fix: ed25519KeyIdentity generates unique identities when no seed is p…

…rovided (#851)

docs/generated/changelog.html

@@ -12,6 +12,7 @@ <h1>Agent-JS Changelog</h1>
     <section>
       <h2>Version x.x.x</h2>
       <ul>
+        <li>fix: ed25519KeyIdentity was not generating unique identities when no seed was provided. This issue was introduced in v0.20.0-beta.0. If your code was affected please upgrade to >=1.0.1</li>
         <li>chore: export `AuthClientStorage` to aid with custom implementations</li>
       </ul>
       <h2>Version 1.0.0</h2>

packages/identity/src/identity/ed25519.test.ts

@@ -114,6 +114,20 @@ describe('Ed25519KeyIdentity tests', () => {
 
     expect(isValid).toBe(true);
   });
+
+  it('generates random private keys', () => {
+    const key1 = Ed25519KeyIdentity.generate();
+    const key2 = Ed25519KeyIdentity.generate();
+    expect(key1.toJSON().toString()).not.toEqual(key2.toJSON().toString());
+  });
+
+  it('should warn if the key is an Uint8Array consisting of all zeroes', () => {
+    const consoleSpy = jest.spyOn(console, 'warn').mockImplementation(() => {});
+
+    const baseKey = new Uint8Array(new Array(32).fill(0));
+    Ed25519KeyIdentity.generate(baseKey);
+    expect(consoleSpy).toHaveBeenCalledWith("Seed is all zeros. This is not a secure seed. Please provide a seed with sufficient entropy if this is a production environment.");
+  });
 });
 
 test('from JSON', async () => {

packages/identity/src/identity/ed25519.ts

@@ -1,3 +1,4 @@
+import { bufEquals } from '@dfinity/agent';
 import {
   DerEncodedPublicKey,
   KeyPair,
@@ -105,12 +106,25 @@ export class Ed25519PublicKey implements PublicKey {
   }
 }
 
+/**
+ * Ed25519KeyIdentity is an implementation of SignIdentity that uses Ed25519 keys. This class is used to sign and verify messages for an agent.
+ */
 export class Ed25519KeyIdentity extends SignIdentity {
-  public static generate(seed = new Uint8Array(32)): Ed25519KeyIdentity {
+  /**
+   * Generate a new Ed25519KeyIdentity.
+   * @param seed a 32-byte seed for the private key. If not provided, a random seed will be generated.
+   * @returns Ed25519KeyIdentity
+   */
+  public static generate(seed?: Uint8Array): Ed25519KeyIdentity {
+
     if (seed && seed.length !== 32) {
       throw new Error('Ed25519 Seed needs to be 32 bytes long.');
     }
     if (!seed) seed = ed25519.utils.randomPrivateKey();
+    // Check if the seed is all zeros
+    if(bufEquals(seed, new Uint8Array(new Array(32).fill(0)))) {
+      console.warn('Seed is all zeros. This is not a secure seed. Please provide a seed with sufficient entropy if this is a production environment.');
+    }
     const sk = new Uint8Array(32);
     for (let i = 0; i < 32; i++) sk[i] = new Uint8Array(seed)[i];