[PATCH v3 10/11] tpm: Add TPM2 support for write_lock

[Ilias Apalodimas <ilias.apalodimas@linaro.org>]

On Sat, Jan 23, 2021 at 10:26:06AM -0700, Simon Glass wrote:
> Implement this API function for TPM2.
> 
> Signed-off-by: Simon Glass <sjg@chromium.org>
> ---
> 
> (no changes since v1)
> 
>  include/tpm-v2.h | 12 ++++++++++++
>  lib/tpm-v2.c     | 23 +++++++++++++++++++++++
>  lib/tpm_api.c    |  2 +-
>  3 files changed, 36 insertions(+), 1 deletion(-)
> 
> diff --git a/include/tpm-v2.h b/include/tpm-v2.h
> index 6a400771af1..1ca1e7e2011 100644
> --- a/include/tpm-v2.h
> +++ b/include/tpm-v2.h
> @@ -241,6 +241,7 @@ enum tpm2_command_codes {
>  	TPM2_CC_NV_DEFINE_SPACE	= 0x012a,
>  	TPM2_CC_PCR_SETAUTHPOL	= 0x012C,
>  	TPM2_CC_NV_WRITE	= 0x0137,
> +	TPM2_CC_NV_WRITELOCK	= 0x0138,
>  	TPM2_CC_DAM_RESET	= 0x0139,
>  	TPM2_CC_DAM_PARAMETERS	= 0x013A,
>  	TPM2_CC_NV_READ         = 0x014E,
> @@ -570,4 +571,15 @@ u32 tpm2_pcr_setauthvalue(struct udevice *dev, const char *pw,
>   */
>  u32 tpm2_get_random(struct udevice *dev, void *data, u32 count);
>  
> +/**
> + * Lock data in the TPM
> + *
> + * Once locked the data cannot be written until after a reboot
> + *
> + * @dev		TPM device
> + * @index	Index of data to lock
> + * @return code of the operation
> + */
> +u32 tpm2_write_lock(struct udevice *dev, u32 index);
> +
>  #endif /* __TPM_V2_H */
> diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c
> index 7bf43264ab0..35f3917aeb5 100644
> --- a/lib/tpm-v2.c
> +++ b/lib/tpm-v2.c
> @@ -602,3 +602,26 @@ u32 tpm2_get_random(struct udevice *dev, void *data, u32 count)
>  
>  	return 0;
>  }
> +
> +u32 tpm2_write_lock(struct udevice *dev, u32 index)
> +{
> +	u8 command_v2[COMMAND_BUFFER_SIZE] = {
> +		/* header 10 bytes */
> +		tpm_u16(TPM2_ST_SESSIONS),	/* TAG */
> +		tpm_u32(10 + 8 + 13), /* Length */
> +		tpm_u32(TPM2_CC_NV_WRITELOCK), /* Command code */
> +
> +		/* handles 8 bytes */
> +		tpm_u32(TPM2_RH_PLATFORM),	/* Primary platform seed */
> +		tpm_u32(HR_NV_INDEX + index),	/* Password authorisation */
> +
> +		/* session header 9 bytes */
> +		tpm_u32(9),			/* Header size */
> +		tpm_u32(TPM2_RS_PW),		/* Password authorisation */
> +		tpm_u16(0),			/* nonce_size */
> +		0,				/* session_attrs */
> +		tpm_u16(0),			/* auth_size */
> +	};
> +
> +	return tpm_sendrecv_command(dev, command_v2, NULL, NULL);
> +}
> diff --git a/lib/tpm_api.c b/lib/tpm_api.c
> index 687fc8bc7ee..4c662640a92 100644
> --- a/lib/tpm_api.c
> +++ b/lib/tpm_api.c
> @@ -144,7 +144,7 @@ u32 tpm_write_lock(struct udevice *dev, u32 index)
>  	if (is_tpm1(dev))
>  		return -ENOSYS;
>  	else if (is_tpm2(dev))
> -		return -ENOSYS;
> +		return tpm2_write_lock(dev, index);
>  	else
>  		return -ENOSYS;
>  }
> -- 
> 2.30.0.280.ga3ce27912f-goog
> 
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>