struct tpm_input_header tpm2_pcrextend_header = {
300 .tag = cpu_to_be16(TPM2_ST_SESSIONS),
301 .length = cpu_to_be32(TPM2_GET_PCREXTEND_IN_SIZE),
302 .ordinal = cpu_to_be32(TPM2_CC_PCR_EXTEND)
303 };
304
305 /**
306 * tpm2_pcr_extend() - extend a PCR value
307 * @chip: TPM chip to use.
308 * @pcr_idx: index of the PCR.
309 * @hash: hash value to use for the extend operation.
310 *
311 * 0 is returned when the operation is successful. If a negative number is
312 * returned it remarks a POSIX error code. If a positive number is returned
313 * it remarks a TPM error.
314 */
tpm2_pcr_extend(struct tpm_chip * chip,int pcr_idx,const u8 * hash)315 int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash)
316 {
317 struct tpm2_cmd cmd;
318 int rc;
319
320 cmd.header.in = tpm2_pcrextend_header;
321 cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
322 cmd.params.pcrextend_in.auth_area_size =
323 cpu_to_be32(sizeof(struct tpm2_null_auth_area));
324 cmd.params.pcrextend_in.auth_area.handle =
325 cpu_to_be32(TPM2_RS_PW);
326 cmd.params.pcrextend_in.auth_area.nonce_size = 0;
327 cmd.params.pcrextend_in.auth_area.attributes = 0;
328 cmd.params.pcrextend_in.auth_area.auth_size = 0;
329 cmd.params.pcrextend_in.digest_cnt = cpu_to_be32(1);
330 cmd.params.pcrextend_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
331 memcpy(cmd.params.pcrextend_in.digest, hash, TPM_DIGEST_SIZE);
332
333 rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0,
334 "attempting extend a PCR value");
335
336 return rc;
337 }
338
339 #define TPM2_GETRANDOM_IN_SIZE \
340 (sizeof(struct tpm_input_header) + \
341 sizeof(struct tpm2_get_random_in))
342
343 static const struct tpm_input_header tpm2_getrandom_header = {
344 .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
345 .length = cpu_to_be32(TPM2_GETRANDOM_IN_SIZE),
346 .ordinal = cpu_to_be32(TPM2_CC_GET_RANDOM)
347 };
348
349 /**
350 * tpm2_get_random() - get random bytes from the TPM RNG
351 * @chip: TPM chip to use
352 * @out: destination buffer for the random bytes
353 * @max: the max number of bytes to write to @out
354 *
355 * 0 is returned when the operation is successful. If a negative number is
356 * returned it remarks a POSIX error code. If a positive number is returned
357 * it remarks a TPM error.
358 */
tpm2_get_random(struct tpm_chip * chip,u8 * out,size_t max)359 int tpm2_get_random(struct tpm_chip *chip, u8 *out, size_t max)
360 {
361 struct tpm2_cmd cmd;
362 u32 recd;
363 u32 num_bytes;
364 int err;
365 int total = 0;
366 int retries = 5;
367 u8 *dest = out;
368
369 num_bytes = min_t(u32, max, sizeof(cmd.params.getrandom_out.buffer));
370
371 if (!out || !num_bytes ||
372 max > sizeof(cmd.params.getrandom_out.buffer))
373 return -EINVAL;
374
375 do {
376 cmd.header.in = tpm2_getrandom_header;
377 cmd.params.getrandom_in.size = cpu_to_be16(num_bytes);
378
379 err = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0,
380 "attempting get random");
381 if (err)
382 break;
383
384 recd = min_t(u32, be16_to_cpu(cmd.params.getrandom_out.size),
385 num_bytes);
386 memcpy(dest, cmd.params.getrandom_out.buffer, recd);
387
388 dest += recd;
389 total += recd;
390 num_bytes -= recd;
391 } while (retries-- && total < max);
392
393 return total ? total : -EIO;
394 }
395
396 #define TPM2_GET_TPM_PT_IN_SIZE \
397 (sizeof(struct tpm_input_header) + \
398 sizeof(struct tpm2_get_tpm_pt_in))
399
400 static const struct tpm_input_header tpm2_get_tpm_pt_header = {
401 .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
402 .length = cpu_to_be32(TPM2_GET_TPM_PT_IN_SIZE),
403 .ordinal = cpu_to_be32(TPM2_CC_GET_CAPABILITY)
404 };
405
406 /**
407 * Append TPMS_AUTH_COMMAND to the buffer. The buffer must be allocated with
408 * tpm_buf_alloc().
409 *
410 * @param buf: an allocated tpm_buf instance
411 * @param nonce: the session nonce, may be NULL if not used
412 * @param nonce_len: the session nonce length, may be 0 if not used
413 * @param attributes: the session attributes
414 * @param hmac: the session HMAC or password, may be NULL if not used
415 * @param hmac_len: the session HMAC or password length, maybe 0 if not used
416 */
tpm2_buf_append_auth(struct tpm_buf * buf,u32 session_handle,const u8 * nonce,u16 nonce_len,u8 attributes,const u8 * hmac,u16 hmac_len)417 static void tpm2_buf_append_auth(struct tpm_buf *buf, u32 session_handle,
418 const u8 *nonce, u16 nonce_len,
419 u8 attributes,
420 const u8 *hmac, u16 hmac_len)
421 {
422 tpm_buf_append_u32(buf, 9 + nonce_len + hmac_len);
423 tpm_buf_append_u32(buf, session_handle);
424 tpm_buf_append_u16(buf, nonce_len);
425
426 if (nonce && nonce_len)
427 tpm_buf_append(buf, nonce, nonce_len);
428
429 tpm_buf_append_u8(buf, attributes);
430 tpm_buf_append_u16(buf, hmac_len);
431
432 if (hmac && hmac_len)
433 tpm_buf_append(buf, hmac, hmac_len);
434 }
435
436 /**
437 * tpm2_seal_trusted() - seal the payload of a trusted key
438 * @chip_num: TPM chip to use
439 * @payload: the key data in clear and encrypted form
440 * @options: authentication values and other options
441 *
442 * Return: < 0 on error and 0 on success.
443 */
tpm2_seal_trusted(struct tpm_chip * chip,struct trusted_key_payload * payload,struct trusted_key_options * options)444 int tpm2_seal_trusted(struct tpm_chip *chip,
445 struct trusted_key_payload *payload,
446 struct trusted_key_options *options)
447 {
448 unsigned int blob_len;
449 struct tpm_buf buf;
450 u32 hash;
451 int i;
452 int rc;
453
454 for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
455 if (options->hash == tpm2_hash_map[i].crypto_id) {
456 hash = tpm2_hash_map[i].tpm_id;
457 break;
458 }
459 }
460
461 if (i == ARRAY_SIZE(tpm2_hash_map))
462 return -EINVAL;
463
464 rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE);
465 if (rc)
466 return rc;
467
468 tpm_buf_append_u32(&buf, options->keyhandle);
469 tpm2_buf_append_auth(&buf, TPM2_RS_PW,
470 NULL /* nonce */, 0,
471 0 /* session_attributes */,
472 options->keyauth /* hmac */,
473 TPM_DIGEST_SIZE);
474
475 /* sensitive */
476 tpm_buf_append_u16(&buf, 4 + TPM_DIGEST_SIZE + payload->key_len + 1);
477
478 tpm_buf_append_u16(&buf, TPM_DIGEST_SIZE);
479 tpm_buf_append(&buf, options->blobauth, TPM_DIGEST_SIZE);
480 tpm_buf_append_u16(&buf, payload->key_len + 1);
481 tpm_buf_append(&buf, payload->key, payload->key_len);
482 tpm_buf_append_u8(&buf, payload->migratable);
483
484 /* public */
485 tpm_buf_append_u16(&buf, 14 + options->policydigest_len);
486 tpm_buf_append_u16(&buf, TPM2_ALG_KEYEDHASH);
487 tpm_buf_append_u16(&buf, hash);
488
489 /* policy */
490 if (options->policydigest_len) {
491 tpm_buf_append_u32(&buf, 0);
492 tpm_buf_append_u16(&buf, options->policydigest_len);
493 tpm_buf_append(&buf, options->policydigest,
494 options->policydigest_len);
495 } else {
496 tpm_buf_append_u32(&buf, TPM2_OA_USER_WITH_AUTH);
497 tpm_buf_append_u16(&buf, 0);
498 }
499
500 /* public parameters */
501 tpm_buf_append_u16(&buf, TPM2_ALG_NULL);
502 tpm_buf_append_u16(&buf, 0);
503
504 /* outside info */
505 tpm_buf_append_u16(&buf, 0);
506
507 /* creation PCR */
508 tpm_buf_append_u32(&buf, 0);
509
510 if (buf.flags & TPM_BUF_OVERFLOW) {
511 rc = -E2BIG;
512 goto out;
513 }
514
515 rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, 0, "sealing data");
516 if (rc)
517 goto out;
518
519 blob_len = be32_to_cpup((__be32 *) &buf.data[TPM_HEADER_SIZE]);
520 if (blob_len > MAX_BLOB_SIZE) {
521 rc = -E2BIG;
522 goto out;
523 }
524
525 memcpy(payload->blob, &buf.data[TPM_HEADER_SIZE + 4], blob_len);
526 payload->blob_len = blob_len;
527
528 out:
529 tpm_buf_destroy(&buf);
530
531 if (rc > 0) {
532 if (tpm2_rc_value(rc) == TPM2_RC_HASH)
533 rc = -EINVAL;
534 else
535 rc = -EPERM;
536 }
537
538 return rc;
539 }
540
541 /**
542 * tpm2_load_cmd() - execute a TPM2_Load command
543 * @chip_num: TPM chip to use
544 * @payload: the key data in clear and encrypted form
545 * @options: authentication values and other options
546 *
547 * Return: same as with tpm_transmit_cmd
548 */
tpm2_load_cmd(struct tpm_chip * chip,struct trusted_key_payload * payload,struct trusted_key_options * options,u32 * blob_handle,unsigned int flags)549 static int tpm2_load_cmd(struct tpm_chip *chip,
550 struct trusted_key_payload *payload,
551 struct trusted_key_options *options,
552 u32 *blob_handle, unsigned int flags)
553 {
554 struct tpm_buf buf;
555 unsigned int private_len;
556 unsigned int public_len;
557 unsigned int blob_len;
558 int rc;
559
560 private_len = be16_to_cpup((__be16 *) &payload->blob[0]);
561 if (private_len > (payload->blob_len - 2))
562 return -E2BIG;
563
564 public_len = be16_to_cpup((__be16 *) &payload->blob[2 + private_len]);
565 blob_len = private_len + public_len + 4;
566 if (blob_len > payload->blob_len)
567 return -E2BIG;
568
569 rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
570 if (rc)
571 return rc;
572
573 tpm_buf_append_u32(&buf, options->keyhandle);
574 tpm2_buf_append_auth(&buf, TPM2_RS_PW,
575 NULL /* nonce */, 0,
576 0 /* session_attributes */,
577 options->keyauth /* hmac */,
578 TPM_DIGEST_SIZE);
579
580 tpm_buf_append(&buf, payload->blob, blob_len);
581
582 if (buf.flags & TPM_BUF_OVERFLOW) {
583 rc = -E2BIG;
584 goto out;
585 }
586
587 rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, flags, "loading blob");
588 if (!rc)
589 *blob_handle = be32_to_cpup(
590 (__be32 *) &buf.data[TPM_HEADER_SIZE]);
591
592 out:
593 tpm_buf_destroy(&buf);
594
595 if (rc > 0)
596 rc = -EPERM;
597
598 return rc;
599 }
600
601 /**
602 * tpm2_flush_context_cmd() - execute a TPM2_FlushContext command
603 * @chip_num: TPM chip to use
604 * @payload: the key data in clear and encrypted form
605 * @options: authentication values and other options
606 *
607 * Return: same as with tpm_transmit_cmd
608 */
tpm2_flush_context_cmd(struct tpm_chip * chip,u32 handle,unsigned int flags)609 static void tpm2_flush_context_cmd(struct tpm_chip *chip, u32 handle,
610 unsigned int flags)
611 {
612 struct tpm_buf buf;
613 int rc;
614
615 rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_FLUSH_CONTEXT);
616 if (rc) {
617 dev_warn(&chip->dev, "0x%08x was not flushed, out of memory\n",
618 handle);
619 return;
620 }
621
622 tpm_buf_append_u32(&buf, handle);
623
624 rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, flags,
625 "flushing context");
626 if (rc)
627 dev_warn(&chip->dev, "0x%08x was not flushed, rc=%d\n", handle,
628 rc);
629
630 tpm_buf_destroy(&buf);
631 }
632
633 /**
634 * tpm2_unseal_cmd() - execute a TPM2_Unload command
635 * @chip_num: TPM chip to use
636 * @payload: the key data in clear and encrypted form
637 * @options: authentication values and other options
638 *
639 * Return: same as with tpm_transmit_cmd
640 */
tpm2_unseal_cmd(struct tpm_chip * chip,struct trusted_key_payload * payload,struct trusted_key_options * options,u32 blob_handle,unsigned int flags)641 static int tpm2_unseal_cmd(struct tpm_chip *chip,
642 struct trusted_key_payload *payload,
643 struct trusted_key_options *options,
644 u32 blob_handle, unsigned int flags)
645 {
646 struct tpm_buf buf;
647 u16 data_len;
648 u8 *data;
649 int rc;
650
651 rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL);
652 if (rc)
653 return rc;
654
655 tpm_buf_append_u32(&buf, blob_handle);
656 tpm2_buf_append_auth(&buf,
657 options->policyhandle ?
658 options->policyhandle : TPM2_RS_PW,
659 NULL /* nonce */, 0,
660 TPM2_SA_CONTINUE_SESSION,
661 options->blobauth /* hmac */,
662 TPM_DIGEST_SIZE);
663
664 rc = tpm_transmit_cmd(chip, buf.data, PAGE_SIZE, flags, "unsealing");
665 if (rc > 0)
666 rc = -EPERM;
667
668 if (!rc) {
669 data_len = be16_to_cpup(
670 (__be16 *) &buf.data[TPM_HEADER_SIZE + 4]);
671 if (data_len < MIN_KEY_SIZE || data_len > MAX_KEY_SIZE + 1) {
672 rc = -EFAULT;
673 goto out;
674 }
675
676 data = &buf.data[TPM_HEADER_SIZE + 6];
677
678 memcpy(payload->key, data, data_len - 1);
679 payload->key_len = data_len - 1;
680 payload->migratable = data[data_len - 1];
681 }
682
683 out:
684 tpm_buf_destroy(&buf);
685 return rc;
686 }
687
688 /**
689 * tpm_unseal_trusted() - unseal the payload of a trusted key
690 * @chip_num: TPM chip to use
691 * @payload: the key data in clear and encrypted form
692 * @options: authentication values and other options
693 *
694 * Return: < 0 on error and 0 on success.
695 */
tpm2_unseal_trusted(struct tpm_chip * chip,struct trusted_key_payload * payload,struct trusted_key_options * options)696 int tpm2_unseal_trusted(struct tpm_chip *chip,
697 struct trusted_key_payload *payload,
698 struct trusted_key_options *options)
699 {
700 u32 blob_handle;
701 int rc;
702
703 mutex_lock(&chip->tpm_mutex);
704 rc = tpm2_load_cmd(chip, payload, options, &blob_handle,
705 TPM_TRANSMIT_UNLOCKED);
706 if (rc)
707 goto out;
708
709 rc = tpm2_unseal_cmd(chip, payload, options, blob_handle,
710 TPM_TRANSMIT_UNLOCKED);
711 tpm2_flush_context_cmd(chip, blob_handle, TPM_TRANSMIT_UNLOCKED);
712 out:
713 mutex_unlock(&chip->tpm_mutex);
714 return rc;
715 }
716
717 /**
718 * tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property
719 * @chip: TPM chip to use.
720 * @property_id: property ID.
721 * @value: output variable.
722 * @desc: passed to tpm_transmit_cmd()
723 *
724 * 0 is returned when the operation is successful. If a negative number is
725 * returned it remarks a POSIX error code. If a positive number is returned
726 * it remarks a TPM error.
727 */
tpm2_get_tpm_pt(struct tpm_chip * chip,u32 property_id,u32 * value,const char * desc)728 ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id, u32 *value,
729 const char *desc)
730 {
731 struct tpm2_cmd cmd;
732 int rc;
733
734 cmd.header.in = tpm2_get_tpm_pt_header;
735 cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
736 cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(property_id);
737 cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
738
739 rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, desc);
740 if (!rc)
741 *value = be32_to_cpu(cmd.params.get_tpm_pt_out.value);
742
743 return rc;
744 }
745 EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt);
746
747 #define TPM2_STARTUP_IN_SIZE \
748 (sizeof(struct tpm_input_header) + \
749 sizeof(struct tpm2_startup_in))
750
751 static const struct tpm_input_header tpm2_startup_header = {
752 .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
753 .length = cpu_to_be32(TPM2_STARTUP_IN_SIZE),
754 .ordinal = cpu_to_be32(TPM2_CC_STARTUP)
755 };
756
757 /**
758 * tpm2_startup() - send startup command to the TPM chip
759 * @chip: TPM chip to use.
760 * @startup_type startup type. The value is either
761 * TPM_SU_CLEAR or TPM_SU_STATE.
762 *
763 * 0 is returned when the operation is successful. If a negative number is
764 * returned it remarks a POSIX error code. If a positive number is returned
765 * it remarks a TPM error.
766 */
tpm2_startup(struct tpm_chip * chip,u16 startup_type)767 static int tpm2_startup(struct tpm_chip *chip, u16 startup_type)
768 {
769 struct tpm2_cmd cmd;
770
771 cmd.header.in = tpm2_startup_header;
772
773 cmd.params.startup_in.startup_type = cpu_to_be16(startup_type);
774 return tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0,
775 "attempting to start the TPM");
776 }
777
778 #define TPM2_SHUTDOWN_IN_SIZE \
779 (sizeof(struct tpm_input_header) + \
780 sizeof(struct tpm2_startup_in))
781
782 static const struct tpm_input_header tpm2_shutdown_header = {
783 .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
784 .length = cpu_to_be32(TPM2_SHUTDOWN_IN_SIZE),
785 .ordinal = cpu_to_be32(TPM2_CC_SHUTDOWN)
786 };
787
788 /**
789 * tpm2_shutdown() - send shutdown command to the TPM chip
790 * @chip: TPM chip to use.
791 * @shutdown_type shutdown type. The value is either
792 * TPM_SU_CLEAR or TPM_SU_STATE.
793 */
tpm2_shutdown(struct tpm_chip * chip,u16 shutdown_type)794 void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
795 {
796 struct tpm2_cmd cmd;
797 int rc;
798
799 cmd.header.in = tpm2_shutdown_header;
800 cmd.params.startup_in.startup_type = cpu_to_be16(shutdown_type);
801
802 rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, "stopping the TPM");
803
804 /* In places where shutdown command is sent there's no much we can do
805 * except print the error code on a system failure.
806 */
807 if (rc < 0)
808 dev_warn(&chip->dev, "transmit returned %d while stopping the TPM",
809 rc);
810 }
811
812 /*
813 * tpm2_calc_ordinal_duration() - maximum duration for a command
814 * @chip: TPM chip to use.
815 * @ordinal: command code number.
816 *
817 * 0 is returned when the operation is successful. If a negative number is
818 * returned it remarks a POSIX error code. If a positive number is returned
819 * it remarks a TPM error.
820 */
tpm2_calc_ordinal_duration(struct tpm_chip * chip,u32 ordinal)821 unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
822 {
823 int index = TPM_UNDEFINED;
824 int duration = 0;
825
826 if (ordinal >= TPM2_CC_FIRST && ordinal <= TPM2_CC_LAST)
827 index = tpm2_ordinal_duration[ordinal - TPM2_CC_FIRST];
828
829 if (index != TPM_UNDEFINED)
830 duration = chip->duration[index];
831
832 if (duration <= 0)
833 duration = 2 * 60 * HZ;
834
835 return duration;
836 }
837 EXPORT_SYMBOL_GPL(tpm2_calc_ordinal_duration);
838
839 #define TPM2_SELF_TEST_IN_SIZE \
840 (sizeof(struct tpm_input_header) + \
841 sizeof(struct tpm2_self_test_in))
842
843 static const struct tpm_input_header tpm2_selftest_header = {
844 .tag = cpu_to_be16(TPM2_ST_NO_SESSIONS),
845 .length = cpu_to_be32(TPM2_SELF_TEST_IN_SIZE),
846 .ordinal = cpu_to_be32(TPM2_CC_SELF_TEST)
847 };
848
849 /**
850 * tpm2_continue_selftest() - start a self test
851 * @chip: TPM chip to use
852 * @full: test all commands instead of testing only those that were not
853 * previously tested.
854 *
855 * 0 is returned when the operation is successful. If a negative number is
856 * returned it remarks a POSIX error code. If a positive number is returned
857 * it remarks a TPM error.
858 */
tpm2_start_selftest(struct tpm_chip * chip,bool full)859 static int tpm2_start_selftest(struct tpm_chip *chip, bool full)
860 {
861 int rc;
862 struct tpm2_cmd cmd;
863
864 cmd.header.in = tpm2_selftest_header;
865 cmd.params.selftest_in.full_test = full;
866
867 rc = tpm_transmit_cmd(chip, &cmd, TPM2_SELF_TEST_IN_SIZE, 0,
868 "continue selftest");
869
870 /* At least some prototype chips seem to give RC_TESTING error
871 * immediately. This is a workaround for that.
872 */
873 if (rc == TPM2_RC_TESTING) {
874 dev_warn(&chip->dev, "Got RC_TESTING, ignoring\n");
875 rc = 0;
876 }
877
878 return rc;
879 }
880
881 /**
882 * tpm2_do_selftest() - run a full self test
883 * @chip: TPM chip to use
884 *
885 * During the self test TPM2 commands return with the error code RC_TESTING.
886 * Waiting is done by issuing PCR read until it executes successfully.
887 *
888 * 0 is returned when the operation is successful. If a negative number is
889 * returned it remarks a POSIX error code. If a positive number is returned
890 * it remarks a TPM error.
891 */
tpm2_do_selftest(struct tpm_chip * chip)892 static int tpm2_do_selftest(struct tpm_chip *chip)
893 {
894 int rc;
895 unsigned int loops;
896 unsigned int delay_msec = 100;
897 unsigned long duration;
898 struct tpm2_cmd cmd;
899 int i;
900
901 duration = tpm2_calc_ordinal_duration(chip, TPM2_CC_SELF_TEST);
902
903 loops = jiffies_to_msecs(duration) / delay_msec;
904
905 rc = tpm2_start_selftest(chip, true);
906 if (rc)
907 return rc;
908
909 for (i = 0; i < loops; i++) {
910 /* Attempt to read a PCR value */
911 cmd.header.in = tpm2_pcrread_header;
912 cmd.params.pcrread_in.pcr_selects_cnt = cpu_to_be32(1);
913 cmd.params.pcrread_in.hash_alg = cpu_to_be16(TPM2_ALG_SHA1);
914 cmd.params.pcrread_in.pcr_select_size = TPM2_PCR_SELECT_MIN;
915 cmd.params.pcrread_in.pcr_select[0] = 0x01;
916 cmd.params.pcrread_in.pcr_select[1] = 0x00;
917 cmd.params.pcrread_in.pcr_select[2] = 0x00;
918
919 rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, NULL);
920 if (rc < 0)
921 break;
922
923 rc = be32_to_cpu(cmd.header.out.return_code);
924 if (rc != TPM2_RC_TESTING)
925 break;
926
927 msleep(delay_msec);
928 }
929
930 return rc;
931 }
932
933 /**
934 * tpm2_probe() - probe TPM 2.0
935 * @chip: TPM chip to use
936 *
937 * Send idempotent TPM 2.0 command and see whether TPM 2.0 chip replied based on
938 * the reply tag.
939 */
tpm2_probe(struct tpm_chip * chip)940 int tpm2_probe(struct tpm_chip *chip)
941 {
942 struct tpm2_cmd cmd;
943 int rc;
944
945 cmd.header.in = tpm2_get_tpm_pt_header;
946 cmd.params.get_tpm_pt_in.cap_id = cpu_to_be32(TPM2_CAP_TPM_PROPERTIES);
947 cmd.params.get_tpm_pt_in.property_id = cpu_to_be32(0x100);
948 cmd.params.get_tpm_pt_in.property_cnt = cpu_to_be32(1);
949
950 rc = tpm_transmit_cmd(chip, &cmd, sizeof(cmd), 0, NULL);
951 if (rc < 0)
952 return rc;
953
954 if (be16_to_cpu(cmd.header.out.tag) == TPM2_ST_NO_SESSIONS)
955 chip->flags |= TPM_CHIP_FLAG_TPM2;
956
957 return 0;
958 }
959 EXPORT_SYMBOL_GPL(tpm2_probe);
960
961 /**
962 * tpm2_auto_startup - Perform the standard automatic TPM initialization
963 * sequence
964 * @chip: TPM chip to use
965 *
966 * Returns 0 on success, < 0 in case of fatal error.
967 */
tpm2_auto_startup(struct tpm_chip * chip)968 int tpm2_auto_startup(struct tpm_chip *chip)
969 {
970 int rc;
971
972 rc = tpm_get_timeouts(chip);
973 if (rc)
974 goto out;
975
976 rc = tpm2_do_selftest(chip);
977 if (rc != 0 && rc != TPM2_RC_INITIALIZE) {
978 dev_err(&chip->dev, "TPM self test failed\n");
979 goto out;
980 }
981
982 if (rc == TPM2_RC_INITIALIZE) {
983 rc = tpm2_startup(chip, TPM2_SU_CLEAR);
984 if (rc)
985 goto out;
986
987 rc = tpm2_do_selftest(chip);
988 if (rc) {
989 dev_err(&chip->dev, "TPM self test failed\n");
990 goto out;
991 }
992 }
993
994 out:
995 if (rc > 0)
996 rc = -ENODEV;
997 return rc;
998 }
999