| /* |
| * Copyright (C) 2010 IBM Corporation |
| * |
| * Author: |
| * David Safford <safford@us.ibm.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation, version 2 of the License. |
| * |
| * See Documentation/security/keys-trusted-encrypted.txt |
| */ |
| |
| #include <crypto/hash_info.h> |
| #include <linux/uaccess.h> |
| #include <linux/module.h> |
| #include <linux/init.h> |
| #include <linux/slab.h> |
| #include <linux/parser.h> |
| #include <linux/string.h> |
| #include <linux/err.h> |
| #include <keys/user-type.h> |
| #include <keys/trusted-type.h> |
| #include <linux/key-type.h> |
| #include <linux/rcupdate.h> |
| #include <linux/crypto.h> |
| #include <crypto/hash.h> |
| #include <crypto/sha.h> |
| #include <linux/capability.h> |
| #include <linux/tpm.h> |
| #include <linux/tpm_command.h> |
| |
| #include "trusted.h" |
| |
| static const char hmac_alg[] = "hmac(sha1)"; |
| static const char hash_alg[] = "sha1"; |
| |
| struct sdesc { |
| struct shash_desc shash; |
| char ctx[]; |
| }; |
| |
| static struct crypto_shash *hashalg; |
| static struct crypto_shash *hmacalg; |
| |
| static struct sdesc *init_sdesc(struct crypto_shash *alg) |
| { |
| struct sdesc *sdesc; |
| int size; |
| |
| size = sizeof(struct shash_desc) + crypto_shash_descsize(alg); |
| sdesc = kmalloc(size, GFP_KERNEL); |
| if (!sdesc) |
| return ERR_PTR(-ENOMEM); |
| sdesc->shash.tfm = alg; |
| sdesc->shash.flags = 0x0; |
| return sdesc; |
| } |
| |
| static int TSS_sha1(const unsigned char *data, unsigned int datalen, |
| unsigned char *digest) |
| { |
| struct sdesc *sdesc; |
| int ret; |
| |
| sdesc = init_sdesc(hashalg); |
| if (IS_ERR(sdesc)) { |
| pr_info("trusted_key: can't alloc %s\n", hash_alg); |
| return PTR_ERR(sdesc); |
| } |
| |
| ret = crypto_shash_digest(&sdesc->shash, data, datalen, digest); |
| kfree(sdesc); |
| return ret; |
| } |
| |
| static int TSS_rawhmac(unsigned char *digest, const unsigned char *key, |
| unsigned int keylen, ...) |
| { |
| struct sdesc *sdesc; |
| va_list argp; |
| unsigned int dlen; |
| unsigned char *data; |
| int ret; |
| |
| sdesc = init_sdesc(hmacalg); |
| if (IS_ERR(sdesc)) { |
| pr_info("trusted_key: can't alloc %s\n", hmac_alg); |
| return PTR_ERR(sdesc); |
| } |
| |
| ret = crypto_shash_setkey(hmacalg, key, keylen); |
| if (ret < 0) |
| goto out; |
| ret = crypto_shash_init(&sdesc->shash); |
| if (ret < 0) |
| goto out; |
| |
| va_start(argp, keylen); |
| for (;;) { |
| dlen = va_arg(argp, unsigned int); |
| if (dlen == 0) |
| break; |
| data = va_arg(argp, unsigned char *); |
| if (data == NULL) { |
| ret = -EINVAL; |
| break; |
| } |
| ret = crypto_shash_update(&sdesc->shash, data, dlen); |
| if (ret < 0) |
| break; |
| } |
| va_end(argp); |
| if (!ret) |
| ret = crypto_shash_final(&sdesc->shash, digest); |
| out: |
| kfree(sdesc); |
| return ret; |
| } |
| |
| /* |
| * calculate authorization info fields to send to TPM |
| */ |
| static int TSS_authhmac(unsigned char *digest, const unsigned char *key, |
| unsigned int keylen, unsigned char *h1, |
| unsigned char *h2, unsigned char h3, ...) |
| { |
| unsigned char paramdigest[SHA1_DIGEST_SIZE]; |
| struct sdesc *sdesc; |
| unsigned int dlen; |
| unsigned char *data; |
| unsigned char c; |
| int ret; |
| va_list argp; |
| |
| sdesc = init_sdesc(hashalg); |
| if (IS_ERR(sdesc)) { |
| pr_info("trusted_key: can't alloc %s\n", hash_alg); |
| return PTR_ERR(sdesc); |
| } |
| |
| c = h3; |
| ret = crypto_shash_init(&sdesc->shash); |
| if (ret < 0) |
| goto out; |
| va_start(argp, h3); |
| for (;;) { |
| dlen = va_arg(argp, unsigned int); |
| if (dlen == 0) |
| break; |
| data = va_arg(argp, unsigned char *); |
| if (!data) { |
| ret = -EINVAL; |
| break; |
| } |
| ret = crypto_shash_update(&sdesc->shash, data, dlen); |
| if (ret < 0) |
| break; |
| } |
| va_end(argp); |
| if (!ret) |
| ret = crypto_shash_final(&sdesc->shash, paramdigest); |
| if (!ret) |
| ret = TSS_rawhmac(digest, key, keylen, SHA1_DIGEST_SIZE, |
| paramdigest, TPM_NONCE_SIZE, h1, |
| TPM_NONCE_SIZE, h2, 1, &c, 0, 0); |
| out: |
| kfree(sdesc); |
| return ret; |
| } |
| |
| /* |
| * verify the AUTH1_COMMAND (Seal) result from TPM |
| */ |
| static int TSS_checkhmac1(unsigned char *buffer, |
| const uint32_t command, |
| const unsigned char *ononce, |
| const unsigned char *key, |
| unsigned int keylen, ...) |
| { |
| uint32_t bufsize; |
| uint16_t tag; |
| uint32_t ordinal; |
| uint32_t result; |
| unsigned char *enonce; |
| unsigned char *continueflag; |
| unsigned char *authdata; |
| unsigned char testhmac[SHA1_DIGEST_SIZE]; |
| unsigned char paramdigest[SHA1_DIGEST_SIZE]; |
| struct sdesc *sdesc; |
| unsigned int dlen; |
| unsigned int dpos; |
| va_list argp; |
| int ret; |
| |
| bufsize = LOAD32(buffer, TPM_SIZE_OFFSET); |
| tag = LOAD16(buffer, 0); |
| ordinal = command; |
| result = LOAD32N(buffer, TPM_RETURN_OFFSET); |
| if (tag == TPM_TAG_RSP_COMMAND) |
| return 0; |
| if (tag != TPM_TAG_RSP_AUTH1_COMMAND) |
| return -EINVAL; |
| authdata = buffer + bufsize - SHA1_DIGEST_SIZE; |
| continueflag = authdata - 1; |
| enonce = continueflag - TPM_NONCE_SIZE; |
| |
| sdesc = init_sdesc(hashalg); |
| if (IS_ERR(sdesc)) { |
| pr_info("trusted_key: can't alloc %s\n", hash_alg); |
| return PTR_ERR(sdesc); |
| } |
| ret = crypto_shash_init(&sdesc->shash); |
| if (ret < 0) |
| goto out; |
| ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result, |
| sizeof result); |
| if (ret < 0) |
| goto out; |
| ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal, |
| sizeof ordinal); |
| if (ret < 0) |
| goto out; |
| va_start(argp, keylen); |
| for (;;) { |
| dlen = va_arg(argp, unsigned int); |
| if (dlen == 0) |
| break; |
| dpos = va_arg(argp, unsigned int); |
| ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen); |
| if (ret < 0) |
| break; |
| } |
| va_end(argp); |
| if (!ret) |
| ret = crypto_shash_final(&sdesc->shash, paramdigest); |
| if (ret < 0) |
| goto out; |
| |
| ret = TSS_rawhmac(testhmac, key, keylen, SHA1_DIGEST_SIZE, paramdigest, |
| TPM_NONCE_SIZE, enonce, TPM_NONCE_SIZE, ononce, |
| 1, continueflag, 0, 0); |
| if (ret < 0) |
| goto out; |
| |
| if (memcmp(testhmac, authdata, SHA1_DIGEST_SIZE)) |
| ret = -EINVAL; |
| out: |
| kfree(sdesc); |
| return ret; |
| } |
| |
| /* |
| * verify the AUTH2_COMMAND (unseal) result from TPM |
| */ |
| static int TSS_checkhmac2(unsigned char *buffer, |
| const uint32_t command, |
| const unsigned char *ononce, |
| const unsigned char *key1, |
| unsigned int keylen1, |
| const unsigned char *key2, |
| unsigned int keylen2, ...) |
| { |
| uint32_t bufsize; |
| uint16_t tag; |
| uint32_t ordinal; |
| uint32_t result; |
| unsigned char *enonce1; |
| unsigned char *continueflag1; |
| unsigned char *authdata1; |
| unsigned char *enonce2; |
| unsigned char *continueflag2; |
| unsigned char *authdata2; |
| unsigned char testhmac1[SHA1_DIGEST_SIZE]; |
| unsigned char testhmac2[SHA1_DIGEST_SIZE]; |
| unsigned char paramdigest[SHA1_DIGEST_SIZE]; |
| struct sdesc *sdesc; |
| unsigned int dlen; |
| unsigned int dpos; |
| va_list argp; |
| int ret; |
| |
| bufsize = LOAD32(buffer, TPM_SIZE_OFFSET); |
| tag = LOAD16(buffer, 0); |
| ordinal = command; |
| result = LOAD32N(buffer, TPM_RETURN_OFFSET); |
| |
| if (tag == TPM_TAG_RSP_COMMAND) |
| return 0; |
| if (tag != TPM_TAG_RSP_AUTH2_COMMAND) |
| return -EINVAL; |
| authdata1 = buffer + bufsize - (SHA1_DIGEST_SIZE + 1 |
| + SHA1_DIGEST_SIZE + SHA1_DIGEST_SIZE); |
| authdata2 = buffer + bufsize - (SHA1_DIGEST_SIZE); |
| continueflag1 = authdata1 - 1; |
| continueflag2 = authdata2 - 1; |
| enonce1 = continueflag1 - TPM_NONCE_SIZE; |
| enonce2 = continueflag2 - TPM_NONCE_SIZE; |
| |
| sdesc = init_sdesc(hashalg); |
| if (IS_ERR(sdesc)) { |
| pr_info("trusted_key: can't alloc %s\n", hash_alg); |
| return PTR_ERR(sdesc); |
| } |
| ret = crypto_shash_init(&sdesc->shash); |
| if (ret < 0) |
| goto out; |
| ret = crypto_shash_update(&sdesc->shash, (const u8 *)&result, |
| sizeof result); |
| if (ret < 0) |
| goto out; |
| ret = crypto_shash_update(&sdesc->shash, (const u8 *)&ordinal, |
| sizeof ordinal); |
| if (ret < 0) |
| goto out; |
| |
| va_start(argp, keylen2); |
| for (;;) { |
| dlen = va_arg(argp, unsigned int); |
| if (dlen == 0) |
| break; |
| dpos = va_arg(argp, unsigned int); |
| ret = crypto_shash_update(&sdesc->shash, buffer + dpos, dlen); |
| if (ret < 0) |
| break; |
| } |
| va_end(argp); |
| if (!ret) |
| ret = crypto_shash_final(&sdesc->shash, paramdigest); |
| if (ret < 0) |
| goto out; |
| |
| ret = TSS_rawhmac(testhmac1, key1, keylen1, SHA1_DIGEST_SIZE, |
| paramdigest, TPM_NONCE_SIZE, enonce1, |
| TPM_NONCE_SIZE, ononce, 1, continueflag1, 0, 0); |
| if (ret < 0) |
| goto out; |
| if (memcmp(testhmac1, authdata1, SHA1_DIGEST_SIZE)) { |
| ret = -EINVAL; |
| goto out; |
| } |
| ret = TSS_rawhmac(testhmac2, key2, keylen2, SHA1_DIGEST_SIZE, |
| paramdigest, TPM_NONCE_SIZE, enonce2, |
| TPM_NONCE_SIZE, ononce, 1, continueflag2, 0, 0); |
| if (ret < 0) |
| goto out; |
| if (memcmp(testhmac2, authdata2, SHA1_DIGEST_SIZE)) |
| ret = -EINVAL; |
| out: |
| kfree(sdesc); |
| return ret; |
| } |
| |
| /* |
| * For key specific tpm requests, we will generate and send our |
| * own TPM command packets using the drivers send function. |
| */ |
| static int trusted_tpm_send(const u32 chip_num, unsigned char *cmd, |
| size_t buflen) |
| { |
| int rc; |
| |
| dump_tpm_buf(cmd); |
| rc = tpm_send(chip_num, cmd, buflen); |
| dump_tpm_buf(cmd); |
| if (rc > 0) |
| /* Can't return positive return codes values to keyctl */ |
| rc = -EPERM; |
| return rc; |
| } |
| |
| /* |
| * Lock a trusted key, by extending a selected PCR. |
| * |
| * Prevents a trusted key that is sealed to PCRs from being accessed. |
| * This uses the tpm driver's extend function. |
| */ |
| static int pcrlock(const int pcrnum) |
| { |
| unsigned char hash[SHA1_DIGEST_SIZE]; |
| int ret; |
| |
| if (!capable(CAP_SYS_ADMIN)) |
| return -EPERM; |
| ret = tpm_get_random(TPM_ANY_NUM, hash, SHA1_DIGEST_SIZE); |
| if (ret != SHA1_DIGEST_SIZE) |
| return ret; |
| return tpm_pcr_extend(TPM_ANY_NUM, pcrnum, hash) ? -EINVAL : 0; |
| } |
| |
| /* |
| * Create an object specific authorisation protocol (OSAP) session |
| */ |
| static int osap(struct tpm_buf *tb, struct osapsess *s, |
| const unsigned char *key, uint16_t type, uint32_t handle) |
| { |
| unsigned char enonce[TPM_NONCE_SIZE]; |
| unsigned char ononce[TPM_NONCE_SIZE]; |
| int ret; |
| |
| ret = tpm_get_random(TPM_ANY_NUM, ononce, TPM_NONCE_SIZE); |
| if (ret != TPM_NONCE_SIZE) |
| return ret; |
| |
| INIT_BUF(tb); |
| store16(tb, TPM_TAG_RQU_COMMAND); |
| store32(tb, TPM_OSAP_SIZE); |
| store32(tb, TPM_ORD_OSAP); |
| store16(tb, type); |
| store32(tb, handle); |
| storebytes(tb, ononce, TPM_NONCE_SIZE); |
| |
| ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); |
| if (ret < 0) |
| return ret; |
| |
| s->handle = LOAD32(tb->data, TPM_DATA_OFFSET); |
| memcpy(s->enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)]), |
| TPM_NONCE_SIZE); |
| memcpy(enonce, &(tb->data[TPM_DATA_OFFSET + sizeof(uint32_t) + |
| TPM_NONCE_SIZE]), TPM_NONCE_SIZE); |
| return TSS_rawhmac(s->secret, key, SHA1_DIGEST_SIZE, TPM_NONCE_SIZE, |
| enonce, TPM_NONCE_SIZE, ononce, 0, 0); |
| } |
| |
| /* |
| * Create an object independent authorisation protocol (oiap) session |
| */ |
| static int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce) |
| { |
| int ret; |
| |
| INIT_BUF(tb); |
| store16(tb, TPM_TAG_RQU_COMMAND); |
| store32(tb, TPM_OIAP_SIZE); |
| store32(tb, TPM_ORD_OIAP); |
| ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); |
| if (ret < 0) |
| return ret; |
| |
| *handle = LOAD32(tb->data, TPM_DATA_OFFSET); |
| memcpy(nonce, &tb->data[TPM_DATA_OFFSET + sizeof(uint32_t)], |
| TPM_NONCE_SIZE); |
| return 0; |
| } |
| |
| struct tpm_digests { |
| unsigned char encauth[SHA1_DIGEST_SIZE]; |
| unsigned char pubauth[SHA1_DIGEST_SIZE]; |
| unsigned char xorwork[SHA1_DIGEST_SIZE * 2]; |
| unsigned char xorhash[SHA1_DIGEST_SIZE]; |
| unsigned char nonceodd[TPM_NONCE_SIZE]; |
| }; |
| |
| /* |
| * Have the TPM seal(encrypt) the trusted key, possibly based on |
| * Platform Configuration Registers (PCRs). AUTH1 for sealing key. |
| */ |
| static int tpm_seal(struct tpm_buf *tb, uint16_t keytype, |
| uint32_t keyhandle, const unsigned char *keyauth, |
| const unsigned char *data, uint32_t datalen, |
| unsigned char *blob, uint32_t *bloblen, |
| const unsigned char *blobauth, |
| const unsigned char *pcrinfo, uint32_t pcrinfosize) |
| { |
| struct osapsess sess; |
| struct tpm_digests *td; |
| unsigned char cont; |
| uint32_t ordinal; |
| uint32_t pcrsize; |
| uint32_t datsize; |
| int sealinfosize; |
| int encdatasize; |
| int storedsize; |
| int ret; |
| int i; |
| |
| /* alloc some work space for all the hashes */ |
| td = kmalloc(sizeof *td, GFP_KERNEL); |
| if (!td) |
| return -ENOMEM; |
| |
| /* get session for sealing key */ |
| ret = osap(tb, &sess, keyauth, keytype, keyhandle); |
| if (ret < 0) |
| goto out; |
| dump_sess(&sess); |
| |
| /* calculate encrypted authorization value */ |
| memcpy(td->xorwork, sess.secret, SHA1_DIGEST_SIZE); |
| memcpy(td->xorwork + SHA1_DIGEST_SIZE, sess.enonce, SHA1_DIGEST_SIZE); |
| ret = TSS_sha1(td->xorwork, SHA1_DIGEST_SIZE * 2, td->xorhash); |
| if (ret < 0) |
| goto out; |
| |
| ret = tpm_get_random(TPM_ANY_NUM, td->nonceodd, TPM_NONCE_SIZE); |
| if (ret != TPM_NONCE_SIZE) |
| goto out; |
| ordinal = htonl(TPM_ORD_SEAL); |
| datsize = htonl(datalen); |
| pcrsize = htonl(pcrinfosize); |
| cont = 0; |
| |
| /* encrypt data authorization key */ |
| for (i = 0; i < SHA1_DIGEST_SIZE; ++i) |
| td->encauth[i] = td->xorhash[i] ^ blobauth[i]; |
| |
| /* calculate authorization HMAC value */ |
| if (pcrinfosize == 0) { |
| /* no pcr info specified */ |
| ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE, |
| sess.enonce, td->nonceodd, cont, |
| sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE, |
| td->encauth, sizeof(uint32_t), &pcrsize, |
| sizeof(uint32_t), &datsize, datalen, data, 0, |
| 0); |
| } else { |
| /* pcr info specified */ |
| ret = TSS_authhmac(td->pubauth, sess.secret, SHA1_DIGEST_SIZE, |
| sess.enonce, td->nonceodd, cont, |
| sizeof(uint32_t), &ordinal, SHA1_DIGEST_SIZE, |
| td->encauth, sizeof(uint32_t), &pcrsize, |
| pcrinfosize, pcrinfo, sizeof(uint32_t), |
| &datsize, datalen, data, 0, 0); |
| } |
| if (ret < 0) |
| goto out; |
| |
| /* build and send the TPM request packet */ |
| INIT_BUF(tb); |
| store16(tb, TPM_TAG_RQU_AUTH1_COMMAND); |
| store32(tb, TPM_SEAL_SIZE + pcrinfosize + datalen); |
| store32(tb, TPM_ORD_SEAL); |
| store32(tb, keyhandle); |
| storebytes(tb, td->encauth, SHA1_DIGEST_SIZE); |
| store32(tb, pcrinfosize); |
| storebytes(tb, pcrinfo, pcrinfosize); |
| store32(tb, datalen); |
| storebytes(tb, data, datalen); |
| store32(tb, sess.handle); |
| storebytes(tb, td->nonceodd, TPM_NONCE_SIZE); |
| store8(tb, cont); |
| storebytes(tb, td->pubauth, SHA1_DIGEST_SIZE); |
| |
| ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); |
| if (ret < 0) |
| goto out; |
| |
| /* calculate the size of the returned Blob */ |
| sealinfosize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t)); |
| encdatasize = LOAD32(tb->data, TPM_DATA_OFFSET + sizeof(uint32_t) + |
| sizeof(uint32_t) + sealinfosize); |
| storedsize = sizeof(uint32_t) + sizeof(uint32_t) + sealinfosize + |
| sizeof(uint32_t) + encdatasize; |
| |
| /* check the HMAC in the response */ |
| ret = TSS_checkhmac1(tb->data, ordinal, td->nonceodd, sess.secret, |
| SHA1_DIGEST_SIZE, storedsize, TPM_DATA_OFFSET, 0, |
| 0); |
| |
| /* copy the returned blob to caller */ |
| if (!ret) { |
| memcpy(blob, tb->data + TPM_DATA_OFFSET, storedsize); |
| *bloblen = storedsize; |
| } |
| out: |
| kfree(td); |
| return ret; |
| } |
| |
| /* |
| * use the AUTH2_COMMAND form of unseal, to authorize both key and blob |
| */ |
| static int tpm_unseal(struct tpm_buf *tb, |
| uint32_t keyhandle, const unsigned char *keyauth, |
| const unsigned char *blob, int bloblen, |
| const unsigned char *blobauth, |
| unsigned char *data, unsigned int *datalen) |
| { |
| unsigned char nonceodd[TPM_NONCE_SIZE]; |
| unsigned char enonce1[TPM_NONCE_SIZE]; |
| unsigned char enonce2[TPM_NONCE_SIZE]; |
| unsigned char authdata1[SHA1_DIGEST_SIZE]; |
| unsigned char authdata2[SHA1_DIGEST_SIZE]; |
| uint32_t authhandle1 = 0; |
| uint32_t authhandle2 = 0; |
| unsigned char cont = 0; |
| uint32_t ordinal; |
| uint32_t keyhndl; |
| int ret; |
| |
| /* sessions for unsealing key and data */ |
| ret = oiap(tb, &authhandle1, enonce1); |
| if (ret < 0) { |
| pr_info("trusted_key: oiap failed (%d)\n", ret); |
| return ret; |
| } |
| ret = oiap(tb, &authhandle2, enonce2); |
| if (ret < 0) { |
| pr_info("trusted_key: oiap failed (%d)\n", ret); |
| return ret; |
| } |
| |
| ordinal = htonl(TPM_ORD_UNSEAL); |
| keyhndl = htonl(SRKHANDLE); |
| ret = tpm_get_random(TPM_ANY_NUM, nonceodd, TPM_NONCE_SIZE); |
| if (ret != TPM_NONCE_SIZE) { |
| pr_info("trusted_key: tpm_get_random failed (%d)\n", ret); |
| return ret; |
| } |
| ret = TSS_authhmac(authdata1, keyauth, TPM_NONCE_SIZE, |
| enonce1, nonceodd, cont, sizeof(uint32_t), |
| &ordinal, bloblen, blob, 0, 0); |
| if (ret < 0) |
| return ret; |
| ret = TSS_authhmac(authdata2, blobauth, TPM_NONCE_SIZE, |
| enonce2, nonceodd, cont, sizeof(uint32_t), |
| &ordinal, bloblen, blob, 0, 0); |
| if (ret < 0) |
| return ret; |
| |
| /* build and send TPM request packet */ |
| INIT_BUF(tb); |
| store16(tb, TPM_TAG_RQU_AUTH2_COMMAND); |
| store32(tb, TPM_UNSEAL_SIZE + bloblen); |
| store32(tb, TPM_ORD_UNSEAL); |
| store32(tb, keyhandle); |
| storebytes(tb, blob, bloblen); |
| store32(tb, authhandle1); |
| storebytes(tb, nonceodd, TPM_NONCE_SIZE); |
| store8(tb, cont); |
| storebytes(tb, authdata1, SHA1_DIGEST_SIZE); |
| store32(tb, authhandle2); |
| storebytes(tb, nonceodd, TPM_NONCE_SIZE); |
| store8(tb, cont); |
| storebytes(tb, authdata2, SHA1_DIGEST_SIZE); |
| |
| ret = trusted_tpm_send(TPM_ANY_NUM, tb->data, MAX_BUF_SIZE); |
| if (ret < 0) { |
| pr_info("trusted_key: authhmac failed (%d)\n", ret); |
| return ret; |
| } |
| |
| *datalen = LOAD32(tb->data, TPM_DATA_OFFSET); |
| ret = TSS_checkhmac2(tb->data, ordinal, nonceodd, |
| keyauth, SHA1_DIGEST_SIZE, |
| blobauth, SHA1_DIGEST_SIZE, |
| sizeof(uint32_t), TPM_DATA_OFFSET, |
| *datalen, TPM_DATA_OFFSET + sizeof(uint32_t), 0, |
| 0); |
| if (ret < 0) { |
| pr_info("trusted_key: TSS_checkhmac2 failed (%d)\n", ret); |
| return ret; |
| } |
| memcpy(data, tb->data + TPM_DATA_OFFSET + sizeof(uint32_t), *datalen); |
| return 0; |
| } |
| |
| /* |
| * Have the TPM seal(encrypt) the symmetric key |
| */ |
| static int key_seal(struct trusted_key_payload *p, |
| struct trusted_key_options *o) |
| { |
| struct tpm_buf *tb; |
| int ret; |
| |
| tb = kzalloc(sizeof *tb, GFP_KERNEL); |
| if (!tb) |
| return -ENOMEM; |
| |
| /* include migratable flag at end of sealed key */ |
| p->key[p->key_len] = p->migratable; |
| |
| ret = tpm_seal(tb, o->keytype, o->keyhandle, o->keyauth, |
| p->key, p->key_len + 1, p->blob, &p->blob_len, |
| o->blobauth, o->pcrinfo, o->pcrinfo_len); |
| if (ret < 0) |
| pr_info("trusted_key: srkseal failed (%d)\n", ret); |
| |
| kfree(tb); |
| return ret; |
| } |
| |
| /* |
| * Have the TPM unseal(decrypt) the symmetric key |
| */ |
| static int key_unseal(struct trusted_key_payload *p, |
| struct trusted_key_options *o) |
| { |
| struct tpm_buf *tb; |
| int ret; |
| |
| tb = kzalloc(sizeof *tb, GFP_KERNEL); |
| if (!tb) |
| return -ENOMEM; |
| |
| ret = tpm_unseal(tb, o->keyhandle, o->keyauth, p->blob, p->blob_len, |
| o->blobauth, p->key, &p->key_len); |
| if (ret < 0) |
| pr_info("trusted_key: srkunseal failed (%d)\n", ret); |
| else |
| /* pull migratable flag out of sealed key */ |
| p->migratable = p->key[--p->key_len]; |
| |
| kfree(tb); |
| return ret; |
| } |
| |
| enum { |
| Opt_err = -1, |
| Opt_new, Opt_load, Opt_update, |
| Opt_keyhandle, Opt_keyauth, Opt_blobauth, |
| Opt_pcrinfo, Opt_pcrlock, Opt_migratable, |
| Opt_hash, |
| Opt_policydigest, |
| Opt_policyhandle, |
| }; |
| |
| static const match_table_t key_tokens = { |
| {Opt_new, "new"}, |
| {Opt_load, "load"}, |
| {Opt_update, "update"}, |
| {Opt_keyhandle, "keyhandle=%s"}, |
| {Opt_keyauth, "keyauth=%s"}, |
| {Opt_blobauth, "blobauth=%s"}, |
| {Opt_pcrinfo, "pcrinfo=%s"}, |
| {Opt_pcrlock, "pcrlock=%s"}, |
| {Opt_migratable, "migratable=%s"}, |
| {Opt_hash, "hash=%s"}, |
| {Opt_policydigest, "policydigest=%s"}, |
| {Opt_policyhandle, "policyhandle=%s"}, |
| {Opt_err, NULL} |
| }; |
| |
| /* can have zero or more token= options */ |
| static int getoptions(char *c, struct trusted_key_payload *pay, |
| struct trusted_key_options *opt) |
| { |
| substring_t args[MAX_OPT_ARGS]; |
| char *p = c; |
| int token; |
| int res; |
| unsigned long handle; |
| unsigned long lock; |
| unsigned long token_mask = 0; |
| unsigned int digest_len; |
| int i; |
| int tpm2; |
| |
| tpm2 = tpm_is_tpm2(TPM_ANY_NUM); |
| if (tpm2 < 0) |
| return tpm2; |
| |
| opt->hash = tpm2 ? HASH_ALGO_SHA256 : HASH_ALGO_SHA1; |
| |
| while ((p = strsep(&c, " \t"))) { |
| if (*p == '\0' || *p == ' ' || *p == '\t') |
| continue; |
| token = match_token(p, key_tokens, args); |
| if (test_and_set_bit(token, &token_mask)) |
| return -EINVAL; |
| |
| switch (token) { |
| case Opt_pcrinfo: |
| opt->pcrinfo_len = strlen(args[0].from) / 2; |
| if (opt->pcrinfo_len > MAX_PCRINFO_SIZE) |
| return -EINVAL; |
| res = hex2bin(opt->pcrinfo, args[0].from, |
| opt->pcrinfo_len); |
| if (res < 0) |
| return -EINVAL; |
| break; |
| case Opt_keyhandle: |
| res = kstrtoul(args[0].from, 16, &handle); |
| if (res < 0) |
| return -EINVAL; |
| opt->keytype = SEAL_keytype; |
| opt->keyhandle = handle; |
| break; |
| case Opt_keyauth: |
| if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE) |
| return -EINVAL; |
| res = hex2bin(opt->keyauth, args[0].from, |
| SHA1_DIGEST_SIZE); |
| if (res < 0) |
| return -EINVAL; |
| break; |
| case Opt_blobauth: |
| if (strlen(args[0].from) != 2 * SHA1_DIGEST_SIZE) |
| return -EINVAL; |
| res = hex2bin(opt->blobauth, args[0].from, |
| SHA1_DIGEST_SIZE); |
| if (res < 0) |
| return -EINVAL; |
| break; |
| case Opt_migratable: |
| if (*args[0].from == '0') |
| pay->migratable = 0; |
| else |
| return -EINVAL; |
| break; |
| case Opt_pcrlock: |
| res = kstrtoul(args[0].from, 10, &lock); |
| if (res < 0) |
| return -EINVAL; |
| opt->pcrlock = lock; |
| break; |
| case Opt_hash: |
| if (test_bit(Opt_policydigest, &token_mask)) |
| return -EINVAL; |
| for (i = 0; i < HASH_ALGO__LAST; i++) { |
| if (!strcmp(args[0].from, hash_algo_name[i])) { |
| opt->hash = i; |
| break; |
| } |
| } |
| if (i == HASH_ALGO__LAST) |
| return -EINVAL; |
| if (!tpm2 && i != HASH_ALGO_SHA1) { |
| pr_info("trusted_key: TPM 1.x only supports SHA-1.\n"); |
| return -EINVAL; |
| } |
| break; |
| case Opt_policydigest: |
| digest_len = hash_digest_size[opt->hash]; |
| if (!tpm2 || strlen(args[0].from) != (2 * digest_len)) |
| return -EINVAL; |
| res = hex2bin(opt->policydigest, args[0].from, |
| digest_len); |
| if (res < 0) |
| return -EINVAL; |
| opt->policydigest_len = digest_len; |
| break; |
| case Opt_policyhandle: |
| if (!tpm2) |
| return -EINVAL; |
| res = kstrtoul(args[0].from, 16, &handle); |
| if (res < 0) |
| return -EINVAL; |
| opt->policyhandle = handle; |
| break; |
| default: |
| return -EINVAL; |
| } |
| } |
| return 0; |
| } |
| |
| /* |
| * datablob_parse - parse the keyctl data and fill in the |
| * payload and options structures |
| * |
| * On success returns 0, otherwise -EINVAL. |
| */ |
| static int datablob_parse(char *datablob, struct trusted_key_payload *p, |
| struct trusted_key_options *o) |
| { |
| substring_t args[MAX_OPT_ARGS]; |
| long keylen; |
| int ret = -EINVAL; |
| int key_cmd; |
| char *c; |
| |
| /* main command */ |
| c = strsep(&datablob, " \t"); |
| if (!c) |
| return -EINVAL; |
| key_cmd = match_token(c, key_tokens, args); |
| switch (key_cmd) { |
| case Opt_new: |
| /* first argument is key size */ |
| c = strsep(&datablob, " \t"); |
| if (!c) |
| return -EINVAL; |
| ret = kstrtol(c, 10, &keylen); |
| if (ret < 0 || keylen < MIN_KEY_SIZE || keylen > MAX_KEY_SIZE) |
| return -EINVAL; |
| p->key_len = keylen; |
| ret = getoptions(datablob, p, o); |
| if (ret < 0) |
| return ret; |
| ret = Opt_new; |
| break; |
| case Opt_load: |
| /* first argument is sealed blob */ |
| c = strsep(&datablob, " \t"); |
| if (!c) |
| return -EINVAL; |
| p->blob_len = strlen(c) / 2; |
| if (p->blob_len > MAX_BLOB_SIZE) |
| return -EINVAL; |
| ret = hex2bin(p->blob, c, p->blob_len); |
| if (ret < 0) |
| return -EINVAL; |
| ret = getoptions(datablob, p, o); |
| if (ret < 0) |
| return ret; |
| ret = Opt_load; |
| break; |
| case Opt_update: |
| /* all arguments are options */ |
| ret = getoptions(datablob, p, o); |
| if (ret < 0) |
| return ret; |
| ret = Opt_update; |
| break; |
| case Opt_err: |
| return -EINVAL; |
| break; |
| } |
| return ret; |
| } |
| |
| static struct trusted_key_options *trusted_options_alloc(void) |
| { |
| struct trusted_key_options *options; |
| int tpm2; |
| |
| tpm2 = tpm_is_tpm2(TPM_ANY_NUM); |
| if (tpm2 < 0) |
| return NULL; |
| |
| options = kzalloc(sizeof *options, GFP_KERNEL); |
| if (options) { |
| /* set any non-zero defaults */ |
| options->keytype = SRK_keytype; |
| |
| if (!tpm2) |
| options->keyhandle = SRKHANDLE; |
| } |
| return options; |
| } |
| |
| static struct trusted_key_payload *trusted_payload_alloc(struct key *key) |
| { |
| struct trusted_key_payload *p = NULL; |
| int ret; |
| |
| ret = key_payload_reserve(key, sizeof *p); |
| if (ret < 0) |
| return p; |
| p = kzalloc(sizeof *p, GFP_KERNEL); |
| if (p) |
| p->migratable = 1; /* migratable by default */ |
| return p; |
| } |
| |
| /* |
| * trusted_instantiate - create a new trusted key |
| * |
| * Unseal an existing trusted blob or, for a new key, get a |
| * random key, then seal and create a trusted key-type key, |
| * adding it to the specified keyring. |
| * |
| * On success, return 0. Otherwise return errno. |
| */ |
| static int trusted_instantiate(struct key *key, |
| struct key_preparsed_payload *prep) |
| { |
| struct trusted_key_payload *payload = NULL; |
| struct trusted_key_options *options = NULL; |
| size_t datalen = prep->datalen; |
| char *datablob; |
| int ret = 0; |
| int key_cmd; |
| size_t key_len; |
| int tpm2; |
| |
| tpm2 = tpm_is_tpm2(TPM_ANY_NUM); |
| if (tpm2 < 0) |
| return tpm2; |
| |
| if (datalen <= 0 || datalen > 32767 || !prep->data) |
| return -EINVAL; |
| |
| datablob = kmalloc(datalen + 1, GFP_KERNEL); |
| if (!datablob) |
| return -ENOMEM; |
| memcpy(datablob, prep->data, datalen); |
| datablob[datalen] = '\0'; |
| |
| options = trusted_options_alloc(); |
| if (!options) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| payload = trusted_payload_alloc(key); |
| if (!payload) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| key_cmd = datablob_parse(datablob, payload, options); |
| if (key_cmd < 0) { |
| ret = key_cmd; |
| goto out; |
| } |
| |
| if (!options->keyhandle) { |
| ret = -EINVAL; |
| goto out; |
| } |
| |
| dump_payload(payload); |
| dump_options(options); |
| |
| switch (key_cmd) { |
| case Opt_load: |
| if (tpm2) |
| ret = tpm_unseal_trusted(TPM_ANY_NUM, payload, options); |
| else |
| ret = key_unseal(payload, options); |
| dump_payload(payload); |
| dump_options(options); |
| if (ret < 0) |
| pr_info("trusted_key: key_unseal failed (%d)\n", ret); |
| break; |
| case Opt_new: |
| key_len = payload->key_len; |
| ret = tpm_get_random(TPM_ANY_NUM, payload->key, key_len); |
| if (ret != key_len) { |
| pr_info("trusted_key: key_create failed (%d)\n", ret); |
| goto out; |
| } |
| if (tpm2) |
| ret = tpm_seal_trusted(TPM_ANY_NUM, payload, options); |
| else |
| ret = key_seal(payload, options); |
| if (ret < 0) |
| pr_info("trusted_key: key_seal failed (%d)\n", ret); |
| break; |
| default: |
| ret = -EINVAL; |
| goto out; |
| } |
| if (!ret && options->pcrlock) |
| ret = pcrlock(options->pcrlock); |
| out: |
| kfree(datablob); |
| kfree(options); |
| if (!ret) |
| rcu_assign_keypointer(key, payload); |
| else |
| kfree(payload); |
| return ret; |
| } |
| |
| static void trusted_rcu_free(struct rcu_head *rcu) |
| { |
| struct trusted_key_payload *p; |
| |
| p = container_of(rcu, struct trusted_key_payload, rcu); |
| memset(p->key, 0, p->key_len); |
| kfree(p); |
| } |
| |
| /* |
| * trusted_update - reseal an existing key with new PCR values |
| */ |
| static int trusted_update(struct key *key, struct key_preparsed_payload *prep) |
| { |
| struct trusted_key_payload *p; |
| struct trusted_key_payload *new_p; |
| struct trusted_key_options *new_o; |
| size_t datalen = prep->datalen; |
| char *datablob; |
| int ret = 0; |
| |
| if (key_is_negative(key)) |
| return -ENOKEY; |
| p = key->payload.data[0]; |
| if (!p->migratable) |
| return -EPERM; |
| if (datalen <= 0 || datalen > 32767 || !prep->data) |
| return -EINVAL; |
| |
| datablob = kmalloc(datalen + 1, GFP_KERNEL); |
| if (!datablob) |
| return -ENOMEM; |
| new_o = trusted_options_alloc(); |
| if (!new_o) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| new_p = trusted_payload_alloc(key); |
| if (!new_p) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| memcpy(datablob, prep->data, datalen); |
| datablob[datalen] = '\0'; |
| ret = datablob_parse(datablob, new_p, new_o); |
| if (ret != Opt_update) { |
| ret = -EINVAL; |
| kfree(new_p); |
| goto out; |
| } |
| |
| if (!new_o->keyhandle) { |
| ret = -EINVAL; |
| kfree(new_p); |
| goto out; |
| } |
| |
| /* copy old key values, and reseal with new pcrs */ |
| new_p->migratable = p->migratable; |
| new_p->key_len = p->key_len; |
| memcpy(new_p->key, p->key, p->key_len); |
| dump_payload(p); |
| dump_payload(new_p); |
| |
| ret = key_seal(new_p, new_o); |
| if (ret < 0) { |
| pr_info("trusted_key: key_seal failed (%d)\n", ret); |
| kfree(new_p); |
| goto out; |
| } |
| if (new_o->pcrlock) { |
| ret = pcrlock(new_o->pcrlock); |
| if (ret < 0) { |
| pr_info("trusted_key: pcrlock failed (%d)\n", ret); |
| kfree(new_p); |
| goto out; |
| } |
| } |
| rcu_assign_keypointer(key, new_p); |
| call_rcu(&p->rcu, trusted_rcu_free); |
| out: |
| kfree(datablob); |
| kfree(new_o); |
| return ret; |
| } |
| |
| /* |
| * trusted_read - copy the sealed blob data to userspace in hex. |
| * On success, return to userspace the trusted key datablob size. |
| */ |
| static long trusted_read(const struct key *key, char __user *buffer, |
| size_t buflen) |
| { |
| struct trusted_key_payload *p; |
| char *ascii_buf; |
| char *bufp; |
| int i; |
| |
| p = rcu_dereference_key(key); |
| if (!p) |
| return -EINVAL; |
| if (!buffer || buflen <= 0) |
| return 2 * p->blob_len; |
| ascii_buf = kmalloc(2 * p->blob_len, GFP_KERNEL); |
| if (!ascii_buf) |
| return -ENOMEM; |
| |
| bufp = ascii_buf; |
| for (i = 0; i < p->blob_len; i++) |
| bufp = hex_byte_pack(bufp, p->blob[i]); |
| if ((copy_to_user(buffer, ascii_buf, 2 * p->blob_len)) != 0) { |
| kfree(ascii_buf); |
| return -EFAULT; |
| } |
| kfree(ascii_buf); |
| return 2 * p->blob_len; |
| } |
| |
| /* |
| * trusted_destroy - before freeing the key, clear the decrypted data |
| */ |
| static void trusted_destroy(struct key *key) |
| { |
| struct trusted_key_payload *p = key->payload.data[0]; |
| |
| if (!p) |
| return; |
| memset(p->key, 0, p->key_len); |
| kfree(key->payload.data[0]); |
| } |
| |
| struct key_type key_type_trusted = { |
| .name = "trusted", |
| .instantiate = trusted_instantiate, |
| .update = trusted_update, |
| .destroy = trusted_destroy, |
| .describe = user_describe, |
| .read = trusted_read, |
| }; |
| |
| EXPORT_SYMBOL_GPL(key_type_trusted); |
| |
| static void trusted_shash_release(void) |
| { |
| if (hashalg) |
| crypto_free_shash(hashalg); |
| if (hmacalg) |
| crypto_free_shash(hmacalg); |
| } |
| |
| static int __init trusted_shash_alloc(void) |
| { |
| int ret; |
| |
| hmacalg = crypto_alloc_shash(hmac_alg, 0, CRYPTO_ALG_ASYNC); |
| if (IS_ERR(hmacalg)) { |
| pr_info("trusted_key: could not allocate crypto %s\n", |
| hmac_alg); |
| return PTR_ERR(hmacalg); |
| } |
| |
| hashalg = crypto_alloc_shash(hash_alg, 0, CRYPTO_ALG_ASYNC); |
| if (IS_ERR(hashalg)) { |
| pr_info("trusted_key: could not allocate crypto %s\n", |
| hash_alg); |
| ret = PTR_ERR(hashalg); |
| goto hashalg_fail; |
| } |
| |
| return 0; |
| |
| hashalg_fail: |
| crypto_free_shash(hmacalg); |
| return ret; |
| } |
| |
| static int __init init_trusted(void) |
| { |
| int ret; |
| |
| ret = trusted_shash_alloc(); |
| if (ret < 0) |
| return ret; |
| ret = register_key_type(&key_type_trusted); |
| if (ret < 0) |
| trusted_shash_release(); |
| return ret; |
| } |
| |
| static void __exit cleanup_trusted(void) |
| { |
| trusted_shash_release(); |
| unregister_key_type(&key_type_trusted); |
| } |
| |
| late_initcall(init_trusted); |
| module_exit(cleanup_trusted); |
| |
| MODULE_LICENSE("GPL"); |