Split persistence and key id validation

With key usage based on key identifiers and not
key handles (openless APIs), volatile keys will
also have a key identifier. Thus, isolate key
identifier validation from key persistence
validation to clarify that key identifiers
are not specific to persistent keys.

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
This commit is contained in:
Ronald Cron 2020-07-17 16:11:30 +02:00
parent a455e71588
commit d2ed4815da
3 changed files with 49 additions and 45 deletions

View File

@ -1776,17 +1776,28 @@ static psa_status_t psa_validate_key_attributes(
psa_se_drv_table_entry_t **p_drv )
{
psa_status_t status = PSA_ERROR_INVALID_ARGUMENT;
psa_key_lifetime_t lifetime = psa_get_key_lifetime( attributes );
status = psa_validate_key_location( psa_get_key_lifetime( attributes ),
p_drv );
if( status != PSA_SUCCESS )
return( status );
status = psa_validate_key_persistence( psa_get_key_lifetime( attributes ),
psa_get_key_id( attributes ) );
status = psa_validate_key_persistence( lifetime );
if( status != PSA_SUCCESS )
return( status );
/* Validate the key identifier only in the case of a persistent key. */
if ( ! PSA_KEY_LIFETIME_IS_VOLATILE( lifetime ) )
{
status = psa_validate_key_id(
psa_get_key_id( attributes ),
psa_key_lifetime_is_external( lifetime ) );
if( status != PSA_SUCCESS )
return( status );
}
status = psa_validate_key_policy( &attributes->core.policy );
if( status != PSA_SUCCESS )
return( status );

View File

@ -51,6 +51,22 @@ typedef struct
static psa_global_data_t global_data;
psa_status_t psa_validate_key_id( mbedtls_svc_key_id_t key, int vendor_ok )
{
psa_key_id_t key_id = MBEDTLS_SVC_KEY_ID_GET_KEY_ID( key );
if( ( PSA_KEY_ID_USER_MIN <= key_id ) &&
( key_id <= PSA_KEY_ID_USER_MAX ) )
return( PSA_SUCCESS );
if( vendor_ok &&
( PSA_KEY_ID_VENDOR_MIN <= key_id ) &&
( key_id <= PSA_KEY_ID_VENDOR_MAX ) )
return( PSA_SUCCESS );
return( PSA_ERROR_INVALID_ARGUMENT );
}
/* Access a key slot at the given handle. The handle of a key slot is
* the index of the slot in the global slot array, plus one so that handles
* start at 1 and not 0. */
@ -150,31 +166,6 @@ exit:
psa_free_persistent_key_data( key_data, key_data_length );
return( status );
}
/** Check whether a key identifier is acceptable.
*
* For backward compatibility, key identifiers that were valid in a
* past released version must remain valid, unless a migration path
* is provided.
*
* \param key The key identifier to check.
* \param vendor_ok Nonzero to allow key ids in the vendor range.
* 0 to allow only key ids in the application range.
*
* \return 1 if \p key is acceptable, otherwise 0.
*/
static int psa_is_key_id_valid( mbedtls_svc_key_id_t key, int vendor_ok )
{
psa_key_id_t key_id = MBEDTLS_SVC_KEY_ID_GET_KEY_ID( key );
if( PSA_KEY_ID_USER_MIN <= key_id && key_id <= PSA_KEY_ID_USER_MAX )
return( 1 );
else if( vendor_ok &&
PSA_KEY_ID_VENDOR_MIN <= key_id &&
key_id <= PSA_KEY_ID_VENDOR_MAX )
return( 1 );
else
return( 0 );
}
#endif /* defined(MBEDTLS_PSA_CRYPTO_STORAGE_C) */
psa_status_t psa_validate_key_location( psa_key_lifetime_t lifetime,
@ -202,8 +193,7 @@ psa_status_t psa_validate_key_location( psa_key_lifetime_t lifetime,
return( PSA_SUCCESS );
}
psa_status_t psa_validate_key_persistence( psa_key_lifetime_t lifetime,
mbedtls_svc_key_id_t key )
psa_status_t psa_validate_key_persistence( psa_key_lifetime_t lifetime )
{
if ( PSA_KEY_LIFETIME_IS_VOLATILE( lifetime ) )
{
@ -214,13 +204,8 @@ psa_status_t psa_validate_key_persistence( psa_key_lifetime_t lifetime,
{
/* Persistent keys require storage support */
#if defined(MBEDTLS_PSA_CRYPTO_STORAGE_C)
if( psa_is_key_id_valid( key,
psa_key_lifetime_is_external( lifetime ) ) )
return( PSA_SUCCESS );
else
return( PSA_ERROR_INVALID_ARGUMENT );
return( PSA_SUCCESS );
#else /* MBEDTLS_PSA_CRYPTO_STORAGE_C */
(void) key;
return( PSA_ERROR_NOT_SUPPORTED );
#endif /* !MBEDTLS_PSA_CRYPTO_STORAGE_C */
}
@ -234,8 +219,9 @@ psa_status_t psa_open_key( mbedtls_svc_key_id_t key, psa_key_handle_t *handle )
*handle = 0;
if( ! psa_is_key_id_valid( key, 1 ) )
return( PSA_ERROR_INVALID_ARGUMENT );
status = psa_validate_key_id( key, 1 );
if( status != PSA_SUCCESS )
return( status );
status = psa_get_empty_key_slot( handle, &slot );
if( status != PSA_SUCCESS )

View File

@ -108,18 +108,25 @@ static inline int psa_key_lifetime_is_external( psa_key_lifetime_t lifetime )
psa_status_t psa_validate_key_location( psa_key_lifetime_t lifetime,
psa_se_drv_table_entry_t **p_drv );
/** Validate that a key's persistence attributes are valid.
*
* This function checks whether a key's declared persistence level and key ID
* attributes are valid and known to the PSA Core in its actual configuration.
/** Validate the persistence of a key.
*
* \param[in] lifetime The key lifetime attribute.
* \param[in] key The key identifier.
*
* \retval #PSA_SUCCESS
* \retval #PSA_ERROR_INVALID_ARGUMENT
* \retval #PSA_ERROR_INVALID_ARGUMENT The key is persistent but persistent
* keys are not supported.
*/
psa_status_t psa_validate_key_persistence( psa_key_lifetime_t lifetime,
mbedtls_svc_key_id_t key );
psa_status_t psa_validate_key_persistence( psa_key_lifetime_t lifetime );
/** Validate a key identifier.
*
* \param[in] key The key identifier.
* \param[in] vendor_ok Non-zero to indicate that key identifiers in the
* vendor range are allowed, \c 0 otherwise.
*
* \retval #PSA_SUCCESS The identifier is valid.
* \retval #PSA_ERROR_INVALID_ARGUMENT The key identifier is not valid.
*/
psa_status_t psa_validate_key_id( mbedtls_svc_key_id_t key, int vendor_ok );
#endif /* PSA_CRYPTO_SLOT_MANAGEMENT_H */