fix(askar): generate nonce suitable for anoncreds (#1295)

Signed-off-by: Ariel Gentile <[email protected]>
openwallet-foundation · Feb 13, 2023 · ecce0a7 · ecce0a7
1 parent c63350c
commit ecce0a7
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Showing 3 changed files with 10 additions and 3 deletions.
diff --git a/packages/askar/package.json b/packages/askar/package.json
@@ -26,12 +26,14 @@
   "dependencies": {
     "@aries-framework/core": "0.3.3",
     "@hyperledger/aries-askar-shared": "^0.1.0-dev.1",
+    "bn.js": "^5.2.1",
     "class-transformer": "^0.5.1",
     "class-validator": "^0.14.0",
     "rxjs": "^7.2.0",
     "tsyringe": "^4.7.0"
   },
   "devDependencies": {
+    "@types/bn.js": "^5.1.0",
     "@hyperledger/aries-askar-nodejs": "^0.1.0-dev.1",
     "reflect-metadata": "^0.1.13",
     "rimraf": "^4.0.7",

diff --git a/packages/askar/src/wallet/AskarWallet.ts b/packages/askar/src/wallet/AskarWallet.ts
@@ -34,7 +34,6 @@ import {
   FileSystem,
   WalletNotFoundError,
 } from '@aries-framework/core'
-// eslint-disable-next-line import/order
 import {
   StoreKeyMethod,
   KeyAlgs,
@@ -43,6 +42,8 @@ import {
   Key as AskarKey,
   keyAlgFromString,
 } from '@hyperledger/aries-askar-shared'
+// eslint-disable-next-line import/order
+import BigNumber from 'bn.js'
 
 const isError = (error: unknown): error is Error => error instanceof Error
 
@@ -669,7 +670,9 @@ export class AskarWallet implements Wallet {
 
   public async generateNonce(): Promise<string> {
     try {
-      return TypedArrayEncoder.toUtf8String(CryptoBox.randomNonce())
+      // generate an 80-bit nonce suitable for AnonCreds proofs
+      const nonce = CryptoBox.randomNonce().slice(0, 10)
+      return new BigNumber(nonce).toString()
     } catch (error) {
       if (!isError(error)) {
         throw new AriesFrameworkError('Attempted to throw error, but it was not of type Error', { cause: error })

diff --git a/packages/askar/src/wallet/__tests__/AskarWallet.test.ts b/packages/askar/src/wallet/__tests__/AskarWallet.test.ts
@@ -57,7 +57,9 @@ describe('AskarWallet basic operations', () => {
   })
 
   test('Generate Nonce', async () => {
-    await expect(askarWallet.generateNonce()).resolves.toEqual(expect.any(String))
+    const nonce = await askarWallet.generateNonce()
+
+    expect(nonce).toMatch(/[0-9]+/)
   })
 
   test('Create ed25519 keypair', async () => {