From 1ed448a0d876b220d04615d7ea1340f836c2ccd9 Mon Sep 17 00:00:00 2001
From: sonytooo <simeonpetkov11999977@gmail.com>
Date: Mon, 10 Feb 2025 11:23:48 +0200
Subject: [PATCH 01/12] impl entropy generator and add extra entropy to the
 addSecret method

---
 src/controllers/keystore/keystore.test.ts     |  6 +--
 src/controllers/keystore/keystore.ts          | 38 +++++++---------
 src/libs/entropyGenerator/entropyGenerator.ts | 45 +++++++++++++++++++
 3 files changed, 65 insertions(+), 24 deletions(-)
 create mode 100644 src/libs/entropyGenerator/entropyGenerator.ts

diff --git a/src/controllers/keystore/keystore.test.ts b/src/controllers/keystore/keystore.test.ts
index b166f001a..0fef51d1e 100644
--- a/src/controllers/keystore/keystore.test.ts
+++ b/src/controllers/keystore/keystore.test.ts
@@ -107,7 +107,7 @@ describe('KeystoreController', () => {
   })
 
   test('should add a secret', (done) => {
-    keystore.addSecret('password', pass, '', false)
+    keystore.addSecret('password', pass, null, false)
 
     const unsubscribe = keystore.onUpdate(async () => {
       if (keystore.statuses.addSecret === 'SUCCESS') {
@@ -556,11 +556,11 @@ describe('import/export with pub key test', () => {
     keystore = new KeystoreController(produceMemoryStore(), keystoreSigners, windowManager)
     keystore2 = new KeystoreController(produceMemoryStore(), keystoreSigners, windowManager)
 
-    await keystore2.addSecret('123', '123', '', false)
+    await keystore2.addSecret('123', '123', null, false)
     await keystore2.unlockWithSecret('123', '123')
     uid2 = await keystore2.getKeyStoreUid()
 
-    await keystore.addSecret('a', 'b', '', false)
+    await keystore.addSecret('a', 'b', null, false)
     await keystore.unlockWithSecret('a', 'b')
   })
 
diff --git a/src/controllers/keystore/keystore.ts b/src/controllers/keystore/keystore.ts
index 529f0b035..f5cf5d627 100644
--- a/src/controllers/keystore/keystore.ts
+++ b/src/controllers/keystore/keystore.ts
@@ -9,16 +9,7 @@ import {
   encryptWithPublicKey,
   publicKeyByPrivateKey
 } from 'eth-crypto'
-import {
-  concat,
-  getBytes,
-  hexlify,
-  keccak256,
-  Mnemonic,
-  randomBytes,
-  toUtf8Bytes,
-  Wallet
-} from 'ethers'
+import { concat, getBytes, hexlify, keccak256, Mnemonic, toUtf8Bytes, Wallet } from 'ethers'
 import scrypt from 'scrypt-js'
 
 import EmittableError from '../../classes/EmittableError'
@@ -38,6 +29,7 @@ import {
 } from '../../interfaces/keystore'
 import { Storage } from '../../interfaces/storage'
 import { WindowManager } from '../../interfaces/window'
+import { EntropyGenerator } from '../../libs/entropyGenerator/entropyGenerator'
 import {
   getDefaultKeyLabel,
   getShouldMigrateKeyMetaNullToKeyMetaCreatedAt,
@@ -116,6 +108,8 @@ export class KeystoreController extends EventEmitter {
 
   #keystoreKeys: StoredKey[] = []
 
+  #entropyGenerator = new EntropyGenerator()
+
   keyStoreUid: string | null
 
   isReadyToStoreKeys: boolean = false
@@ -287,7 +281,7 @@ export class KeystoreController extends EventEmitter {
   async #addSecret(
     secretId: string,
     secret: string,
-    extraEntropy: string = '',
+    extraEntropy: Uint8Array | null = null,
     leaveUnlocked: boolean = false
   ) {
     await this.#initialLoadPromise
@@ -301,16 +295,13 @@ export class KeystoreController extends EventEmitter {
       })
 
     let mainKey: MainKey | null = this.#mainKey
+
     // We are not unlocked
     if (!mainKey) {
       if (!this.#keystoreSecrets.length) {
-        const key = getBytes(keccak256(concat([randomBytes(32), toUtf8Bytes(extraEntropy)]))).slice(
-          0,
-          16
-        )
         mainKey = {
-          key,
-          iv: randomBytes(16)
+          key: this.#entropyGenerator.generateRandomBytes(16, extraEntropy),
+          iv: this.#entropyGenerator.generateRandomBytes(16, extraEntropy)
         }
       } else
         throw new EmittableError({
@@ -324,7 +315,7 @@ export class KeystoreController extends EventEmitter {
       }
     }
 
-    const salt = randomBytes(32)
+    const salt = this.#entropyGenerator.generateRandomBytes(32, extraEntropy)
     const key = await scrypt.scrypt(
       getBytesForSecret(secret),
       salt,
@@ -334,7 +325,7 @@ export class KeystoreController extends EventEmitter {
       scryptDefaults.dkLen,
       () => {}
     )
-    const iv = randomBytes(16)
+    const iv = this.#entropyGenerator.generateRandomBytes(16, extraEntropy)
     const derivedKey = key.slice(0, 16)
     const macPrefix = key.slice(16, 32)
     const counter = new aes.Counter(iv)
@@ -365,7 +356,12 @@ export class KeystoreController extends EventEmitter {
     this.isReadyToStoreKeys = true
   }
 
-  async addSecret(secretId: string, secret: string, extraEntropy: string, leaveUnlocked: boolean) {
+  async addSecret(
+    secretId: string,
+    secret: string,
+    extraEntropy: Uint8Array | null,
+    leaveUnlocked: boolean
+  ) {
     await this.withStatus('addSecret', () =>
       this.#addSecret(secretId, secret, extraEntropy, leaveUnlocked)
     )
@@ -901,7 +897,7 @@ export class KeystoreController extends EventEmitter {
       })
 
     await this.#removeSecret('password')
-    await this.#addSecret('password', newSecret, '', true)
+    await this.#addSecret('password', newSecret, null, true)
   }
 
   async changeKeystorePassword(newSecret: string, oldSecret?: string) {
diff --git a/src/libs/entropyGenerator/entropyGenerator.ts b/src/libs/entropyGenerator/entropyGenerator.ts
new file mode 100644
index 000000000..787200912
--- /dev/null
+++ b/src/libs/entropyGenerator/entropyGenerator.ts
@@ -0,0 +1,45 @@
+/* eslint-disable no-bitwise */
+import { getBytes, keccak256, randomBytes } from 'ethers'
+
+export class EntropyGenerator {
+  #entropyPool: Uint8Array = new Uint8Array(0)
+
+  generateRandomBytes(length: number, extraEntropy: Uint8Array | null): Uint8Array {
+    this.#addSystemNoiseEntropy()
+    this.#addTimeEntropy()
+
+    if (extraEntropy) this.addEntropy(extraEntropy)
+
+    if (this.#entropyPool.length === 0) throw new Error('Entropy pool is empty')
+
+    const hash = getBytes(keccak256(this.#entropyPool))
+    const randomBytesGenerated = randomBytes(length)
+    for (let i = 0; i < length; i++) {
+      randomBytesGenerated[i] ^= hash[i % hash.length]
+    }
+
+    return randomBytesGenerated
+  }
+
+  #addTimeEntropy(): void {
+    const now = performance.now()
+
+    if (!now) return
+
+    const timeEntropy = new Uint8Array(new Float64Array([now]).buffer)
+    console.log('addTimeEntropy', timeEntropy)
+    this.addEntropy(timeEntropy)
+  }
+
+  #addSystemNoiseEntropy(): void {
+    const systemNoise = randomBytes(16)
+    this.addEntropy(systemNoise)
+  }
+
+  addEntropy(newEntropy: Uint8Array): void {
+    const combined = new Uint8Array(this.#entropyPool.length + newEntropy.length)
+    combined.set(this.#entropyPool)
+    combined.set(newEntropy, this.#entropyPool.length)
+    this.#entropyPool = combined
+  }
+}

From 8b4477be9b9dd150564d498c72b4867d2e0bc596 Mon Sep 17 00:00:00 2001
From: sonytooo <simeonpetkov11999977@gmail.com>
Date: Mon, 10 Feb 2025 13:39:40 +0200
Subject: [PATCH 02/12] extra entropy improvements

---
 src/controllers/keystore/keystore.test.ts     |  6 ++---
 src/controllers/keystore/keystore.ts          | 22 +++++++------------
 src/libs/entropyGenerator/entropyGenerator.ts | 14 +++++++++---
 3 files changed, 22 insertions(+), 20 deletions(-)

diff --git a/src/controllers/keystore/keystore.test.ts b/src/controllers/keystore/keystore.test.ts
index 0fef51d1e..b166f001a 100644
--- a/src/controllers/keystore/keystore.test.ts
+++ b/src/controllers/keystore/keystore.test.ts
@@ -107,7 +107,7 @@ describe('KeystoreController', () => {
   })
 
   test('should add a secret', (done) => {
-    keystore.addSecret('password', pass, null, false)
+    keystore.addSecret('password', pass, '', false)
 
     const unsubscribe = keystore.onUpdate(async () => {
       if (keystore.statuses.addSecret === 'SUCCESS') {
@@ -556,11 +556,11 @@ describe('import/export with pub key test', () => {
     keystore = new KeystoreController(produceMemoryStore(), keystoreSigners, windowManager)
     keystore2 = new KeystoreController(produceMemoryStore(), keystoreSigners, windowManager)
 
-    await keystore2.addSecret('123', '123', null, false)
+    await keystore2.addSecret('123', '123', '', false)
     await keystore2.unlockWithSecret('123', '123')
     uid2 = await keystore2.getKeyStoreUid()
 
-    await keystore.addSecret('a', 'b', null, false)
+    await keystore.addSecret('a', 'b', '', false)
     await keystore.unlockWithSecret('a', 'b')
   })
 
diff --git a/src/controllers/keystore/keystore.ts b/src/controllers/keystore/keystore.ts
index f5cf5d627..165fd7b34 100644
--- a/src/controllers/keystore/keystore.ts
+++ b/src/controllers/keystore/keystore.ts
@@ -108,8 +108,6 @@ export class KeystoreController extends EventEmitter {
 
   #keystoreKeys: StoredKey[] = []
 
-  #entropyGenerator = new EntropyGenerator()
-
   keyStoreUid: string | null
 
   isReadyToStoreKeys: boolean = false
@@ -281,7 +279,7 @@ export class KeystoreController extends EventEmitter {
   async #addSecret(
     secretId: string,
     secret: string,
-    extraEntropy: Uint8Array | null = null,
+    extraEntropy: string = '',
     leaveUnlocked: boolean = false
   ) {
     await this.#initialLoadPromise
@@ -295,13 +293,14 @@ export class KeystoreController extends EventEmitter {
       })
 
     let mainKey: MainKey | null = this.#mainKey
+    const entropyGenerator = new EntropyGenerator()
 
     // We are not unlocked
     if (!mainKey) {
       if (!this.#keystoreSecrets.length) {
         mainKey = {
-          key: this.#entropyGenerator.generateRandomBytes(16, extraEntropy),
-          iv: this.#entropyGenerator.generateRandomBytes(16, extraEntropy)
+          key: entropyGenerator.generateRandomBytes(16, extraEntropy),
+          iv: entropyGenerator.generateRandomBytes(16, extraEntropy)
         }
       } else
         throw new EmittableError({
@@ -315,7 +314,7 @@ export class KeystoreController extends EventEmitter {
       }
     }
 
-    const salt = this.#entropyGenerator.generateRandomBytes(32, extraEntropy)
+    const salt = entropyGenerator.generateRandomBytes(32, extraEntropy)
     const key = await scrypt.scrypt(
       getBytesForSecret(secret),
       salt,
@@ -325,7 +324,7 @@ export class KeystoreController extends EventEmitter {
       scryptDefaults.dkLen,
       () => {}
     )
-    const iv = this.#entropyGenerator.generateRandomBytes(16, extraEntropy)
+    const iv = entropyGenerator.generateRandomBytes(16, extraEntropy)
     const derivedKey = key.slice(0, 16)
     const macPrefix = key.slice(16, 32)
     const counter = new aes.Counter(iv)
@@ -356,12 +355,7 @@ export class KeystoreController extends EventEmitter {
     this.isReadyToStoreKeys = true
   }
 
-  async addSecret(
-    secretId: string,
-    secret: string,
-    extraEntropy: Uint8Array | null,
-    leaveUnlocked: boolean
-  ) {
+  async addSecret(secretId: string, secret: string, extraEntropy: string, leaveUnlocked: boolean) {
     await this.withStatus('addSecret', () =>
       this.#addSecret(secretId, secret, extraEntropy, leaveUnlocked)
     )
@@ -897,7 +891,7 @@ export class KeystoreController extends EventEmitter {
       })
 
     await this.#removeSecret('password')
-    await this.#addSecret('password', newSecret, null, true)
+    await this.#addSecret('password', newSecret, '', true)
   }
 
   async changeKeystorePassword(newSecret: string, oldSecret?: string) {
diff --git a/src/libs/entropyGenerator/entropyGenerator.ts b/src/libs/entropyGenerator/entropyGenerator.ts
index 787200912..3a5d565fd 100644
--- a/src/libs/entropyGenerator/entropyGenerator.ts
+++ b/src/libs/entropyGenerator/entropyGenerator.ts
@@ -4,11 +4,16 @@ import { getBytes, keccak256, randomBytes } from 'ethers'
 export class EntropyGenerator {
   #entropyPool: Uint8Array = new Uint8Array(0)
 
-  generateRandomBytes(length: number, extraEntropy: Uint8Array | null): Uint8Array {
+  generateRandomBytes(length: number, extraEntropy: string): Uint8Array {
+    this.#resetEntropyPool()
     this.#addSystemNoiseEntropy()
     this.#addTimeEntropy()
 
-    if (extraEntropy) this.addEntropy(extraEntropy)
+    if (extraEntropy) {
+      const encoder = new TextEncoder()
+      const uint8Array = encoder.encode(extraEntropy)
+      this.addEntropy(uint8Array)
+    }
 
     if (this.#entropyPool.length === 0) throw new Error('Entropy pool is empty')
 
@@ -27,7 +32,6 @@ export class EntropyGenerator {
     if (!now) return
 
     const timeEntropy = new Uint8Array(new Float64Array([now]).buffer)
-    console.log('addTimeEntropy', timeEntropy)
     this.addEntropy(timeEntropy)
   }
 
@@ -42,4 +46,8 @@ export class EntropyGenerator {
     combined.set(newEntropy, this.#entropyPool.length)
     this.#entropyPool = combined
   }
+
+  #resetEntropyPool() {
+    this.#entropyPool = new Uint8Array(0)
+  }
 }

From f40742bbc2ddd0128efc35ba6a8a3bb6a8623457 Mon Sep 17 00:00:00 2001
From: sonytooo <simeonpetkov11999977@gmail.com>
Date: Mon, 10 Feb 2025 14:57:43 +0200
Subject: [PATCH 03/12] add comment

---
 src/libs/entropyGenerator/entropyGenerator.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/libs/entropyGenerator/entropyGenerator.ts b/src/libs/entropyGenerator/entropyGenerator.ts
index 3a5d565fd..159b9ac21 100644
--- a/src/libs/entropyGenerator/entropyGenerator.ts
+++ b/src/libs/entropyGenerator/entropyGenerator.ts
@@ -19,6 +19,7 @@ export class EntropyGenerator {
 
     const hash = getBytes(keccak256(this.#entropyPool))
     const randomBytesGenerated = randomBytes(length)
+    // ensures non-deterministic final output
     for (let i = 0; i < length; i++) {
       randomBytesGenerated[i] ^= hash[i % hash.length]
     }

From a65a59a20bb023342a76ce35711e5819ee2fc0e1 Mon Sep 17 00:00:00 2001
From: sonytooo <simeonpetkov11999977@gmail.com>
Date: Mon, 10 Feb 2025 15:20:07 +0200
Subject: [PATCH 04/12] rename functions

---
 src/libs/entropyGenerator/entropyGenerator.ts | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/libs/entropyGenerator/entropyGenerator.ts b/src/libs/entropyGenerator/entropyGenerator.ts
index 159b9ac21..e103b94d7 100644
--- a/src/libs/entropyGenerator/entropyGenerator.ts
+++ b/src/libs/entropyGenerator/entropyGenerator.ts
@@ -6,8 +6,8 @@ export class EntropyGenerator {
 
   generateRandomBytes(length: number, extraEntropy: string): Uint8Array {
     this.#resetEntropyPool()
-    this.#addSystemNoiseEntropy()
-    this.#addTimeEntropy()
+    this.#collectSystemNoiseEntropy()
+    this.#collectTimeEntropy()
 
     if (extraEntropy) {
       const encoder = new TextEncoder()
@@ -27,7 +27,7 @@ export class EntropyGenerator {
     return randomBytesGenerated
   }
 
-  #addTimeEntropy(): void {
+  #collectTimeEntropy(): void {
     const now = performance.now()
 
     if (!now) return
@@ -36,7 +36,7 @@ export class EntropyGenerator {
     this.addEntropy(timeEntropy)
   }
 
-  #addSystemNoiseEntropy(): void {
+  #collectSystemNoiseEntropy(): void {
     const systemNoise = randomBytes(16)
     this.addEntropy(systemNoise)
   }

From 8ef052ca37689b3973ab82afed584c1f96522b3e Mon Sep 17 00:00:00 2001
From: sonytooo <simeonpetkov11999977@gmail.com>
Date: Mon, 17 Feb 2025 14:31:45 +0200
Subject: [PATCH 05/12] add: entropyGenerator tests

---
 .../entropyGenerator/entropyGenerator.test.ts | 57 +++++++++++++++++++
 src/libs/entropyGenerator/entropyGenerator.ts |  7 +--
 2 files changed, 60 insertions(+), 4 deletions(-)
 create mode 100644 src/libs/entropyGenerator/entropyGenerator.test.ts

diff --git a/src/libs/entropyGenerator/entropyGenerator.test.ts b/src/libs/entropyGenerator/entropyGenerator.test.ts
new file mode 100644
index 000000000..6a42163a1
--- /dev/null
+++ b/src/libs/entropyGenerator/entropyGenerator.test.ts
@@ -0,0 +1,57 @@
+import { EntropyGenerator } from './entropyGenerator'
+
+describe('EntropyGenerator', () => {
+  let generator: EntropyGenerator
+
+  beforeEach(() => {
+    generator = new EntropyGenerator()
+  })
+
+  test('should generate random bytes with extra entropy', () => {
+    const length = 32
+    const extraEntropy = 'extra randomness'
+    const result = generator.generateRandomBytes(length, extraEntropy)
+
+    expect(result).toBeInstanceOf(Uint8Array)
+    expect(result.length).toBe(length)
+  })
+  test('should throw an error when entropy pool is empty', () => {
+    jest.spyOn(generator, 'addEntropy').mockImplementation(() => {})
+    expect(() => generator.generateRandomBytes(16, '')).toThrow('Entropy pool is empty')
+  })
+  test('should collect time entropy', () => {
+    jest.spyOn(generator, 'addEntropy')
+    generator.generateRandomBytes(16, 'test')
+    expect(generator.addEntropy).toHaveBeenCalled()
+  })
+  test('should collect system noise entropy', () => {
+    jest.spyOn(generator, 'addEntropy')
+    generator.generateRandomBytes(16, 'test')
+    expect(generator.addEntropy).toHaveBeenCalled()
+  })
+  test('should produce different outputs on consecutive calls', () => {
+    const length = 32
+    const extraEntropy = 'extra randomness'
+    const result1 = generator.generateRandomBytes(length, extraEntropy)
+    const result2 = generator.generateRandomBytes(length, extraEntropy)
+    expect(result1).not.toEqual(result2)
+  })
+  test('should ensure randomness by checking uniform distribution', () => {
+    const length = 32
+    const occurrences = new Map()
+    for (let i = 0; i < 1000; i++) {
+      const result = generator.generateRandomBytes(length, 'entropy-test')
+      occurrences.set(result.toString(), (occurrences.get(result.toString()) || 0) + 1)
+    }
+    expect(occurrences.size).toBeGreaterThan(999) // Expect at least 999 unique values out of 1000
+  })
+  test('should not produce predictable patterns', () => {
+    const length = 32
+    const results: Uint8Array[] = []
+    for (let i = 0; i < 100; i++) {
+      results.push(generator.generateRandomBytes(length, ''))
+    }
+    const diffs = results.map((r, i) => (i > 0 ? r.toString() !== results[i - 1].toString() : true))
+    expect(diffs.includes(false)).toBe(false)
+  })
+})
diff --git a/src/libs/entropyGenerator/entropyGenerator.ts b/src/libs/entropyGenerator/entropyGenerator.ts
index e103b94d7..2f27424cd 100644
--- a/src/libs/entropyGenerator/entropyGenerator.ts
+++ b/src/libs/entropyGenerator/entropyGenerator.ts
@@ -6,7 +6,7 @@ export class EntropyGenerator {
 
   generateRandomBytes(length: number, extraEntropy: string): Uint8Array {
     this.#resetEntropyPool()
-    this.#collectSystemNoiseEntropy()
+    this.#collectSystemNoiseEntropy(length)
     this.#collectTimeEntropy()
 
     if (extraEntropy) {
@@ -36,9 +36,8 @@ export class EntropyGenerator {
     this.addEntropy(timeEntropy)
   }
 
-  #collectSystemNoiseEntropy(): void {
-    const systemNoise = randomBytes(16)
-    this.addEntropy(systemNoise)
+  #collectSystemNoiseEntropy(length: number): void {
+    this.addEntropy(randomBytes(length))
   }
 
   addEntropy(newEntropy: Uint8Array): void {

From a8655e29478300597857fb5898614271923097b7 Mon Sep 17 00:00:00 2001
From: sonytooo <simeonpetkov11999977@gmail.com>
Date: Mon, 17 Feb 2025 14:54:08 +0200
Subject: [PATCH 06/12] add: extra entropy to the change keystore function

---
 src/controllers/keystore/keystore.ts | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/controllers/keystore/keystore.ts b/src/controllers/keystore/keystore.ts
index 165fd7b34..f1dcc9e16 100644
--- a/src/controllers/keystore/keystore.ts
+++ b/src/controllers/keystore/keystore.ts
@@ -861,7 +861,7 @@ export class KeystoreController extends EventEmitter {
     return { seed: decryptedSeed, hdPathTemplate }
   }
 
-  async #changeKeystorePassword(newSecret: string, oldSecret?: string) {
+  async #changeKeystorePassword(newSecret: string, oldSecret?: string, extraEntropy?: string) {
     await this.#initialLoadPromise
 
     // In the case the user wants to change their device password,
@@ -891,12 +891,12 @@ export class KeystoreController extends EventEmitter {
       })
 
     await this.#removeSecret('password')
-    await this.#addSecret('password', newSecret, '', true)
+    await this.#addSecret('password', newSecret, extraEntropy, true)
   }
 
-  async changeKeystorePassword(newSecret: string, oldSecret?: string) {
+  async changeKeystorePassword(newSecret: string, oldSecret?: string, extraEntropy?: string) {
     await this.withStatus('changeKeystorePassword', () =>
-      this.#changeKeystorePassword(newSecret, oldSecret)
+      this.#changeKeystorePassword(newSecret, oldSecret, extraEntropy)
     )
   }
 

From a3c41a5597157b30467100e26e42a67aea141e85 Mon Sep 17 00:00:00 2001
From: sonytooo <simeonpetkov11999977@gmail.com>
Date: Mon, 17 Feb 2025 16:24:55 +0200
Subject: [PATCH 07/12] add: generateRandomMnemonic

---
 src/libs/entropyGenerator/entropyGenerator.ts | 10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

diff --git a/src/libs/entropyGenerator/entropyGenerator.ts b/src/libs/entropyGenerator/entropyGenerator.ts
index 2f27424cd..866b58364 100644
--- a/src/libs/entropyGenerator/entropyGenerator.ts
+++ b/src/libs/entropyGenerator/entropyGenerator.ts
@@ -1,5 +1,5 @@
 /* eslint-disable no-bitwise */
-import { getBytes, keccak256, randomBytes } from 'ethers'
+import { getBytes, keccak256, LangEn, Mnemonic, randomBytes } from 'ethers'
 
 export class EntropyGenerator {
   #entropyPool: Uint8Array = new Uint8Array(0)
@@ -27,6 +27,14 @@ export class EntropyGenerator {
     return randomBytesGenerated
   }
 
+  generateRandomMnemonic(wordCount: 12 | 24, extraEntropy: string): Mnemonic {
+    const wordCountToBytesLength = { 12: 16, 24: 32 }
+    const bytesLength = wordCountToBytesLength[wordCount] || 16
+    const entropy = this.generateRandomBytes(bytesLength, extraEntropy)
+    const mnemonic = Mnemonic.fromEntropy(entropy, '', LangEn.wordlist())
+    return mnemonic
+  }
+
   #collectTimeEntropy(): void {
     const now = performance.now()
 

From 1cd2eb7f8d7256403a0691a8b7b9b6b91edc533f Mon Sep 17 00:00:00 2001
From: sonytooo <simeonpetkov11999977@gmail.com>
Date: Mon, 17 Feb 2025 17:29:26 +0200
Subject: [PATCH 08/12] add more tests

---
 .../entropyGenerator/entropyGenerator.test.ts | 25 +++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/src/libs/entropyGenerator/entropyGenerator.test.ts b/src/libs/entropyGenerator/entropyGenerator.test.ts
index 6a42163a1..ea9f828dc 100644
--- a/src/libs/entropyGenerator/entropyGenerator.test.ts
+++ b/src/libs/entropyGenerator/entropyGenerator.test.ts
@@ -54,4 +54,29 @@ describe('EntropyGenerator', () => {
     const diffs = results.map((r, i) => (i > 0 ? r.toString() !== results[i - 1].toString() : true))
     expect(diffs.includes(false)).toBe(false)
   })
+  test('should generate a valid mnemonic of 12 words', () => {
+    const mnemonic = generator.generateRandomMnemonic(12, 'extra entropy')
+    expect(mnemonic).toHaveProperty('phrase')
+    expect(mnemonic.phrase.split(' ').length).toBe(12)
+  })
+  test('should generate a valid mnemonic of 24 words', () => {
+    const mnemonic = generator.generateRandomMnemonic(24, 'extra entropy')
+    expect(mnemonic).toHaveProperty('phrase')
+    expect(mnemonic.phrase.split(' ').length).toBe(24)
+  })
+  test('should generate different mnemonics on consecutive calls', () => {
+    const mnemonic1 = generator.generateRandomMnemonic(12, 'extra entropy')
+    const mnemonic2 = generator.generateRandomMnemonic(12, 'extra entropy')
+    expect(mnemonic1.phrase).not.toEqual(mnemonic2.phrase)
+  })
+  test('should use correct entropy length for 12-word mnemonic', () => {
+    jest.spyOn(generator, 'generateRandomBytes')
+    generator.generateRandomMnemonic(12, 'extra entropy')
+    expect(generator.generateRandomBytes).toHaveBeenCalledWith(16, 'extra entropy')
+  })
+  test('should use correct entropy length for 24-word mnemonic', () => {
+    jest.spyOn(generator, 'generateRandomBytes')
+    generator.generateRandomMnemonic(24, 'extra entropy')
+    expect(generator.generateRandomBytes).toHaveBeenCalledWith(32, 'extra entropy')
+  })
 })

From 6c2924e69143ebf92bc16cd3f9c5faeab631ef85 Mon Sep 17 00:00:00 2001
From: sonytooo <simeonpetkov11999977@gmail.com>
Date: Mon, 17 Feb 2025 17:44:10 +0200
Subject: [PATCH 09/12] feedpack fixes and optimizations

---
 src/libs/entropyGenerator/entropyGenerator.ts | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/src/libs/entropyGenerator/entropyGenerator.ts b/src/libs/entropyGenerator/entropyGenerator.ts
index 866b58364..9cb8cbd77 100644
--- a/src/libs/entropyGenerator/entropyGenerator.ts
+++ b/src/libs/entropyGenerator/entropyGenerator.ts
@@ -6,7 +6,7 @@ export class EntropyGenerator {
 
   generateRandomBytes(length: number, extraEntropy: string): Uint8Array {
     this.#resetEntropyPool()
-    this.#collectSystemNoiseEntropy(length)
+    this.#collectCryptographicEntropy(length)
     this.#collectTimeEntropy()
 
     if (extraEntropy) {
@@ -19,7 +19,7 @@ export class EntropyGenerator {
 
     const hash = getBytes(keccak256(this.#entropyPool))
     const randomBytesGenerated = randomBytes(length)
-    // ensures non-deterministic final output
+    // Introduces additional entropy mixing via XOR
     for (let i = 0; i < length; i++) {
       randomBytesGenerated[i] ^= hash[i % hash.length]
     }
@@ -44,15 +44,12 @@ export class EntropyGenerator {
     this.addEntropy(timeEntropy)
   }
 
-  #collectSystemNoiseEntropy(length: number): void {
+  #collectCryptographicEntropy(length: number): void {
     this.addEntropy(randomBytes(length))
   }
 
   addEntropy(newEntropy: Uint8Array): void {
-    const combined = new Uint8Array(this.#entropyPool.length + newEntropy.length)
-    combined.set(this.#entropyPool)
-    combined.set(newEntropy, this.#entropyPool.length)
-    this.#entropyPool = combined
+    this.#entropyPool = new Uint8Array(Buffer.concat([this.#entropyPool, newEntropy]))
   }
 
   #resetEntropyPool() {

From fdb7bb224a79ee5b4e153767263d83ebb35c6b3b Mon Sep 17 00:00:00 2001
From: sonytooo <simeonpetkov11999977@gmail.com>
Date: Mon, 17 Feb 2025 17:46:16 +0200
Subject: [PATCH 10/12] add: comment

---
 src/libs/entropyGenerator/entropyGenerator.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/libs/entropyGenerator/entropyGenerator.ts b/src/libs/entropyGenerator/entropyGenerator.ts
index 9cb8cbd77..8f916e769 100644
--- a/src/libs/entropyGenerator/entropyGenerator.ts
+++ b/src/libs/entropyGenerator/entropyGenerator.ts
@@ -29,7 +29,7 @@ export class EntropyGenerator {
 
   generateRandomMnemonic(wordCount: 12 | 24, extraEntropy: string): Mnemonic {
     const wordCountToBytesLength = { 12: 16, 24: 32 }
-    const bytesLength = wordCountToBytesLength[wordCount] || 16
+    const bytesLength = wordCountToBytesLength[wordCount] || 16 // defaults to 12-word phrase
     const entropy = this.generateRandomBytes(bytesLength, extraEntropy)
     const mnemonic = Mnemonic.fromEntropy(entropy, '', LangEn.wordlist())
     return mnemonic

From 8dc02b519ab6a4869039c7a43c4c22c0e897b87b Mon Sep 17 00:00:00 2001
From: sonytooo <simeonpetkov11999977@gmail.com>
Date: Wed, 19 Feb 2025 11:56:32 +0200
Subject: [PATCH 11/12] feedback fixes

---
 src/libs/entropyGenerator/entropyGenerator.ts | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/libs/entropyGenerator/entropyGenerator.ts b/src/libs/entropyGenerator/entropyGenerator.ts
index 8f916e769..d69367187 100644
--- a/src/libs/entropyGenerator/entropyGenerator.ts
+++ b/src/libs/entropyGenerator/entropyGenerator.ts
@@ -1,6 +1,10 @@
 /* eslint-disable no-bitwise */
 import { getBytes, keccak256, LangEn, Mnemonic, randomBytes } from 'ethers'
 
+// Custom entropy generator that enhances ethers' randomBytes by incorporating:
+// - Time-based entropy for additional randomness.
+// - Optional extra entropy (like mouse position, timestamp...) provided by the user for added security.
+// This helps improve the security of mainKey generation and random seed phrase creation.
 export class EntropyGenerator {
   #entropyPool: Uint8Array = new Uint8Array(0)
 
@@ -36,6 +40,7 @@ export class EntropyGenerator {
   }
 
   #collectTimeEntropy(): void {
+    // TODO: add a polyfill for the mobile app
     const now = performance.now()
 
     if (!now) return

From f3a980b01c91b42cb77d9270199b96410c5b846a Mon Sep 17 00:00:00 2001
From: sonytooo <simeonpetkov11999977@gmail.com>
Date: Wed, 19 Feb 2025 12:14:14 +0200
Subject: [PATCH 12/12] improve commnet

---
 src/libs/entropyGenerator/entropyGenerator.ts | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/libs/entropyGenerator/entropyGenerator.ts b/src/libs/entropyGenerator/entropyGenerator.ts
index d69367187..38f3adc0a 100644
--- a/src/libs/entropyGenerator/entropyGenerator.ts
+++ b/src/libs/entropyGenerator/entropyGenerator.ts
@@ -40,7 +40,12 @@ export class EntropyGenerator {
   }
 
   #collectTimeEntropy(): void {
-    // TODO: add a polyfill for the mobile app
+    // TODO: steps to add support for the mobile app:
+    // 1. install the polyfill: `yarn add react-native-performance`
+    // 2. add it globally in a top-level file:
+    // if (typeof performance === "undefined") {
+    //   global.performance = { now }
+    // }
     const now = performance.now()
 
     if (!now) return