diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 6538175..06e720d 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -3556,13 +3556,15 @@
 psa_status_t psa_sign_hash_start(
     psa_sign_hash_interruptible_operation_t *operation,
     mbedtls_svc_key_id_t key, psa_algorithm_t alg,
-    const uint8_t *hash, size_t hash_length)
+    const uint8_t *hash_external, size_t hash_length)
 {
     psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
     psa_status_t unlock_status = PSA_ERROR_CORRUPTION_DETECTED;
     psa_key_slot_t *slot;
     psa_key_attributes_t attributes;
 
+    LOCAL_INPUT_DECLARE(hash_external, hash);
+
     /* Check that start has not been previously called, or operation has not
      * previously errored. */
     if (operation->id != 0 || operation->error_occurred) {
@@ -3588,6 +3590,8 @@
         goto exit;
     }
 
+    LOCAL_INPUT_ALLOC(hash_external, hash_length, hash);
+
     attributes = (psa_key_attributes_t) {
         .core = slot->attr
     };
@@ -3612,17 +3616,21 @@
         operation->error_occurred = 1;
     }
 
+    LOCAL_INPUT_FREE(hash_external, hash);
+
     return (status == PSA_SUCCESS) ? unlock_status : status;
 }
 
 
 psa_status_t psa_sign_hash_complete(
     psa_sign_hash_interruptible_operation_t *operation,
-    uint8_t *signature, size_t signature_size,
+    uint8_t *signature_external, size_t signature_size,
     size_t *signature_length)
 {
     psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
 
+    LOCAL_OUTPUT_DECLARE(signature_external, signature);
+
     *signature_length = 0;
 
     /* Check that start has been called first, and that operation has not
@@ -3639,6 +3647,8 @@
         goto exit;
     }
 
+    LOCAL_OUTPUT_ALLOC(signature_external, signature_size, signature);
+
     status = psa_driver_wrapper_sign_hash_complete(operation, signature,
                                                    signature_size,
                                                    signature_length);
@@ -3659,6 +3669,8 @@
         psa_sign_hash_abort_internal(operation);
     }
 
+    LOCAL_OUTPUT_FREE(signature_external, signature);
+
     return status;
 }