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>
diff --git a/library/psa_crypto_slot_management.c b/library/psa_crypto_slot_management.c
index f9ea369..7809c0c 100644
--- a/library/psa_crypto_slot_management.c
+++ b/library/psa_crypto_slot_management.c
@@ -302,6 +302,19 @@
/* 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 @@
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 );
diff --git a/tests/src/drivers/key_management.c b/tests/src/drivers/key_management.c
index 5daec6b..a0626fb 100644
--- a/tests/src/drivers/key_management.c
+++ b/tests/src/drivers/key_management.c
@@ -343,9 +343,6 @@
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_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_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 );