tpm1: implement tpm1_pcr_read_dev() using tpm_buf structure (5e335b5e) · Commits · 戴 / test

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.

+21 −17

Original line number	Diff line number	Diff line
		@@ -571,29 +571,33 @@ out:
		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;
		}