Fix AES encryption error in browsers for messages larger than 3MB (#1506

)

In browsers, encryption of messages larger than 3MB (or a custom value
based on `config.minBytesForWebCrypto`) would throw the error `Error encrypting
message: 'crypto.getCipher' is not a function`.

The issue was introduced in v5.1 .

src/crypto/mode/cfb.js

@@ -23,8 +23,8 @@
  */
 
 import { AES_CFB } from '@openpgp/asmcrypto.js/dist_es8/aes/cfb';
-
 import * as stream from '@openpgp/web-stream-tools';
+import { getCipher } from '../crypto';
 import * as cipher from '../cipher';
 import util from '../../util';
 import enums from '../../enums';
@@ -160,7 +160,7 @@ function xorMut(a, b) {
 async function webEncrypt(algo, key, pt, iv) {
   const ALGO = 'AES-CBC';
   const _key = await webCrypto.importKey('raw', key, { name: ALGO }, false, ['encrypt']);
-  const { blockSize } = crypto.getCipher(algo);
+  const { blockSize } = getCipher(algo);
   const cbc_pt = util.concatUint8Array([new Uint8Array(blockSize), pt]);
   const ct = new Uint8Array(await webCrypto.encrypt({ name: ALGO, iv }, _key, cbc_pt)).subarray(0, pt.length);
   xorMut(ct, pt);

test/crypto/crypto.js

@@ -1,4 +1,5 @@
 const openpgp = typeof window !== 'undefined' && window.openpgp ? window.openpgp : require('../..');
+const sandbox = require('sinon/lib/sinon/sandbox');
 const crypto = require('../../src/crypto');
 const util = require('../../src/util');
 
@@ -237,13 +238,13 @@ module.exports = () => describe('API functional testing', function() {
       algo => algo !== 'idea' && algo !== 'plaintext'
     );
 
-    async function testCFB(plaintext) {
+    async function testCFB(plaintext, config = openpgp.config) {
       await Promise.all(symmAlgoNames.map(async function(algoName) {
         const algo = openpgp.enums.write(openpgp.enums.symmetric, algoName);
         const { blockSize } = crypto.getCipher(algo);
         const symmKey = await crypto.generateSessionKey(algo);
         const IV = new Uint8Array(blockSize);
-        const symmencData = await crypto.mode.cfb.encrypt(algo, symmKey, util.stringToUint8Array(plaintext), IV, openpgp.config);
+        const symmencData = await crypto.mode.cfb.encrypt(algo, symmKey, util.stringToUint8Array(plaintext), IV, config);
         const text = util.uint8ArrayToString(await crypto.mode.cfb.decrypt(algo, symmKey, symmencData, new Uint8Array(blockSize)));
         expect(text).to.equal(plaintext);
       }));
@@ -253,6 +254,19 @@ module.exports = () => describe('API functional testing', function() {
       await testCFB('1234567');
       await testCFB('foobarfoobar1234567890');
       await testCFB('12345678901234567890123456789012345678901234567890');
+      // test using webCrypto
+      const sinonSandbox = sandbox.create();
+      const webCrypto = util.getWebCrypto();
+      if (webCrypto) {
+        const webCryptoSpy = sinonSandbox.spy(webCrypto, 'encrypt');
+        try {
+          await testCFB('12345678901234567890123456789012345678901234567890', { ...openpgp.config, minBytesForWebCrypto: 0 });
+        } finally {
+          expect(webCryptoSpy.called).to.be.true;
+          sinonSandbox.restore();
+        }
+      }
+
     });
 
     it('Asymmetric using RSA with eme_pkcs1 padding', async function () {