remove browserify-cipher, use crypto.subtle for nip04.

Author: fiatjaf

.eslintrc.json

@@ -24,6 +24,7 @@
     "document": false,
     "navigator": false,
     "window": false,
+    "crypto": false,
     "location": false,
     "URL": false,
     "URLSearchParams": false,

README.md

@@ -171,7 +171,7 @@ let pk2 = getPublicKey(sk2)
 
 // on the sender side
 let message = 'hello'
-let ciphertext = nip04.encrypt(sk1, pk2, 'hello')
+let ciphertext = await nip04.encrypt(sk1, pk2, 'hello')
 
 let event = {
   kind: 4,
@@ -187,7 +187,7 @@ sendEvent(event)
 sub.on('event', (event) => {
   let sender = event.tags.find(([k, v]) => k === 'p' && && v && v !== '')[1]
   pk1 === sender
-  let plaintext = nip04.decrypt(sk2, pk1, event.content)
+  let plaintext = await nip04.decrypt(sk2, pk1, event.content)
 })
 ```
 

nip04.test.js

@@ -2,13 +2,13 @@
 
 const {nip04, getPublicKey, generatePrivateKey} = require('./lib/nostr.cjs')
 
-test('encrypt and decrypt message', () => {
+test('encrypt and decrypt message', async () => {
   let sk1 = generatePrivateKey()
   let sk2 = generatePrivateKey()
   let pk1 = getPublicKey(sk1)
   let pk2 = getPublicKey(sk2)
 
-  expect(nip04.decrypt(sk2, pk1, nip04.encrypt(sk1, pk2, 'hello'))).toEqual(
-    'hello'
-  )
+  expect(
+    await nip04.decrypt(sk2, pk1, await nip04.encrypt(sk1, pk2, 'hello'))
+  ).toEqual('hello')
 })

nip04.ts

@@ -1,45 +1,66 @@
-import {Buffer} from 'buffer'
 import {randomBytes} from '@noble/hashes/utils'
 import * as secp256k1 from '@noble/secp256k1'
-// @ts-ignore
-import aes from 'browserify-cipher'
+import {encode as b64encode, decode as b64decode} from 'base64-arraybuffer'
 
-export function encrypt(privkey: string, pubkey: string, text: string): string {
+import {utf8Decoder, utf8Encoder} from './utils'
+
+export async function encrypt(
+  privkey: string,
+  pubkey: string,
+  text: string
+): Promise<string> {
   const key = secp256k1.getSharedSecret(privkey, '02' + pubkey)
   const normalizedKey = getNormalizedX(key)
 
   let iv = Uint8Array.from(randomBytes(16))
-  var cipher = aes.createCipheriv(
-    'aes-256-cbc',
-    Buffer.from(normalizedKey, 'hex'),
-    iv
+  let plaintext = utf8Encoder.encode(text)
+  let cryptoKey = await crypto.subtle.importKey(
+    'raw',
+    normalizedKey,
+    {name: 'AES-CBC'},
+    false,
+    ['encrypt']
   )
-  let encryptedMessage = cipher.update(text, 'utf8', 'base64')
-  encryptedMessage += cipher.final('base64')
+  let ciphertext = await crypto.subtle.encrypt(
+    {name: 'AES-CBC', iv},
+    cryptoKey,
+    plaintext
+  )
+  let ctb64 = b64encode(ciphertext)
+  let ivb64 = b64encode(iv.buffer)
 
-  return `${encryptedMessage}?iv=${Buffer.from(iv.buffer).toString('base64')}`
+  return `${ctb64}?iv=${ivb64}`
 }
 
-export function decrypt(
+export async function decrypt(
   privkey: string,
   pubkey: string,
-  ciphertext: string
-): string {
-  let [cip, iv] = ciphertext.split('?iv=')
+  data: string
+): Promise<string> {
+  let [ctb64, ivb64] = data.split('?iv=')
   let key = secp256k1.getSharedSecret(privkey, '02' + pubkey)
   let normalizedKey = getNormalizedX(key)
 
-  var decipher = aes.createDecipheriv(
-    'aes-256-cbc',
-    Buffer.from(normalizedKey, 'hex'),
-    Buffer.from(iv, 'base64')
+  let cryptoKey = await crypto.subtle.importKey(
+    'raw',
+    normalizedKey,
+    {name: 'AES-CBC'},
+    false,
+    ['decrypt']
+  )
+  let ciphertext = b64decode(ctb64)
+  let iv = b64decode(ivb64)
+
+  let plaintext = await crypto.subtle.decrypt(
+    {name: 'AES-CBC', iv},
+    cryptoKey,
+    ciphertext
   )
-  let decryptedMessage = decipher.update(cip, 'base64', 'utf8')
-  decryptedMessage += decipher.final('utf8')
 
-  return decryptedMessage
+  let text = utf8Decoder.decode(plaintext)
+  return text
 }
 
-function getNormalizedX(key: Uint8Array): string {
-  return Buffer.from(key.slice(1, 33)).toString('hex')
+function getNormalizedX(key: Uint8Array): Uint8Array {
+  return key.slice(1, 33)
 }

nip19.ts

@@ -1,6 +1,8 @@
 import * as secp256k1 from '@noble/secp256k1'
 import {bech32} from 'bech32'
 
+import {utf8Decoder, utf8Encoder} from './utils'
+
 export type ProfilePointer = {
   pubkey: string // hex
   relays?: string[]
@@ -11,9 +13,6 @@ export type EventPointer = {
   relays?: string[]
 }
 
-let utf8Decoder = new TextDecoder('utf-8')
-let utf8Encoder = new TextEncoder()
-
 export function decode(nip19: string): {
   type: string
   data: ProfilePointer | EventPointer | string

package.json

@@ -13,9 +13,9 @@
     "@noble/secp256k1": "^1.7.0",
     "@scure/bip32": "^1.1.1",
     "@scure/bip39": "^1.1.0",
+    "base64-arraybuffer": "^1.0.2",
     "bech32": "^2.0.0",
-    "browserify-cipher": ">=1",
-    "buffer": "^6.0.3",
+    "readable-stream": "^4.2.0",
     "websocket-polyfill": "^0.0.3"
   },
   "keywords": [

utils.ts

@@ -0,0 +1,2 @@
+export const utf8Decoder = new TextDecoder('utf-8')
+export const utf8Encoder = new TextEncoder()