Commit 433d390f authored by Tomas Winkler's avatar Tomas Winkler Committed by Jarkko Sakkinen
Browse files

tpm: factor out tpm1_get_random into tpm1-cmd.c 



Factor out get random implementation from tpm-interface.c
into tpm1_get_random function in tpm1-cmd.c.
No functional changes.

Signed-off-by: default avatarTomas Winkler <tomas.winkler@intel.com>
Reviewed-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: default avatarJarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
parent f4d916b7

drivers/char/tpm/tpm-interface.c

+7 −51
Original line number Diff line number Diff line
@@ -811,14 +811,6 @@ int tpm_pm_resume(struct device *dev) 
}

EXPORT_SYMBOL_GPL(tpm_pm_resume);



#define TPM_ORD_GET_RANDOM 70

#define TPM_GETRANDOM_RESULT_SIZE	18

static const struct tpm_input_header tpm_getrandom_header = {

	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),

	.length = cpu_to_be32(14),

	.ordinal = cpu_to_be32(TPM_ORD_GET_RANDOM)

};



/**

 * tpm_get_random() - get random bytes from the TPM's RNG

 * @chip:	a &struct tpm_chip instance, %NULL for the default chip
@@ -829,58 +821,22 @@ static const struct tpm_input_header tpm_getrandom_header = { 
 */

int tpm_get_random(struct tpm_chip *chip, u8 *out, size_t max)

{

	struct tpm_cmd_t tpm_cmd;

	u32 recd, num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA), rlength;

	int err, total = 0, retries = 5;

	u8 *dest = out;

	int rc;



	if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)

	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) {

		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, NULL, &tpm_cmd,

				       TPM_GETRANDOM_RESULT_SIZE + num_bytes,

				       offsetof(struct tpm_getrandom_out,

						rng_data),

				       0, "attempting get random");

		if (err)

			break;



		recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);

		if (recd > num_bytes) {

			total = -EFAULT;

			break;

		}



		rlength = be32_to_cpu(tpm_cmd.header.out.length);

		if (rlength < TPM_HEADER_SIZE +

			      offsetof(struct tpm_getrandom_out, rng_data) +

			      recd) {

			total = -EFAULT;

			break;

		}

		memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);



		dest += recd;

		total += recd;

		num_bytes -= recd;

	} while (retries-- && total < max);

	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 total ? total : -EIO;

	return rc;

}

EXPORT_SYMBOL_GPL(tpm_get_random);

drivers/char/tpm/tpm.h

+1 −0
Original line number Diff line number Diff line
@@ -551,6 +551,7 @@ int tpm1_pcr_extend(struct tpm_chip *chip, int pcr_idx, const u8 *hash, 
		    const char *log_msg);

ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap,

		    const char *desc, size_t min_cap_length);

int tpm1_get_random(struct tpm_chip *chip, u8 *out, size_t max);

unsigned long tpm_calc_ordinal_duration(struct tpm_chip *chip, u32 ordinal);

int tpm_pm_suspend(struct device *dev);

int tpm_pm_resume(struct device *dev);

drivers/char/tpm/tpm1-cmd.c

+55 −0
Original line number Diff line number Diff line
@@ -469,3 +469,58 @@ ssize_t tpm1_getcap(struct tpm_chip *chip, u32 subcap_id, cap_t *cap, 
	return rc;

}

EXPORT_SYMBOL_GPL(tpm1_getcap);



#define TPM_ORD_GET_RANDOM 70

#define TPM_GETRANDOM_RESULT_SIZE	18

static const struct tpm_input_header tpm_getrandom_header = {

	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),

	.length = cpu_to_be32(14),

	.ordinal = cpu_to_be32(TPM_ORD_GET_RANDOM)

};



int tpm1_get_random(struct tpm_chip *chip, u8 *out, size_t max)

{

	struct tpm_cmd_t tpm_cmd;

	u32 recd;

	u32 num_bytes = min_t(u32, max, TPM_MAX_RNG_DATA);

	u32 rlength;

	int err, total = 0, retries = 5;

	u8 *dest = out;



	if (!out || !num_bytes || max > TPM_MAX_RNG_DATA)

		return -EINVAL;



	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, NULL, &tpm_cmd,

				       TPM_GETRANDOM_RESULT_SIZE + num_bytes,

				       offsetof(struct tpm_getrandom_out,

						rng_data),

				       0, "attempting get random");

		if (err)

			break;



		recd = be32_to_cpu(tpm_cmd.params.getrandom_out.rng_data_len);

		if (recd > num_bytes) {

			total = -EFAULT;

			break;

		}



		rlength = be32_to_cpu(tpm_cmd.header.out.length);

		if (rlength < TPM_HEADER_SIZE +

			      offsetof(struct tpm_getrandom_out, rng_data) +

			      recd) {

			total = -EFAULT;

			break;

		}

		memcpy(dest, tpm_cmd.params.getrandom_out.rng_data, recd);



		dest += recd;

		total += recd;

		num_bytes -= recd;

	} while (retries-- && (size_t)total < max);



	return total ? total : -EIO;

}