forked from Qortal/Brooklyn
You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
1299 lines
30 KiB
1299 lines
30 KiB
// SPDX-License-Identifier: GPL-2.0-only |
|
/* |
|
* Copyright (C) 2010 IBM Corporation |
|
* |
|
* Author: |
|
* David Safford <[email protected]> |
|
* |
|
* See Documentation/security/keys/trusted-encrypted.rst |
|
*/ |
|
|
|
#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/sha1.h> |
|
#include <linux/capability.h> |
|
#include <linux/tpm.h> |
|
#include <linux/tpm_command.h> |
|
|
|
#include <keys/trusted_tpm.h> |
|
|
|
static const char hmac_alg[] = "hmac(sha1)"; |
|
static const char hash_alg[] = "sha1"; |
|
static struct tpm_chip *chip; |
|
static struct tpm_digest *digests; |
|
|
|
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; |
|
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_sensitive(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_sensitive(sdesc); |
|
return ret; |
|
} |
|
|
|
/* |
|
* calculate authorization info fields to send to TPM |
|
*/ |
|
int TSS_authhmac(unsigned char *digest, const unsigned char *key, |
|
unsigned int keylen, unsigned char *h1, |
|
unsigned char *h2, unsigned int h3, ...) |
|
{ |
|
unsigned char paramdigest[SHA1_DIGEST_SIZE]; |
|
struct sdesc *sdesc; |
|
unsigned int dlen; |
|
unsigned char *data; |
|
unsigned char c; |
|
int ret; |
|
va_list argp; |
|
|
|
if (!chip) |
|
return -ENODEV; |
|
|
|
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_sensitive(sdesc); |
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(TSS_authhmac); |
|
|
|
/* |
|
* verify the AUTH1_COMMAND (Seal) result from TPM |
|
*/ |
|
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; |
|
|
|
if (!chip) |
|
return -ENODEV; |
|
|
|
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_sensitive(sdesc); |
|
return ret; |
|
} |
|
EXPORT_SYMBOL_GPL(TSS_checkhmac1); |
|
|
|
/* |
|
* 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_sensitive(sdesc); |
|
return ret; |
|
} |
|
|
|
/* |
|
* For key specific tpm requests, we will generate and send our |
|
* own TPM command packets using the drivers send function. |
|
*/ |
|
int trusted_tpm_send(unsigned char *cmd, size_t buflen) |
|
{ |
|
int rc; |
|
|
|
if (!chip) |
|
return -ENODEV; |
|
|
|
dump_tpm_buf(cmd); |
|
rc = tpm_send(chip, cmd, buflen); |
|
dump_tpm_buf(cmd); |
|
if (rc > 0) |
|
/* Can't return positive return codes values to keyctl */ |
|
rc = -EPERM; |
|
return rc; |
|
} |
|
EXPORT_SYMBOL_GPL(trusted_tpm_send); |
|
|
|
/* |
|
* 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) |
|
{ |
|
if (!capable(CAP_SYS_ADMIN)) |
|
return -EPERM; |
|
|
|
return tpm_pcr_extend(chip, pcrnum, digests) ? -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(chip, ononce, TPM_NONCE_SIZE); |
|
if (ret < 0) |
|
return ret; |
|
|
|
if (ret != TPM_NONCE_SIZE) |
|
return -EIO; |
|
|
|
tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OSAP); |
|
tpm_buf_append_u16(tb, type); |
|
tpm_buf_append_u32(tb, handle); |
|
tpm_buf_append(tb, ononce, TPM_NONCE_SIZE); |
|
|
|
ret = trusted_tpm_send(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 |
|
*/ |
|
int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce) |
|
{ |
|
int ret; |
|
|
|
if (!chip) |
|
return -ENODEV; |
|
|
|
tpm_buf_reset(tb, TPM_TAG_RQU_COMMAND, TPM_ORD_OIAP); |
|
ret = trusted_tpm_send(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; |
|
} |
|
EXPORT_SYMBOL_GPL(oiap); |
|
|
|
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(chip, td->nonceodd, TPM_NONCE_SIZE); |
|
if (ret < 0) |
|
goto out; |
|
|
|
if (ret != TPM_NONCE_SIZE) { |
|
ret = -EIO; |
|
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 */ |
|
tpm_buf_reset(tb, TPM_TAG_RQU_AUTH1_COMMAND, TPM_ORD_SEAL); |
|
tpm_buf_append_u32(tb, keyhandle); |
|
tpm_buf_append(tb, td->encauth, SHA1_DIGEST_SIZE); |
|
tpm_buf_append_u32(tb, pcrinfosize); |
|
tpm_buf_append(tb, pcrinfo, pcrinfosize); |
|
tpm_buf_append_u32(tb, datalen); |
|
tpm_buf_append(tb, data, datalen); |
|
tpm_buf_append_u32(tb, sess.handle); |
|
tpm_buf_append(tb, td->nonceodd, TPM_NONCE_SIZE); |
|
tpm_buf_append_u8(tb, cont); |
|
tpm_buf_append(tb, td->pubauth, SHA1_DIGEST_SIZE); |
|
|
|
ret = trusted_tpm_send(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_sensitive(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; |
|
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); |
|
ret = tpm_get_random(chip, nonceodd, TPM_NONCE_SIZE); |
|
if (ret < 0) |
|
return ret; |
|
|
|
if (ret != TPM_NONCE_SIZE) { |
|
pr_info("trusted_key: tpm_get_random failed (%d)\n", ret); |
|
return -EIO; |
|
} |
|
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 */ |
|
tpm_buf_reset(tb, TPM_TAG_RQU_AUTH2_COMMAND, TPM_ORD_UNSEAL); |
|
tpm_buf_append_u32(tb, keyhandle); |
|
tpm_buf_append(tb, blob, bloblen); |
|
tpm_buf_append_u32(tb, authhandle1); |
|
tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE); |
|
tpm_buf_append_u8(tb, cont); |
|
tpm_buf_append(tb, authdata1, SHA1_DIGEST_SIZE); |
|
tpm_buf_append_u32(tb, authhandle2); |
|
tpm_buf_append(tb, nonceodd, TPM_NONCE_SIZE); |
|
tpm_buf_append_u8(tb, cont); |
|
tpm_buf_append(tb, authdata2, SHA1_DIGEST_SIZE); |
|
|
|
ret = trusted_tpm_send(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; |
|
|
|
ret = tpm_buf_init(&tb, 0, 0); |
|
if (ret) |
|
return ret; |
|
|
|
/* 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); |
|
|
|
tpm_buf_destroy(&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; |
|
|
|
ret = tpm_buf_init(&tb, 0, 0); |
|
if (ret) |
|
return ret; |
|
|
|
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]; |
|
|
|
tpm_buf_destroy(&tb); |
|
return ret; |
|
} |
|
|
|
enum { |
|
Opt_err, |
|
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(chip); |
|
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: |
|
/* |
|
* TPM 1.2 authorizations are sha1 hashes passed in as |
|
* hex strings. TPM 2.0 authorizations are simple |
|
* passwords (although it can take a hash as well) |
|
*/ |
|
opt->blobauth_len = strlen(args[0].from); |
|
|
|
if (opt->blobauth_len == 2 * TPM_DIGEST_SIZE) { |
|
res = hex2bin(opt->blobauth, args[0].from, |
|
TPM_DIGEST_SIZE); |
|
if (res < 0) |
|
return -EINVAL; |
|
|
|
opt->blobauth_len = TPM_DIGEST_SIZE; |
|
break; |
|
} |
|
|
|
if (tpm2 && opt->blobauth_len <= sizeof(opt->blobauth)) { |
|
memcpy(opt->blobauth, args[0].from, |
|
opt->blobauth_len); |
|
break; |
|
} |
|
|
|
return -EINVAL; |
|
|
|
break; |
|
|
|
case Opt_migratable: |
|
if (*args[0].from == '0') |
|
pay->migratable = 0; |
|
else if (*args[0].from != '1') |
|
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(chip); |
|
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(chip); |
|
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 = tpm2_unseal_trusted(chip, 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(chip, payload->key, key_len); |
|
if (ret < 0) |
|
goto out; |
|
|
|
if (ret != key_len) { |
|
pr_info("trusted_key: key_create failed (%d)\n", ret); |
|
ret = -EIO; |
|
goto out; |
|
} |
|
if (tpm2) |
|
ret = tpm2_seal_trusted(chip, 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_sensitive(datablob); |
|
kfree_sensitive(options); |
|
if (!ret) |
|
rcu_assign_keypointer(key, payload); |
|
else |
|
kfree_sensitive(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); |
|
kfree_sensitive(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_sensitive(new_p); |
|
goto out; |
|
} |
|
|
|
if (!new_o->keyhandle) { |
|
ret = -EINVAL; |
|
kfree_sensitive(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_sensitive(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_sensitive(new_p); |
|
goto out; |
|
} |
|
} |
|
rcu_assign_keypointer(key, new_p); |
|
call_rcu(&p->rcu, trusted_rcu_free); |
|
out: |
|
kfree_sensitive(datablob); |
|
kfree_sensitive(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 *buffer, |
|
size_t buflen) |
|
{ |
|
const struct trusted_key_payload *p; |
|
char *bufp; |
|
int i; |
|
|
|
p = dereference_key_locked(key); |
|
if (!p) |
|
return -EINVAL; |
|
|
|
if (buffer && buflen >= 2 * p->blob_len) { |
|
bufp = buffer; |
|
for (i = 0; i < p->blob_len; i++) |
|
bufp = hex_byte_pack(bufp, p->blob[i]); |
|
} |
|
return 2 * p->blob_len; |
|
} |
|
|
|
/* |
|
* trusted_destroy - clear and free the key's payload |
|
*/ |
|
static void trusted_destroy(struct key *key) |
|
{ |
|
kfree_sensitive(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, 0); |
|
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, 0); |
|
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_digests(void) |
|
{ |
|
int i; |
|
|
|
digests = kcalloc(chip->nr_allocated_banks, sizeof(*digests), |
|
GFP_KERNEL); |
|
if (!digests) |
|
return -ENOMEM; |
|
|
|
for (i = 0; i < chip->nr_allocated_banks; i++) |
|
digests[i].alg_id = chip->allocated_banks[i].alg_id; |
|
|
|
return 0; |
|
} |
|
|
|
static int __init init_trusted(void) |
|
{ |
|
int ret; |
|
|
|
/* encrypted_keys.ko depends on successful load of this module even if |
|
* TPM is not used. |
|
*/ |
|
chip = tpm_default_chip(); |
|
if (!chip) |
|
return 0; |
|
|
|
ret = init_digests(); |
|
if (ret < 0) |
|
goto err_put; |
|
ret = trusted_shash_alloc(); |
|
if (ret < 0) |
|
goto err_free; |
|
ret = register_key_type(&key_type_trusted); |
|
if (ret < 0) |
|
goto err_release; |
|
return 0; |
|
err_release: |
|
trusted_shash_release(); |
|
err_free: |
|
kfree(digests); |
|
err_put: |
|
put_device(&chip->dev); |
|
return ret; |
|
} |
|
|
|
static void __exit cleanup_trusted(void) |
|
{ |
|
if (chip) { |
|
put_device(&chip->dev); |
|
kfree(digests); |
|
trusted_shash_release(); |
|
unregister_key_type(&key_type_trusted); |
|
} |
|
} |
|
|
|
late_initcall(init_trusted); |
|
module_exit(cleanup_trusted); |
|
|
|
MODULE_LICENSE("GPL");
|
|
|