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TOMOYO Linux Cross Reference
Linux/security/keys/trusted.c

Version: ~ [ linux-5.12 ] ~ [ linux-5.11.16 ] ~ [ linux-5.10.32 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.114 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.188 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.231 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.267 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.267 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
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  1 /*
  2  * Copyright (C) 2010 IBM Corporation
  3  *
  4  * Author:
  5  * David Safford <safford@us.ibm.com>
  6  *
  7  * This program is free software; you can redistribute it and/or modify
  8  * it under the terms of the GNU General Public License as published by
  9  * the Free Software Foundation, version 2 of the License.
 10  *
 11  * See Documentation/security/keys/trusted-encrypted.rst
 12  */
 13 
 14 #include <crypto/hash_info.h>
 15 #include <linux/uaccess.h>
 16 #include <linux/module.h>
 17 #include <linux/init.h>
 18 #include <linux/slab.h>
 19 #include <linux/parser.h>
 20 #include <linux/string.h>
 21 #include <linux/err.h>
 22 #include <keys/user-type.h>
 23 #include <keys/trusted-type.h>
 24 #include <linux/key-type.h>
 25 #include <linux/rcupdate.h>
 26 #include <linux/crypto.h>
 27 #include <crypto/hash.h>
 28 #include <crypto/sha.h>
 29 #include <linux/capability.h>
 30 #include <linux/tpm.h>
 31 #include <linux/tpm_command.h>
 32 
 33 #include "trusted.h"
 34 
 35 static const char hmac_alg[] = "hmac(sha1)";
 36 static const char hash_alg[] = "sha1";
 37 
 38 struct sdesc {
 39         struct shash_desc shash;
 40         char ctx[];
 41 };
 42 
 43 static struct crypto_shash *hashalg;
 44 static struct crypto_shash *hmacalg;
 45 
 46 static struct sdesc *init_sdesc(struct crypto_shash *alg)
 47 {
 48         struct sdesc *sdesc;
 49         int size;
 50 
 51         size = sizeof(struct shash_desc) + crypto_shash_descsize(alg);
 52         sdesc = kmalloc(size, GFP_KERNEL);
 53         if (!sdesc)
 54                 return ERR_PTR(-ENOMEM);
 55         sdesc->shash.tfm = alg;
 56         sdesc->shash.flags = 0x0;
 57         return sdesc;
 58 }
 59 
 60 static int TSS_sha1(const unsigned char *data, unsigned int datalen,
 61                     unsigned char *digest)
 62 {
 63         struct sdesc *sdesc;
 64         int ret;
 65 
 66         sdesc = init_sdesc(hashalg);
 67         if (IS_ERR(sdesc)) {
 68                 pr_info("trusted_key: can't alloc %s\n", hash_alg);
 69                 return PTR_ERR(sdesc);
 70         }
 71 
 72         ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest);
 73         kzfree(sdesc);
 74         return ret;
 75 }
 76 
 77 static int TSS_rawhmac(unsigned char *digest, const unsigned char *key,
 78                        unsigned int keylen, ...)
 79 {
 80         struct sdesc *sdesc;
 81         va_list argp;
 82         unsigned int dlen;
 83         unsigned char *data;
 84         int ret;
 85 
 86         sdesc = init_sdesc(hmacalg);
 87         if (IS_ERR(sdesc)) {
 88                 pr_info("trusted_key: can't alloc %s\n", hmac_alg);
 89                 return PTR_ERR(sdesc);
 90         }
 91 
 92         ret = crypto_shash_setkey(hmacalg, key, keylen);
 93         if (ret < 0)
 94                 goto out;
 95         ret = crypto_shash_init(&sdesc->shash);
 96         if (ret < 0)
 97                 goto out;
 98 
 99         va_start(argp, keylen);
100         for (;;) {
101                 dlen = va_arg(argp, unsigned int);
102                 if (dlen == 0)
103                         break;
104                 data = va_arg(argp, unsigned char *);
105                 if (data == NULL) {
106                         ret = -EINVAL;
107                         break;
108                 }
109                 ret = crypto_shash_update(&sdesc->shash, data, dlen);
110                 if (ret < 0)
111                         break;
112         }
113         va_end(argp);
114         if (!ret)
115                 ret = crypto_shash_final(&sdesc->shash, digest);
116 out:
117         kzfree(sdesc);
118         return ret;
119 }
120 
121 /*
122  * calculate authorization info fields to send to TPM
123  */
124 static int TSS_authhmac(unsigned char *digest, const unsigned char *key,
125                         unsigned int keylen, unsigned char *h1,
126                         unsigned char *h2, unsigned char h3, ...)
127 {
128         unsigned char paramdigest[SHA1_DIGEST_SIZE];
129         struct sdesc *sdesc;
130         unsigned int dlen;
131         unsigned char *data;
132         unsigned char c;
133         int ret;
134         va_list argp;
135 
136         sdesc = init_sdesc(hashalg);
137         if (IS_ERR(sdesc)) {
138                 pr_info("trusted_key: can't alloc %s\n", hash_alg);
139                 return PTR_ERR(sdesc);
140         }
141 
142         c = h3;
143         ret = crypto_shash_init(&sdesc->shash);
144         if (ret < 0)
145                 goto out;
146         va_start(argp, h3);
147         for (;;) {
148                 dlen = va_arg(argp, unsigned int);
149                 if (dlen == 0)
150                         break;
151                 data = va_arg(argp, unsigned char *);
152                 if (!data) {
153                         ret = -EINVAL;
154                         break;
155                 }
156                 ret = crypto_shash_update(&sdesc->shash, data, dlen);
157                 if (ret < 0)
158                         break;
159         }
160         va_end(argp);
161         if (!ret)
162                 ret = crypto_shash_final(&sdesc->shash, paramdigest);
163         if (!ret)
164                 ret = TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE,
165                                   paramdigest, TPM_NONCE_SIZE, h1,
166                                   TPM_NONCE_SIZE, h2, 1, &c, 0, 0);
167 out:
168         kzfree(sdesc);
169         return ret;
170 }
171 
172 /*
173  * verify the AUTH1_COMMAND (Seal) result from TPM
174  */
175 static int TSS_checkhmac1(unsigned char *buffer,
176                           const uint32_t command,
177                           const unsigned char *ononce,
178                           const unsigned char *key,
179                           unsigned int keylen, ...)
180 {
181         uint32_t bufsize;
182         uint16_t tag;
183         uint32_t ordinal;
184         uint32_t result;
185         unsigned char *enonce;
186         unsigned char *continueflag;
187         unsigned char *authdata;
188         unsigned char testhmac[SHA1_DIGEST_SIZE];
189         unsigned char paramdigest[SHA1_DIGEST_SIZE];
190         struct sdesc *sdesc;
191         unsigned int dlen;
192         unsigned int dpos;
193         va_list argp;
194         int ret;
195 
196         bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
197         tag = LOAD16(buffer, 0);
198         ordinal = command;
199         result = LOAD32N(buffer, TPM_RETURN_OFFSET);
200         if (tag == TPM_TAG_RSP_COMMAND)
201                 return 0;
202         if (tag != TPM_TAG_RSP_AUTH1_COMMAND)
203                 return -EINVAL;
204         authdata = buffer + bufsize - SHA1_DIGEST_SIZE;
205         continueflag = authdata - 1;
206         enonce = continueflag - TPM_NONCE_SIZE;
207 
208         sdesc = init_sdesc(hashalg);
209         if (IS_ERR(sdesc)) {
210                 pr_info("trusted_key: can't alloc %s\n", hash_alg);
211                 return PTR_ERR(sdesc);
212         }
213         ret = crypto_shash_init(&sdesc->shash);
214         if (ret < 0)
215                 goto out;
216         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
217                                   sizeof result);
218         if (ret < 0)
219                 goto out;
220         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
221                                   sizeof ordinal);
222         if (ret < 0)
223                 goto out;
224         va_start(argp, keylen);
225         for (;;) {
226                 dlen = va_arg(argp, unsigned int);
227                 if (dlen == 0)
228                         break;
229                 dpos = va_arg(argp, unsigned int);
230                 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
231                 if (ret < 0)
232                         break;
233         }
234         va_end(argp);
235         if (!ret)
236                 ret = crypto_shash_final(&sdesc->shash, paramdigest);
237         if (ret < 0)
238                 goto out;
239 
240         ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest,
241                           TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce,
242                           1, continueflag, 0, 0);
243         if (ret < 0)
244                 goto out;
245 
246         if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE))
247                 ret = -EINVAL;
248 out:
249         kzfree(sdesc);
250         return ret;
251 }
252 
253 /*
254  * verify the AUTH2_COMMAND (unseal) result from TPM
255  */
256 static int TSS_checkhmac2(unsigned char *buffer,
257                           const uint32_t command,
258                           const unsigned char *ononce,
259                           const unsigned char *key1,
260                           unsigned int keylen1,
261                           const unsigned char *key2,
262                           unsigned int keylen2, ...)
263 {
264         uint32_t bufsize;
265         uint16_t tag;
266         uint32_t ordinal;
267         uint32_t result;
268         unsigned char *enonce1;
269         unsigned char *continueflag1;
270         unsigned char *authdata1;
271         unsigned char *enonce2;
272         unsigned char *continueflag2;
273         unsigned char *authdata2;
274         unsigned char testhmac1[SHA1_DIGEST_SIZE];
275         unsigned char testhmac2[SHA1_DIGEST_SIZE];
276         unsigned char paramdigest[SHA1_DIGEST_SIZE];
277         struct sdesc *sdesc;
278         unsigned int dlen;
279         unsigned int dpos;
280         va_list argp;
281         int ret;
282 
283         bufsize = LOAD32(buffer, TPM_SIZE_OFFSET);
284         tag = LOAD16(buffer, 0);
285         ordinal = command;
286         result = LOAD32N(buffer, TPM_RETURN_OFFSET);
287 
288         if (tag == TPM_TAG_RSP_COMMAND)
289                 return 0;
290         if (tag != TPM_TAG_RSP_AUTH2_COMMAND)
291                 return -EINVAL;
292         authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1
293                         + SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE);
294         authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE);
295         continueflag1 = authdata1 - 1;
296         continueflag2 = authdata2 - 1;
297         enonce1 = continueflag1 - TPM_NONCE_SIZE;
298         enonce2 = continueflag2 - TPM_NONCE_SIZE;
299 
300         sdesc = init_sdesc(hashalg);
301         if (IS_ERR(sdesc)) {
302                 pr_info("trusted_key: can't alloc %s\n", hash_alg);
303                 return PTR_ERR(sdesc);
304         }
305         ret = crypto_shash_init(&sdesc->shash);
306         if (ret < 0)
307                 goto out;
308         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result,
309                                   sizeof result);
310         if (ret < 0)
311                 goto out;
312         ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal,
313                                   sizeof ordinal);
314         if (ret < 0)
315                 goto out;
316 
317         va_start(argp, keylen2);
318         for (;;) {
319                 dlen = va_arg(argp, unsigned int);
320                 if (dlen == 0)
321                         break;
322                 dpos = va_arg(argp, unsigned int);
323                 ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen);
324                 if (ret < 0)
325                         break;
326         }
327         va_end(argp);
328         if (!ret)
329                 ret = crypto_shash_final(&sdesc->shash, paramdigest);
330         if (ret < 0)
331                 goto out;
332 
333         ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE,
334                           paramdigest, TPM_NONCE_SIZE, enonce1,
335                           TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0);
336         if (ret < 0)
337                 goto out;
338         if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) {
339                 ret = -EINVAL;
340                 goto out;
341         }
342         ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE,
343                           paramdigest, TPM_NONCE_SIZE, enonce2,
344                           TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0);
345         if (ret < 0)
346                 goto out;
347         if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE))
348                 ret = -EINVAL;
349 out:
350         kzfree(sdesc);
351         return ret;
352 }
353 
354 /*
355  * For key specific tpm requests, we will generate and send our
356  * own TPM command packets using the drivers send function.
357  */
358 static int trusted_tpm_send(const u32 chip_num, unsigned char *cmd,
359                             size_t buflen)
360 {
361         int rc;
362 
363         dump_tpm_buf(cmd);
364         rc = tpm_send(chip_num, cmd, buflen);
365         dump_tpm_buf(cmd);
366         if (rc > 0)
367                 /* Can't return positive return codes values to keyctl */
368                 rc = -EPERM;
369         return rc;
370 }
371 
372 /*
373  * Lock a trusted key, by extending a selected PCR.
374  *
375  * Prevents a trusted key that is sealed to PCRs from being accessed.
376  * This uses the tpm driver's extend function.
377  */
378 static int pcrlock(const int pcrnum)
379 {
380         unsigned char hash[SHA1_DIGEST_SIZE];
381         int ret;
382 
383         if (!capable(CAP_SYS_ADMIN))
384                 return -EPERM;
385         ret = tpm_get_random(TPM_ANY_NUM, hash, SHA1_DIGEST_SIZE);
386         if (ret != SHA1_DIGEST_SIZE)
387                 return ret;
388         return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0;
389 }
390 
391 /*
392  * Create an object specific authorisation protocol (OSAP) session
393  */
394 static int osap(struct tpm_buf *tb, struct osapsess *s,
395                 const unsigned char *key, uint16_t type, uint32_t handle)
396 {
397         unsigned char enonce[TPM_NONCE_SIZE];
398         unsigned char ononce[TPM_NONCE_SIZE];
399         int ret;
400 
401         ret = tpm_get_random(TPM_ANY_NUM, ononce, TPM_NONCE_SIZE);
402         if (ret != TPM_NONCE_SIZE)
403                 return ret;
404 
405         INIT_BUF(tb);
406         store16(tb, TPM_TAG_RQU_COMMAND);
407         store32(tb, TPM_OSAP_SIZE);
408         store32(tb, TPM_ORD_OSAP);
409         store16(tb, type);
410         store32(tb, handle);
411         storebytes(tb, ononce, TPM_NONCE_SIZE);
412 
413         ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
414         if (ret < 0)
415                 return ret;
416 
417         s->handle = LOAD32(tb->data, TPM_DATA_OFFSET);
418         memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]),
419                TPM_NONCE_SIZE);
420         memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) +
421                                   TPM_NONCE_SIZE]), TPM_NONCE_SIZE);
422         return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE,
423                            enonce, TPM_NONCE_SIZE, ononce, 0, 0);
424 }
425 
426 /*
427  * Create an object independent authorisation protocol (oiap) session
428  */
429 static int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce)
430 {
431         int ret;
432 
433         INIT_BUF(tb);
434         store16(tb, TPM_TAG_RQU_COMMAND);
435         store32(tb, TPM_OIAP_SIZE);
436         store32(tb, TPM_ORD_OIAP);
437         ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
438         if (ret < 0)
439                 return ret;
440 
441         *handle = LOAD32(tb->data, TPM_DATA_OFFSET);
442         memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)],
443                TPM_NONCE_SIZE);
444         return 0;
445 }
446 
447 struct tpm_digests {
448         unsigned char encauth[SHA1_DIGEST_SIZE];
449         unsigned char pubauth[SHA1_DIGEST_SIZE];
450         unsigned char xorwork[SHA1_DIGEST_SIZE * 2];
451         unsigned char xorhash[SHA1_DIGEST_SIZE];
452         unsigned char nonceodd[TPM_NONCE_SIZE];
453 };
454 
455 /*
456  * Have the TPM seal(encrypt) the trusted key, possibly based on
457  * Platform Configuration Registers (PCRs). AUTH1 for sealing key.
458  */
459 static int tpm_seal(struct tpm_buf *tb, uint16_t keytype,
460                     uint32_t keyhandle, const unsigned char *keyauth,
461                     const unsigned char *data, uint32_t datalen,
462                     unsigned char *blob, uint32_t *bloblen,
463                     const unsigned char *blobauth,
464                     const unsigned char *pcrinfo, uint32_t pcrinfosize)
465 {
466         struct osapsess sess;
467         struct tpm_digests *td;
468         unsigned char cont;
469         uint32_t ordinal;
470         uint32_t pcrsize;
471         uint32_t datsize;
472         int sealinfosize;
473         int encdatasize;
474         int storedsize;
475         int ret;
476         int i;
477 
478         /* alloc some work space for all the hashes */
479         td = kmalloc(sizeof *td, GFP_KERNEL);
480         if (!td)
481                 return -ENOMEM;
482 
483         /* get session for sealing key */
484         ret = osap(tb, &sess, keyauth, keytype, keyhandle);
485         if (ret < 0)
486                 goto out;
487         dump_sess(&sess);
488 
489         /* calculate encrypted authorization value */
490         memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE);
491         memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE);
492         ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash);
493         if (ret < 0)
494                 goto out;
495 
496         ret = tpm_get_random(TPM_ANY_NUM, td->nonceodd, TPM_NONCE_SIZE);
497         if (ret != TPM_NONCE_SIZE)
498                 goto out;
499         ordinal = htonl(TPM_ORD_SEAL);
500         datsize = htonl(datalen);
501         pcrsize = htonl(pcrinfosize);
502         cont = 0;
503 
504         /* encrypt data authorization key */
505         for (i = 0; i < SHA1_DIGEST_SIZE; ++i)
506                 td->encauth[i] = td->xorhash[i] ^ blobauth[i];
507 
508         /* calculate authorization HMAC value */
509         if (pcrinfosize == 0) {
510                 /* no pcr info specified */
511                 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
512                                    sess.enonce, td->nonceodd, cont,
513                                    sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
514                                    td->encauth, sizeof(uint32_t), &pcrsize,
515                                    sizeof(uint32_t), &datsize, datalen, data, 0,
516                                    0);
517         } else {
518                 /* pcr info specified */
519                 ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE,
520                                    sess.enonce, td->nonceodd, cont,
521                                    sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE,
522                                    td->encauth, sizeof(uint32_t), &pcrsize,
523                                    pcrinfosize, pcrinfo, sizeof(uint32_t),
524                                    &datsize, datalen, data, 0, 0);
525         }
526         if (ret < 0)
527                 goto out;
528 
529         /* build and send the TPM request packet */
530         INIT_BUF(tb);
531         store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
532         store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen);
533         store32(tb, TPM_ORD_SEAL);
534         store32(tb, keyhandle);
535         storebytes(tb, td->encauth, SHA1_DIGEST_SIZE);
536         store32(tb, pcrinfosize);
537         storebytes(tb, pcrinfo, pcrinfosize);
538         store32(tb, datalen);
539         storebytes(tb, data, datalen);
540         store32(tb, sess.handle);
541         storebytes(tb, td->nonceodd, TPM_NONCE_SIZE);
542         store8(tb, cont);
543         storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE);
544 
545         ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
546         if (ret < 0)
547                 goto out;
548 
549         /* calculate the size of the returned Blob */
550         sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t));
551         encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) +
552                              sizeof(uint32_t) + sealinfosize);
553         storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize +
554             sizeof(uint32_t) + encdatasize;
555 
556         /* check the HMAC in the response */
557         ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret,
558                              SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0,
559                              0);
560 
561         /* copy the returned blob to caller */
562         if (!ret) {
563                 memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize);
564                 *bloblen = storedsize;
565         }
566 out:
567         kzfree(td);
568         return ret;
569 }
570 
571 /*
572  * use the AUTH2_COMMAND form of unseal, to authorize both key and blob
573  */
574 static int tpm_unseal(struct tpm_buf *tb,
575                       uint32_t keyhandle, const unsigned char *keyauth,
576                       const unsigned char *blob, int bloblen,
577                       const unsigned char *blobauth,
578                       unsigned char *data, unsigned int *datalen)
579 {
580         unsigned char nonceodd[TPM_NONCE_SIZE];
581         unsigned char enonce1[TPM_NONCE_SIZE];
582         unsigned char enonce2[TPM_NONCE_SIZE];
583         unsigned char authdata1[SHA1_DIGEST_SIZE];
584         unsigned char authdata2[SHA1_DIGEST_SIZE];
585         uint32_t authhandle1 = 0;
586         uint32_t authhandle2 = 0;
587         unsigned char cont = 0;
588         uint32_t ordinal;
589         uint32_t keyhndl;
590         int ret;
591 
592         /* sessions for unsealing key and data */
593         ret = oiap(tb, &authhandle1, enonce1);
594         if (ret < 0) {
595                 pr_info("trusted_key: oiap failed (%d)\n", ret);
596                 return ret;
597         }
598         ret = oiap(tb, &authhandle2, enonce2);
599         if (ret < 0) {
600                 pr_info("trusted_key: oiap failed (%d)\n", ret);
601                 return ret;
602         }
603 
604         ordinal = htonl(TPM_ORD_UNSEAL);
605         keyhndl = htonl(SRKHANDLE);
606         ret = tpm_get_random(TPM_ANY_NUM, nonceodd, TPM_NONCE_SIZE);
607         if (ret != TPM_NONCE_SIZE) {
608                 pr_info("trusted_key: tpm_get_random failed (%d)\n", ret);
609                 return ret;
610         }
611         ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE,
612                            enonce1, nonceodd, cont, sizeof(uint32_t),
613                            &ordinal, bloblen, blob, 0, 0);
614         if (ret < 0)
615                 return ret;
616         ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE,
617                            enonce2, nonceodd, cont, sizeof(uint32_t),
618                            &ordinal, bloblen, blob, 0, 0);
619         if (ret < 0)
620                 return ret;
621 
622         /* build and send TPM request packet */
623         INIT_BUF(tb);
624         store16(tb, TPM_TAG_RQU_AUTH2_COMMAND);
625         store32(tb, TPM_UNSEAL_SIZE + bloblen);
626         store32(tb, TPM_ORD_UNSEAL);
627         store32(tb, keyhandle);
628         storebytes(tb, blob, bloblen);
629         store32(tb, authhandle1);
630         storebytes(tb, nonceodd, TPM_NONCE_SIZE);
631         store8(tb, cont);
632         storebytes(tb, authdata1, SHA1_DIGEST_SIZE);
633         store32(tb, authhandle2);
634         storebytes(tb, nonceodd, TPM_NONCE_SIZE);
635         store8(tb, cont);
636         storebytes(tb, authdata2, SHA1_DIGEST_SIZE);
637 
638         ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE);
639         if (ret < 0) {
640                 pr_info("trusted_key: authhmac failed (%d)\n", ret);
641                 return ret;
642         }
643 
644         *datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
645         ret = TSS_checkhmac2(tb->data, ordinal, nonceodd,
646                              keyauth, SHA1_DIGEST_SIZE,
647                              blobauth, SHA1_DIGEST_SIZE,
648                              sizeof(uint32_t), TPM_DATA_OFFSET,
649                              *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0,
650                              0);
651         if (ret < 0) {
652                 pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret);
653                 return ret;
654         }
655         memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen);
656         return 0;
657 }
658 
659 /*
660  * Have the TPM seal(encrypt) the symmetric key
661  */
662 static int key_seal(struct trusted_key_payload *p,
663                     struct trusted_key_options *o)
664 {
665         struct tpm_buf *tb;
666         int ret;
667 
668         tb = kzalloc(sizeof *tb, GFP_KERNEL);
669         if (!tb)
670                 return -ENOMEM;
671 
672         /* include migratable flag at end of sealed key */
673         p->key[p->key_len] = p->migratable;
674 
675         ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth,
676                        p->key, p->key_len + 1, p->blob, &p->blob_len,
677                        o->blobauth, o->pcrinfo, o->pcrinfo_len);
678         if (ret < 0)
679                 pr_info("trusted_key: srkseal failed (%d)\n", ret);
680 
681         kzfree(tb);
682         return ret;
683 }
684 
685 /*
686  * Have the TPM unseal(decrypt) the symmetric key
687  */
688 static int key_unseal(struct trusted_key_payload *p,
689                       struct trusted_key_options *o)
690 {
691         struct tpm_buf *tb;
692         int ret;
693 
694         tb = kzalloc(sizeof *tb, GFP_KERNEL);
695         if (!tb)
696                 return -ENOMEM;
697 
698         ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len,
699                          o->blobauth, p->key, &p->key_len);
700         if (ret < 0)
701                 pr_info("trusted_key: srkunseal failed (%d)\n", ret);
702         else
703                 /* pull migratable flag out of sealed key */
704                 p->migratable = p->key[--p->key_len];
705 
706         kzfree(tb);
707         return ret;
708 }
709 
710 enum {
711         Opt_err = -1,
712         Opt_new, Opt_load, Opt_update,
713         Opt_keyhandle, Opt_keyauth, Opt_blobauth,
714         Opt_pcrinfo, Opt_pcrlock, Opt_migratable,
715         Opt_hash,
716         Opt_policydigest,
717         Opt_policyhandle,
718 };
719 
720 static const match_table_t key_tokens = {
721         {Opt_new, "new"},
722         {Opt_load, "load"},
723         {Opt_update, "update"},
724         {Opt_keyhandle, "keyhandle=%s"},
725         {Opt_keyauth, "keyauth=%s"},
726         {Opt_blobauth, "blobauth=%s"},
727         {Opt_pcrinfo, "pcrinfo=%s"},
728         {Opt_pcrlock, "pcrlock=%s"},
729         {Opt_migratable, "migratable=%s"},
730         {Opt_hash, "hash=%s"},
731         {Opt_policydigest, "policydigest=%s"},
732         {Opt_policyhandle, "policyhandle=%s"},
733         {Opt_err, NULL}
734 };
735 
736 /* can have zero or more token= options */
737 static int getoptions(char *c, struct trusted_key_payload *pay,
738                       struct trusted_key_options *opt)
739 {
740         substring_t args[MAX_OPT_ARGS];
741         char *p = c;
742         int token;
743         int res;
744         unsigned long handle;
745         unsigned long lock;
746         unsigned long token_mask = 0;
747         unsigned int digest_len;
748         int i;
749         int tpm2;
750 
751         tpm2 = tpm_is_tpm2(TPM_ANY_NUM);
752         if (tpm2 < 0)
753                 return tpm2;
754 
755         opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1;
756 
757         while ((p = strsep(&c, " \t"))) {
758                 if (*p == '\0' || *p == ' ' || *p == '\t')
759                         continue;
760                 token = match_token(p, key_tokens, args);
761                 if (test_and_set_bit(token, &token_mask))
762                         return -EINVAL;
763 
764                 switch (token) {
765                 case Opt_pcrinfo:
766                         opt->pcrinfo_len = strlen(args[0].from) / 2;
767                         if (opt->pcrinfo_len > MAX_PCRINFO_SIZE)
768                                 return -EINVAL;
769                         res = hex2bin(opt->pcrinfo, args[0].from,
770                                       opt->pcrinfo_len);
771                         if (res < 0)
772                                 return -EINVAL;
773                         break;
774                 case Opt_keyhandle:
775                         res = kstrtoul(args[0].from, 16, &handle);
776                         if (res < 0)
777                                 return -EINVAL;
778                         opt->keytype = SEAL_keytype;
779                         opt->keyhandle = handle;
780                         break;
781                 case Opt_keyauth:
782                         if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
783                                 return -EINVAL;
784                         res = hex2bin(opt->keyauth, args[0].from,
785                                       SHA1_DIGEST_SIZE);
786                         if (res < 0)
787                                 return -EINVAL;
788                         break;
789                 case Opt_blobauth:
790                         if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE)
791                                 return -EINVAL;
792                         res = hex2bin(opt->blobauth, args[0].from,
793                                       SHA1_DIGEST_SIZE);
794                         if (res < 0)
795                                 return -EINVAL;
796                         break;
797                 case Opt_migratable:
798                         if (*args[0].from == '')
799                                 pay->migratable = 0;
800                         else
801                                 return -EINVAL;
802                         break;
803                 case Opt_pcrlock:
804                         res = kstrtoul(args[0].from, 10, &lock);
805                         if (res < 0)
806                                 return -EINVAL;
807                         opt->pcrlock = lock;
808                         break;
809                 case Opt_hash:
810                         if (test_bit(Opt_policydigest, &token_mask))
811                                 return -EINVAL;
812                         for (i = 0; i < HASH_ALGO__LAST; i++) {
813                                 if (!strcmp(args[0].from, hash_algo_name[i])) {
814                                         opt->hash = i;
815                                         break;
816                                 }
817                         }
818                         if (i == HASH_ALGO__LAST)
819                                 return -EINVAL;
820                         if  (!tpm2 && i != HASH_ALGO_SHA1) {
821                                 pr_info("trusted_key: TPM 1.x only supports SHA-1.\n");
822                                 return -EINVAL;
823                         }
824                         break;
825                 case Opt_policydigest:
826                         digest_len = hash_digest_size[opt->hash];
827                         if (!tpm2 || strlen(args[0].from) != (2 * digest_len))
828                                 return -EINVAL;
829                         res = hex2bin(opt->policydigest, args[0].from,
830                                       digest_len);
831                         if (res < 0)
832                                 return -EINVAL;
833                         opt->policydigest_len = digest_len;
834                         break;
835                 case Opt_policyhandle:
836                         if (!tpm2)
837                                 return -EINVAL;
838                         res = kstrtoul(args[0].from, 16, &handle);
839                         if (res < 0)
840                                 return -EINVAL;
841                         opt->policyhandle = handle;
842                         break;
843                 default:
844                         return -EINVAL;
845                 }
846         }
847         return 0;
848 }
849 
850 /*
851  * datablob_parse - parse the keyctl data and fill in the
852  *                  payload and options structures
853  *
854  * On success returns 0, otherwise -EINVAL.
855  */
856 static int datablob_parse(char *datablob, struct trusted_key_payload *p,
857                           struct trusted_key_options *o)
858 {
859         substring_t args[MAX_OPT_ARGS];
860         long keylen;
861         int ret = -EINVAL;
862         int key_cmd;
863         char *c;
864 
865         /* main command */
866         c = strsep(&datablob, " \t");
867         if (!c)
868                 return -EINVAL;
869         key_cmd = match_token(c, key_tokens, args);
870         switch (key_cmd) {
871         case Opt_new:
872                 /* first argument is key size */
873                 c = strsep(&datablob, " \t");
874                 if (!c)
875                         return -EINVAL;
876                 ret = kstrtol(c, 10, &keylen);
877                 if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE)
878                         return -EINVAL;
879                 p->key_len = keylen;
880                 ret = getoptions(datablob, p, o);
881                 if (ret < 0)
882                         return ret;
883                 ret = Opt_new;
884                 break;
885         case Opt_load:
886                 /* first argument is sealed blob */
887                 c = strsep(&datablob, " \t");
888                 if (!c)
889                         return -EINVAL;
890                 p->blob_len = strlen(c) / 2;
891                 if (p->blob_len > MAX_BLOB_SIZE)
892                         return -EINVAL;
893                 ret = hex2bin(p->blob, c, p->blob_len);
894                 if (ret < 0)
895                         return -EINVAL;
896                 ret = getoptions(datablob, p, o);
897                 if (ret < 0)
898                         return ret;
899                 ret = Opt_load;
900                 break;
901         case Opt_update:
902                 /* all arguments are options */
903                 ret = getoptions(datablob, p, o);
904                 if (ret < 0)
905                         return ret;
906                 ret = Opt_update;
907                 break;
908         case Opt_err:
909                 return -EINVAL;
910                 break;
911         }
912         return ret;
913 }
914 
915 static struct trusted_key_options *trusted_options_alloc(void)
916 {
917         struct trusted_key_options *options;
918         int tpm2;
919 
920         tpm2 = tpm_is_tpm2(TPM_ANY_NUM);
921         if (tpm2 < 0)
922                 return NULL;
923 
924         options = kzalloc(sizeof *options, GFP_KERNEL);
925         if (options) {
926                 /* set any non-zero defaults */
927                 options->keytype = SRK_keytype;
928 
929                 if (!tpm2)
930                         options->keyhandle = SRKHANDLE;
931         }
932         return options;
933 }
934 
935 static struct trusted_key_payload *trusted_payload_alloc(struct key *key)
936 {
937         struct trusted_key_payload *p = NULL;
938         int ret;
939 
940         ret = key_payload_reserve(key, sizeof *p);
941         if (ret < 0)
942                 return p;
943         p = kzalloc(sizeof *p, GFP_KERNEL);
944         if (p)
945                 p->migratable = 1; /* migratable by default */
946         return p;
947 }
948 
949 /*
950  * trusted_instantiate - create a new trusted key
951  *
952  * Unseal an existing trusted blob or, for a new key, get a
953  * random key, then seal and create a trusted key-type key,
954  * adding it to the specified keyring.
955  *
956  * On success, return 0. Otherwise return errno.
957  */
958 static int trusted_instantiate(struct key *key,
959                                struct key_preparsed_payload *prep)
960 {
961         struct trusted_key_payload *payload = NULL;
962         struct trusted_key_options *options = NULL;
963         size_t datalen = prep->datalen;
964         char *datablob;
965         int ret = 0;
966         int key_cmd;
967         size_t key_len;
968         int tpm2;
969 
970         tpm2 = tpm_is_tpm2(TPM_ANY_NUM);
971         if (tpm2 < 0)
972                 return tpm2;
973 
974         if (datalen <= 0 || datalen > 32767 || !prep->data)
975                 return -EINVAL;
976 
977         datablob = kmalloc(datalen + 1, GFP_KERNEL);
978         if (!datablob)
979                 return -ENOMEM;
980         memcpy(datablob, prep->data, datalen);
981         datablob[datalen] = '\0';
982 
983         options = trusted_options_alloc();
984         if (!options) {
985                 ret = -ENOMEM;
986                 goto out;
987         }
988         payload = trusted_payload_alloc(key);
989         if (!payload) {
990                 ret = -ENOMEM;
991                 goto out;
992         }
993 
994         key_cmd = datablob_parse(datablob, payload, options);
995         if (key_cmd < 0) {
996                 ret = key_cmd;
997                 goto out;
998         }
999 
1000         if (!options->keyhandle) {
1001                 ret = -EINVAL;
1002                 goto out;
1003         }
1004 
1005         dump_payload(payload);
1006         dump_options(options);
1007 
1008         switch (key_cmd) {
1009         case Opt_load:
1010                 if (tpm2)
1011                         ret = tpm_unseal_trusted(TPM_ANY_NUM, payload, options);
1012                 else
1013                         ret = key_unseal(payload, options);
1014                 dump_payload(payload);
1015                 dump_options(options);
1016                 if (ret < 0)
1017                         pr_info("trusted_key: key_unseal failed (%d)\n", ret);
1018                 break;
1019         case Opt_new:
1020                 key_len = payload->key_len;
1021                 ret = tpm_get_random(TPM_ANY_NUM, payload->key, key_len);
1022                 if (ret != key_len) {
1023                         pr_info("trusted_key: key_create failed (%d)\n", ret);
1024                         goto out;
1025                 }
1026                 if (tpm2)
1027                         ret = tpm_seal_trusted(TPM_ANY_NUM, payload, options);
1028                 else
1029                         ret = key_seal(payload, options);
1030                 if (ret < 0)
1031                         pr_info("trusted_key: key_seal failed (%d)\n", ret);
1032                 break;
1033         default:
1034                 ret = -EINVAL;
1035                 goto out;
1036         }
1037         if (!ret && options->pcrlock)
1038                 ret = pcrlock(options->pcrlock);
1039 out:
1040         kzfree(datablob);
1041         kzfree(options);
1042         if (!ret)
1043                 rcu_assign_keypointer(key, payload);
1044         else
1045                 kzfree(payload);
1046         return ret;
1047 }
1048 
1049 static void trusted_rcu_free(struct rcu_head *rcu)
1050 {
1051         struct trusted_key_payload *p;
1052 
1053         p = container_of(rcu, struct trusted_key_payload, rcu);
1054         kzfree(p);
1055 }
1056 
1057 /*
1058  * trusted_update - reseal an existing key with new PCR values
1059  */
1060 static int trusted_update(struct key *key, struct key_preparsed_payload *prep)
1061 {
1062         struct trusted_key_payload *p;
1063         struct trusted_key_payload *new_p;
1064         struct trusted_key_options *new_o;
1065         size_t datalen = prep->datalen;
1066         char *datablob;
1067         int ret = 0;
1068 
1069         if (key_is_negative(key))
1070                 return -ENOKEY;
1071         p = key->payload.data[0];
1072         if (!p->migratable)
1073                 return -EPERM;
1074         if (datalen <= 0 || datalen > 32767 || !prep->data)
1075                 return -EINVAL;
1076 
1077         datablob = kmalloc(datalen + 1, GFP_KERNEL);
1078         if (!datablob)
1079                 return -ENOMEM;
1080         new_o = trusted_options_alloc();
1081         if (!new_o) {
1082                 ret = -ENOMEM;
1083                 goto out;
1084         }
1085         new_p = trusted_payload_alloc(key);
1086         if (!new_p) {
1087                 ret = -ENOMEM;
1088                 goto out;
1089         }
1090 
1091         memcpy(datablob, prep->data, datalen);
1092         datablob[datalen] = '\0';
1093         ret = datablob_parse(datablob, new_p, new_o);
1094         if (ret != Opt_update) {
1095                 ret = -EINVAL;
1096                 kzfree(new_p);
1097                 goto out;
1098         }
1099 
1100         if (!new_o->keyhandle) {
1101                 ret = -EINVAL;
1102                 kzfree(new_p);
1103                 goto out;
1104         }
1105 
1106         /* copy old key values, and reseal with new pcrs */
1107         new_p->migratable = p->migratable;
1108         new_p->key_len = p->key_len;
1109         memcpy(new_p->key, p->key, p->key_len);
1110         dump_payload(p);
1111         dump_payload(new_p);
1112 
1113         ret = key_seal(new_p, new_o);
1114         if (ret < 0) {
1115                 pr_info("trusted_key: key_seal failed (%d)\n", ret);
1116                 kzfree(new_p);
1117                 goto out;
1118         }
1119         if (new_o->pcrlock) {
1120                 ret = pcrlock(new_o->pcrlock);
1121                 if (ret < 0) {
1122                         pr_info("trusted_key: pcrlock failed (%d)\n", ret);
1123                         kzfree(new_p);
1124                         goto out;
1125                 }
1126         }
1127         rcu_assign_keypointer(key, new_p);
1128         call_rcu(&p->rcu, trusted_rcu_free);
1129 out:
1130         kzfree(datablob);
1131         kzfree(new_o);
1132         return ret;
1133 }
1134 
1135 /*
1136  * trusted_read - copy the sealed blob data to userspace in hex.
1137  * On success, return to userspace the trusted key datablob size.
1138  */
1139 static long trusted_read(const struct key *key, char __user *buffer,
1140                          size_t buflen)
1141 {
1142         const struct trusted_key_payload *p;
1143         char *ascii_buf;
1144         char *bufp;
1145         int i;
1146 
1147         p = dereference_key_locked(key);
1148         if (!p)
1149                 return -EINVAL;
1150 
1151         if (buffer && buflen >= 2 * p->blob_len) {
1152                 ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL);
1153                 if (!ascii_buf)
1154                         return -ENOMEM;
1155 
1156                 bufp = ascii_buf;
1157                 for (i = 0; i < p->blob_len; i++)
1158                         bufp = hex_byte_pack(bufp, p->blob[i]);
1159                 if (copy_to_user(buffer, ascii_buf, 2 * p->blob_len) != 0) {
1160                         kzfree(ascii_buf);
1161                         return -EFAULT;
1162                 }
1163                 kzfree(ascii_buf);
1164         }
1165         return 2 * p->blob_len;
1166 }
1167 
1168 /*
1169  * trusted_destroy - clear and free the key's payload
1170  */
1171 static void trusted_destroy(struct key *key)
1172 {
1173         kzfree(key->payload.data[0]);
1174 }
1175 
1176 struct key_type key_type_trusted = {
1177         .name = "trusted",
1178         .instantiate = trusted_instantiate,
1179         .update = trusted_update,
1180         .destroy = trusted_destroy,
1181         .describe = user_describe,
1182         .read = trusted_read,
1183 };
1184 
1185 EXPORT_SYMBOL_GPL(key_type_trusted);
1186 
1187 static void trusted_shash_release(void)
1188 {
1189         if (hashalg)
1190                 crypto_free_shash(hashalg);
1191         if (hmacalg)
1192                 crypto_free_shash(hmacalg);
1193 }
1194 
1195 static int __init trusted_shash_alloc(void)
1196 {
1197         int ret;
1198 
1199         hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC);
1200         if (IS_ERR(hmacalg)) {
1201                 pr_info("trusted_key: could not allocate crypto %s\n",
1202                         hmac_alg);
1203                 return PTR_ERR(hmacalg);
1204         }
1205 
1206         hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC);
1207         if (IS_ERR(hashalg)) {
1208                 pr_info("trusted_key: could not allocate crypto %s\n",
1209                         hash_alg);
1210                 ret = PTR_ERR(hashalg);
1211                 goto hashalg_fail;
1212         }
1213 
1214         return 0;
1215 
1216 hashalg_fail:
1217         crypto_free_shash(hmacalg);
1218         return ret;
1219 }
1220 
1221 static int __init init_trusted(void)
1222 {
1223         int ret;
1224 
1225         ret = trusted_shash_alloc();
1226         if (ret < 0)
1227                 return ret;
1228         ret = register_key_type(&key_type_trusted);
1229         if (ret < 0)
1230                 trusted_shash_release();
1231         return ret;
1232 }
1233 
1234 static void __exit cleanup_trusted(void)
1235 {
1236         trusted_shash_release();
1237         unregister_key_type(&key_type_trusted);
1238 }
1239 
1240 late_initcall(init_trusted);
1241 module_exit(cleanup_trusted);
1242 
1243 MODULE_LICENSE("GPL");
1244 

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