Pass the key creation method to drivers

Pass the key creation method (import/generate/derive/copy) to the
driver methods to allocate or validate a slot number. This allows
drivers to enforce policies such as "this key slot can only be used
for keys generated inside the secure element".

library/psa_crypto.c

@@ -1506,16 +1506,6 @@ static psa_status_t psa_validate_key_attributes(
     return( PSA_SUCCESS );
 }
 
-/** An enumeration indicating how a key is created.
- */
-typedef enum
-{
-    PSA_KEY_CREATION_IMPORT,
-    PSA_KEY_CREATION_GENERATE,
-    PSA_KEY_CREATION_DERIVE,
-    PSA_KEY_CREATION_COPY,
-} psa_key_creation_method_t;
-
 /** Prepare a key slot to receive key material.
  *
  * This function allocates a key slot and sets its metadata.
@@ -1595,7 +1585,7 @@ static psa_status_t psa_start_key_creation(
      * we can roll back to a state where the key doesn't exist. */
     if( *p_drv != NULL )
     {
-        status = psa_find_se_slot_for_key( attributes, *p_drv,
+        status = psa_find_se_slot_for_key( attributes, method, *p_drv,
                                            &slot->data.se.slot_number );
         if( status != PSA_SUCCESS )
             return( status );

library/psa_crypto_se.c

@@ -197,6 +197,7 @@ psa_status_t psa_destroy_se_persistent_data( psa_key_lifetime_t lifetime )
 
 psa_status_t psa_find_se_slot_for_key(
     const psa_key_attributes_t *attributes,
+    psa_key_creation_method_t method,
     psa_se_drv_table_entry_t *driver,
     psa_key_slot_number_t *slot_number )
 {
@@ -220,7 +221,8 @@ psa_status_t psa_find_se_slot_for_key(
             driver->methods->key_management->p_validate_slot_number;
         if( p_validate_slot_number == NULL )
             return( PSA_ERROR_NOT_SUPPORTED );
-        status = p_validate_slot_number( &driver->context, attributes,
+        status = p_validate_slot_number( &driver->context,
+                                         attributes, method,
                                          *slot_number );
     }
     else
@@ -233,7 +235,7 @@ psa_status_t psa_find_se_slot_for_key(
             return( PSA_ERROR_NOT_SUPPORTED );
         status = p_allocate( &driver->context,
                              driver->internal.persistent_data,
-                             attributes,
+                             attributes, method,
                              slot_number );
     }
     return( status );

library/psa_crypto_se.h

@@ -135,6 +135,7 @@ psa_drv_se_context_t *psa_get_se_driver_context(
  */
 psa_status_t psa_find_se_slot_for_key(
     const psa_key_attributes_t *attributes,
+    psa_key_creation_method_t method,
     psa_se_drv_table_entry_t *driver,
     psa_key_slot_number_t *slot_number );