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linux-sg2042/drivers/char/tpm/tpm2-cmd.c

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/*
* Copyright (C) 2014, 2015 Intel Corporation
*
* Authors:
* Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
*
* Maintained by: <tpmdd-devel@lists.sourceforge.net>
*
* This file contains TPM2 protocol implementations of the commands
* used by the kernel internally.
*
* 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.
*/
#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, TPM2_ALG_SHA1},
{HASH_ALGO_SHA256, TPM2_ALG_SHA256},
{HASH_ALGO_SHA384, TPM2_ALG_SHA384},
{HASH_ALGO_SHA512, TPM2_ALG_SHA512},
{HASH_ALGO_SM3_256, TPM2_ALG_SM3_256},
};
int tpm2_get_timeouts(struct tpm_chip *chip)
{
/* Fixed timeouts for TPM2 */
chip->timeout_a = msecs_to_jiffies(TPM2_TIMEOUT_A);
chip->timeout_b = msecs_to_jiffies(TPM2_TIMEOUT_B);
chip->timeout_c = msecs_to_jiffies(TPM2_TIMEOUT_C);
chip->timeout_d = msecs_to_jiffies(TPM2_TIMEOUT_D);
/* PTP spec timeouts */
chip->duration[TPM_SHORT] = msecs_to_jiffies(TPM2_DURATION_SHORT);
chip->duration[TPM_MEDIUM] = msecs_to_jiffies(TPM2_DURATION_MEDIUM);
chip->duration[TPM_LONG] = msecs_to_jiffies(TPM2_DURATION_LONG);
/* Key creation commands long timeouts */
chip->duration[TPM_LONG_LONG] =
msecs_to_jiffies(TPM2_DURATION_LONG_LONG);
chip->flags |= TPM_CHIP_FLAG_HAVE_TIMEOUTS;
return 0;
}
/**
* tpm2_ordinal_duration_index() - returns an index to the chip duration table
* @ordinal: TPM command ordinal.
*
* The function returns an index to the chip duration table
* (enum tpm_duration), that describes the maximum amount of
* time the chip could take to return the result for a particular ordinal.
*
* The values of the MEDIUM, and LONG durations are taken
* from the PC Client Profile (PTP) specification (750, 2000 msec)
*
* LONG_LONG is for commands that generates keys which empirically takes
* a longer time on some systems.
*
* Return:
* * TPM_MEDIUM
* * TPM_LONG
* * TPM_LONG_LONG
* * TPM_UNDEFINED
*/
static u8 tpm2_ordinal_duration_index(u32 ordinal)
{
switch (ordinal) {
/* Startup */
case TPM2_CC_STARTUP: /* 144 */
return TPM_MEDIUM;
case TPM2_CC_SELF_TEST: /* 143 */
return TPM_LONG;
case TPM2_CC_GET_RANDOM: /* 17B */
return TPM_LONG;
case TPM2_CC_SEQUENCE_UPDATE: /* 15C */
return TPM_MEDIUM;
case TPM2_CC_SEQUENCE_COMPLETE: /* 13E */
return TPM_MEDIUM;
case TPM2_CC_EVENT_SEQUENCE_COMPLETE: /* 185 */
return TPM_MEDIUM;
case TPM2_CC_HASH_SEQUENCE_START: /* 186 */
return TPM_MEDIUM;
case TPM2_CC_VERIFY_SIGNATURE: /* 177 */
return TPM_LONG;
case TPM2_CC_PCR_EXTEND: /* 182 */
return TPM_MEDIUM;
case TPM2_CC_HIERARCHY_CONTROL: /* 121 */
return TPM_LONG;
case TPM2_CC_HIERARCHY_CHANGE_AUTH: /* 129 */
return TPM_LONG;
case TPM2_CC_GET_CAPABILITY: /* 17A */
return TPM_MEDIUM;
case TPM2_CC_NV_READ: /* 14E */
return TPM_LONG;
case TPM2_CC_CREATE_PRIMARY: /* 131 */
return TPM_LONG_LONG;
case TPM2_CC_CREATE: /* 153 */
return TPM_LONG_LONG;
case TPM2_CC_CREATE_LOADED: /* 191 */
return TPM_LONG_LONG;
default:
return TPM_UNDEFINED;
}
}
/**
* tpm2_calc_ordinal_duration() - calculate the maximum command duration
* @chip: TPM chip to use.
* @ordinal: TPM command ordinal.
*
* The function returns the maximum amount of time the chip could take
* to return the result for a particular ordinal in jiffies.
*
* Return: A maximal duration time for an ordinal in jiffies.
*/
unsigned long tpm2_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal)
{
unsigned int index;
index = tpm2_ordinal_duration_index(ordinal);
if (index != TPM_UNDEFINED)
return chip->duration[index];
else
return msecs_to_jiffies(TPM2_DURATION_DEFAULT);
}
struct tpm2_pcr_read_out {
__be32 update_cnt;
__be32 pcr_selects_cnt;
__be16 hash_alg;
u8 pcr_select_size;
u8 pcr_select[TPM2_PCR_SELECT_MIN];
__be32 digests_cnt;
__be16 digest_size;
u8 digest[];
} __packed;
/**
* tpm2_pcr_read() - read a PCR value
* @chip: TPM chip to use.
* @pcr_idx: index of the PCR to read.
* @res_buf: buffer to store the resulting hash.
*
* Return: Same as with tpm_transmit_cmd.
*/
int tpm2_pcr_read(struct tpm_chip *chip, u32 pcr_idx, u8 *res_buf)
{
int rc;
struct tpm_buf buf;
struct tpm2_pcr_read_out *out;
u8 pcr_select[TPM2_PCR_SELECT_MIN] = {0};
if (pcr_idx >= TPM2_PLATFORM_PCR)
return -EINVAL;
rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_PCR_READ);
if (rc)
return rc;
pcr_select[pcr_idx >> 3] = 1 << (pcr_idx & 0x7);
tpm_buf_append_u32(&buf, 1);
tpm_buf_append_u16(&buf, TPM2_ALG_SHA1);
tpm_buf_append_u8(&buf, TPM2_PCR_SELECT_MIN);
tpm_buf_append(&buf, (const unsigned char *)pcr_select,
sizeof(pcr_select));
rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
res_buf ? "attempting to read a pcr value" : NULL);
if (rc == 0 && res_buf) {
out = (struct tpm2_pcr_read_out *)&buf.data[TPM_HEADER_SIZE];
memcpy(res_buf, out->digest, SHA1_DIGEST_SIZE);
}
tpm_buf_destroy(&buf);
return rc;
}
struct tpm2_null_auth_area {
__be32 handle;
__be16 nonce_size;
u8 attributes;
__be16 auth_size;
} __packed;
/**
* tpm2_pcr_extend() - extend a PCR value
*
* @chip: TPM chip to use.
* @pcr_idx: index of the PCR.
* @count: number of digests passed.
* @digests: list of pcr banks and corresponding digest values to extend.
*
* Return: Same as with tpm_transmit_cmd.
*/
int tpm2_pcr_extend(struct tpm_chip *chip, u32 pcr_idx, u32 count,
struct tpm2_digest *digests)
{
struct tpm_buf buf;
struct tpm2_null_auth_area auth_area;
int rc;
int i;
int j;
if (count > ARRAY_SIZE(chip->active_banks))
return -EINVAL;
rc = tpm_buf_init(&buf, TPM2_ST_SESSIONS, TPM2_CC_PCR_EXTEND);
if (rc)
return rc;
tpm_buf_append_u32(&buf, pcr_idx);
auth_area.handle = cpu_to_be32(TPM2_RS_PW);
auth_area.nonce_size = 0;
auth_area.attributes = 0;
auth_area.auth_size = 0;
tpm_buf_append_u32(&buf, sizeof(struct tpm2_null_auth_area));
tpm_buf_append(&buf, (const unsigned char *)&auth_area,
sizeof(auth_area));
tpm_buf_append_u32(&buf, count);
for (i = 0; i < count; i++) {
for (j = 0; j < ARRAY_SIZE(tpm2_hash_map); j++) {
if (digests[i].alg_id != tpm2_hash_map[j].tpm_id)
continue;
tpm_buf_append_u16(&buf, digests[i].alg_id);
tpm_buf_append(&buf, (const unsigned char
*)&digests[i].digest,
hash_digest_size[tpm2_hash_map[j].crypto_id]);
}
}
rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
"attempting extend a PCR value");
tpm_buf_destroy(&buf);
return rc;
}
struct tpm2_get_random_out {
__be16 size;
u8 buffer[TPM_MAX_RNG_DATA];
} __packed;
/**
* tpm2_get_random() - get random bytes from the TPM RNG
*
* @chip: a &tpm_chip instance
* @dest: destination buffer
* @max: the max number of random bytes to pull
*
* Return:
* size of the buffer on success,
* -errno otherwise
*/
int tpm2_get_random(struct tpm_chip *chip, u8 *dest, size_t max)
{
struct tpm2_get_random_out *out;
struct tpm_buf buf;
u32 recd;
u32 num_bytes = max;
int err;
int total = 0;
int retries = 5;
u8 *dest_ptr = dest;
if (!num_bytes || max > TPM_MAX_RNG_DATA)
return -EINVAL;
err = tpm_buf_init(&buf, 0, 0);
if (err)
return err;
do {
tpm_buf_reset(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_RANDOM);
tpm_buf_append_u16(&buf, num_bytes);
err = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
offsetof(struct tpm2_get_random_out,
buffer),
0, "attempting get random");
if (err)
goto out;
out = (struct tpm2_get_random_out *)
&buf.data[TPM_HEADER_SIZE];
recd = min_t(u32, be16_to_cpu(out->size), num_bytes);
if (tpm_buf_length(&buf) <
TPM_HEADER_SIZE +
offsetof(struct tpm2_get_random_out, buffer) +
recd) {
err = -EFAULT;
goto out;
}
memcpy(dest_ptr, out->buffer, recd);
dest_ptr += recd;
total += recd;
num_bytes -= recd;
} while (retries-- && total < max);
tpm_buf_destroy(&buf);
return total ? total : -EIO;
out:
tpm_buf_destroy(&buf);
return err;
}
/**
* tpm2_flush_context_cmd() - execute a TPM2_FlushContext command
* @chip: TPM chip to use
* @handle: context handle
* @flags: tpm transmit flags - bitmap
*
*/
void tpm2_flush_context_cmd(struct tpm_chip *chip, u32 handle,
unsigned int flags)
{
struct tpm_buf buf;
int rc;
rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_FLUSH_CONTEXT);
if (rc) {
dev_warn(&chip->dev, "0x%08x was not flushed, out of memory\n",
handle);
return;
}
tpm_buf_append_u32(&buf, handle);
(void) tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, flags,
"flushing context");
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, TPM2_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, TPM2_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, NULL, buf.data, PAGE_SIZE, 4, 0,
"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
* @flags: tpm transmit flags
*
* 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, unsigned int flags)
{
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, NULL, buf.data, PAGE_SIZE, 4, flags,
"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
* @flags: tpm_transmit_cmd flags
*
* 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, unsigned int flags)
{
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, NULL, buf.data, PAGE_SIZE, 6, flags,
"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;
mutex_lock(&chip->tpm_mutex);
rc = tpm2_load_cmd(chip, payload, options, &blob_handle,
TPM_TRANSMIT_UNLOCKED);
if (rc)
goto out;
rc = tpm2_unseal_cmd(chip, payload, options, blob_handle,
TPM_TRANSMIT_UNLOCKED);
tpm2_flush_context_cmd(chip, blob_handle, TPM_TRANSMIT_UNLOCKED);
out:
mutex_unlock(&chip->tpm_mutex);
return rc;
}
struct tpm2_get_cap_out {
u8 more_data;
__be32 subcap_id;
__be32 property_cnt;
__be32 property_id;
__be32 value;
} __packed;
/**
* tpm2_get_tpm_pt() - get value of a TPM_CAP_TPM_PROPERTIES type property
* @chip: a &tpm_chip instance
* @property_id: property ID.
* @value: output variable.
* @desc: passed to tpm_transmit_cmd()
*
* Return:
* 0 on success,
* -errno or a TPM return code otherwise
*/
ssize_t tpm2_get_tpm_pt(struct tpm_chip *chip, u32 property_id, u32 *value,
const char *desc)
{
struct tpm2_get_cap_out *out;
struct tpm_buf buf;
int rc;
rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
if (rc)
return rc;
tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
tpm_buf_append_u32(&buf, property_id);
tpm_buf_append_u32(&buf, 1);
rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0, NULL);
if (!rc) {
out = (struct tpm2_get_cap_out *)
&buf.data[TPM_HEADER_SIZE];
*value = be32_to_cpu(out->value);
}
tpm_buf_destroy(&buf);
return rc;
}
EXPORT_SYMBOL_GPL(tpm2_get_tpm_pt);
/**
* tpm2_shutdown() - send a TPM shutdown command
*
* Sends a TPM shutdown command. The shutdown command is used in call
* sites where the system is going down. If it fails, there is not much
* that can be done except print an error message.
*
* @chip: a &tpm_chip instance
* @shutdown_type: TPM_SU_CLEAR or TPM_SU_STATE.
*/
void tpm2_shutdown(struct tpm_chip *chip, u16 shutdown_type)
{
struct tpm_buf buf;
int rc;
rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SHUTDOWN);
if (rc)
return;
tpm_buf_append_u16(&buf, shutdown_type);
tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
"stopping the TPM");
tpm_buf_destroy(&buf);
}
/**
* tpm2_do_selftest() - ensure that all self tests have passed
*
* @chip: TPM chip to use
*
* Return: Same as with tpm_transmit_cmd.
*
* The TPM can either run all self tests synchronously and then return
* RC_SUCCESS once all tests were successful. Or it can choose to run the tests
* asynchronously and return RC_TESTING immediately while the self tests still
* execute in the background. This function handles both cases and waits until
* all tests have completed.
*/
static int tpm2_do_selftest(struct tpm_chip *chip)
{
struct tpm_buf buf;
int full;
int rc;
for (full = 0; full < 2; full++) {
rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_SELF_TEST);
if (rc)
return rc;
tpm_buf_append_u8(&buf, full);
rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
"attempting the self test");
tpm_buf_destroy(&buf);
if (rc == TPM2_RC_TESTING)
rc = TPM2_RC_SUCCESS;
if (rc == TPM2_RC_INITIALIZE || rc == TPM2_RC_SUCCESS)
return rc;
}
return rc;
}
/**
* tpm2_probe() - probe for the TPM 2.0 protocol
* @chip: a &tpm_chip instance
*
* Send an idempotent TPM 2.0 command and see whether there is TPM2 chip in the
* other end based on the response tag. The flag TPM_CHIP_FLAG_TPM2 is set by
* this function if this is the case.
*
* Return:
* 0 on success,
* -errno otherwise
*/
int tpm2_probe(struct tpm_chip *chip)
{
struct tpm_output_header *out;
struct tpm_buf buf;
int rc;
rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
if (rc)
return rc;
tpm_buf_append_u32(&buf, TPM2_CAP_TPM_PROPERTIES);
tpm_buf_append_u32(&buf, TPM_PT_TOTAL_COMMANDS);
tpm_buf_append_u32(&buf, 1);
rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0, NULL);
/* We ignore TPM return codes on purpose. */
if (rc >= 0) {
out = (struct tpm_output_header *)buf.data;
if (be16_to_cpu(out->tag) == TPM2_ST_NO_SESSIONS)
chip->flags |= TPM_CHIP_FLAG_TPM2;
}
tpm_buf_destroy(&buf);
return 0;
}
EXPORT_SYMBOL_GPL(tpm2_probe);
struct tpm2_pcr_selection {
__be16 hash_alg;
u8 size_of_select;
u8 pcr_select[3];
} __packed;
static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
{
struct tpm2_pcr_selection pcr_selection;
struct tpm_buf buf;
void *marker;
void *end;
void *pcr_select_offset;
unsigned int count;
u32 sizeof_pcr_selection;
u32 rsp_len;
int rc;
int i = 0;
rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
if (rc)
return rc;
tpm_buf_append_u32(&buf, TPM2_CAP_PCRS);
tpm_buf_append_u32(&buf, 0);
tpm_buf_append_u32(&buf, 1);
rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 9, 0,
"get tpm pcr allocation");
if (rc)
goto out;
count = be32_to_cpup(
(__be32 *)&buf.data[TPM_HEADER_SIZE + 5]);
if (count > ARRAY_SIZE(chip->active_banks)) {
rc = -ENODEV;
goto out;
}
marker = &buf.data[TPM_HEADER_SIZE + 9];
rsp_len = be32_to_cpup((__be32 *)&buf.data[2]);
end = &buf.data[rsp_len];
for (i = 0; i < count; i++) {
pcr_select_offset = marker +
offsetof(struct tpm2_pcr_selection, size_of_select);
if (pcr_select_offset >= end) {
rc = -EFAULT;
break;
}
memcpy(&pcr_selection, marker, sizeof(pcr_selection));
chip->active_banks[i] = be16_to_cpu(pcr_selection.hash_alg);
sizeof_pcr_selection = sizeof(pcr_selection.hash_alg) +
sizeof(pcr_selection.size_of_select) +
pcr_selection.size_of_select;
marker = marker + sizeof_pcr_selection;
}
out:
if (i < ARRAY_SIZE(chip->active_banks))
chip->active_banks[i] = TPM2_ALG_ERROR;
tpm_buf_destroy(&buf);
return rc;
}
static int tpm2_get_cc_attrs_tbl(struct tpm_chip *chip)
{
struct tpm_buf buf;
u32 nr_commands;
__be32 *attrs;
u32 cc;
int i;
int rc;
rc = tpm2_get_tpm_pt(chip, TPM_PT_TOTAL_COMMANDS, &nr_commands, NULL);
if (rc)
goto out;
if (nr_commands > 0xFFFFF) {
rc = -EFAULT;
goto out;
}
chip->cc_attrs_tbl = devm_kcalloc(&chip->dev, 4, nr_commands,
GFP_KERNEL);
rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_GET_CAPABILITY);
if (rc)
goto out;
tpm_buf_append_u32(&buf, TPM2_CAP_COMMANDS);
tpm_buf_append_u32(&buf, TPM2_CC_FIRST);
tpm_buf_append_u32(&buf, nr_commands);
rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,
9 + 4 * nr_commands, 0, NULL);
if (rc) {
tpm_buf_destroy(&buf);
goto out;
}
if (nr_commands !=
be32_to_cpup((__be32 *)&buf.data[TPM_HEADER_SIZE + 5])) {
tpm_buf_destroy(&buf);
goto out;
}
chip->nr_commands = nr_commands;
attrs = (__be32 *)&buf.data[TPM_HEADER_SIZE + 9];
for (i = 0; i < nr_commands; i++, attrs++) {
chip->cc_attrs_tbl[i] = be32_to_cpup(attrs);
cc = chip->cc_attrs_tbl[i] & 0xFFFF;
if (cc == TPM2_CC_CONTEXT_SAVE || cc == TPM2_CC_FLUSH_CONTEXT) {
chip->cc_attrs_tbl[i] &=
~(GENMASK(2, 0) << TPM2_CC_ATTR_CHANDLES);
chip->cc_attrs_tbl[i] |= 1 << TPM2_CC_ATTR_CHANDLES;
}
}
tpm_buf_destroy(&buf);
out:
if (rc > 0)
rc = -ENODEV;
return rc;
}
/**
* tpm2_startup - turn on the TPM
* @chip: TPM chip to use
*
* Normally the firmware should start the TPM. This function is provided as a
* workaround if this does not happen. A legal case for this could be for
* example when a TPM emulator is used.
*
* Return: same as tpm_transmit_cmd()
*/
static int tpm2_startup(struct tpm_chip *chip)
{
struct tpm_buf buf;
int rc;
dev_info(&chip->dev, "starting up the TPM manually\n");
rc = tpm_buf_init(&buf, TPM2_ST_NO_SESSIONS, TPM2_CC_STARTUP);
if (rc < 0)
return rc;
tpm_buf_append_u16(&buf, TPM2_SU_CLEAR);
rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
"attempting to start the TPM");
tpm_buf_destroy(&buf);
return rc;
}
/**
* tpm2_auto_startup - Perform the standard automatic TPM initialization
* sequence
* @chip: TPM chip to use
*
* Returns 0 on success, < 0 in case of fatal error.
*/
int tpm2_auto_startup(struct tpm_chip *chip)
{
int rc;
rc = tpm2_get_timeouts(chip);
if (rc)
goto out;
rc = tpm2_do_selftest(chip);
if (rc && rc != TPM2_RC_INITIALIZE)
goto out;
if (rc == TPM2_RC_INITIALIZE) {
rc = tpm2_startup(chip);
if (rc)
goto out;
rc = tpm2_do_selftest(chip);
if (rc)
goto out;
}
rc = tpm2_get_pcr_allocation(chip);
if (rc)
goto out;
rc = tpm2_get_cc_attrs_tbl(chip);
out:
if (rc > 0)
rc = -ENODEV;
return rc;
}
int tpm2_find_cc(struct tpm_chip *chip, u32 cc)
{
int i;
for (i = 0; i < chip->nr_commands; i++)
if (cc == (chip->cc_attrs_tbl[i] & GENMASK(15, 0)))
return i;
return -1;
}
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