make recoverPublicKey universal

packages/status-js/src/client/community/delete_handle-channel-chat-message.ts

@@ -1,4 +1,4 @@
-import { recoverPublicKeyFromMetadata } from '~/src/utils/recover-public-key-from-metadata'
+import { recoverPublicKey } from '~/src/utils/recover-public-key'
 
 import { ApplicationMetadataMessage } from '../../../protos/application-metadata-message'
 import { ChatMessage } from '../../../protos/chat-message'
@@ -48,7 +48,10 @@ export function handleChannelChatMessage(
     return
   }
 
-  const publicKey = recoverPublicKeyFromMetadata(decodedMetadata)
+  const publicKey = recoverPublicKey(
+    decodedMetadata.signature,
+    decodedMetadata.payload
+  )
 
   const decodedPayload = ChatMessage.decode(messageToDecode)
 

packages/status-js/src/client/community/handle-channel-chat-message.ts

@@ -2,7 +2,7 @@
 // todo?: rename to handle-message
 import { bytesToHex } from 'ethereum-cryptography/utils'
 
-import { recoverPublicKeyFromMetadata } from '~/src/utils/recover-public-key-from-metadata'
+import { recoverPublicKey } from '~/src/utils/recover-public-key'
 
 import { ApplicationMetadataMessage } from '../../../protos/application-metadata-message'
 import {
@@ -63,7 +63,10 @@ export function handleChannelChatMessage(
   //   break
   // }
 
-  const publicKey = recoverPublicKeyFromMetadata(decodedMetadata)
+  const publicKey = recoverPublicKey(
+    decodedMetadata.signature,
+    decodedMetadata.payload
+  )
 
   // todo: merge and process other types of messages
   // TODO?: ignore messages which are messageType !== COMMUNITY_CHAT

packages/status-js/src/utils/recover-public-key-from-metadata.ts

@@ -1,24 +0,0 @@
-import { keccak256 } from 'ethereum-cryptography/keccak'
-import { recoverPublicKey } from 'ethereum-cryptography/secp256k1'
-
-import type { ApplicationMetadataMessage } from '../../protos/application-metadata-message'
-
-/**
- * returns the public key of the signer
- * msg must be the  32-byte keccak hash of the message to be signed.
- * sig must be a 65-byte compact ECDSA signature containing the recovery id as the last element.
- */
-export function recoverPublicKeyFromMetadata(
-  metadata: ApplicationMetadataMessage
-): Uint8Array {
-  const signature = metadata.signature.slice(0, 64)
-  const recoveryId = metadata.signature.slice(-1)
-
-  const pk = recoverPublicKey(
-    keccak256(metadata.payload),
-    signature,
-    Number(recoveryId)
-  )
-
-  return pk
-}

packages/status-js/src/utils/recover-public-key.test.ts

@@ -1,10 +1,25 @@
-import { recoverPublicKeyFromMetadata } from './recover-public-key-from-metadata'
+import { bytesToHex, utf8ToBytes } from 'ethereum-cryptography/utils'
 
-import type { ApplicationMetadataMessage } from '../../protos/application-metadata-message'
+import { Account } from '../account'
+import { recoverPublicKey } from './recover-public-key'
 
-describe('TODO: recoverPublicKeyFromMetadata', () => {
+import type { ApplicationMetadataMessage } from '~/protos/application-metadata-message'
+
+describe('recoverPublicKey', () => {
   it('should recover public key', async () => {
-    const metadataFixture = {
+    const payload = utf8ToBytes('hello')
+
+    const account = new Account()
+    const signature = await account.sign(payload)
+
+    expect(bytesToHex(recoverPublicKey(signature, payload))).toEqual(
+      account.publicKey
+    )
+  })
+
+  it('should recover public key from fixture', async () => {
+    const metadataFixture: ApplicationMetadataMessage = {
+      type: 'TYPE_EMOJI_REACTION' as ApplicationMetadataMessage.Type,
       signature: new Uint8Array([
         250, 132, 234, 119, 159, 124, 98, 93, 197, 108, 99, 52, 186, 234, 142,
         101, 147, 180, 50, 190, 102, 61, 219, 189, 95, 124, 29, 74, 43, 46, 106,
@@ -25,8 +40,7 @@ describe('TODO: recoverPublicKeyFromMetadata', () => {
         102, 55, 99, 48, 98, 55, 55, 97, 55, 99, 48, 97, 53, 101, 98, 97, 53,
         102, 97, 57, 100, 52, 100, 57, 49, 98, 97, 56, 32, 5, 40, 2,
       ]),
-      type: 'TYPE_EMOJI_REACTION',
-    } as unknown as ApplicationMetadataMessage
+    }
 
     const publicKeySnapshot = new Uint8Array([
       4, 172, 65, 157, 172, 154, 139, 187, 88, 130, 90, 60, 222, 96, 238, 240,
@@ -36,8 +50,33 @@ describe('TODO: recoverPublicKeyFromMetadata', () => {
       99, 24, 17,
     ])
 
-    const result = recoverPublicKeyFromMetadata(metadataFixture)
+    const result = recoverPublicKey(
+      metadataFixture.signature,
+      metadataFixture.payload
+    )
 
     expect(result).toEqual(publicKeySnapshot)
   })
+
+  it('should not recover public key with different payload', async () => {
+    const payload = utf8ToBytes('1')
+
+    const account = new Account()
+    const signature = await account.sign(payload)
+
+    const payload2 = utf8ToBytes('2')
+    expect(recoverPublicKey(signature, payload2)).not.toEqual(account.publicKey)
+  })
+
+  it('should throw error when signature length is not 65 bytes', async () => {
+    const payload = utf8ToBytes('hello')
+    const signature = new Uint8Array([
+      1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
+    ])
+
+    // TODO: use toThrowErrorMatchingInlineSnapshot
+    expect(recoverPublicKey(signature, payload)).toThrow(
+      'Signature must be 65 bytes long'
+    )
+  })
 })

packages/status-js/src/utils/recover-public-key.ts

@@ -0,0 +1,25 @@
+import { keccak256 } from 'ethereum-cryptography/keccak'
+import { recoverPublicKey as secpRecoverPublicKey } from 'ethereum-cryptography/secp256k1'
+
+/**
+ * returns the public key of the signer
+ * msg must be the  32-byte keccak hash of the message to be signed.
+ * sig must be a 65-byte compact ECDSA signature containing the recovery id as the last element.
+ */
+export function recoverPublicKey(
+  sig: Uint8Array,
+  payload: Uint8Array
+): Uint8Array {
+  if (sig.length !== 65) {
+    throw new Error('Signature must be 65 bytes long')
+  }
+
+  if (sig[64] >= 4) {
+    throw new Error('Recovery id must be less than 4')
+  }
+
+  const signature = sig.slice(0, 64)
+  const recoveryId = sig.slice(-1)
+
+  return secpRecoverPublicKey(keccak256(payload), signature, Number(recoveryId))
+}