[PATCH v4 1/6] integrity: PowerVM support for loading CA keys on machine keyring

R Nageswara Sastry rnsastry at linux.ibm.com
Thu Aug 17 00:40:45 AEST 2023



On 15/08/23 4:57 pm, Nayna Jain wrote:
> Keys that derive their trust from an entity such as a security officer,
> administrator, system owner, or machine owner are said to have "imputed
> trust". CA keys with imputed trust can be loaded onto the machine keyring.
> The mechanism for loading these keys onto the machine keyring is platform
> dependent.
> 
> Load keys stored in the variable trustedcadb onto the .machine keyring
> on PowerVM platform.
> 
> Signed-off-by: Nayna Jain <nayna at linux.ibm.com>
> Reviewed-and-tested-by: Mimi Zohar <zohar at linux.ibm.com>

Tested with trustedcadb, moduledb scenarios
Tested-by: Nageswara R Sastry <rnsastry at linux.ibm.com>


> ---
>   .../integrity/platform_certs/keyring_handler.c  |  8 ++++++++
>   .../integrity/platform_certs/keyring_handler.h  |  5 +++++
>   .../integrity/platform_certs/load_powerpc.c     | 17 +++++++++++++++++
>   3 files changed, 30 insertions(+)
> 
> diff --git a/security/integrity/platform_certs/keyring_handler.c b/security/integrity/platform_certs/keyring_handler.c
> index 8a1124e4d769..1649d047e3b8 100644
> --- a/security/integrity/platform_certs/keyring_handler.c
> +++ b/security/integrity/platform_certs/keyring_handler.c
> @@ -69,6 +69,14 @@ __init efi_element_handler_t get_handler_for_mok(const efi_guid_t *sig_type)
>   	return NULL;
>   }
>   
> +__init efi_element_handler_t get_handler_for_ca_keys(const efi_guid_t *sig_type)
> +{
> +	if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0)
> +		return add_to_machine_keyring;
> +
> +	return NULL;
> +}
> +
>   /*
>    * Return the appropriate handler for particular signature list types found in
>    * the UEFI dbx and MokListXRT tables.
> diff --git a/security/integrity/platform_certs/keyring_handler.h b/security/integrity/platform_certs/keyring_handler.h
> index 212d894a8c0c..6f15bb4cc8dc 100644
> --- a/security/integrity/platform_certs/keyring_handler.h
> +++ b/security/integrity/platform_certs/keyring_handler.h
> @@ -29,6 +29,11 @@ efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type);
>    */
>   efi_element_handler_t get_handler_for_mok(const efi_guid_t *sig_type);
>   
> +/*
> + * Return the handler for particular signature list types for CA keys.
> + */
> +efi_element_handler_t get_handler_for_ca_keys(const efi_guid_t *sig_type);
> +
>   /*
>    * Return the handler for particular signature list types found in the dbx.
>    */
> diff --git a/security/integrity/platform_certs/load_powerpc.c b/security/integrity/platform_certs/load_powerpc.c
> index 170789dc63d2..339053d9726d 100644
> --- a/security/integrity/platform_certs/load_powerpc.c
> +++ b/security/integrity/platform_certs/load_powerpc.c
> @@ -59,6 +59,7 @@ static __init void *get_cert_list(u8 *key, unsigned long keylen, u64 *size)
>   static int __init load_powerpc_certs(void)
>   {
>   	void *db = NULL, *dbx = NULL, *data = NULL;
> +	void *trustedca;
>   	u64 dsize = 0;
>   	u64 offset = 0;
>   	int rc = 0;
> @@ -120,6 +121,22 @@ static int __init load_powerpc_certs(void)
>   		kfree(data);
>   	}
>   
> +	data = get_cert_list("trustedcadb", 12,  &dsize);
> +	if (!data) {
> +		pr_info("Couldn't get trustedcadb list from firmware\n");
> +	} else if (IS_ERR(data)) {
> +		rc = PTR_ERR(data);
> +		pr_err("Error reading trustedcadb from firmware: %d\n", rc);
> +	} else {
> +		extract_esl(trustedca, data, dsize, offset);
> +
> +		rc = parse_efi_signature_list("powerpc:trustedca", trustedca, dsize,
> +					      get_handler_for_ca_keys);
> +		if (rc)
> +			pr_err("Couldn't parse trustedcadb signatures: %d\n", rc);
> +		kfree(data);
> +	}
> +
>   	return rc;
>   }
>   late_initcall(load_powerpc_certs);

-- 
Thanks and Regards
R.Nageswara Sastry


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