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Commit 5e335b5e authored by Tomas Winkler's avatar Tomas Winkler Committed by Jarkko Sakkinen
Browse files

tpm1: implement tpm1_pcr_read_dev() using tpm_buf structure 



Implement tpm1_pcr_read_dev() using tpm_buf and remove
now unneeded structures from tpm.h

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 7aee9c52

drivers/char/tpm/tpm.h

+2 −16
Original line number Diff line number Diff line
@@ -382,13 +382,10 @@ typedef union { 
	struct	tpm_output_header out;

} tpm_cmd_header;



struct tpm_pcrread_out {

	u8	pcr_result[TPM_DIGEST_SIZE];

struct tpm_cmd_t {

	tpm_cmd_header	header;

} __packed;



struct tpm_pcrread_in {

	__be32	pcr_idx;

} __packed;



/* 128 bytes is an arbitrary cap. This could be as large as TPM_BUFSIZE - 18

 * bytes, but 128 is still a relatively large number of random bytes and
@@ -396,17 +393,6 @@ struct tpm_pcrread_in { 
 * compiler warnings about stack frame size. */

#define TPM_MAX_RNG_DATA	128



typedef union {

	struct	tpm_pcrread_in	pcrread_in;

	struct	tpm_pcrread_out	pcrread_out;

} tpm_cmd_params;



struct tpm_cmd_t {

	tpm_cmd_header	header;

	tpm_cmd_params	params;

} __packed;





/* A string buffer type for constructing TPM commands. This is based on the

 * ideas of string buffer code in security/keys/trusted.h but is heap based

 * in order to keep the stack usage minimal.

drivers/char/tpm/tpm1-cmd.c

+21 −17
Original line number Diff line number Diff line
@@ -571,29 +571,33 @@ int tpm1_get_random(struct tpm_chip *chip, u8 *dest, size_t max) 
	return rc;

}



#define TPM_ORDINAL_PCRREAD 21

#define READ_PCR_RESULT_SIZE 30

#define READ_PCR_RESULT_BODY_SIZE 20

static const struct tpm_input_header pcrread_header = {

	.tag = cpu_to_be16(TPM_TAG_RQU_COMMAND),

	.length = cpu_to_be32(14),

	.ordinal = cpu_to_be32(TPM_ORDINAL_PCRREAD)

};



#define TPM_ORD_PCRREAD 21

int tpm1_pcr_read_dev(struct tpm_chip *chip, int pcr_idx, u8 *res_buf)

{

	struct tpm_buf buf;

	int rc;

	struct tpm_cmd_t cmd;



	cmd.header.in = pcrread_header;

	cmd.params.pcrread_in.pcr_idx = cpu_to_be32(pcr_idx);

	rc = tpm_transmit_cmd(chip, NULL, &cmd, READ_PCR_RESULT_SIZE,

			      READ_PCR_RESULT_BODY_SIZE, 0,

	rc = tpm_buf_init(&buf, TPM_TAG_RQU_COMMAND, TPM_ORD_PCRREAD);

	if (rc)

		return rc;



	tpm_buf_append_u32(&buf, pcr_idx);



	rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE,

			      TPM_DIGEST_SIZE, 0,

			      "attempting to read a pcr value");

	if (rc)

		goto out;



	if (tpm_buf_length(&buf) < TPM_DIGEST_SIZE) {

		rc = -EFAULT;

		goto out;

	}



	memcpy(res_buf, &buf.data[TPM_HEADER_SIZE], TPM_DIGEST_SIZE);



	if (rc == 0)

		memcpy(res_buf, cmd.params.pcrread_out.pcr_result,

		       TPM_DIGEST_SIZE);

out:

	tpm_buf_destroy(&buf);

	return rc;

}