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KEYS: trusted: Move TPM2 trusted keys code

Browse Source 
Move TPM2 trusted keys code to trusted keys subsystem. The reason
being it's better to consolidate all the trusted keys code to a single
location so that it can be maintained sanely.

Also, utilize existing tpm_send() exported API which wraps the internal
tpm_transmit_cmd() API.

Suggested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
This commit is contained in:
Sumit Garg 2019-10-16 10:44:55 +05:30 committed by Jarkko Sakkinen
parent 47f9c27968
commit 2e19e10131
8 changed files with 342 additions and 394 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

56
drivers/char/tpm/tpm-interface.c
View File

@ -459,62 +459,6 @@ int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
}
EXPORT_SYMBOL_GPL(tpm_get_random);
/**
* tpm_seal_trusted() - seal a trusted key payload
* @chip: a &struct tpm_chip instance, %NULL for the default chip
* @options: authentication values and other options
* @payload: the key data in clear and encrypted form
*
* Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
* the keyring subsystem.
*
* Return: same as with tpm_transmit_cmd()
*/
int tpm_seal_trusted(struct tpm_chip *chip, struct trusted_key_payload *payload,
struct trusted_key_options *options)
{
int rc;
chip = tpm_find_get_ops(chip);
if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
return -ENODEV;
rc = tpm2_seal_trusted(chip, payload, options);
tpm_put_ops(chip);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_seal_trusted);
/**
* tpm_unseal_trusted() - unseal a trusted key
* @chip: a &struct tpm_chip instance, %NULL for the default chip
* @options: authentication values and other options
* @payload: the key data in clear and encrypted form
*
* Note: only TPM 2.0 chip are supported. TPM 1.x implementation is located in
* the keyring subsystem.
*
* Return: same as with tpm_transmit_cmd()
*/
int tpm_unseal_trusted(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options)
{
int rc;
chip = tpm_find_get_ops(chip);
if (!chip || !(chip->flags & TPM_CHIP_FLAG_TPM2))
return -ENODEV;
rc = tpm2_unseal_trusted(chip, payload, options);
tpm_put_ops(chip);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_unseal_trusted);
static int __init tpm_init(void)
{
int rc;

11
drivers/char/tpm/tpm.h
View File

@ -212,11 +212,6 @@ static inline void tpm_add_ppi(struct tpm_chip *chip)
}
#endif
static inline u32 tpm2_rc_value(u32 rc)
{
return (rc & BIT(7)) ? rc & 0xff : rc;
}
int tpm2_get_timeouts(struct tpm_chip *chip);
int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
struct tpm_digest *digest, u16 *digest_size_ptr);
@ -224,12 +219,6 @@ int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
struct tpm_digest *digests);
int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max);
void tpm2_flush_context(struct tpm_chip *chip, u32 handle);
int tpm2_seal_trusted(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options);
int tpm2_unseal_trusted(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options);
ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id,
u32 *value, const char *desc);

307
drivers/char/tpm/tpm2-cmd.c
View File

@ -13,20 +13,6 @@
#include "tpm.h"
#include <crypto/hash_info.h>
#include <keys/trusted-type.h>
enum tpm2_object_attributes {
TPM2_OA_USER_WITH_AUTH = BIT(6),
};
enum tpm2_session_attributes {
TPM2_SA_CONTINUE_SESSION = BIT(0),
};
struct tpm2_hash {
unsigned int crypto_id;
unsigned int tpm_id;
};
static struct tpm2_hash tpm2_hash_map[] = {
{HASH_ALGO_SHA1, TPM_ALG_SHA1},
@ -377,299 +363,6 @@ void tpm2_flush_context(struct tpm_chip *chip, u32 handle)
tpm_buf_destroy(&buf);
}
/**
* tpm_buf_append_auth() - append TPMS_AUTH_COMMAND to the buffer.
*
* @buf: an allocated tpm_buf instance
* @session_handle: session handle
* @nonce: the session nonce, may be NULL if not used
* @nonce_len: the session nonce length, may be 0 if not used
* @attributes: the session attributes
* @hmac: the session HMAC or password, may be NULL if not used
* @hmac_len: the session HMAC or password length, maybe 0 if not used
*/
static void tpm2_buf_append_auth(struct tpm_buf *buf, u32 session_handle,
const u8 *nonce, u16 nonce_len,
u8 attributes,
const u8 *hmac, u16 hmac_len)
{
tpm_buf_append_u32(buf, 9 + nonce_len + hmac_len);
tpm_buf_append_u32(buf, session_handle);
tpm_buf_append_u16(buf, nonce_len);
if (nonce && nonce_len)
tpm_buf_append(buf, nonce, nonce_len);
tpm_buf_append_u8(buf, attributes);
tpm_buf_append_u16(buf, hmac_len);
if (hmac && hmac_len)
tpm_buf_append(buf, hmac, hmac_len);
}
/**
* tpm2_seal_trusted() - seal the payload of a trusted key
*
* @chip: TPM chip to use
* @payload: the key data in clear and encrypted form
* @options: authentication values and other options
*
* Return: < 0 on error and 0 on success.
*/
int tpm2_seal_trusted(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options)
{
unsigned int blob_len;
struct tpm_buf buf;
u32 hash;
int i;
int rc;
for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
if (options->hash == tpm2_hash_map[i].crypto_id) {
hash = tpm2_hash_map[i].tpm_id;
break;
}
}
if (i == ARRAY_SIZE(tpm2_hash_map))
return -EINVAL;
rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE);
if (rc)
return rc;
tpm_buf_append_u32(&buf, options->keyhandle);
tpm2_buf_append_auth(&buf, TPM2_RS_PW,
NULL /* nonce */, 0,
0 /* session_attributes */,
options->keyauth /* hmac */,
TPM_DIGEST_SIZE);
/* sensitive */
tpm_buf_append_u16(&buf, 4 + TPM_DIGEST_SIZE + payload->key_len + 1);
tpm_buf_append_u16(&buf, TPM_DIGEST_SIZE);
tpm_buf_append(&buf, options->blobauth, TPM_DIGEST_SIZE);
tpm_buf_append_u16(&buf, payload->key_len + 1);
tpm_buf_append(&buf, payload->key, payload->key_len);
tpm_buf_append_u8(&buf, payload->migratable);
/* public */
tpm_buf_append_u16(&buf, 14 + options->policydigest_len);
tpm_buf_append_u16(&buf, TPM_ALG_KEYEDHASH);
tpm_buf_append_u16(&buf, hash);
/* policy */
if (options->policydigest_len) {
tpm_buf_append_u32(&buf, 0);
tpm_buf_append_u16(&buf, options->policydigest_len);
tpm_buf_append(&buf, options->policydigest,
options->policydigest_len);
} else {
tpm_buf_append_u32(&buf, TPM2_OA_USER_WITH_AUTH);
tpm_buf_append_u16(&buf, 0);
}
/* public parameters */
tpm_buf_append_u16(&buf, TPM_ALG_NULL);
tpm_buf_append_u16(&buf, 0);
/* outside info */
tpm_buf_append_u16(&buf, 0);
/* creation PCR */
tpm_buf_append_u32(&buf, 0);
if (buf.flags & TPM_BUF_OVERFLOW) {
rc = -E2BIG;
goto out;
}
rc = tpm_transmit_cmd(chip, &buf, 4, "sealing data");
if (rc)
goto out;
blob_len = be32_to_cpup((__be32 *) &buf.data[TPM_HEADER_SIZE]);
if (blob_len > MAX_BLOB_SIZE) {
rc = -E2BIG;
goto out;
}
if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 4 + blob_len) {
rc = -EFAULT;
goto out;
}
memcpy(payload->blob, &buf.data[TPM_HEADER_SIZE + 4], blob_len);
payload->blob_len = blob_len;
out:
tpm_buf_destroy(&buf);
if (rc > 0) {
if (tpm2_rc_value(rc) == TPM2_RC_HASH)
rc = -EINVAL;
else
rc = -EPERM;
}
return rc;
}
/**
* tpm2_load_cmd() - execute a TPM2_Load command
*
* @chip: TPM chip to use
* @payload: the key data in clear and encrypted form
* @options: authentication values and other options
* @blob_handle: returned blob handle
*
* Return: 0 on success.
* -E2BIG on wrong payload size.
* -EPERM on tpm error status.
* < 0 error from tpm_transmit_cmd.
*/
static int tpm2_load_cmd(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options,
u32 *blob_handle)
{
struct tpm_buf buf;
unsigned int private_len;
unsigned int public_len;
unsigned int blob_len;
int rc;
private_len = be16_to_cpup((__be16 *) &payload->blob[0]);
if (private_len > (payload->blob_len - 2))
return -E2BIG;
public_len = be16_to_cpup((__be16 *) &payload->blob[2 + private_len]);
blob_len = private_len + public_len + 4;
if (blob_len > payload->blob_len)
return -E2BIG;
rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
if (rc)
return rc;
tpm_buf_append_u32(&buf, options->keyhandle);
tpm2_buf_append_auth(&buf, TPM2_RS_PW,
NULL /* nonce */, 0,
0 /* session_attributes */,
options->keyauth /* hmac */,
TPM_DIGEST_SIZE);
tpm_buf_append(&buf, payload->blob, blob_len);
if (buf.flags & TPM_BUF_OVERFLOW) {
rc = -E2BIG;
goto out;
}
rc = tpm_transmit_cmd(chip, &buf, 4, "loading blob");
if (!rc)
*blob_handle = be32_to_cpup(
(__be32 *) &buf.data[TPM_HEADER_SIZE]);
out:
tpm_buf_destroy(&buf);
if (rc > 0)
rc = -EPERM;
return rc;
}
/**
* tpm2_unseal_cmd() - execute a TPM2_Unload command
*
* @chip: TPM chip to use
* @payload: the key data in clear and encrypted form
* @options: authentication values and other options
* @blob_handle: blob handle
*
* Return: 0 on success
* -EPERM on tpm error status
* < 0 error from tpm_transmit_cmd
*/
static int tpm2_unseal_cmd(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options,
u32 blob_handle)
{
struct tpm_buf buf;
u16 data_len;
u8 *data;
int rc;
rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL);
if (rc)
return rc;
tpm_buf_append_u32(&buf, blob_handle);
tpm2_buf_append_auth(&buf,
options->policyhandle ?
options->policyhandle : TPM2_RS_PW,
NULL /* nonce */, 0,
TPM2_SA_CONTINUE_SESSION,
options->blobauth /* hmac */,
TPM_DIGEST_SIZE);
rc = tpm_transmit_cmd(chip, &buf, 6, "unsealing");
if (rc > 0)
rc = -EPERM;
if (!rc) {
data_len = be16_to_cpup(
(__be16 *) &buf.data[TPM_HEADER_SIZE + 4]);
if (data_len < MIN_KEY_SIZE || data_len > MAX_KEY_SIZE + 1) {
rc = -EFAULT;
goto out;
}
if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 6 + data_len) {
rc = -EFAULT;
goto out;
}
data = &buf.data[TPM_HEADER_SIZE + 6];
memcpy(payload->key, data, data_len - 1);
payload->key_len = data_len - 1;
payload->migratable = data[data_len - 1];
}
out:
tpm_buf_destroy(&buf);
return rc;
}
/**
* tpm2_unseal_trusted() - unseal the payload of a trusted key
*
* @chip: TPM chip to use
* @payload: the key data in clear and encrypted form
* @options: authentication values and other options
*
* Return: Same as with tpm_transmit_cmd.
*/
int tpm2_unseal_trusted(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options)
{
u32 blob_handle;
int rc;
rc = tpm2_load_cmd(chip, payload, options, &blob_handle);
if (rc)
return rc;
rc = tpm2_unseal_cmd(chip, payload, options, blob_handle);
tpm2_flush_context(chip, blob_handle);
return rc;
}
struct tpm2_get_cap_out {
u8 more_data;
__be32 subcap_id;

7
include/keys/trusted_tpm.h
View File

@ -40,6 +40,13 @@ int TSS_checkhmac1(unsigned char *buffer,
int trusted_tpm_send(unsigned char *cmd, size_t buflen);
int oiap(struct tpm_buf *tb, uint32_t *handle, unsigned char *nonce);
int tpm2_seal_trusted(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options);
int tpm2_unseal_trusted(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options);
#define TPM_DEBUG 0
#if TPM_DEBUG

36
include/linux/tpm.h
View File

@ -296,6 +296,19 @@ struct tpm_buf {
u8 *data;
};
enum tpm2_object_attributes {
TPM2_OA_USER_WITH_AUTH = BIT(6),
};
enum tpm2_session_attributes {
TPM2_SA_CONTINUE_SESSION = BIT(0),
};
struct tpm2_hash {
unsigned int crypto_id;
unsigned int tpm_id;
};
static inline void tpm_buf_reset(struct tpm_buf *buf, u16 tag, u32 ordinal)
{
struct tpm_header *head = (struct tpm_header *)buf->data;
@ -375,6 +388,11 @@ static inline void tpm_buf_append_u32(struct tpm_buf *buf, const u32 value)
tpm_buf_append(buf, (u8 *) &value2, 4);
}
static inline u32 tpm2_rc_value(u32 rc)
{
return (rc & BIT(7)) ? rc & 0xff : rc;
}
#if defined(CONFIG_TCG_TPM) || defined(CONFIG_TCG_TPM_MODULE)
extern int tpm_is_tpm2(struct tpm_chip *chip);
@ -384,12 +402,6 @@ extern int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
struct tpm_digest *digests);
extern int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen);
extern int tpm_get_random(struct tpm_chip *chip, u8 *data, size_t max);
extern int tpm_seal_trusted(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options);
extern int tpm_unseal_trusted(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options);
extern struct tpm_chip *tpm_default_chip(void);
#else
static inline int tpm_is_tpm2(struct tpm_chip *chip)
@ -418,18 +430,6 @@ static inline int tpm_get_random(struct tpm_chip *chip, u8 *data, size_t max)
return -ENODEV;
}
static inline int tpm_seal_trusted(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options)
{
return -ENODEV;
}
static inline int tpm_unseal_trusted(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options)
{
return -ENODEV;
}
static inline struct tpm_chip *tpm_default_chip(void)
{
return NULL;

1
security/keys/trusted-keys/Makefile
View File

@ -5,3 +5,4 @@
obj-$(CONFIG_TRUSTED_KEYS) += trusted.o
trusted-y += trusted_tpm1.o
trusted-y += trusted_tpm2.o

4
security/keys/trusted-keys/trusted_tpm1.c
View File

@ -1004,7 +1004,7 @@ static int trusted_instantiate(struct key *key,
switch (key_cmd) {
case Opt_load:
if (tpm2)
ret = tpm_unseal_trusted(chip, payload, options);
ret = tpm2_unseal_trusted(chip, payload, options);
else
ret = key_unseal(payload, options);
dump_payload(payload);
@ -1020,7 +1020,7 @@ static int trusted_instantiate(struct key *key,
goto out;
}
if (tpm2)
ret = tpm_seal_trusted(chip, payload, options);
ret = tpm2_seal_trusted(chip, payload, options);
else
ret = key_seal(payload, options);
if (ret < 0)

314
security/keys/trusted-keys/trusted_tpm2.c Normal file
View File

@ -0,0 +1,314 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2004 IBM Corporation
* Copyright (C) 2014 Intel Corporation
*/
#include <linux/string.h>
#include <linux/err.h>
#include <linux/tpm.h>
#include <linux/tpm_command.h>
#include <keys/trusted-type.h>
#include <keys/trusted_tpm.h>
static struct tpm2_hash tpm2_hash_map[] = {
{HASH_ALGO_SHA1, TPM_ALG_SHA1},
{HASH_ALGO_SHA256, TPM_ALG_SHA256},
{HASH_ALGO_SHA384, TPM_ALG_SHA384},
{HASH_ALGO_SHA512, TPM_ALG_SHA512},
{HASH_ALGO_SM3_256, TPM_ALG_SM3_256},
};
/**
* tpm_buf_append_auth() - append TPMS_AUTH_COMMAND to the buffer.
*
* @buf: an allocated tpm_buf instance
* @session_handle: session handle
* @nonce: the session nonce, may be NULL if not used
* @nonce_len: the session nonce length, may be 0 if not used
* @attributes: the session attributes
* @hmac: the session HMAC or password, may be NULL if not used
* @hmac_len: the session HMAC or password length, maybe 0 if not used
*/
static void tpm2_buf_append_auth(struct tpm_buf *buf, u32 session_handle,
const u8 *nonce, u16 nonce_len,
u8 attributes,
const u8 *hmac, u16 hmac_len)
{
tpm_buf_append_u32(buf, 9 + nonce_len + hmac_len);
tpm_buf_append_u32(buf, session_handle);
tpm_buf_append_u16(buf, nonce_len);
if (nonce && nonce_len)
tpm_buf_append(buf, nonce, nonce_len);
tpm_buf_append_u8(buf, attributes);
tpm_buf_append_u16(buf, hmac_len);
if (hmac && hmac_len)
tpm_buf_append(buf, hmac, hmac_len);
}
/**
* tpm2_seal_trusted() - seal the payload of a trusted key
*
* @chip: TPM chip to use
* @payload: the key data in clear and encrypted form
* @options: authentication values and other options
*
* Return: < 0 on error and 0 on success.
*/
int tpm2_seal_trusted(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options)
{
unsigned int blob_len;
struct tpm_buf buf;
u32 hash;
int i;
int rc;
for (i = 0; i < ARRAY_SIZE(tpm2_hash_map); i++) {
if (options->hash == tpm2_hash_map[i].crypto_id) {
hash = tpm2_hash_map[i].tpm_id;
break;
}
}
if (i == ARRAY_SIZE(tpm2_hash_map))
return -EINVAL;
rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_CREATE);
if (rc)
return rc;
tpm_buf_append_u32(&buf, options->keyhandle);
tpm2_buf_append_auth(&buf, TPM2_RS_PW,
NULL /* nonce */, 0,
0 /* session_attributes */,
options->keyauth /* hmac */,
TPM_DIGEST_SIZE);
/* sensitive */
tpm_buf_append_u16(&buf, 4 + TPM_DIGEST_SIZE + payload->key_len + 1);
tpm_buf_append_u16(&buf, TPM_DIGEST_SIZE);
tpm_buf_append(&buf, options->blobauth, TPM_DIGEST_SIZE);
tpm_buf_append_u16(&buf, payload->key_len + 1);
tpm_buf_append(&buf, payload->key, payload->key_len);
tpm_buf_append_u8(&buf, payload->migratable);
/* public */
tpm_buf_append_u16(&buf, 14 + options->policydigest_len);
tpm_buf_append_u16(&buf, TPM_ALG_KEYEDHASH);
tpm_buf_append_u16(&buf, hash);
/* policy */
if (options->policydigest_len) {
tpm_buf_append_u32(&buf, 0);
tpm_buf_append_u16(&buf, options->policydigest_len);
tpm_buf_append(&buf, options->policydigest,
options->policydigest_len);
} else {
tpm_buf_append_u32(&buf, TPM2_OA_USER_WITH_AUTH);
tpm_buf_append_u16(&buf, 0);
}
/* public parameters */
tpm_buf_append_u16(&buf, TPM_ALG_NULL);
tpm_buf_append_u16(&buf, 0);
/* outside info */
tpm_buf_append_u16(&buf, 0);
/* creation PCR */
tpm_buf_append_u32(&buf, 0);
if (buf.flags & TPM_BUF_OVERFLOW) {
rc = -E2BIG;
goto out;
}
rc = tpm_send(chip, buf.data, tpm_buf_length(&buf));
if (rc)
goto out;
blob_len = be32_to_cpup((__be32 *) &buf.data[TPM_HEADER_SIZE]);
if (blob_len > MAX_BLOB_SIZE) {
rc = -E2BIG;
goto out;
}
if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 4 + blob_len) {
rc = -EFAULT;
goto out;
}
memcpy(payload->blob, &buf.data[TPM_HEADER_SIZE + 4], blob_len);
payload->blob_len = blob_len;
out:
tpm_buf_destroy(&buf);
if (rc > 0) {
if (tpm2_rc_value(rc) == TPM2_RC_HASH)
rc = -EINVAL;
else
rc = -EPERM;
}
return rc;
}
/**
* tpm2_load_cmd() - execute a TPM2_Load command
*
* @chip: TPM chip to use
* @payload: the key data in clear and encrypted form
* @options: authentication values and other options
* @blob_handle: returned blob handle
*
* Return: 0 on success.
* -E2BIG on wrong payload size.
* -EPERM on tpm error status.
* < 0 error from tpm_send.
*/
static int tpm2_load_cmd(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options,
u32 *blob_handle)
{
struct tpm_buf buf;
unsigned int private_len;
unsigned int public_len;
unsigned int blob_len;
int rc;
private_len = be16_to_cpup((__be16 *) &payload->blob[0]);
if (private_len > (payload->blob_len - 2))
return -E2BIG;
public_len = be16_to_cpup((__be16 *) &payload->blob[2 + private_len]);
blob_len = private_len + public_len + 4;
if (blob_len > payload->blob_len)
return -E2BIG;
rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_LOAD);
if (rc)
return rc;
tpm_buf_append_u32(&buf, options->keyhandle);
tpm2_buf_append_auth(&buf, TPM2_RS_PW,
NULL /* nonce */, 0,
0 /* session_attributes */,
options->keyauth /* hmac */,
TPM_DIGEST_SIZE);
tpm_buf_append(&buf, payload->blob, blob_len);
if (buf.flags & TPM_BUF_OVERFLOW) {
rc = -E2BIG;
goto out;
}
rc = tpm_send(chip, buf.data, tpm_buf_length(&buf));
if (!rc)
*blob_handle = be32_to_cpup(
(__be32 *) &buf.data[TPM_HEADER_SIZE]);
out:
tpm_buf_destroy(&buf);
if (rc > 0)
rc = -EPERM;
return rc;
}
/**
* tpm2_unseal_cmd() - execute a TPM2_Unload command
*
* @chip: TPM chip to use
* @payload: the key data in clear and encrypted form
* @options: authentication values and other options
* @blob_handle: blob handle
*
* Return: 0 on success
* -EPERM on tpm error status
* < 0 error from tpm_send
*/
static int tpm2_unseal_cmd(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options,
u32 blob_handle)
{
struct tpm_buf buf;
u16 data_len;
u8 *data;
int rc;
rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_UNSEAL);
if (rc)
return rc;
tpm_buf_append_u32(&buf, blob_handle);
tpm2_buf_append_auth(&buf,
options->policyhandle ?
options->policyhandle : TPM2_RS_PW,
NULL /* nonce */, 0,
TPM2_SA_CONTINUE_SESSION,
options->blobauth /* hmac */,
TPM_DIGEST_SIZE);
rc = tpm_send(chip, buf.data, tpm_buf_length(&buf));
if (rc > 0)
rc = -EPERM;
if (!rc) {
data_len = be16_to_cpup(
(__be16 *) &buf.data[TPM_HEADER_SIZE + 4]);
if (data_len < MIN_KEY_SIZE || data_len > MAX_KEY_SIZE + 1) {
rc = -EFAULT;
goto out;
}
if (tpm_buf_length(&buf) < TPM_HEADER_SIZE + 6 + data_len) {
rc = -EFAULT;
goto out;
}
data = &buf.data[TPM_HEADER_SIZE + 6];
memcpy(payload->key, data, data_len - 1);
payload->key_len = data_len - 1;
payload->migratable = data[data_len - 1];
}
out:
tpm_buf_destroy(&buf);
return rc;
}
/**
* tpm2_unseal_trusted() - unseal the payload of a trusted key
*
* @chip: TPM chip to use
* @payload: the key data in clear and encrypted form
* @options: authentication values and other options
*
* Return: Same as with tpm_send.
*/
int tpm2_unseal_trusted(struct tpm_chip *chip,
struct trusted_key_payload *payload,
struct trusted_key_options *options)
{
u32 blob_handle;
int rc;
rc = tpm2_load_cmd(chip, payload, options, &blob_handle);
if (rc)
return rc;
rc = tpm2_unseal_cmd(chip, payload, options, blob_handle);
return rc;
}