Add finish buffer size test

Signed-off-by: Paul Elliott <paul.elliott@arm.com>
diff --git a/tests/suites/test_suite_psa_crypto.function b/tests/suites/test_suite_psa_crypto.function
index 32be56e..b8023ee 100644
--- a/tests/suites/test_suite_psa_crypto.function
+++ b/tests/suites/test_suite_psa_crypto.function
@@ -3950,6 +3950,87 @@
 }
 /* END_CASE */
 
+/* BEGIN_CASE */
+void aead_multipart_finish_buffer_test( int key_type_arg, data_t *key_data,
+                                        int alg_arg,
+                                        int buffer_size,
+                                        data_t *nonce,
+                                        data_t *additional_data,
+                                        data_t *input_data,
+                                        int expected_status_arg )
+{
+
+    mbedtls_svc_key_id_t key = MBEDTLS_SVC_KEY_ID_INIT;
+    psa_key_type_t key_type = key_type_arg;
+    psa_algorithm_t alg = alg_arg;
+    psa_aead_operation_t operation;
+    psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
+    psa_status_t status = PSA_ERROR_GENERIC_ERROR;
+    psa_status_t expected_status = expected_status_arg;
+    unsigned char *output_data = NULL;
+    unsigned char *final_data = NULL;
+    size_t output_size = 0;
+    size_t output_length = 0;
+    size_t tag_length = 0;
+    uint8_t tag_buffer[PSA_AEAD_TAG_MAX_SIZE];
+
+    PSA_ASSERT( psa_crypto_init( ) );
+
+    psa_set_key_usage_flags( &attributes, PSA_KEY_USAGE_ENCRYPT  );
+    psa_set_key_algorithm( &attributes, alg );
+    psa_set_key_type( &attributes, key_type );
+
+    PSA_ASSERT( psa_import_key( &attributes, key_data->x, key_data->len,
+                                &key ) );
+
+    PSA_ASSERT( psa_get_key_attributes( key, &attributes ) );
+
+    output_size = PSA_AEAD_UPDATE_OUTPUT_SIZE( key_type, alg, input_data->len );
+
+    ASSERT_ALLOC( output_data, output_size );
+
+    TEST_ASSERT( buffer_size <= PSA_AEAD_FINISH_OUTPUT_MAX_SIZE );
+
+    ASSERT_ALLOC( final_data, buffer_size );
+
+    operation = psa_aead_operation_init( );
+
+    status = psa_aead_encrypt_setup( &operation, key, alg );
+
+    /* If the operation is not supported, just skip and not fail in case the
+     * encryption involves a common limitation of cryptography hardwares and
+     * an alternative implementation. */
+    if( status == PSA_ERROR_NOT_SUPPORTED )
+    {
+        MBEDTLS_TEST_PSA_SKIP_IF_ALT_AES_192( key_type, key_data->len * 8 );
+        MBEDTLS_TEST_PSA_SKIP_IF_ALT_GCM_NOT_12BYTES_NONCE( alg, nonce->len );
+    }
+
+    PSA_ASSERT( status );
+
+    PSA_ASSERT( psa_aead_set_nonce( &operation, nonce->x, nonce->len ) );
+
+    PSA_ASSERT( psa_aead_update_ad( &operation, additional_data->x,
+                                    additional_data->len ) );
+
+    PSA_ASSERT( psa_aead_update( &operation, input_data->x, input_data->len,
+                              output_data, output_size, &output_length ) );
+
+    /* Ensure we can still complete operation. */
+    status = psa_aead_finish( &operation, final_data, buffer_size,
+                              &output_length, tag_buffer,
+                              PSA_AEAD_TAG_MAX_SIZE, &tag_length );
+
+    TEST_EQUAL( status, expected_status );
+
+exit:
+    psa_destroy_key( key );
+    mbedtls_free( output_data );
+    mbedtls_free( final_data );
+    psa_aead_abort( &operation );
+    PSA_DONE( );
+}
+/* END_CASE */
 
 /* BEGIN_CASE */
 void aead_multipart_state_test( int key_type_arg, data_t *key_data,