Key derivation dispatch doesn't depend on the key type
At least for all currently specified algorithms.
Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/docs/proposed/psa-driver-interface.md b/docs/proposed/psa-driver-interface.md
index 5cae1ff..dd35ed2 100644
--- a/docs/proposed/psa-driver-interface.md
+++ b/docs/proposed/psa-driver-interface.md
@@ -311,9 +311,10 @@
The core decides whether to dispatch a key derivation operation to a driver based on the location associated with of the input step `PSA_KEY_DERIVATION_INPUT_SECRET`.
1. If this step is passed via `psa_key_derivation_input_key()` for a key in a secure element:
- * If the driver for this secure element implements the `"key_derivation"` family for the specified key type and algorithm, the core calls that driver's `"key_derivation_setup"` and subsequent entry points.
+ * If the driver for this secure element implements the `"key_derivation"` family for the specified algorithm, the core calls that driver's `"key_derivation_setup"` and subsequent entry points.
+ Note that for all currently specified algorithms, the key type for the secret input does not matter.
* Otherwise the core calls the secure element driver's [`"export_key"`](#key-management-with-opaque-drivers) entry point.
-2. Otherwise ([or on fallback?](#fallback-for-key-derivation-in-opaque-drivers)), if there is a transparent driver for the specified key type and algorithm, the core calls that driver's `"key_derivation_setup"` and subsequent entry points.
+2. Otherwise ([or on fallback?](#fallback-for-key-derivation-in-opaque-drivers)), if there is a transparent driver for the specified algorithm, the core calls that driver's `"key_derivation_setup"` and subsequent entry points.
3. Otherwise, or on fallback, the core uses its built-in implementation.
#### Summary of entry points for the operation family `"key_derivation"`