Get a builtin key's attributes in order to correctly get its size

Leverage the fact that the get_builtin_key entrypoint returns a key's
attributes, such that a proper size for the builtin key's buffer can
be calculated through the driver's get_key_buffer_size hook.

Signed-off-by: Steven Cooreman <steven.cooreman@silabs.com>
This commit is contained in:
Steven Cooreman 2021-04-07 18:09:53 +02:00
parent 7ddee7f7c5
commit ce48702448
2 changed files with 20 additions and 4 deletions

View file

@ -302,6 +302,19 @@ static psa_status_t psa_load_builtin_key_into_slot( psa_key_slot_t *slot )
/* Set mapped lifetime on the attributes */
psa_set_key_lifetime( &attributes, lifetime );
/* Get the full key attributes from the driver in order to be able to
* calculate the required buffer size. */
status = psa_driver_wrapper_get_builtin_key(
slot_number, &attributes,
NULL, 0, NULL );
if( status != PSA_ERROR_BUFFER_TOO_SMALL )
{
/* Builtin keys cannot be defined by the attributes alone */
if( status == PSA_SUCCESS )
status = PSA_ERROR_CORRUPTION_DETECTED;
goto exit;
}
/* If the key should exist according to the platform, then ask the driver
* what its expected size is. */
status = psa_driver_wrapper_get_key_buffer_size( &attributes,
@ -310,7 +323,7 @@ static psa_status_t psa_load_builtin_key_into_slot( psa_key_slot_t *slot )
return( status );
/* Allocate a buffer of the required size and load the builtin key directly
* into the slot buffer. */
* into the (now properly sized) slot buffer. */
status = psa_allocate_buffer_to_slot( slot, key_buffer_size );
if( status != PSA_SUCCESS )
return( status );

View file

@ -343,9 +343,6 @@ psa_status_t test_opaque_get_builtin_key(
psa_key_attributes_t *attributes,
uint8_t *key_buffer, size_t key_buffer_size, size_t *key_buffer_length )
{
if( key_buffer_size < sizeof( psa_drv_slot_number_t ) )
return( PSA_ERROR_BUFFER_TOO_SMALL );
switch( slot_number )
{
case PSA_CRYPTO_TEST_DRIVER_BUILTIN_AES_KEY_SLOT:
@ -358,6 +355,9 @@ psa_status_t test_opaque_get_builtin_key(
PSA_KEY_USAGE_EXPORT );
psa_set_key_algorithm( attributes, PSA_ALG_CTR );
if( key_buffer_size < sizeof( psa_drv_slot_number_t ) )
return( PSA_ERROR_BUFFER_TOO_SMALL );
*( (psa_drv_slot_number_t*) key_buffer ) =
PSA_CRYPTO_TEST_DRIVER_BUILTIN_AES_KEY_SLOT;
*key_buffer_length = sizeof( psa_drv_slot_number_t );
@ -375,6 +375,9 @@ psa_status_t test_opaque_get_builtin_key(
psa_set_key_algorithm(
attributes, PSA_ALG_ECDSA( PSA_ALG_ANY_HASH ) );
if( key_buffer_size < sizeof( psa_drv_slot_number_t ) )
return( PSA_ERROR_BUFFER_TOO_SMALL );
*( (psa_drv_slot_number_t*) key_buffer ) =
PSA_CRYPTO_TEST_DRIVER_BUILTIN_ECDSA_KEY_SLOT;
*key_buffer_length = sizeof( psa_drv_slot_number_t );