Implement buffer copy code in psa_hash_compare

Signed-off-by: Thomas Daubney <thomas.daubney@arm.com>
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index 7adabfb..23cd1c4 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -2493,17 +2493,23 @@
 }
 
 psa_status_t psa_hash_compare(psa_algorithm_t alg,
-                              const uint8_t *input, size_t input_length,
-                              const uint8_t *hash, size_t hash_length)
+                              const uint8_t *input_external, size_t input_length,
+                              const uint8_t *hash_external, size_t hash_length)
 {
     uint8_t actual_hash[PSA_HASH_MAX_SIZE];
     size_t actual_hash_length;
+    psa_status_t status = PSA_ERROR_CORRUPTION_DETECTED;
+
+    LOCAL_INPUT_DECLARE(input_external, input);
+    LOCAL_INPUT_DECLARE(hash_external, hash);
 
     if (!PSA_ALG_IS_HASH(alg)) {
-        return PSA_ERROR_INVALID_ARGUMENT;
+        status = PSA_ERROR_INVALID_ARGUMENT;
+        return status;
     }
 
-    psa_status_t status = psa_driver_wrapper_hash_compute(
+    LOCAL_INPUT_ALLOC(input_external, input_length, input);
+    status = psa_driver_wrapper_hash_compute(
         alg, input, input_length,
         actual_hash, sizeof(actual_hash),
         &actual_hash_length);
@@ -2514,12 +2520,18 @@
         status = PSA_ERROR_INVALID_SIGNATURE;
         goto exit;
     }
+
+    LOCAL_INPUT_ALLOC(hash_external, hash_length, hash);
     if (mbedtls_ct_memcmp(hash, actual_hash, actual_hash_length) != 0) {
         status = PSA_ERROR_INVALID_SIGNATURE;
     }
 
 exit:
     mbedtls_platform_zeroize(actual_hash, sizeof(actual_hash));
+
+    LOCAL_INPUT_FREE(input_external, input);
+    LOCAL_INPUT_FREE(hash_external, hash);
+
     return status;
 }