int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
{
struct tpm_cmd_t cmd;
int rc;
struct tpm_chip *chip;
chip = tpm_chip_find_get(chip_num);
if (chip == NULL)
return -ENODEV;
if (chip->flags & TPM_CHIP_FLAG_TPM2) {
rc = tpm2_pcr_extend(chip, pcr_idx, hash);
tpm_put_ops(chip);
return rc;
}
cmd.header.in = pcrextend_header;
cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(pcr_idx);
memcpy(cmd.params.pcrextend_in.hash, hash, TPM_DIGEST_SIZE);
rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
"attempting extend a PCR value");
tpm_put_ops(chip);
return rc;
}
/**
* tpm_pcr_extend - extend a PCR value in SHA1 bank.
* @chip: a &struct tpm_chip instance, %NULL for the default chip
* @pcr_idx: the PCR to be retrieved
* @digests: array of tpm_digest structures used to extend PCRs
*
* Note: callers must pass a digest for every allocated PCR bank, in the same
* order of the banks in chip->allocated_banks.
*
* Return: same as with tpm_transmit_cmd()
*/
int tpm_pcr_extend(struct tpm_chip *chip, u32 pcr_idx,
struct tpm_digest *digests)
{
int rc;
int i;
chip = tpm_find_get_ops(chip);
if (!chip)
return -ENODEV;
for (i = 0; i < chip->nr_allocated_banks; i++)
if (digests[i].alg_id != chip->allocated_banks[i].alg_id)
return -EINVAL;
if (chip->flags & TPM_CHIP_FLAG_TPM2) {
rc = tpm2_pcr_extend(chip, pcr_idx, digests);
tpm_put_ops(chip);
return rc;
}
rc = tpm1_pcr_extend(chip, pcr_idx, digests[0].digest,
"attempting extend a PCR value");
tpm_put_ops(chip);
return rc;
}
int tpm_send(u32 chip_num, void *cmd, size_t buflen)
{
struct tpm_chip *chip;
int rc;
chip = tpm_chip_find_get(chip_num);
if (chip == NULL)
return -ENODEV;
rc = tpm_transmit_cmd(chip, cmd, buflen, 0, "attempting tpm_cmd");
tpm_put_ops(chip);
return rc;
}
static ssize_t tpm_write(struct file *file, const char __user *buf,
size_t size, loff_t *off)
{
struct file_priv *priv = file->private_data;
size_t in_size = size;
ssize_t out_size;
/* cannot perform a write until the read has cleared
either via tpm_read or a user_read_timer timeout.
This also prevents splitted buffered writes from blocking here.
*/
if (atomic_read(&priv->data_pending) != 0)
return -EBUSY;
if (in_size > TPM_BUFSIZE)
return -E2BIG;
mutex_lock(&priv->buffer_mutex);
if (copy_from_user
(priv->data_buffer, (void __user *) buf, in_size)) {
mutex_unlock(&priv->buffer_mutex);
return -EFAULT;
}
/* atomic tpm command send and result receive. We only hold the ops
* lock during this period so that the tpm can be unregistered even if
* the char dev is held open.
*/
if (tpm_try_get_ops(priv->chip)) {
mutex_unlock(&priv->buffer_mutex);
return -EPIPE;
}
out_size = tpm_transmit(priv->chip, priv->data_buffer,
sizeof(priv->data_buffer));
tpm_put_ops(priv->chip);
if (out_size < 0) {
mutex_unlock(&priv->buffer_mutex);
return out_size;
}
atomic_set(&priv->data_pending, out_size);
mutex_unlock(&priv->buffer_mutex);
/* Set a timeout by which the reader must come claim the result */
mod_timer(&priv->user_read_timer, jiffies + (60 * HZ));
return in_size;
}
/**
* 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;
}
/**
* tpm_is_tpm2 - do we a have a TPM2 chip?
* @chip: a &struct tpm_chip instance, %NULL for the default chip
*
* Return:
* 1 if we have a TPM2 chip.
* 0 if we don't have a TPM2 chip.
* A negative number for system errors (errno).
*/
int tpm_is_tpm2(struct tpm_chip *chip)
{
int rc;
chip = tpm_find_get_ops(chip);
if (!chip)
return -ENODEV;
rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
tpm_put_ops(chip);
return rc;
}
/**
* tpm_pcr_read - read a pcr value
* @chip_num: tpm idx # or ANY
* @pcr_idx: pcr idx to retrieve
* @res_buf: TPM_PCR value
* size of res_buf is 20 bytes (or NULL if you don't care)
*
* The TPM driver should be built-in, but for whatever reason it
* isn't, protect against the chip disappearing, by incrementing
* the module usage count.
*/
int tpm_pcr_read(u32 chip_num, int pcr_idx, u8 *res_buf)
{
struct tpm_chip *chip;
int rc;
chip = tpm_chip_find_get(chip_num);
if (chip == NULL)
return -ENODEV;
if (chip->flags & TPM_CHIP_FLAG_TPM2)
rc = tpm2_pcr_read(chip, pcr_idx, res_buf);
else
rc = tpm_pcr_read_dev(chip, pcr_idx, res_buf);
tpm_put_ops(chip);
return rc;
}
/**
* tpm_is_tpm2 - is the chip a TPM2 chip?
* @chip_num: tpm idx # or ANY
*
* Returns < 0 on error, and 1 or 0 on success depending whether the chip
* is a TPM2 chip.
*/
int tpm_is_tpm2(u32 chip_num)
{
struct tpm_chip *chip;
int rc;
chip = tpm_chip_find_get(chip_num);
if (chip == NULL)
return -ENODEV;
rc = (chip->flags & TPM_CHIP_FLAG_TPM2) != 0;
tpm_put_ops(chip);
return rc;
}
/**
* tpm_pcr_read - read a PCR value from SHA1 bank
* @chip: a &struct tpm_chip instance, %NULL for the default chip
* @pcr_idx: the PCR to be retrieved
* @digest: the PCR bank and buffer current PCR value is written to
*
* Return: same as with tpm_transmit_cmd()
*/
int tpm_pcr_read(struct tpm_chip *chip, u32 pcr_idx,
struct tpm_digest *digest)
{
int rc;
chip = tpm_find_get_ops(chip);
if (!chip)
return -ENODEV;
if (chip->flags & TPM_CHIP_FLAG_TPM2)
rc = tpm2_pcr_read(chip, pcr_idx, digest, NULL);
else
rc = tpm1_pcr_read(chip, pcr_idx, digest->digest);
tpm_put_ops(chip);
return rc;
}
static void tpm_dev_async_work(struct work_struct *work)
{
struct file_priv *priv =
container_of(work, struct file_priv, async_work);
ssize_t ret;
mutex_lock(&priv->buffer_mutex);
priv->command_enqueued = false;
ret = tpm_dev_transmit(priv->chip, priv->space, priv->data_buffer,
sizeof(priv->data_buffer));
tpm_put_ops(priv->chip);
if (ret > 0) {
priv->response_length = ret;
mod_timer(&priv->user_read_timer, jiffies + (120 * HZ));
}
mutex_unlock(&priv->buffer_mutex);
wake_up_interruptible(&priv->async_wait);
}
/**
* tpm_get_random() - get random bytes from the TPM's RNG
* @chip: a &struct tpm_chip instance, %NULL for the default chip
* @out: destination buffer for the random bytes
* @max: the max number of bytes to write to @out
*
* Return: number of random bytes read or a negative error value.
*/
int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)
{
int rc;
if (!out || max > TPM_MAX_RNG_DATA)
return -EINVAL;
chip = tpm_find_get_ops(chip);
if (!chip)
return -ENODEV;
if (chip->flags & TPM_CHIP_FLAG_TPM2)
rc = tpm2_get_random(chip, out, max);
else
rc = tpm1_get_random(chip, out, max);
tpm_put_ops(chip);
return rc;
}
/**
* tpm_send - send a TPM command
* @chip: a &struct tpm_chip instance, %NULL for the default chip
* @cmd: a TPM command buffer
* @buflen: the length of the TPM command buffer
*
* Return: same as with tpm_transmit_cmd()
*/
int tpm_send(struct tpm_chip *chip, void *cmd, size_t buflen)
{
struct tpm_buf buf;
int rc;
chip = tpm_find_get_ops(chip);
if (!chip)
return -ENODEV;
rc = tpm_buf_init(&buf, 0, 0);
if (rc)
goto out;
memcpy(buf.data, cmd, buflen);
rc = tpm_transmit_cmd(chip, &buf, 0, "attempting to a send a command");
tpm_buf_destroy(&buf);
out:
tpm_put_ops(chip);
return rc;
}
/*
* We are about to suspend. Save the TPM state
* so that it can be restored.
*/
int tpm_pm_suspend(struct device *dev)
{
struct tpm_chip *chip = dev_get_drvdata(dev);
struct tpm_cmd_t cmd;
int rc, try;
u8 dummy_hash[TPM_DIGEST_SIZE] = { 0 };
if (chip == NULL)
return -ENODEV;
if (chip->flags & TPM_CHIP_FLAG_TPM2) {
tpm2_shutdown(chip, TPM2_SU_STATE);
return 0;
}
/* for buggy tpm, flush pcrs with extend to selected dummy */
if (tpm_suspend_pcr) {
cmd.header.in = pcrextend_header;
cmd.params.pcrextend_in.pcr_idx = cpu_to_be32(tpm_suspend_pcr);
memcpy(cmd.params.pcrextend_in.hash, dummy_hash,
TPM_DIGEST_SIZE);
rc = tpm_transmit_cmd(chip, &cmd, EXTEND_PCR_RESULT_SIZE, 0,
"extending dummy pcr before suspend");
}
/* now do the actual savestate */
for (try = 0; try < TPM_RETRY; try++) {
cmd.header.in = savestate_header;
rc = tpm_transmit_cmd(chip, &cmd, SAVESTATE_RESULT_SIZE, 0,
NULL);
/*
* If the TPM indicates that it is too busy to respond to
* this command then retry before giving up. It can take
* several seconds for this TPM to be ready.
*
* This can happen if the TPM has already been sent the
* SaveState command before the driver has loaded. TCG 1.2
* specification states that any communication after SaveState
* may cause the TPM to invalidate previously saved state.
*/
if (rc != TPM_WARN_RETRY)
break;
msleep(TPM_TIMEOUT_RETRY);
}
if (rc)
dev_err(&chip->dev,
"Error (%d) sending savestate before suspend\n", rc);
else if (try > 0)
dev_warn(&chip->dev, "TPM savestate took %dms\n",
try * TPM_TIMEOUT_RETRY);
return rc;
}
EXPORT_SYMBOL_GPL(tpm_pm_suspend);
/*
* Resume from a power safe. The BIOS already restored
* the TPM state.
*/
int tpm_pm_resume(struct device *dev)
{
struct tpm_chip *chip = dev_get_drvdata(dev);
if (chip == NULL)
return -ENODEV;
return 0;
}
EXPORT_SYMBOL_GPL(tpm_pm_resume);
#define TPM_GETRANDOM_RESULT_SIZE 18
static const struct tpm_input_header tpm_getrandom_header = {
.tag = TPM_TAG_RQU_COMMAND,
.length = cpu_to_be32(14),
.ordinal = TPM_ORD_GET_RANDOM
};
/**
* tpm_get_random() - Get random bytes from the tpm's RNG
* @chip_num: A specific chip number for the request or TPM_ANY_NUM
* @out: destination buffer for the random bytes
* @max: the max number of bytes to write to @out
*
* Returns < 0 on error and the number of bytes read on success
*/
int tpm_get_random(u32 chip_num, u8 *out, size_t max)
{
struct tpm_chip *chip;
struct tpm_cmd_t tpm_cmd;
u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);
int err, total = 0, retries = 5;
u8 *dest = out;
if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)
return -EINVAL;
chip = tpm_chip_find_get(chip_num);
if (chip == NULL)
return -ENODEV;
if (chip->flags & TPM_CHIP_FLAG_TPM2) {
err = tpm2_get_random(chip, out, max);
tpm_put_ops(chip);
return err;
}
do {
tpm_cmd.header.in = tpm_getrandom_header;
tpm_cmd.params.getrandom_in.num_bytes = cpu_to_be32(num_bytes);
err = tpm_transmit_cmd(chip, &tpm_cmd,
TPM_GETRANDOM_RESULT_SIZE + num_bytes,
0, "attempting get random");
if (err)
break;
recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);
memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);
dest += recd;
total += recd;
num_bytes -= recd;
} while (retries-- && total < max);
tpm_put_ops(chip);
return total ? total : -EIO;
}
EXPORT_SYMBOL_GPL(tpm_get_random);
/**
* tpm_seal_trusted() - seal a trusted key
* @chip_num: A specific chip number for the request or TPM_ANY_NUM
* @options: authentication values and other options
* @payload: the key data in clear and encrypted form
*
* Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
* are supported.
*/
int tpm_seal_trusted(u32 chip_num, struct trusted_key_payload *payload,
struct trusted_key_options *options)
{
struct tpm_chip *chip;
int rc;
chip = tpm_chip_find_get(chip_num);
if (chip == NULL || !(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_num: A specific chip number for the request or TPM_ANY_NUM
* @options: authentication values and other options
* @payload: the key data in clear and encrypted form
*
* Returns < 0 on error and 0 on success. At the moment, only TPM 2.0 chips
* are supported.
*/
int tpm_unseal_trusted(u32 chip_num, struct trusted_key_payload *payload,
struct trusted_key_options *options)
{
struct tpm_chip *chip;
int rc;
chip = tpm_chip_find_get(chip_num);
if (chip == NULL || !(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;
tpm_class = class_create(THIS_MODULE, "tpm");
if (IS_ERR(tpm_class)) {
pr_err("couldn't create tpm class\n");
return PTR_ERR(tpm_class);
}
rc = alloc_chrdev_region(&tpm_devt, 0, TPM_NUM_DEVICES, "tpm");
if (rc < 0) {
pr_err("tpm: failed to allocate char dev region\n");
class_destroy(tpm_class);
return rc;
}
return 0;
}
static void __exit tpm_exit(void)
{
idr_destroy(&dev_nums_idr);
class_destroy(tpm_class);
unregister_chrdev_region(tpm_devt, TPM_NUM_DEVICES);
}
ssize_t tpm_common_write(struct file *file, const char __user *buf,
size_t size, loff_t *off)
{
struct file_priv *priv = file->private_data;
int ret = 0;
if (size > TPM_BUFSIZE)
return -E2BIG;
mutex_lock(&priv->buffer_mutex);
/* Cannot perform a write until the read has cleared either via
* tpm_read or a user_read_timer timeout. This also prevents split
* buffered writes from blocking here.
*/
if ((!priv->response_read && priv->response_length) ||
priv->command_enqueued) {
ret = -EBUSY;
goto out;
}
if (copy_from_user(priv->data_buffer, buf, size)) {
ret = -EFAULT;
goto out;
}
if (size < 6 ||
size < be32_to_cpu(*((__be32 *)(priv->data_buffer + 2)))) {
ret = -EINVAL;
goto out;
}
/* atomic tpm command send and result receive. We only hold the ops
* lock during this period so that the tpm can be unregistered even if
* the char dev is held open.
*/
if (tpm_try_get_ops(priv->chip)) {
ret = -EPIPE;
goto out;
}
priv->response_length = 0;
priv->response_read = false;
*off = 0;
/*
* If in nonblocking mode schedule an async job to send
* the command return the size.
* In case of error the err code will be returned in
* the subsequent read call.
*/
if (file->f_flags & O_NONBLOCK) {
priv->command_enqueued = true;
queue_work(tpm_dev_wq, &priv->async_work);
mutex_unlock(&priv->buffer_mutex);
return size;
}
ret = tpm_dev_transmit(priv->chip, priv->space, priv->data_buffer,
sizeof(priv->data_buffer));
tpm_put_ops(priv->chip);
if (ret > 0) {
priv->response_length = ret;
mod_timer(&priv->user_read_timer, jiffies + (120 * HZ));
ret = size;
}
out:
mutex_unlock(&priv->buffer_mutex);
return ret;
}
