added migration file

Signed-off-by: Manuel Scurti <manuel.scurti@agilelab.it>

plugins/auth-backend/migrations/20200619125845_init.js

@@ -20,13 +20,6 @@
  * @param {import('knex').Knex} knex
  */
 exports.up = async function up(knex) {
-  /**
-   * key field length. must be enough for the chosen JWT signing algorithm.
-   * the default value is set to be enough for all supported algorithms of the
-   * `jose` library.
-   */
-  const SIGNING_KEY_MAX_LENGTH = 512;
-
   return knex.schema.createTable('signing_keys', table => {
     table.comment(
       'Signing keys that are currently in use or have recently been used to issue tokens',
@@ -41,10 +34,7 @@ exports.up = async function up(knex) {
       .notNullable()
       .defaultTo(knex.fn.now())
       .comment('The creation time of the key');
-    table
-      .string('key', SIGNING_KEY_MAX_LENGTH)
-      .notNullable()
-      .comment('The serialized signing key');
+    table.string('key').notNullable().comment('The serialized signing key');
   });
 };
 

plugins/auth-backend/migrations/20220522100910_key_field_size.js

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2020 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+// @ts-check
+
+/**
+ * @param {import('knex').Knex} knex
+ */
+exports.up = async function up(knex) {
+  // Sqlite does not support alter column.
+  if (!knex.client.config.client.includes('sqlite3')) {
+    await knex.schema.alterTable('signing_keys', table => {
+      table
+        .text('key')
+        .notNullable()
+        .comment('The serialized signing key')
+        .alter({ alterType: true });
+    });
+  }
+};
+
+/**
+ * @param {import('knex').Knex} knex
+ */
+exports.down = async function down(knex) {
+  // Sqlite does not support alter column.
+  if (!knex.client.config.client.includes('sqlite3')) {
+    await knex.schema.alterTable('signing_keys', table => {
+      table
+        .string('key')
+        .notNullable()
+        .comment('The serialized signing key')
+        .alter({ alterType: true });
+    });
+  }
+};

plugins/auth-backend/src/identity/TokenFactory.ts

@@ -36,7 +36,7 @@ type Options = {
    * Must match one of the algorithms defined for IdentityClient.
    * When setting a different algorithm, check if the `key` field
    * of the `signing_keys` table can fit the length of the generated keys.
-   * If not, modify the migration file in the migrations folder.
+   * If not, add a knex migration file in the migrations folder.
    * More info on supported algorithms: https://github.com/panva/jose */
   algorithm?: string;
 };