feat: add sha256 and hmac_sha256 filters for cryptographic operations (#889)

src/build/crypto-impl-browser.spec.ts

@@ -0,0 +1,45 @@
+import { webcrypto } from 'crypto'
+import * as cryptoImpl from './crypto-impl-browser'
+
+describe('crypto-impl/browser', function () {
+  beforeEach(function () {
+    Object.defineProperty(global, 'crypto', {
+      value: webcrypto,
+      writable: true,
+      configurable: true
+    })
+  })
+
+  afterEach(function () {
+    delete (global as any).crypto
+  })
+
+  describe('#sha256()', function () {
+    it('should hash the Shopify reference example', async function () {
+      expect(await cryptoImpl.sha256('Polyjuice'))
+        .toBe('44ac1d7a2936e30a5de07082fd65d6fe9b1fb658a1a98bfe65bc5959beac5dd0')
+    })
+
+    it('should hash an empty string', async function () {
+      expect(await cryptoImpl.sha256(''))
+        .toBe('e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855')
+    })
+
+    it('should hash unicode characters', async function () {
+      expect(await cryptoImpl.sha256('你好世界'))
+        .toBe('beca6335b20ff57ccc47403ef4d9e0b8fccb4442b3151c2e7d50050673d43172')
+    })
+  })
+
+  describe('#hmacSha256()', function () {
+    it('should hash the Shopify reference example', async function () {
+      expect(await cryptoImpl.hmacSha256('Polyjuice', 'Polina'))
+        .toBe('8e0d5d65cff1242a4af66c8f4a32854fd5fb80edcc8aabe9b302b29c7c71dc20')
+    })
+
+    it('should hash an empty message with a key', async function () {
+      expect(await cryptoImpl.hmacSha256('', 'key'))
+        .toBe('5d5d139563c95b5967b9bd9a8c9b233a9dedb45072794cd232dc1b74832607d0')
+    })
+  })
+})

src/build/crypto-impl-browser.ts

@@ -0,0 +1,27 @@
+function bufferToHex (buffer: ArrayBuffer): string {
+  const bytes = new Uint8Array(buffer)
+  let hex = ''
+  for (let i = 0; i < bytes.length; i++) {
+    hex += bytes[i].toString(16).padStart(2, '0')
+  }
+  return hex
+}
+
+export async function sha256 (str: string): Promise<string> {
+  const data = new TextEncoder().encode(str)
+  const digest = await crypto.subtle.digest('SHA-256', data)
+  return bufferToHex(digest)
+}
+
+export async function hmacSha256 (str: string, key: string): Promise<string> {
+  const encoder = new TextEncoder()
+  const cryptoKey = await crypto.subtle.importKey(
+    'raw',
+    encoder.encode(key),
+    { name: 'HMAC', hash: 'SHA-256' },
+    false,
+    ['sign']
+  )
+  const signature = await crypto.subtle.sign('HMAC', cryptoKey, encoder.encode(str))
+  return bufferToHex(signature)
+}

src/filters/crypto-impl.ts

@@ -0,0 +1,9 @@
+import { createHash, createHmac } from 'crypto'
+
+export function sha256 (str: string): string {
+  return createHash('sha256').update(str, 'utf8').digest('hex')
+}
+
+export function hmacSha256 (str: string, key: string): string {
+  return createHmac('sha256', key).update(str, 'utf8').digest('hex')
+}

src/filters/crypto.ts

@@ -0,0 +1,22 @@
+/**
+ * Crypto related filters
+ *
+ * Implements sha256 and hmac_sha256 filters for Shopify compatibility
+ */
+
+import { FilterImpl } from '../template'
+import { stringify } from '../util'
+import { sha256 as sha256Impl, hmacSha256 as hmacSha256Impl } from './crypto-impl'
+
+export function sha256 (this: FilterImpl, value: unknown): string | Promise<string> {
+  const str = stringify(value)
+  this.context.memoryLimit.use(str.length)
+  return sha256Impl(str)
+}
+
+export function hmac_sha256 (this: FilterImpl, value: unknown, key: unknown): string | Promise<string> {
+  const str = stringify(value)
+  const keyStr = stringify(key)
+  this.context.memoryLimit.use(str.length + keyStr.length)
+  return hmacSha256Impl(str, keyStr)
+}

src/filters/index.ts

@@ -5,6 +5,7 @@ import * as arrayFilters from './array'
 import * as dateFilters from './date'
 import * as stringFilters from './string'
 import * as base64Filters from './base64'
+import * as cryptoFilters from './crypto'
 import misc from './misc'
 import { FilterImplOptions } from '../template'
 
@@ -16,5 +17,6 @@ export const filters: Record<string, FilterImplOptions> = {
   ...dateFilters,
   ...stringFilters,
   ...base64Filters,
+  ...cryptoFilters,
   ...misc
 }