1 // SPDX-License-Identifier: GPL-2.0
2 #define pr_fmt(fmt) "ASYM-TPM: "fmt
3 #include <linux/slab.h>
4 #include <linux/module.h>
5 #include <linux/export.h>
6 #include <linux/kernel.h>
7 #include <linux/seq_file.h>
8 #include <linux/scatterlist.h>
10 #include <linux/tpm_command.h>
11 #include <crypto/akcipher.h>
12 #include <crypto/hash.h>
13 #include <crypto/sha.h>
14 #include <asm/unaligned.h>
15 #include <keys/asymmetric-subtype.h>
16 #include <keys/trusted.h>
17 #include <crypto/asym_tpm_subtype.h>
18 #include <crypto/public_key.h>
20 #define TPM_ORD_FLUSHSPECIFIC 186
21 #define TPM_ORD_LOADKEY2 65
22 #define TPM_ORD_UNBIND 30
23 #define TPM_ORD_SIGN 60
24 #define TPM_LOADKEY2_SIZE 59
25 #define TPM_FLUSHSPECIFIC_SIZE 18
26 #define TPM_UNBIND_SIZE 63
27 #define TPM_SIGN_SIZE 63
29 #define TPM_RT_KEY 0x00000001
32 * Load a TPM key from the blob provided by userspace
34 static int tpm_loadkey2(struct tpm_buf *tb,
35 uint32_t keyhandle, unsigned char *keyauth,
36 const unsigned char *keyblob, int keybloblen,
39 unsigned char nonceodd[TPM_NONCE_SIZE];
40 unsigned char enonce[TPM_NONCE_SIZE];
41 unsigned char authdata[SHA1_DIGEST_SIZE];
42 uint32_t authhandle = 0;
43 unsigned char cont = 0;
47 ordinal = htonl(TPM_ORD_LOADKEY2);
49 /* session for loading the key */
50 ret = oiap(tb, &authhandle, enonce);
52 pr_info("oiap failed (%d)\n", ret);
56 /* generate odd nonce */
57 ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE);
59 pr_info("tpm_get_random failed (%d)\n", ret);
63 /* calculate authorization HMAC value */
64 ret = TSS_authhmac(authdata, keyauth, SHA1_DIGEST_SIZE, enonce,
65 nonceodd, cont, sizeof(uint32_t), &ordinal,
66 keybloblen, keyblob, 0, 0);
70 /* build the request buffer */
72 store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
73 store32(tb, TPM_LOADKEY2_SIZE + keybloblen);
74 store32(tb, TPM_ORD_LOADKEY2);
75 store32(tb, keyhandle);
76 storebytes(tb, keyblob, keybloblen);
77 store32(tb, authhandle);
78 storebytes(tb, nonceodd, TPM_NONCE_SIZE);
80 storebytes(tb, authdata, SHA1_DIGEST_SIZE);
82 ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
84 pr_info("authhmac failed (%d)\n", ret);
88 ret = TSS_checkhmac1(tb->data, ordinal, nonceodd, keyauth,
89 SHA1_DIGEST_SIZE, 0, 0);
91 pr_info("TSS_checkhmac1 failed (%d)\n", ret);
95 *newhandle = LOAD32(tb->data, TPM_DATA_OFFSET);
100 * Execute the FlushSpecific TPM command
102 static int tpm_flushspecific(struct tpm_buf *tb, uint32_t handle)
105 store16(tb, TPM_TAG_RQU_COMMAND);
106 store32(tb, TPM_FLUSHSPECIFIC_SIZE);
107 store32(tb, TPM_ORD_FLUSHSPECIFIC);
109 store32(tb, TPM_RT_KEY);
111 return trusted_tpm_send(tb->data, MAX_BUF_SIZE);
115 * Decrypt a blob provided by userspace using a specific key handle.
116 * The handle is a well known handle or previously loaded by e.g. LoadKey2
118 static int tpm_unbind(struct tpm_buf *tb,
119 uint32_t keyhandle, unsigned char *keyauth,
120 const unsigned char *blob, uint32_t bloblen,
121 void *out, uint32_t outlen)
123 unsigned char nonceodd[TPM_NONCE_SIZE];
124 unsigned char enonce[TPM_NONCE_SIZE];
125 unsigned char authdata[SHA1_DIGEST_SIZE];
126 uint32_t authhandle = 0;
127 unsigned char cont = 0;
132 ordinal = htonl(TPM_ORD_UNBIND);
133 datalen = htonl(bloblen);
135 /* session for loading the key */
136 ret = oiap(tb, &authhandle, enonce);
138 pr_info("oiap failed (%d)\n", ret);
142 /* generate odd nonce */
143 ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE);
145 pr_info("tpm_get_random failed (%d)\n", ret);
149 /* calculate authorization HMAC value */
150 ret = TSS_authhmac(authdata, keyauth, SHA1_DIGEST_SIZE, enonce,
151 nonceodd, cont, sizeof(uint32_t), &ordinal,
152 sizeof(uint32_t), &datalen,
153 bloblen, blob, 0, 0);
157 /* build the request buffer */
159 store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
160 store32(tb, TPM_UNBIND_SIZE + bloblen);
161 store32(tb, TPM_ORD_UNBIND);
162 store32(tb, keyhandle);
163 store32(tb, bloblen);
164 storebytes(tb, blob, bloblen);
165 store32(tb, authhandle);
166 storebytes(tb, nonceodd, TPM_NONCE_SIZE);
168 storebytes(tb, authdata, SHA1_DIGEST_SIZE);
170 ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
172 pr_info("authhmac failed (%d)\n", ret);
176 datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
178 ret = TSS_checkhmac1(tb->data, ordinal, nonceodd,
179 keyauth, SHA1_DIGEST_SIZE,
180 sizeof(uint32_t), TPM_DATA_OFFSET,
181 datalen, TPM_DATA_OFFSET + sizeof(uint32_t),
184 pr_info("TSS_checkhmac1 failed (%d)\n", ret);
188 memcpy(out, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t),
189 min(outlen, datalen));
195 * Sign a blob provided by userspace (that has had the hash function applied)
196 * using a specific key handle. The handle is assumed to have been previously
197 * loaded by e.g. LoadKey2.
199 * Note that the key signature scheme of the used key should be set to
200 * TPM_SS_RSASSAPKCS1v15_DER. This allows the hashed input to be of any size
201 * up to key_length_in_bytes - 11 and not be limited to size 20 like the
202 * TPM_SS_RSASSAPKCS1v15_SHA1 signature scheme.
204 static int tpm_sign(struct tpm_buf *tb,
205 uint32_t keyhandle, unsigned char *keyauth,
206 const unsigned char *blob, uint32_t bloblen,
207 void *out, uint32_t outlen)
209 unsigned char nonceodd[TPM_NONCE_SIZE];
210 unsigned char enonce[TPM_NONCE_SIZE];
211 unsigned char authdata[SHA1_DIGEST_SIZE];
212 uint32_t authhandle = 0;
213 unsigned char cont = 0;
218 ordinal = htonl(TPM_ORD_SIGN);
219 datalen = htonl(bloblen);
221 /* session for loading the key */
222 ret = oiap(tb, &authhandle, enonce);
224 pr_info("oiap failed (%d)\n", ret);
228 /* generate odd nonce */
229 ret = tpm_get_random(NULL, nonceodd, TPM_NONCE_SIZE);
231 pr_info("tpm_get_random failed (%d)\n", ret);
235 /* calculate authorization HMAC value */
236 ret = TSS_authhmac(authdata, keyauth, SHA1_DIGEST_SIZE, enonce,
237 nonceodd, cont, sizeof(uint32_t), &ordinal,
238 sizeof(uint32_t), &datalen,
239 bloblen, blob, 0, 0);
243 /* build the request buffer */
245 store16(tb, TPM_TAG_RQU_AUTH1_COMMAND);
246 store32(tb, TPM_SIGN_SIZE + bloblen);
247 store32(tb, TPM_ORD_SIGN);
248 store32(tb, keyhandle);
249 store32(tb, bloblen);
250 storebytes(tb, blob, bloblen);
251 store32(tb, authhandle);
252 storebytes(tb, nonceodd, TPM_NONCE_SIZE);
254 storebytes(tb, authdata, SHA1_DIGEST_SIZE);
256 ret = trusted_tpm_send(tb->data, MAX_BUF_SIZE);
258 pr_info("authhmac failed (%d)\n", ret);
262 datalen = LOAD32(tb->data, TPM_DATA_OFFSET);
264 ret = TSS_checkhmac1(tb->data, ordinal, nonceodd,
265 keyauth, SHA1_DIGEST_SIZE,
266 sizeof(uint32_t), TPM_DATA_OFFSET,
267 datalen, TPM_DATA_OFFSET + sizeof(uint32_t),
270 pr_info("TSS_checkhmac1 failed (%d)\n", ret);
274 memcpy(out, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t),
275 min(datalen, outlen));
280 * Maximum buffer size for the BER/DER encoded public key. The public key
281 * is of the form SEQUENCE { INTEGER n, INTEGER e } where n is a maximum 2048
282 * bit key and e is usually 65537
283 * The encoding overhead is:
284 * - max 4 bytes for SEQUENCE
285 * - max 4 bytes for INTEGER n type/length
287 * - max 2 bytes for INTEGER e type/length
290 #define PUB_KEY_BUF_SIZE (4 + 4 + 257 + 2 + 3)
293 * Provide a part of a description of the key for /proc/keys.
295 static void asym_tpm_describe(const struct key *asymmetric_key,
298 struct tpm_key *tk = asymmetric_key->payload.data[asym_crypto];
303 seq_printf(m, "TPM1.2/Blob");
306 static void asym_tpm_destroy(void *payload0, void *payload3)
308 struct tpm_key *tk = payload0;
319 /* How many bytes will it take to encode the length */
320 static inline uint32_t definite_length(uint32_t len)
329 static inline uint8_t *encode_tag_length(uint8_t *buf, uint8_t tag,
346 put_unaligned_be16(len, buf + 1);
350 static uint32_t derive_pub_key(const void *pub_key, uint32_t len, uint8_t *buf)
353 uint32_t n_len = definite_length(len) + 1 + len + 1;
354 uint32_t e_len = definite_length(3) + 1 + 3;
355 uint8_t e[3] = { 0x01, 0x00, 0x01 };
358 cur = encode_tag_length(cur, 0x30, n_len + e_len);
360 cur = encode_tag_length(cur, 0x02, len + 1);
362 memcpy(cur + 1, pub_key, len);
364 cur = encode_tag_length(cur, 0x02, sizeof(e));
365 memcpy(cur, e, sizeof(e));
372 * Determine the crypto algorithm name.
374 static int determine_akcipher(const char *encoding, const char *hash_algo,
375 char alg_name[CRYPTO_MAX_ALG_NAME])
377 if (strcmp(encoding, "pkcs1") == 0) {
379 strcpy(alg_name, "pkcs1pad(rsa)");
383 if (snprintf(alg_name, CRYPTO_MAX_ALG_NAME, "pkcs1pad(rsa,%s)",
384 hash_algo) >= CRYPTO_MAX_ALG_NAME)
390 if (strcmp(encoding, "raw") == 0) {
391 strcpy(alg_name, "rsa");
399 * Query information about a key.
401 static int tpm_key_query(const struct kernel_pkey_params *params,
402 struct kernel_pkey_query *info)
404 struct tpm_key *tk = params->key->payload.data[asym_crypto];
406 char alg_name[CRYPTO_MAX_ALG_NAME];
407 struct crypto_akcipher *tfm;
408 uint8_t der_pub_key[PUB_KEY_BUF_SIZE];
409 uint32_t der_pub_key_len;
412 /* TPM only works on private keys, public keys still done in software */
413 ret = determine_akcipher(params->encoding, params->hash_algo, alg_name);
417 tfm = crypto_alloc_akcipher(alg_name, 0, 0);
421 der_pub_key_len = derive_pub_key(tk->pub_key, tk->pub_key_len,
424 ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len);
428 len = crypto_akcipher_maxsize(tfm);
430 info->key_size = tk->key_len;
431 info->max_data_size = tk->key_len / 8;
432 info->max_sig_size = len;
433 info->max_enc_size = len;
434 info->max_dec_size = tk->key_len / 8;
436 info->supported_ops = KEYCTL_SUPPORTS_ENCRYPT |
437 KEYCTL_SUPPORTS_DECRYPT |
438 KEYCTL_SUPPORTS_VERIFY |
439 KEYCTL_SUPPORTS_SIGN;
443 crypto_free_akcipher(tfm);
444 pr_devel("<==%s() = %d\n", __func__, ret);
449 * Encryption operation is performed with the public key. Hence it is done
452 static int tpm_key_encrypt(struct tpm_key *tk,
453 struct kernel_pkey_params *params,
454 const void *in, void *out)
456 char alg_name[CRYPTO_MAX_ALG_NAME];
457 struct crypto_akcipher *tfm;
458 struct akcipher_request *req;
459 struct crypto_wait cwait;
460 struct scatterlist in_sg, out_sg;
461 uint8_t der_pub_key[PUB_KEY_BUF_SIZE];
462 uint32_t der_pub_key_len;
465 pr_devel("==>%s()\n", __func__);
467 ret = determine_akcipher(params->encoding, params->hash_algo, alg_name);
471 tfm = crypto_alloc_akcipher(alg_name, 0, 0);
475 der_pub_key_len = derive_pub_key(tk->pub_key, tk->pub_key_len,
478 ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len);
482 req = akcipher_request_alloc(tfm, GFP_KERNEL);
486 sg_init_one(&in_sg, in, params->in_len);
487 sg_init_one(&out_sg, out, params->out_len);
488 akcipher_request_set_crypt(req, &in_sg, &out_sg, params->in_len,
490 crypto_init_wait(&cwait);
491 akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
492 CRYPTO_TFM_REQ_MAY_SLEEP,
493 crypto_req_done, &cwait);
495 ret = crypto_akcipher_encrypt(req);
496 ret = crypto_wait_req(ret, &cwait);
501 akcipher_request_free(req);
503 crypto_free_akcipher(tfm);
504 pr_devel("<==%s() = %d\n", __func__, ret);
509 * Decryption operation is performed with the private key in the TPM.
511 static int tpm_key_decrypt(struct tpm_key *tk,
512 struct kernel_pkey_params *params,
513 const void *in, void *out)
517 uint8_t srkauth[SHA1_DIGEST_SIZE];
518 uint8_t keyauth[SHA1_DIGEST_SIZE];
521 pr_devel("==>%s()\n", __func__);
523 if (params->hash_algo)
526 if (strcmp(params->encoding, "pkcs1"))
529 tb = kzalloc(sizeof(*tb), GFP_KERNEL);
533 /* TODO: Handle a non-all zero SRK authorization */
534 memset(srkauth, 0, sizeof(srkauth));
536 r = tpm_loadkey2(tb, SRKHANDLE, srkauth,
537 tk->blob, tk->blob_len, &keyhandle);
539 pr_devel("loadkey2 failed (%d)\n", r);
543 /* TODO: Handle a non-all zero key authorization */
544 memset(keyauth, 0, sizeof(keyauth));
546 r = tpm_unbind(tb, keyhandle, keyauth,
547 in, params->in_len, out, params->out_len);
549 pr_devel("tpm_unbind failed (%d)\n", r);
551 if (tpm_flushspecific(tb, keyhandle) < 0)
552 pr_devel("flushspecific failed (%d)\n", r);
556 pr_devel("<==%s() = %d\n", __func__, r);
561 * Hash algorithm OIDs plus ASN.1 DER wrappings [RFC4880 sec 5.2.2].
563 static const u8 digest_info_md5[] = {
564 0x30, 0x20, 0x30, 0x0c, 0x06, 0x08,
565 0x2a, 0x86, 0x48, 0x86, 0xf7, 0x0d, 0x02, 0x05, /* OID */
566 0x05, 0x00, 0x04, 0x10
569 static const u8 digest_info_sha1[] = {
570 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
571 0x2b, 0x0e, 0x03, 0x02, 0x1a,
572 0x05, 0x00, 0x04, 0x14
575 static const u8 digest_info_rmd160[] = {
576 0x30, 0x21, 0x30, 0x09, 0x06, 0x05,
577 0x2b, 0x24, 0x03, 0x02, 0x01,
578 0x05, 0x00, 0x04, 0x14
581 static const u8 digest_info_sha224[] = {
582 0x30, 0x2d, 0x30, 0x0d, 0x06, 0x09,
583 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x04,
584 0x05, 0x00, 0x04, 0x1c
587 static const u8 digest_info_sha256[] = {
588 0x30, 0x31, 0x30, 0x0d, 0x06, 0x09,
589 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x01,
590 0x05, 0x00, 0x04, 0x20
593 static const u8 digest_info_sha384[] = {
594 0x30, 0x41, 0x30, 0x0d, 0x06, 0x09,
595 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x02,
596 0x05, 0x00, 0x04, 0x30
599 static const u8 digest_info_sha512[] = {
600 0x30, 0x51, 0x30, 0x0d, 0x06, 0x09,
601 0x60, 0x86, 0x48, 0x01, 0x65, 0x03, 0x04, 0x02, 0x03,
602 0x05, 0x00, 0x04, 0x40
605 static const struct asn1_template {
609 } asn1_templates[] = {
610 #define _(X) { #X, digest_info_##X, sizeof(digest_info_##X) }
622 static const struct asn1_template *lookup_asn1(const char *name)
624 const struct asn1_template *p;
626 for (p = asn1_templates; p->name; p++)
627 if (strcmp(name, p->name) == 0)
633 * Sign operation is performed with the private key in the TPM.
635 static int tpm_key_sign(struct tpm_key *tk,
636 struct kernel_pkey_params *params,
637 const void *in, void *out)
641 uint8_t srkauth[SHA1_DIGEST_SIZE];
642 uint8_t keyauth[SHA1_DIGEST_SIZE];
643 void *asn1_wrapped = NULL;
644 uint32_t in_len = params->in_len;
647 pr_devel("==>%s()\n", __func__);
649 if (strcmp(params->encoding, "pkcs1"))
652 if (params->hash_algo) {
653 const struct asn1_template *asn1 =
654 lookup_asn1(params->hash_algo);
659 /* request enough space for the ASN.1 template + input hash */
660 asn1_wrapped = kzalloc(in_len + asn1->size, GFP_KERNEL);
664 /* Copy ASN.1 template, then the input */
665 memcpy(asn1_wrapped, asn1->data, asn1->size);
666 memcpy(asn1_wrapped + asn1->size, in, in_len);
669 in_len += asn1->size;
672 if (in_len > tk->key_len / 8 - 11) {
674 goto error_free_asn1_wrapped;
678 tb = kzalloc(sizeof(*tb), GFP_KERNEL);
680 goto error_free_asn1_wrapped;
682 /* TODO: Handle a non-all zero SRK authorization */
683 memset(srkauth, 0, sizeof(srkauth));
685 r = tpm_loadkey2(tb, SRKHANDLE, srkauth,
686 tk->blob, tk->blob_len, &keyhandle);
688 pr_devel("loadkey2 failed (%d)\n", r);
692 /* TODO: Handle a non-all zero key authorization */
693 memset(keyauth, 0, sizeof(keyauth));
695 r = tpm_sign(tb, keyhandle, keyauth, in, in_len, out, params->out_len);
697 pr_devel("tpm_sign failed (%d)\n", r);
699 if (tpm_flushspecific(tb, keyhandle) < 0)
700 pr_devel("flushspecific failed (%d)\n", r);
704 error_free_asn1_wrapped:
706 pr_devel("<==%s() = %d\n", __func__, r);
711 * Do encryption, decryption and signing ops.
713 static int tpm_key_eds_op(struct kernel_pkey_params *params,
714 const void *in, void *out)
716 struct tpm_key *tk = params->key->payload.data[asym_crypto];
717 int ret = -EOPNOTSUPP;
719 /* Perform the encryption calculation. */
720 switch (params->op) {
721 case kernel_pkey_encrypt:
722 ret = tpm_key_encrypt(tk, params, in, out);
724 case kernel_pkey_decrypt:
725 ret = tpm_key_decrypt(tk, params, in, out);
727 case kernel_pkey_sign:
728 ret = tpm_key_sign(tk, params, in, out);
738 * Verify a signature using a public key.
740 static int tpm_key_verify_signature(const struct key *key,
741 const struct public_key_signature *sig)
743 const struct tpm_key *tk = key->payload.data[asym_crypto];
744 struct crypto_wait cwait;
745 struct crypto_akcipher *tfm;
746 struct akcipher_request *req;
747 struct scatterlist sig_sg, digest_sg;
748 char alg_name[CRYPTO_MAX_ALG_NAME];
749 uint8_t der_pub_key[PUB_KEY_BUF_SIZE];
750 uint32_t der_pub_key_len;
755 pr_devel("==>%s()\n", __func__);
764 ret = determine_akcipher(sig->encoding, sig->hash_algo, alg_name);
768 tfm = crypto_alloc_akcipher(alg_name, 0, 0);
772 der_pub_key_len = derive_pub_key(tk->pub_key, tk->pub_key_len,
775 ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len);
780 req = akcipher_request_alloc(tfm, GFP_KERNEL);
785 outlen = crypto_akcipher_maxsize(tfm);
786 output = kmalloc(outlen, GFP_KERNEL);
790 sg_init_one(&sig_sg, sig->s, sig->s_size);
791 sg_init_one(&digest_sg, output, outlen);
792 akcipher_request_set_crypt(req, &sig_sg, &digest_sg, sig->s_size,
794 crypto_init_wait(&cwait);
795 akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG |
796 CRYPTO_TFM_REQ_MAY_SLEEP,
797 crypto_req_done, &cwait);
799 /* Perform the verification calculation. This doesn't actually do the
800 * verification, but rather calculates the hash expected by the
801 * signature and returns that to us.
803 ret = crypto_wait_req(crypto_akcipher_verify(req), &cwait);
805 goto out_free_output;
807 /* Do the actual verification step. */
808 if (req->dst_len != sig->digest_size ||
809 memcmp(sig->digest, output, sig->digest_size) != 0)
815 akcipher_request_free(req);
817 crypto_free_akcipher(tfm);
818 pr_devel("<==%s() = %d\n", __func__, ret);
819 if (WARN_ON_ONCE(ret > 0))
825 * Parse enough information out of TPM_KEY structure:
826 * TPM_STRUCT_VER -> 4 bytes
827 * TPM_KEY_USAGE -> 2 bytes
828 * TPM_KEY_FLAGS -> 4 bytes
829 * TPM_AUTH_DATA_USAGE -> 1 byte
830 * TPM_KEY_PARMS -> variable
831 * UINT32 PCRInfoSize -> 4 bytes
832 * BYTE* -> PCRInfoSize bytes
834 * UINT32 encDataSize;
835 * BYTE* -> encDataSize;
838 * TPM_ALGORITHM_ID -> 4 bytes
839 * TPM_ENC_SCHEME -> 2 bytes
840 * TPM_SIG_SCHEME -> 2 bytes
841 * UINT32 parmSize -> 4 bytes
844 static int extract_key_parameters(struct tpm_key *tk)
846 const void *cur = tk->blob;
847 uint32_t len = tk->blob_len;
855 /* Ensure this is a legacy key */
856 if (get_unaligned_be16(cur + 4) != 0x0015)
859 /* Skip to TPM_KEY_PARMS */
866 /* Make sure this is an RSA key */
867 if (get_unaligned_be32(cur) != 0x00000001)
870 /* Make sure this is TPM_ES_RSAESPKCSv15 encoding scheme */
871 if (get_unaligned_be16(cur + 4) != 0x0002)
874 /* Make sure this is TPM_SS_RSASSAPKCS1v15_DER signature scheme */
875 if (get_unaligned_be16(cur + 6) != 0x0003)
878 sz = get_unaligned_be32(cur + 8);
882 /* Move to TPM_RSA_KEY_PARMS */
886 /* Grab the RSA key length */
887 key_len = get_unaligned_be32(cur);
899 /* Move just past TPM_KEY_PARMS */
906 sz = get_unaligned_be32(cur);
910 /* Move to TPM_STORE_PUBKEY */
914 /* Grab the size of the public key, it should jive with the key size */
915 sz = get_unaligned_be32(cur);
921 tk->key_len = key_len;
922 tk->pub_key = pub_key;
923 tk->pub_key_len = sz;
928 /* Given the blob, parse it and load it into the TPM */
929 struct tpm_key *tpm_key_create(const void *blob, uint32_t blob_len)
934 r = tpm_is_tpm2(NULL);
938 /* We don't support TPM2 yet */
945 tk = kzalloc(sizeof(struct tpm_key), GFP_KERNEL);
949 tk->blob = kmemdup(blob, blob_len, GFP_KERNEL);
953 tk->blob_len = blob_len;
955 r = extract_key_parameters(tk);
969 EXPORT_SYMBOL_GPL(tpm_key_create);
972 * TPM-based asymmetric key subtype
974 struct asymmetric_key_subtype asym_tpm_subtype = {
975 .owner = THIS_MODULE,
977 .name_len = sizeof("asym_tpm") - 1,
978 .describe = asym_tpm_describe,
979 .destroy = asym_tpm_destroy,
980 .query = tpm_key_query,
981 .eds_op = tpm_key_eds_op,
982 .verify_signature = tpm_key_verify_signature,
984 EXPORT_SYMBOL_GPL(asym_tpm_subtype);
986 MODULE_DESCRIPTION("TPM based asymmetric key subtype");
987 MODULE_AUTHOR("Intel Corporation");
988 MODULE_LICENSE("GPL v2");