Re: [PATCH v4 6/6] integrity: PowerVM support for loading third party code signing keys

[Mimi Zohar <zohar@linux.ibm.com>]

On Wed, 2023-08-16 at 23:36 +0300, Jarkko Sakkinen wrote:
> On Tue Aug 15, 2023 at 2:27 PM 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@linux.ibm.com>
> > ---
> >  certs/system_keyring.c                        | 30 +++++++++++++++++++
> >  include/keys/system_keyring.h                 |  4 +++
> >  .../platform_certs/keyring_handler.c          |  8 +++++
> >  .../platform_certs/keyring_handler.h          |  5 ++++
> >  .../integrity/platform_certs/load_powerpc.c   | 17 +++++++++++
> >  5 files changed, 64 insertions(+)
> >
> > diff --git a/certs/system_keyring.c b/certs/system_keyring.c
> > index b348e0898d34..33841c91f12c 100644
> > --- a/certs/system_keyring.c
> > +++ b/certs/system_keyring.c
> > @@ -152,6 +152,36 @@ static __init struct key_restriction *get_builtin_and_secondary_restriction(void
> >  
> >  	return restriction;
> >  }
> > +
> > +/**
> > + * 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);
> > +}
> >  #endif
> >  #ifdef CONFIG_INTEGRITY_MACHINE_KEYRING
> >  void __init set_machine_trusted_keys(struct key *keyring)
> > diff --git a/include/keys/system_keyring.h b/include/keys/system_keyring.h
> > index 7e2583208820..8365adf842ef 100644
> > --- a/include/keys/system_keyring.h
> > +++ b/include/keys/system_keyring.h
> > @@ -50,9 +50,13 @@ 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
> > +static inline 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/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 339053d9726d..c85febca3343 100644
> > --- a/security/integrity/platform_certs/load_powerpc.c
> > +++ b/security/integrity/platform_certs/load_powerpc.c
> > @@ -60,6 +60,7 @@ static int __init load_powerpc_certs(void)
> >  {
> >  	void *db = NULL, *dbx = NULL, *data = NULL;
> >  	void *trustedca;
> > +	void *moduledb;
> >  	u64 dsize = 0;
> >  	u64 offset = 0;
> >  	int rc = 0;
> > @@ -137,6 +138,22 @@ 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
> 
> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org>
> 
> I can pick this. My last PR did not went too great partly because of
> mess with tpm_tis but now things are calmer.

Glad things have settled down.  Whatever you prefer is fine.   This
patch set needs to make it into linux-next as soon as possible.  Please
don't forget to add Nageswara's "Tested-by" and fix mine on 4/6.

-- 
thanks,

Mimi