fix(v4-policy): encode special characters (#1169)

* fix(v4-policy): encode special characters * test special character encoding Co-authored-by: Benjamin E. Coe <bencoe@google.com>

Author: jkwlui

conformance-test/v4SignedUrl.ts

@@ -220,16 +220,15 @@ describe('v4 conformance test', () => {
 
  assert.strictEqual(policy.url, testCase.policyOutput.url);
  const outputFields = testCase.policyOutput.fields;
- const decodedPolicy = Buffer.from(
- policy.fields.policy,
- 'base64'
- ).toString();
+ const decodedPolicy = JSON.parse(
+ Buffer.from(policy.fields.policy, 'base64').toString()
+ );
  assert.deepStrictEqual(
  decodedPolicy,
- testCase.policyOutput.expectedDecodedPolicy
+ JSON.parse(testCase.policyOutput.expectedDecodedPolicy)
  );
 
- assert.deepStrictEqual(outputFields, testCase.policyOutput.fields);
+ assert.deepStrictEqual(policy.fields, outputFields);
 
  fakeTimer.restore();
  });

src/file.ts

@@ -63,7 +63,7 @@ import {
 } from '@google-cloud/common/build/src/util';
 // eslint-disable-next-line @typescript-eslint/no-var-requires
 const duplexify: DuplexifyConstructor = require('duplexify');
-import {normalize, objectKeyToLowercase} from './util';
+import {normalize, objectKeyToLowercase, unicodeJSONStringify} from './util';
 import {GaxiosError, Headers, request as gaxiosRequest} from 'gaxios';
 
 export type GetExpirationDateResponse = [Date];
@@ -2611,7 +2611,7 @@ class File extends ServiceObject<File> {
  expiration,
  };
 
- const policyString = JSON.stringify(policy);
+ const policyString = unicodeJSONStringify(policy);
  const policyBase64 = Buffer.from(policyString).toString('base64');
 
  try {

src/util.ts

@@ -90,3 +90,16 @@ export function objectKeyToLowercase<T>(object: {[key: string]: T}) {
  }
  return newObj;
 }
+
+/**
+ * JSON encode str, with unicode \u+ representation.
+ * @param {object} obj The object to encode.
+ * @return {string} Serialized string.
+ */
+export function unicodeJSONStringify(obj: object) {
+ return JSON.stringify(obj).replace(
+ /[\u0080-\uFFFF]/g,
+ (char: string) =>
+ '\\u' + ('0000' + char.charCodeAt(0).toString(16)).slice(-4)
+ );
+}

test/file.ts

@@ -2941,6 +2941,30 @@ describe('File', () => {
  );
  });
 
+ it('should encode special characters in policy', done => {
+ CONFIG = {
+ fields: {
+ 'x-goog-meta-foo': 'bår',
+ },
+ ...CONFIG,
+ };
+
+ file.generateSignedPostPolicyV4(
+ CONFIG,
+ (err: Error, res: SignedPostPolicyV4Output) => {
+ assert.ifError(err);
+
+ assert.strictEqual(res.fields['x-goog-meta-foo'], 'bår');
+ const decodedPolicy = Buffer.from(
+ res.fields.policy,
+ 'base64'
+ ).toString('utf-8');
+ assert(decodedPolicy.includes('"x-goog-meta-foo":"b\\u00e5r"'));
+ done();
+ }
+ );
+ });
+
  it('should not include fields with x-ignore- prefix in conditions', done => {
  CONFIG = {
  fields: {