From 7c9534ee238219551bc77bc741484d6351604c60 Mon Sep 17 00:00:00 2001
From: Joel Thorstensson <joel@3box.io>
Date: Wed, 10 Jan 2024 17:59:22 +0100
Subject: [PATCH] JWS Canon test

---
 .../varsig/src/__tests__/canons/jws.test.ts   | 41 +++++++++++++++++++
 packages/varsig/src/canonicalization.ts       |  1 +
 packages/varsig/src/canons/jws.ts             |  4 +-
 3 files changed, 44 insertions(+), 2 deletions(-)
 create mode 100644 packages/varsig/src/__tests__/canons/jws.test.ts

diff --git a/packages/varsig/src/__tests__/canons/jws.test.ts b/packages/varsig/src/__tests__/canons/jws.test.ts
new file mode 100644
index 00000000..44d64c8c
--- /dev/null
+++ b/packages/varsig/src/__tests__/canons/jws.test.ts
@@ -0,0 +1,41 @@
+import { fromOriginal, prepareCanonicalization } from '../../canons/jws.js'
+import { BytesTape } from '../../bytes-tape.js'
+import * as uint8arrays from 'uint8arrays'
+import { CanonicalizationKind } from '../../canonicalization.js'
+
+//const testJws = 'eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpYXQiOjE1MTYyMzkwMjIsIm5hbWUiOiJKb2huIERvZSIsInN1YiI6IjEyMzQ1Njc4OTAifQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c'
+const testJws = 'eyJhbGciOiAiRVMyNTYifQ.eyJpYXQiOjE1MTYyMzkwMjIsIm5hbWUiOiJKb2huIERvZSIsInN1YiI6IjEyMzQ1Njc4OTAifQ.SflKxwRJSMeKKF2QT4fwpMeJf36POk6yJV_adQssw5c'
+
+const expectedHashInput = uint8arrays.fromString(
+  testJws.slice(0, testJws.lastIndexOf('.'))
+)
+
+test('Encode eip712 message', () => {
+  // @ts-ignore
+  const node = fromOriginal(testJws)
+
+  expect(node._sig.length).toEqual(56)
+  delete node._sig
+  expect(node).toEqual({
+    sub: '1234567890',
+    name: 'John Doe',
+    iat: 1516239022
+})
+})
+
+test('Canonicalize ipld eip712 object', () => {
+  // @ts-ignore
+  const node = fromOriginal(testJws)
+  const tape = new BytesTape(node._sig)
+  tape.readVarint() // skip sigil
+  const keyType = tape.readVarint() // skip key type
+  const hashType = tape.readVarint() // skip hash type
+  tape.readVarint() // skip canonicalizer codec
+  const can = prepareCanonicalization(tape, hashType, keyType)
+  expect(can.kind).toEqual(CanonicalizationKind.JWS)
+  expect(tape.remainder.length).toEqual(32)
+  // @ts-ignore
+  delete node._sig
+  const sigInput = can(node)
+  expect(sigInput).toEqual(expectedHashInput)
+})
diff --git a/packages/varsig/src/canonicalization.ts b/packages/varsig/src/canonicalization.ts
index c391c008..4f4f57f6 100644
--- a/packages/varsig/src/canonicalization.ts
+++ b/packages/varsig/src/canonicalization.ts
@@ -10,6 +10,7 @@ import type { SigningKind } from './signing.js'
 export enum CanonicalizationKind {
   EIP712 = MAGIC.EIP712,
   EIP191 = MAGIC.EIP191,
+  JWS = MAGIC.JOSE,
 }
 
 type IpldNode = Record<string, any>
diff --git a/packages/varsig/src/canons/jws.ts b/packages/varsig/src/canons/jws.ts
index b09cbf05..aea05143 100644
--- a/packages/varsig/src/canons/jws.ts
+++ b/packages/varsig/src/canons/jws.ts
@@ -48,7 +48,7 @@ export function prepareCanonicalization(
 
   const can = (node: IpldNode) => {
     // encode node using dag-json from multiformats
-    const payloadB64u = toB64u(uint8arrays.fromString(JSON.stringify(encode(node))))
+    const payloadB64u = toB64u(encode(node))
     const protectedB64u = toB64u(protectedBytes)
     return uint8arrays.fromString(`${protectedB64u}.${payloadB64u}`)
   }
@@ -96,7 +96,7 @@ interface ProtectedHeader {
 
 function findKeyType({ alg, crv }: ProtectedHeader): number {
   if (!alg) throw new Error(`Missing alg in protected header`)
-  const keyType = KEY_TYPE_BY_ALG_CRV[alg][crv || 'default']
+  const keyType = KEY_TYPE_BY_ALG_CRV[alg]?.[crv || 'default']
   if (!keyType) throw new Error(`Unsupported alg: ${alg}, or crv: ${String(crv)}`)
   return keyType
 }