[PATCH v3 6/6] integrity: PowerVM support for loading third party code signing keys
Jarkko Sakkinen
jarkko at kernel.org
Mon Aug 14 17:42:30 UTC 2023
On Sun Aug 13, 2023 at 5:15 AM EEST, Nayna Jain wrote:
> On secure boot enabled PowerVM LPAR, third party code signing keys are
> needed during early boot to verify signed third party modules. These
> third party keys are stored in moduledb object in the Platform
> KeyStore(PKS).
>
> Load third party code signing keys onto .secondary_trusted_keys keyring.
>
> Signed-off-by: Nayna Jain <nayna at linux.ibm.com>
> ---
> certs/system_keyring.c | 30 +++++++++++++++++++
> include/keys/system_keyring.h | 7 +++++
> security/integrity/integrity.h | 1 +
> .../platform_certs/keyring_handler.c | 8 +++++
> .../platform_certs/keyring_handler.h | 5 ++++
> .../integrity/platform_certs/load_powerpc.c | 18 ++++++++++-
> 6 files changed, 68 insertions(+), 1 deletion(-)
>
> diff --git a/certs/system_keyring.c b/certs/system_keyring.c
> index b348e0898d34..e458d414918d 100644
> --- a/certs/system_keyring.c
> +++ b/certs/system_keyring.c
> @@ -396,3 +396,33 @@ void __init set_platform_trusted_keys(struct key *keyring)
> platform_trusted_keys = keyring;
> }
> #endif
> +
> +/**
> + * add_to_secondary_keyring - Add to secondary keyring.
> + * @source: Source of key
> + * @data: The blob holding the key
> + * @len: The length of the data blob
> + *
> + * Add a key to the secondary keyring. The key must be vouched for by a key in the builtin,
> + * machine or secondary keyring itself.
> + */
> +void __init add_to_secondary_keyring(const char *source, const void *data, size_t len)
> +{
> + key_ref_t key;
> + key_perm_t perm;
> +
> + perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW;
> +
> + key = key_create_or_update(make_key_ref(secondary_trusted_keys, 1),
> + "asymmetric",
> + NULL, data, len, perm,
> + KEY_ALLOC_NOT_IN_QUOTA);
> + if (IS_ERR(key)) {
> + pr_err("Problem loading X.509 certificate from %s to secondary keyring %ld\n",
> + source, PTR_ERR(key));
> + return;
> + }
> +
> + pr_notice("Loaded X.509 cert '%s'\n", key_ref_to_ptr(key)->description);
> + key_ref_put(key);
> +}
> diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h
> index 7e2583208820..4188f75d1bac 100644
> --- a/include/keys/system_keyring.h
> +++ b/include/keys/system_keyring.h
> @@ -50,9 +50,16 @@ int restrict_link_by_digsig_builtin_and_secondary(struct key *keyring,
> const struct key_type *type,
> const union key_payload *payload,
> struct key *restriction_key);
> +void __init add_to_secondary_keyring(const char *source, const void *data,
> + size_t len);
> +
> #else
> #define restrict_link_by_builtin_and_secondary_trusted restrict_link_by_builtin_trusted
> #define restrict_link_by_digsig_builtin_and_secondary restrict_link_by_digsig_builtin
> +void __init add_to_secondary_keyring(const char *source, const void *data,
> + size_t len)
> +{
> +}
> #endif
>
> #ifdef CONFIG_INTEGRITY_MACHINE_KEYRING
> diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h
> index d7553c93f5c0..efaa2eb789ad 100644
> --- a/security/integrity/integrity.h
> +++ b/security/integrity/integrity.h
> @@ -228,6 +228,7 @@ static inline int __init integrity_load_cert(const unsigned int id,
> {
> return 0;
> }
> +
> #endif /* CONFIG_INTEGRITY_SIGNATURE */
>
> #ifdef CONFIG_INTEGRITY_ASYMMETRIC_KEYS
> diff --git a/security/integrity/platform_certs/keyring_handler.c b/security/integrity/platform_certs/keyring_handler.c
> index 586027b9a3f5..13ea17207902 100644
> --- a/security/integrity/platform_certs/keyring_handler.c
> +++ b/security/integrity/platform_certs/keyring_handler.c
> @@ -78,6 +78,14 @@ __init efi_element_handler_t get_handler_for_ca_keys(const efi_guid_t *sig_type)
> return NULL;
> }
>
> +__init efi_element_handler_t get_handler_for_code_signing_keys(const efi_guid_t *sig_type)
> +{
> + if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0)
> + return add_to_secondary_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 6f15bb4cc8dc..f92895cc50f6 100644
> --- a/security/integrity/platform_certs/keyring_handler.h
> +++ b/security/integrity/platform_certs/keyring_handler.h
> @@ -34,6 +34,11 @@ efi_element_handler_t get_handler_for_mok(const efi_guid_t *sig_type);
> */
> efi_element_handler_t get_handler_for_ca_keys(const efi_guid_t *sig_type);
>
> +/*
> + * Return the handler for particular signature list types for code signing keys.
> + */
> +efi_element_handler_t get_handler_for_code_signing_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 6263ce3b3f1e..32c4e5fbf0fb 100644
> --- a/security/integrity/platform_certs/load_powerpc.c
> +++ b/security/integrity/platform_certs/load_powerpc.c
> @@ -59,7 +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 = NULL;
> + void *trustedca = NULL, *moduledb = NULL;
The patch looks otherwise good but I'm not sure about this initialization.
> u64 dsize = 0;
> u64 offset = 0;
> int rc = 0;
> @@ -137,6 +137,22 @@ static int __init load_powerpc_certs(void)
> kfree(data);
> }
>
> + data = get_cert_list("moduledb", 9, &dsize);
> + if (!data) {
> + pr_info("Couldn't get moduledb list from firmware\n");
> + } else if (IS_ERR(data)) {
> + rc = PTR_ERR(data);
> + pr_err("Error reading moduledb from firmware: %d\n", rc);
> + } else {
> + extract_esl(moduledb, data, dsize, offset);
> +
> + rc = parse_efi_signature_list("powerpc:moduledb", moduledb, dsize,
> + get_handler_for_code_signing_keys);
> + if (rc)
> + pr_err("Couldn't parse moduledb signatures: %d\n", rc);
> + kfree(data);
> + }
> +
> return rc;
> }
> late_initcall(load_powerpc_certs);
> --
> 2.31.1
BR, Jarkko
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