feat: Drop IE11 support

BREAKING CHANGE: The AWS Encryption SDK for JavaScript no longer supports Internet Explorer 11 (IE11). The msCrypto shim and related IE11 detection code have been removed from the web-crypto-backend module.

Author: Lucas McDonald

.github/workflows/shared-ci.yml

@@ -22,7 +22,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        node-version: ['18.x', '20.x', '22.x', '24.x', 'latest']
+        node-version: ['22.x', '24.x', 'latest']
         test-type: ['node', 'browser']
         # Determine test categories based on whether testing published packages or source code:
         # - Testing published packages: only run vector tests (don't have build artifacts to test coverage or compliance)

modules/web-crypto-backend/package.json

@@ -19,7 +19,6 @@
   },
   "license": "Apache-2.0",
   "dependencies": {
-    "@aws-crypto/ie11-detection": "4.0.0",
     "@aws-crypto/supports-web-crypto": "5.2.0",
     "@aws-sdk/util-locate-window": "3.310.0",
     "tslib": "^2.2.0"

modules/web-crypto-backend/src/backend-factory.ts

@@ -1,14 +1,12 @@
 // Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
-import { isMsWindow } from '@aws-crypto/ie11-detection'
 import {
   supportsWebCrypto,
   supportsSubtleCrypto,
   supportsZeroByteGCM,
 } from '@aws-crypto/supports-web-crypto'
 import { generateSynchronousRandomValues } from './synchronous_random_values'
-import promisifyMsSubtleCrypto from './promisify-ms-crypto'
 
 type MaybeSubtleCrypto = SubtleCrypto | false
 export type WebCryptoBackend =
@@ -140,7 +138,6 @@ export function pluckSubtleCrypto(window: Window): MaybeSubtleCrypto {
   // if needed webkitSubtle check should be added here
   // see: https://webkit.org/blog/7790/update-on-web-cryptography/
   if (supportsWebCrypto(window)) return window.crypto.subtle
-  if (isMsWindow(window)) return promisifyMsSubtleCrypto(window.msCrypto.subtle)
   return false
 }
 

modules/web-crypto-backend/src/promisify-ms-crypto.ts

@@ -1,7 +1,6 @@
 // Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
 // SPDX-License-Identifier: Apache-2.0
 
-import { isMsWindow } from '@aws-crypto/ie11-detection'
 import { supportsSecureRandom } from '@aws-crypto/supports-web-crypto'
 import { locateWindow } from '@aws-sdk/util-locate-window'
 
@@ -19,10 +18,6 @@ export function generateSynchronousRandomValues(
   return function synchronousRandomValues(byteLength: number): Uint8Array {
     if (supportsSecureRandom(globalScope)) {
       return globalScope.crypto.getRandomValues(new Uint8Array(byteLength))
-    } else if (isMsWindow(globalScope)) {
-      const values = new Uint8Array(byteLength)
-      globalScope.msCrypto.getRandomValues(values)
-      return values
     }
 
     throw new Error(`Unable to locate a secure random source.`)

modules/web-crypto-backend/src/synchronous_random_values.ts

@@ -3,7 +3,12 @@
 
 export const fakeWindowWebCryptoSupportsZeroByteGCM: Window = {
   crypto: {
-    getRandomValues: () => {},
+    getRandomValues: (array: Uint8Array) => {
+      for (let i = 0; i < array.length; i++) {
+        array[i] = Math.floor(Math.random() * 256)
+      }
+      return array
+    },
     subtle: {
       async decrypt() {
         return {} as any
@@ -142,145 +147,3 @@ export const subtleFallbackZeroByteEncryptFail = {
 } as any
 
 export const subtleFallbackNoWebCrypto = {} as any
-
-export const fakeWindowIE11OnComplete = {
-  msCrypto: {
-    getRandomValues: (values: Uint8Array) => {
-      return values.fill(1)
-    },
-    subtle: {
-      decrypt() {
-        const obj = {} as any
-        setTimeout(() => {
-          obj.result = true
-          obj.oncomplete()
-        })
-        return obj
-      },
-      digest() {
-        const obj = {} as any
-        setTimeout(() => {
-          obj.result = true
-          obj.oncomplete()
-        })
-        return obj
-      },
-      encrypt() {
-        const obj = {} as any
-        setTimeout(() => {
-          obj.result = true
-          obj.oncomplete()
-        })
-        return obj
-      },
-      exportKey() {
-        const obj = {} as any
-        setTimeout(() => {
-          obj.result = true
-          obj.oncomplete()
-        })
-        return obj
-      },
-      generateKey() {
-        const obj = {} as any
-        setTimeout(() => {
-          obj.result = true
-          obj.oncomplete()
-        })
-        return obj
-      },
-      importKey() {
-        const obj = {} as any
-        setTimeout(() => {
-          obj.result = true
-          obj.oncomplete()
-        })
-        return obj
-      },
-      sign() {
-        const obj = {} as any
-        setTimeout(() => {
-          obj.result = true
-          obj.oncomplete()
-        })
-        return obj
-      },
-      verify() {
-        const obj = {} as any
-        setTimeout(() => {
-          obj.result = true
-          obj.oncomplete()
-        })
-        return obj
-      },
-    },
-  },
-  MSInputMethodContext: {} as any,
-} as any
-
-export const fakeWindowIE11OnError = {
-  msCrypto: {
-    getRandomValues: (values: Uint8Array) => {
-      return values.fill(1)
-    },
-    subtle: {
-      decrypt() {
-        const obj = {} as any
-        setTimeout(() => {
-          obj.onerror(new Error('stub error'))
-        })
-        return obj
-      },
-      digest() {
-        const obj = {} as any
-        setTimeout(() => {
-          obj.onerror(new Error('stub error'))
-        })
-        return obj
-      },
-      encrypt() {
-        const obj = {} as any
-        setTimeout(() => {
-          obj.onerror(new Error('stub error'))
-        })
-        return obj
-      },
-      exportKey() {
-        const obj = {} as any
-        setTimeout(() => {
-          obj.onerror(new Error('stub error'))
-        })
-        return obj
-      },
-      generateKey() {
-        const obj = {} as any
-        setTimeout(() => {
-          obj.onerror(new Error('stub error'))
-        })
-        return obj
-      },
-      importKey() {
-        const obj = {} as any
-        setTimeout(() => {
-          obj.onerror(new Error('stub error'))
-        })
-        return obj
-      },
-      sign() {
-        const obj = {} as any
-        setTimeout(() => {
-          obj.onerror(new Error('stub error'))
-        })
-        return obj
-      },
-      verify() {
-        const obj = {} as any
-        setTimeout(() => {
-          obj.onerror(new Error('stub error'))
-        })
-        return obj
-      },
-    },
-  },
-  MSInputMethodContext: {} as any,
-} as any

modules/web-crypto-backend/test/fixtures.ts

@@ -5,25 +5,15 @@
 
 import { expect } from 'chai'
 import { generateSynchronousRandomValues } from '../src/synchronous_random_values'
-import { synchronousRandomValues } from '../src/index'
 import * as fixtures from './fixtures'
 
 describe('synchronousRandomValues', () => {
   it('should return random values', () => {
-    const test = synchronousRandomValues(5)
-    expect(test).to.be.instanceOf(Uint8Array)
-    expect(test).lengthOf(5)
-  })
-
-  it('should return msCrypto random values', () => {
     const synchronousRandomValues = generateSynchronousRandomValues(
-      fixtures.fakeWindowIE11OnComplete
+      fixtures.fakeWindowWebCryptoSupportsZeroByteGCM
     )
-
     const test = synchronousRandomValues(5)
     expect(test).to.be.instanceOf(Uint8Array)
     expect(test).lengthOf(5)
-    // The random is a stub, so I know the value
-    expect(test).to.deep.equal(new Uint8Array(5).fill(1))
   })
 })