From 5e335b5ecfa52e77c8e055f62155824e0e878587 Mon Sep 17 00:00:00 2001 From: Tomas Winkler Date: Fri, 19 Oct 2018 21:23:03 +0300 Subject: [PATCH] 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: Tomas Winkler Reviewed-by: Jarkko Sakkinen Tested-by: Jarkko Sakkinen Signed-off-by: Jarkko Sakkinen --- drivers/char/tpm/tpm.h | 18 ++---------------- drivers/char/tpm/tpm1-cmd.c | 38 ++++++++++++++++++++----------------- 2 files changed, 23 insertions(+), 33 deletions(-) diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 6895f183396b..51d147675b1f 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -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. diff --git a/drivers/char/tpm/tpm1-cmd.c b/drivers/char/tpm/tpm1-cmd.c index b5c4fa158c30..d30f336518f6 100644 --- a/drivers/char/tpm/tpm1-cmd.c +++ b/drivers/char/tpm/tpm1-cmd.c @@ -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 (rc == 0) - memcpy(res_buf, cmd.params.pcrread_out.pcr_result, - TPM_DIGEST_SIZE); + if (tpm_buf_length(&buf) < TPM_DIGEST_SIZE) { + rc = -EFAULT; + goto out; + } + + memcpy(res_buf, &buf.data[TPM_HEADER_SIZE], TPM_DIGEST_SIZE); + +out: + tpm_buf_destroy(&buf); return rc; }