Re: [PATCH v3 4/6] tpm: replace TPM algorithms IDs with tpm_pcr_bank_info structs in tpm_chip

Jarkko Sakkinen
2017-06-23T10:33:35Z

On Wed, Jun 21, 2017 at 04:29:39PM +0200, Roberto Sassu wrote:
> This patch replaces the array of TPM algorithms ID, stored in the tpm_chip
> structure, with an array of the new structure tpm_pcr_bank_info.
>
> The array is initialized during the execution of tpm2_get_pcr_allocation(),
> by tpm2_init_pcr_bank_info().
>
> tpm2_pcr_extend() and tpm_pcr_extend() have been modified to use the
> digest size retrieved from the TPM instead of that from the crypto
> subsystem.
>
> Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>

How do you deal with the trusted keys code?

> ---
> drivers/char/tpm/tpm-interface.c | 4 ++--
> drivers/char/tpm/tpm.h | 2 +-
> drivers/char/tpm/tpm2-cmd.c | 22 +++++++++++-----------
> 3 files changed, 14 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
> index d2b4df6..a11598a 100644
> --- a/drivers/char/tpm/tpm-interface.c
> +++ b/drivers/char/tpm/tpm-interface.c
> @@ -897,8 +897,8 @@ int tpm_pcr_extend(u32 chip_num, int pcr_idx, const u8 *hash)
> memset(digest_list, 0, sizeof(digest_list));
>
> for (i = 0; i < ARRAY_SIZE(chip->active_banks) &&
> - chip->active_banks[i] != TPM2_ALG_ERROR; i++) {
> - digest_list[i].alg_id = chip->active_banks[i];
> + chip->active_banks[i].alg_id != TPM2_ALG_ERROR; i++) {
> + digest_list[i].alg_id = chip->active_banks[i].alg_id;
> memcpy(digest_list[i].digest, hash, TPM_DIGEST_SIZE);
> count++;
> }
> diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h
> index 62c600d..d285bc6 100644
> --- a/drivers/char/tpm/tpm.h
> +++ b/drivers/char/tpm/tpm.h
> @@ -208,7 +208,7 @@ struct tpm_chip {
> const struct attribute_group *groups[3];
> unsigned int groups_cnt;
>
> - u16 active_banks[7];
> + struct tpm_pcr_bank_info active_banks[7];
> #ifdef CONFIG_ACPI
> acpi_handle acpi_dev_handle;
> char ppi_version[TPM_PPI_VERSION_LEN + 1];
> diff --git a/drivers/char/tpm/tpm2-cmd.c b/drivers/char/tpm/tpm2-cmd.c
> index 74a68ea..7bd2cf7 100644
> --- a/drivers/char/tpm/tpm2-cmd.c
> +++ b/drivers/char/tpm/tpm2-cmd.c
> @@ -301,7 +301,6 @@ int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, u32 count,
> struct tpm2_null_auth_area auth_area;
> int rc;
> int i;
> - int j;
>
> if (count > ARRAY_SIZE(chip->active_banks))
> return -EINVAL;
> @@ -323,14 +322,10 @@ int tpm2_pcr_extend(struct tpm_chip *chip, int pcr_idx, u32 count,
> tpm_buf_append_u32(&buf, count);
>
> for (i = 0; i < count; i++) {
> - for (j = 0; j < ARRAY_SIZE(tpm2_hash_map); j++) {
> - if (digests[i].alg_id != tpm2_hash_map[j].tpm_id)
> - continue;
> - tpm_buf_append_u16(&buf, digests[i].alg_id);
> - tpm_buf_append(&buf, (const unsigned char
> - *)&digests[i].digest,
> - hash_digest_size[tpm2_hash_map[j].crypto_id]);
> - }
> + /* digests[i].alg_id == chip->active_banks[i].alg_id */
> + tpm_buf_append_u16(&buf, digests[i].alg_id);
> + tpm_buf_append(&buf, (const unsigned char *)&digests[i].digest,
> + chip->active_banks[i].digest_size);
> }
>
> rc = tpm_transmit_cmd(chip, NULL, buf.data, PAGE_SIZE, 0, 0,
> @@ -1076,7 +1071,12 @@ static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
> }
>
> memcpy(&pcr_selection, marker, sizeof(pcr_selection));
> - chip->active_banks[i] = be16_to_cpu(pcr_selection.hash_alg);
> + rc = tpm2_init_pcr_bank_info(chip,
> + be16_to_cpu(pcr_selection.hash_alg),
> + &chip->active_banks[i]);
> + if (rc)
> + break;
> +
> sizeof_pcr_selection = sizeof(pcr_selection.hash_alg) +
> sizeof(pcr_selection.size_of_select) +
> pcr_selection.size_of_select;
> @@ -1085,7 +1085,7 @@ static ssize_t tpm2_get_pcr_allocation(struct tpm_chip *chip)
>
> out:
> if (i < ARRAY_SIZE(chip->active_banks))
> - chip->active_banks[i] = TPM2_ALG_ERROR;
> + chip->active_banks[i].alg_id = TPM2_ALG_ERROR;
>
> tpm_buf_destroy(&buf);
>
> --
> 2.9.3
>

Hard to review the actual code change as it really does not live on its
own.

/Jarkko