fix: aes-sealed matched swift much better now

Author: holtwick

src/common/crypto/aes-sealed.spec.ts

@@ -1,6 +1,6 @@
 import { beforeAll, describe, expect, it } from 'vitest'
 import { deriveKeyPbkdf2 } from '../crypto'
-import { toBase64 } from '../data/bin'
+import { fromBase64, toBase64 } from '../data/bin'
 import { hxDecrypt, hxEncrypt } from './aes-sealed'
 
 describe('aes Encryption and Decryption', () => {
@@ -46,20 +46,34 @@ describe('aes Encryption and Decryption', () => {
   })
 
   it('should decrypt a sample that was generated by Swift code', async () => {
-    const key = await deriveKeyPbkdf2(new Uint8Array([1, 2, 3]), {
-      salt: new Uint8Array([1, 2, 3]),
+    const key = await deriveKeyPbkdf2(new Uint8Array([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]), {
+      salt: new Uint8Array([1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12]),
       iterations: 100000,
     })
     const dataFromKey = await crypto.subtle.exportKey('raw', key)
-    expect(toBase64(dataFromKey)).toMatchInlineSnapshot(`"+EZYmOnuVat0rvokPjZxkwdGacOiFvR2oaukTeVa84M="`)
+    expect(toBase64(dataFromKey)).toMatchInlineSnapshot(`"UDl7buu/Zn/UxCIEp55MOTOKcDHvb959P+eyozok7BA="`)
 
     const sample = new Uint8Array([9, 8, 7, 6, 5, 4, 3, 2, 1, 0])
-    const encryptedData = await hxEncrypt(sample, key)
-    expect(toBase64(encryptedData)).toMatchInlineSnapshot(
-      `"WbwhO/CaS3W4VxiIIG3Zs4WdEa08CzEFgaQLs0TrRDejZ/8G0yu0S1JIV+3bn79O7SeyCfI0"`,
-    )
-    // const encryptedData = fromBase64('br6sc+pnZaIXcV1fTygAs/UJlDZIIBY50i56MMGNampZTcSakt0=')
-    // const decryptedData = await hxDecrypt(encryptedData, key)
-    // expect(decryptedData).toMatchInlineSnapshot()
+    // const encryptedData = await hxEncrypt(sample, key)
+    // expect(toBase64(encryptedData)).toMatchInlineSnapshot(
+    //   `"WbwhO/CaS3W4VxiIIG3Zs4WdEa08CzEFgaQLs0TrRDejZ/8G0yu0S1JIV+3bn79O7SeyCfI0"`,
+    // )
+
+    const encryptedData = fromBase64('AQIDBAUGBwgJCgsMqZ0hGHIvSPG5x0d12q42zezDEJVu8Ic3yB4=')
+    const decryptedData = await hxDecrypt(encryptedData, key)
+    expect(decryptedData).toMatchInlineSnapshot(`
+      Uint8Array [
+        9,
+        8,
+        7,
+        6,
+        5,
+        4,
+        3,
+        2,
+        1,
+        0,
+      ]
+    `)
   })
 })

src/common/crypto/aes-sealed.ts

@@ -27,15 +27,15 @@ export async function hxDecrypt(data: Uint8Array, key: CryptoKey): Promise<Uint8
   //  The data layout of the combined representation is nonce, ciphertext, then tag.
   //  The nonce is 12 bytes, the tag is 16 bytes, and the ciphertext is the rest of the data.
   const iv = data.slice(0, 12) // nonce is the first 12 bytes
-  const encrypted = data.slice(12, -16) // The ciphertext is everything between the nonce and the tag.
-  const tag = data.slice(-16) // The authentication tag has a length of 16 bytes.
-  // console.log({ iv, encrypted, tag })
+  const encrypted = data.slice(12) // The ciphertext is everything between the nonce and the tag.
+  // const tag = data.slice(-16) // The authentication tag has a length of 16 bytes.
+  console.log({ iv, encrypted, data })
 
   const decrypted = await crypto.subtle.decrypt({
     name: 'AES-GCM',
     iv,
-    tagLength: 128,
-    additionalData: tag,
+    // tagLength: 32, // tag.length * 8,
+    additionalData: new Uint8Array(),
   }, key, encrypted)
   return new Uint8Array(decrypted)
 }