Implement standalone FromChat Protocol

2026-09-22 19:15:08 +03:00 · 2025-12-04 23:14:01 +03:00
parent 96cba60804
commit cc29d2d546
27 changed files with 592 additions and 120 deletions
@@ -0,0 +1,7 @@
+node_modules/
+dist/
+*.log
+.DS_Store
+package-lock.json
+
+
@@ -0,0 +1,8 @@
+src/
+tsconfig.json
+node_modules/
+package-lock.json
+*.log
+.DS_Store
+
+
@@ -0,0 +1,171 @@
+# Publishing FromChat Protocol
+
+This guide explains how to publish the `@fromchat/protocol` package to npm or GitHub Packages.
+
+## Prerequisites
+
+1. **npm account**: Create one at [npmjs.com](https://www.npmjs.com/signup)
+2. **GitHub account**: For GitHub Packages
+3. **Node.js**: Version 18 or higher
+
+## Publishing to npm
+
+### Important: Scoped Package Setup
+
+The package uses the `@fromchat` scope. You have two options:
+
+**Option A: Create an npm organization (Recommended)**
+1. Go to [npmjs.com/org/create](https://www.npmjs.com/org/create)
+2. Create an organization named `fromchat`
+3. Add yourself as a member
+4. Then proceed with publishing below
+
+**Option B: Use unscoped package name**
+If you prefer not to create an organization, change the package name in `package.json`:
+```json
+{
+  "name": "fromchat-protocol"  // Remove the @fromchat/ scope
+}
+```
+Then update all imports in your codebase from `@fromchat/protocol` to `fromchat-protocol`.
+
+### 1. Build the package
+
+```bash
+cd frontend/packages/fromchat-protocol
+npm run build
+```
+
+This compiles TypeScript to JavaScript in the `dist/` directory.
+
+### 2. Login to npm
+
+```bash
+npm login
+```
+
+Enter your npm username, password, and email.
+
+### 3. Publish
+
+**If using scoped package (`@fromchat/protocol`):**
+```bash
+npm publish --access public
+```
+
+**If using unscoped package (`fromchat-protocol`):**
+```bash
+npm publish
+```
+
+The `--access public` flag is required for scoped packages (packages starting with `@`).
+
+### 4. Verify
+
+Check your package at: `https://www.npmjs.com/package/@fromchat/protocol`
+
+### 5. Update version for future releases
+
+```bash
+# Patch version (1.0.0 -> 1.0.1)
+npm version patch
+
+# Minor version (1.0.0 -> 1.1.0)
+npm version minor
+
+# Major version (1.0.0 -> 2.0.0)
+npm version major
+
+# Then publish
+npm publish --access public
+```
+
+## Publishing to GitHub Packages
+
+### 1. Create a GitHub Personal Access Token
+
+1. Go to GitHub Settings → Developer settings → Personal access tokens → Tokens (classic)
+2. Generate a new token with `write:packages` and `read:packages` permissions
+3. Save the token securely
+
+### 2. Configure npm to use GitHub Packages
+
+Create or edit `~/.npmrc`:
+
+```
+@fromchat:registry=https://npm.pkg.github.com
+//npm.pkg.github.com/:_authToken=YOUR_GITHUB_TOKEN
+```
+
+Or add to `package.json`:
+
+```json
+{
+  "publishConfig": {
+    "registry": "https://npm.pkg.github.com"
+  }
+}
+```
+
+### 3. Update package.json
+
+Update the repository URL to match your GitHub repository:
+
+```json
+{
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/YOUR_USERNAME/YOUR_REPO.git",
+    "directory": "frontend/packages/fromchat-protocol"
+  }
+}
+```
+
+### 4. Build and publish
+
+```bash
+cd frontend/packages/fromchat-protocol
+npm run build
+npm publish
+```
+
+### 5. Install from GitHub Packages
+
+Users can install your package with:
+
+```bash
+npm install @fromchat/protocol@npm:@fromchat/protocol
+```
+
+Or add to `.npmrc`:
+
+```
+@fromchat:registry=https://npm.pkg.github.com
+```
+
+## Using the Published Package
+
+### From npm
+
+```bash
+npm install @fromchat/protocol
+```
+
+```typescript
+import { FromChatProtocol } from "@fromchat/protocol";
+```
+
+### From GitHub Packages
+
+```bash
+npm install @fromchat/protocol@npm:@fromchat/protocol
+```
+
+## Notes
+
+- The package is built to `dist/` directory
+- Source files in `src/` are excluded from the published package
+- Only `dist/` and `README.md` are included in the published package
+- The package uses ES modules (ESM) format
+- TypeScript definitions are included in `dist/`
+
@@ -0,0 +1,99 @@
+# FromChat Protocol
+
+Simple ECDH-based encryption protocol for direct messages.
+
+## Overview
+
+The FromChat Protocol provides end-to-end encryption for direct messages using:
+- **X25519** (ECDH) for key exchange
+- **HKDF** for key derivation
+- **AES-GCM** for symmetric encryption
+
+This module is completely independent and can be used in any JavaScript/TypeScript project.
+
+## Protocol Flow
+
+### Encryption
+
+1. Generate a random message key (mk) - 32 bytes
+2. Generate a random salt (wkSalt) - 16 bytes
+3. Derive shared secret from ECDH: `ecdhSharedSecret(myPrivateKey, theirPublicKey)`
+4. Derive wrapping key: `deriveWrappingKey(sharedSecret, wkSalt, info)` using HKDF
+5. Encrypt message with mk using AES-GCM → (iv, ciphertext)
+6. Encrypt (wrap) mk with wrapping key using AES-GCM → (iv2, wrappedMk)
+7. Send: `{ iv, ciphertext, salt, iv2, wrappedMk }`
+
+### Decryption
+
+1. Derive shared secret from ECDH
+2. Derive wrapping key from shared secret using salt from message
+3. Decrypt wrappedMk to get mk
+4. Decrypt ciphertext with mk
+
+## Usage
+
+```typescript
+import { FromChatProtocol } from "@fromchat/protocol";
+
+// Initialize with your private key
+const protocol = new FromChatProtocol(privateKey);
+
+// Encrypt a message
+const encrypted = await protocol.encryptMessage(recipientPublicKey, "Hello!");
+
+// Decrypt a message
+const decrypted = await protocol.decryptMessage(senderPublicKey, encrypted);
+```
+
+## API
+
+### `FromChatProtocol`
+
+#### Constructor
+- `constructor(privateKey: Uint8Array)` - Initialize protocol with your X25519 private key
+
+#### Methods
+- `encryptMessage(recipientPublicKey: Uint8Array, plaintext: string): Promise<EncryptedMessage>` - Encrypt a message
+- `decryptMessage(senderPublicKey: Uint8Array, message: EncryptedMessage): Promise<string>` - Decrypt a message
+
+### Types
+
+```typescript
+interface EncryptedMessage {
+  iv: string;        // Base64 encoded IV for message encryption
+  ciphertext: string; // Base64 encoded encrypted message
+  salt: string;      // Base64 encoded salt for wrapping key derivation
+  iv2: string;       // Base64 encoded IV for message key wrapping
+  wrappedMk: string; // Base64 encoded wrapped message key
+}
+```
+
+## Backup & Key Management
+
+The protocol also includes utilities for backing up and restoring private keys:
+
+```typescript
+import { 
+  encryptBackupWithPassword, 
+  decryptBackupWithPassword,
+  encodeBlob,
+  decodeBlob 
+} from "@fromchat/protocol";
+
+// Create a backup of a private key
+const bundle = { version: 1, privateKey: myPrivateKey };
+const encrypted = await encryptBackupWithPassword("my-password", bundle);
+const backupString = encodeBlob(encrypted); // Store this string
+
+// Restore from backup
+const encryptedBlob = decodeBlob(backupString);
+const restored = await decryptBackupWithPassword("my-password", encryptedBlob);
+```
+
+## Security Notes
+
+- Each message uses a fresh random message key
+- The protocol does not provide forward secrecy
+- Keys are derived using HKDF with SHA-256
+- All encryption uses AES-GCM with 12-byte IVs
+- Backup encryption uses PBKDF2 with 210,000 iterations
@@ -0,0 +1,54 @@
+{
+  "name": "@fromchat/protocol",
+  "version": "1.0.0",
+  "description": "FromChat Protocol - Simple ECDH-based encryption for direct messages. Independent and reusable encryption module.",
+  "main": "dist/index.js",
+  "module": "dist/index.js",
+  "types": "dist/index.d.ts",
+  "exports": {
+    ".": {
+      "import": "./dist/index.js",
+      "require": "./dist/index.js",
+      "types": "./dist/index.d.ts"
+    }
+  },
+  "scripts": {
+    "build": "tsc",
+    "typecheck": "tsc --noEmit",
+    "prepublishOnly": "npm run build"
+  },
+  "keywords": [
+    "encryption",
+    "ecdh",
+    "e2ee",
+    "end-to-end-encryption",
+    "x25519",
+    "aes-gcm",
+    "hkdf"
+  ],
+  "author": "denis0001-dev",
+  "license": "GPL-3.0",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/Toolbox-io/FromChat.git",
+    "directory": "frontend/packages/fromchat-protocol"
+  },
+  "bugs": {
+    "url": "https://github.com/Toolbox-io/FromChat/issues"
+  },
+  "homepage": "https://github.com/Toolbox-io/FromChat#readme",
+  "dependencies": {
+    "tweetnacl": "^1.0.3"
+  },
+  "devDependencies": {
+    "@types/node": "^20.0.0",
+    "typescript": "^5.0.0"
+  },
+  "files": [
+    "dist",
+    "README.md"
+  ],
+  "engines": {
+    "node": ">=24.0.0"
+  }
+}
@@ -1,5 +1,4 @@
-import { aesGcmDecrypt, aesGcmEncrypt } from "./symmetric";
-import { importPassword, deriveKEK, randomBytes } from "./kdf";
+import { aesGcmDecrypt, aesGcmEncrypt, importPassword, deriveKEK, randomBytes } from "../crypto/index";

 export interface PrivateKeyBundle {
 	version: 1;
@@ -65,4 +64,3 @@ export function decodeBlob(json: string): EncryptedBackupBlob {
 	return { salt: ub64(obj.salt), iv: ub64(obj.iv), ciphertext: ub64(obj.ciphertext) };
 }

-
@@ -6,18 +6,16 @@ export interface X25519KeyPair {
 	privateKey: Uint8Array;
 }

-export type KeyPair = X25519KeyPair;
-
 export function generateX25519KeyPair(): X25519KeyPair {
 	const kp = nacl.box.keyPair();
 	return { publicKey: kp.publicKey, privateKey: kp.secretKey };
 }

 export function ecdhSharedSecret(myPrivateKey: Uint8Array, theirPublicKey: Uint8Array): Uint8Array {
-	// nacl.box.before returns shared key (Curve25519, XSalsa20-Poly1305 context). We use it as IKM into HKDF.
 	return nacl.box.before(theirPublicKey, myPrivateKey);
 }

 export async function deriveWrappingKey(sharedSecret: Uint8Array, salt: Uint8Array, info: Uint8Array): Promise<Uint8Array> {
 	return hkdfExtractAndExpand(sharedSecret.buffer as ArrayBuffer, salt, info, 32);
-}
+}
+
@@ -0,0 +1,7 @@
+// Re-export all crypto functions for convenience
+export { generateX25519KeyPair, ecdhSharedSecret, deriveWrappingKey } from "./asymmetric";
+export type { X25519KeyPair } from "./asymmetric";
+export { importAesGcmKey, aesGcmEncrypt, aesGcmDecrypt } from "./symmetric";
+export type { AesGcmCiphertext } from "./symmetric";
+export { hkdfExtractAndExpand, randomBytes, importPassword, deriveKEK } from "./kdf";
+
@@ -1,3 +1,19 @@
+export async function hkdfExtractAndExpand(inputKeyMaterial: Uint8Array | ArrayBuffer, salt: Uint8Array | ArrayBuffer, info: Uint8Array | ArrayBuffer, length = 32): Promise<Uint8Array> {
+	const inputBuffer = inputKeyMaterial instanceof Uint8Array ? inputKeyMaterial.buffer as ArrayBuffer : inputKeyMaterial;
+	const saltBuffer = salt instanceof Uint8Array ? salt.buffer as ArrayBuffer : salt;
+	const infoBuffer = info instanceof Uint8Array ? info.buffer as ArrayBuffer : info;
+
+	const ikmKey = await crypto.subtle.importKey("raw", inputBuffer, { name: "HKDF" }, false, ["deriveBits"]);
+	const bits = await crypto.subtle.deriveBits({ name: "HKDF", hash: "SHA-256", salt: saltBuffer, info: infoBuffer }, ikmKey, length * 8);
+	return new Uint8Array(bits);
+}
+
+export function randomBytes(length: number): Uint8Array {
+	const out = new Uint8Array(length);
+	crypto.getRandomValues(out);
+	return out;
+}
+
 export async function importPassword(password: string): Promise<CryptoKey> {
 	const enc = new TextEncoder();
 	return crypto.subtle.importKey("raw", enc.encode(password), "PBKDF2", false, ["deriveKey", "deriveBits"]);
@@ -13,19 +29,3 @@ export async function deriveKEK(passwordKey: CryptoKey, salt: Uint8Array | Array
 		["encrypt", "decrypt"]
 	);
 }
-
-export async function hkdfExtractAndExpand(inputKeyMaterial: Uint8Array | ArrayBuffer, salt: Uint8Array | ArrayBuffer, info: Uint8Array | ArrayBuffer, length = 32): Promise<Uint8Array> {
-	const inputBuffer = inputKeyMaterial instanceof Uint8Array ? inputKeyMaterial.buffer as ArrayBuffer : inputKeyMaterial;
-	const saltBuffer = salt instanceof Uint8Array ? salt.buffer as ArrayBuffer : salt;
-	const infoBuffer = info instanceof Uint8Array ? info.buffer as ArrayBuffer : info;
-
-	const ikmKey = await crypto.subtle.importKey("raw", inputBuffer, { name: "HKDF" }, false, ["deriveBits"]);
-	const bits = await crypto.subtle.deriveBits({ name: "HKDF", hash: "SHA-256", salt: saltBuffer, info: infoBuffer }, ikmKey, length * 8);
-	return new Uint8Array(bits);
-}
-
-export function randomBytes(length: number): Uint8Array {
-	const out = new Uint8Array(length);
-	crypto.getRandomValues(out);
-	return out;
-}
@@ -11,12 +11,10 @@ export async function aesGcmEncrypt(key: CryptoKey, plaintext: Uint8Array | Arra
 }

 export async function aesGcmDecrypt(key: CryptoKey, iv: Uint8Array | ArrayBuffer, ciphertext: Uint8Array | ArrayBuffer): Promise<Uint8Array> {
-	// Normalize IV to ArrayBuffer (12 bytes for AES-GCM)
 	const ivBuf: ArrayBuffer = iv instanceof Uint8Array
 		? (iv.buffer as ArrayBuffer).slice(iv.byteOffset, iv.byteOffset + iv.byteLength)
 		: (iv as ArrayBuffer);

-	// Normalize ciphertext to a contiguous ArrayBuffer slice
 	const ctBuf: ArrayBuffer = ciphertext instanceof Uint8Array
 		? (ciphertext.buffer as ArrayBuffer).slice(ciphertext.byteOffset, ciphertext.byteOffset + ciphertext.byteLength)
 		: (ciphertext as ArrayBuffer);
@@ -26,9 +24,8 @@ export async function aesGcmDecrypt(key: CryptoKey, iv: Uint8Array | ArrayBuffer
 }

 export async function importAesGcmKey(rawKey: Uint8Array | ArrayBuffer): Promise<CryptoKey> {
-	// Normalize to a contiguous ArrayBuffer slice to avoid offset/length issues
 	const keyBuffer = rawKey instanceof Uint8Array
 		? (rawKey.buffer as ArrayBuffer).slice(rawKey.byteOffset, rawKey.byteOffset + rawKey.byteLength)
 		: (rawKey as ArrayBuffer);
 	return crypto.subtle.importKey("raw", keyBuffer, { name: "AES-GCM" }, false, ["encrypt", "decrypt"]);
-}
+}
@@ -0,0 +1,20 @@
+export { FromChatProtocol } from "./protocol/FromChatProtocol";
+export type { EncryptedMessage } from "./protocol/types";
+
+// Export crypto functions
+export { generateX25519KeyPair, ecdhSharedSecret, deriveWrappingKey } from "./crypto/asymmetric";
+export type { X25519KeyPair } from "./crypto/asymmetric";
+export { importAesGcmKey, aesGcmEncrypt, aesGcmDecrypt } from "./crypto/symmetric";
+export type { AesGcmCiphertext } from "./crypto/symmetric";
+export { hkdfExtractAndExpand, randomBytes, importPassword, deriveKEK } from "./crypto/kdf";
+
+// Export backup functions
+export {
+	encryptBackupWithPassword,
+	decryptBackupWithPassword,
+	encodeBlob,
+	decodeBlob,
+	serializeBundle,
+	deserializeBundle
+} from "./backup/backup";
+export type { PrivateKeyBundle, EncryptedBackupBlob } from "./backup/backup";
@@ -0,0 +1,102 @@
+import { ecdhSharedSecret, deriveWrappingKey } from "../crypto/asymmetric";
+import { importAesGcmKey, aesGcmEncrypt, aesGcmDecrypt } from "../crypto/symmetric";
+import { randomBytes } from "../crypto/kdf";
+import type { EncryptedMessage } from "./types";
+
+/**
+ * FromChat Protocol - Simple ECDH-based encryption
+ * 
+ * Protocol:
+ * 1. Generate random message key (mk) - 32 bytes
+ * 2. Generate random salt (wkSalt) - 16 bytes
+ * 3. Derive shared secret from ECDH (X25519)
+ * 4. Derive wrapping key from shared secret using HKDF with salt
+ * 5. Encrypt message with mk using AES-GCM
+ * 6. Encrypt (wrap) mk with wrapping key using AES-GCM
+ * 7. Send: { iv, ciphertext, salt, iv2, wrappedMk }
+ */
+export class FromChatProtocol {
+	private privateKey: Uint8Array;
+
+	constructor(privateKey: Uint8Array) {
+		this.privateKey = privateKey;
+	}
+
+	/**
+	 * Encrypt a message for a recipient
+	 * @param recipientPublicKey - Recipient's X25519 public key
+	 * @param plaintext - Message to encrypt
+	 * @returns Encrypted message with all necessary fields
+	 */
+	async encryptMessage(recipientPublicKey: Uint8Array, plaintext: string): Promise<EncryptedMessage> {
+		// Generate random message key
+		const mk = randomBytes(32);
+		
+		// Generate random salt for wrapping key derivation
+		const wkSalt = randomBytes(16);
+		
+		// Derive shared secret from ECDH
+		const shared = ecdhSharedSecret(this.privateKey, recipientPublicKey);
+		
+		// Derive wrapping key from shared secret using HKDF
+		const wkRaw = await deriveWrappingKey(shared, wkSalt, new Uint8Array([1]));
+		const wk = await importAesGcmKey(wkRaw);
+		
+		// Encrypt the message with message key
+		const plaintextBytes = new TextEncoder().encode(plaintext);
+		const encMsg = await aesGcmEncrypt(await importAesGcmKey(mk), plaintextBytes);
+		
+		// Encrypt (wrap) the message key with wrapping key
+		const wrap = await aesGcmEncrypt(wk, mk);
+		
+		// Convert to base64 for transmission
+		return {
+			iv: btoa(String.fromCharCode(...encMsg.iv)),
+			ciphertext: btoa(String.fromCharCode(...encMsg.ciphertext)),
+			salt: btoa(String.fromCharCode(...wkSalt)),
+			iv2: btoa(String.fromCharCode(...wrap.iv)),
+			wrappedMk: btoa(String.fromCharCode(...wrap.ciphertext))
+		};
+	}
+
+	/**
+	 * Decrypt a message from a sender
+	 * @param senderPublicKey - Sender's X25519 public key
+	 * @param message - Encrypted message
+	 * @returns Decrypted plaintext
+	 */
+	async decryptMessage(senderPublicKey: Uint8Array, message: EncryptedMessage): Promise<string> {
+		// Decode base64 fields
+		const salt = new Uint8Array(
+			atob(message.salt).split("").map(c => c.charCodeAt(0))
+		);
+		const iv2 = new Uint8Array(
+			atob(message.iv2).split("").map(c => c.charCodeAt(0))
+		);
+		const wrappedMk = new Uint8Array(
+			atob(message.wrappedMk).split("").map(c => c.charCodeAt(0))
+		);
+		const iv = new Uint8Array(
+			atob(message.iv).split("").map(c => c.charCodeAt(0))
+		);
+		const ciphertext = new Uint8Array(
+			atob(message.ciphertext).split("").map(c => c.charCodeAt(0))
+		);
+		
+		// Derive shared secret from ECDH
+		const shared = ecdhSharedSecret(this.privateKey, senderPublicKey);
+		
+		// Derive wrapping key from shared secret using salt from message
+		const wkRaw = await deriveWrappingKey(shared, salt, new Uint8Array([1]));
+		const wk = await importAesGcmKey(wkRaw);
+		
+		// Decrypt (unwrap) the message key
+		const mk = await aesGcmDecrypt(wk, iv2, wrappedMk);
+		
+		// Decrypt the message with message key
+		const decrypted = await aesGcmDecrypt(await importAesGcmKey(mk), iv, ciphertext);
+		
+		return new TextDecoder().decode(decrypted);
+	}
+}
+
@@ -0,0 +1,10 @@
+/**
+ * Encrypted message format
+ */
+export interface EncryptedMessage {
+	iv: string; // Base64 encoded IV for message encryption
+	ciphertext: string; // Base64 encoded encrypted message
+	salt: string; // Base64 encoded salt for wrapping key derivation
+	iv2: string; // Base64 encoded IV for message key wrapping
+	wrappedMk: string; // Base64 encoded wrapped message key
+}
@@ -0,0 +1,20 @@
+{
+  "compilerOptions": {
+    "target": "ES2020",
+    "module": "ESNext",
+    "lib": ["ES2020", "DOM"],
+    "declaration": true,
+    "declarationMap": true,
+    "outDir": "./dist",
+    "rootDir": "./src",
+    "strict": true,
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "forceConsistentCasingInFileNames": true,
+    "moduleResolution": "node",
+    "resolveJsonModule": true,
+    "sourceMap": true
+  },
+  "include": ["src/**/*"],
+  "exclude": ["node_modules", "dist"]
+}
@@ -1,9 +1,7 @@
 import { API_BASE_URL } from "@/core/config";
 import type { LoginRequest, RegisterRequest, LoginResponse } from "@/core/types";
-import { generateX25519KeyPair } from "@/utils/crypto/asymmetric";
-import { encodeBlob, encryptBackupWithPassword, decryptBackupWithPassword, decodeBlob } from "@/utils/crypto/backup";
+import { generateX25519KeyPair, hkdfExtractAndExpand, encodeBlob, encryptBackupWithPassword, decryptBackupWithPassword, decodeBlob } from "@fromchat/protocol";
 import { b64, ub64 } from "@/utils/utils";
-import { hkdfExtractAndExpand } from "@/utils/crypto/kdf";
 import { fetchPublicKey, uploadPublicKey, fetchBackupBlob, uploadBackupBlob } from "../crypto";
 import type { Headers } from "@/core/types";

@@ -1,28 +1,19 @@
 import { API_BASE_URL } from "@/core/config";
 import { getAuthHeaders } from "../user/auth";
-import { ecdhSharedSecret, deriveWrappingKey } from "@/utils/crypto/asymmetric";
-import { importAesGcmKey, aesGcmEncrypt, aesGcmDecrypt } from "@/utils/crypto/symmetric";
-import { randomBytes } from "@/utils/crypto/kdf";
 import { getCurrentKeys } from "../user/auth";
 import { request } from "@/core/websocket";
-import type { SendDMRequest, DmEnvelope, DMEditRequest, DmEncryptedJSON, BaseDmEnvelope, User } from "@/core/types";
+import type { SendDMRequest, DmEnvelope, DMEditRequest, BaseDmEnvelope, User } from "@/core/types";
 import { b64, ub64 } from "@/utils/utils";
 import { fetchUserPublicKey } from "../crypto/identity";
 import { fetchUsers, searchUsers } from "../user/search";
+import { getOrInitProtocol } from "@/utils/crypto/fromchatInit";
+import { ecdhSharedSecret, deriveWrappingKey, importAesGcmKey, aesGcmEncrypt, randomBytes } from "@fromchat/protocol";

 export async function decrypt(envelope: DmEnvelope, senderPublicKeyB64: string): Promise<string> {
-    const keys = getCurrentKeys();
-    if (!keys) throw new Error("Keys not initialized");
-
-    // Obtain the key
-    const shared = ecdhSharedSecret(keys.privateKey, ub64(senderPublicKeyB64));
-    const wkRaw = await deriveWrappingKey(shared, ub64(envelope.salt), new Uint8Array([1]));
-    const wk = await importAesGcmKey(wkRaw);
-    const mk = await aesGcmDecrypt(wk, ub64(envelope.iv2), ub64(envelope.wrappedMk));
-
-    // Decrypt
-    const msg = await aesGcmDecrypt(await importAesGcmKey(mk), ub64(envelope.iv), ub64(envelope.ciphertext));
-    return new TextDecoder().decode(msg);
+    const protocol = getOrInitProtocol();
+    const senderPublicKey = ub64(senderPublicKeyB64);
+    
+    return await protocol.decryptMessage(senderPublicKey, envelope);
 }

 export async function fetchMessages(userId: number, token: string, limit: number = 50, beforeId?: number): Promise<{ messages: DmEnvelope[]; has_more: boolean }> {
@@ -39,27 +30,14 @@ export async function fetchMessages(userId: number, token: string, limit: number
 }

 export async function send(recipientId: number, recipientPublicKeyB64: string, plaintext: string, authToken: string, replyToId?: number): Promise<void> {
-    const keys = getCurrentKeys();
-    if (!keys) throw new Error("Keys not initialized");
-
-    // Encryption key
-    const mk = randomBytes(32);
-    const wkSalt = randomBytes(16);
-    const shared = ecdhSharedSecret(keys.privateKey, ub64(recipientPublicKeyB64));
-    const wkRaw = await deriveWrappingKey(shared, wkSalt, new Uint8Array([1]));
-    const wk = await importAesGcmKey(wkRaw);
-
-    // Encrypt the message
-    const encMsg = await aesGcmEncrypt(await importAesGcmKey(mk), new TextEncoder().encode(plaintext));
-    const wrap = await aesGcmEncrypt(wk, mk);
-
+    const protocol = getOrInitProtocol();
+    const recipientPublicKey = ub64(recipientPublicKeyB64);
+    
+    const encrypted = await protocol.encryptMessage(recipientPublicKey, plaintext);
+    
    const payload: SendDMRequest = {
        recipientId: recipientId,
-        iv: b64(encMsg.iv),
-        ciphertext: b64(encMsg.ciphertext),
-        salt: b64(wkSalt),
-        iv2: b64(wrap.iv),
-        wrappedMk: b64(wrap.ciphertext)
+        ...encrypted
    };
    if (replyToId) payload.replyToId = replyToId;

@@ -74,15 +52,16 @@ export async function send(recipientId: number, recipientPublicKeyB64: string, p
 }

 export async function sendWithFiles(recipientId: number, recipientPublicKeyB64: string, plaintextJson: string, files: File[], token: string): Promise<void> {
+    // For files, we need to use the same message key for both the message and files
+    // So we'll do the encryption manually here to reuse the mk
    const keys = getCurrentKeys();
    if (!keys) throw new Error("Keys not initialized");

    const mk = randomBytes(32);
    const wkSalt = randomBytes(16);
-    const shared = await ecdhSharedSecret(keys.privateKey, ub64(recipientPublicKeyB64));
+    const shared = ecdhSharedSecret(keys.privateKey, ub64(recipientPublicKeyB64));
    const wkRaw = await deriveWrappingKey(shared, wkSalt, new Uint8Array([1]));
    const wk = await importAesGcmKey(wkRaw);
-
    const wrap = await aesGcmEncrypt(wk, mk);

    const form = new FormData();
@@ -96,21 +75,14 @@ export async function sendWithFiles(recipientId: number, recipientPublicKeyB64:
        const data = new Uint8Array(await f.arrayBuffer());
        const enc = await aesGcmEncrypt(await importAesGcmKey(mk), data);
        const blob = new Blob([sliceBuffer(enc.iv), sliceBuffer(enc.ciphertext)], { type: "application/octet-stream" });
-        const serverName = f.name; // server uses provided name
+        const serverName = f.name;
        names.push(serverName);
        form.append("files", new File([blob], serverName));
    }
    form.append("fileNames", JSON.stringify(names));

-    // Merge files metadata into plaintext JSON and encrypt
-    let obj: DmEncryptedJSON;
-    try {
-        obj = JSON.parse(plaintextJson);
-    } catch {
-        obj = { type: "text", data: { content: String(plaintextJson) } };
-    }
-
-    const encMsg = await aesGcmEncrypt(await importAesGcmKey(mk), new TextEncoder().encode(JSON.stringify(obj)));
+    // Encrypt the plaintext JSON with the same mk
+    const encMsg = await aesGcmEncrypt(await importAesGcmKey(mk), new TextEncoder().encode(plaintextJson));
    form.append("dm_payload", JSON.stringify({
        recipientId: recipientId,
        iv: b64(encMsg.iv),
@@ -128,28 +100,17 @@ export async function sendWithFiles(recipientId: number, recipientPublicKeyB64:
 }

 export async function edit(id: number, recipientPublicKeyB64: string, newPlaintextJson: string, authToken: string): Promise<void> {
-    const keys = getCurrentKeys();
-    if (!keys) throw new Error("Keys not initialized");
-
-    // We cannot reuse the old mk safely without knowing it; generate a fresh mk and wrap
-    const mk = randomBytes(32);
-    const wkSalt = randomBytes(16);
-    const shared = await ecdhSharedSecret(keys.privateKey, ub64(recipientPublicKeyB64));
-    const wkRaw = await deriveWrappingKey(shared, wkSalt, new Uint8Array([1]));
-    const wk = await importAesGcmKey(wkRaw);
-    const encMsg = await aesGcmEncrypt(await importAesGcmKey(mk), new TextEncoder().encode(newPlaintextJson));
-    const wrap = await aesGcmEncrypt(wk, mk);
+    const protocol = getOrInitProtocol();
+    const recipientPublicKey = ub64(recipientPublicKeyB64);
+    
+    const encrypted = await protocol.encryptMessage(recipientPublicKey, newPlaintextJson);

    await request({
        type: "dmEdit",
        credentials: { scheme: "Bearer", credentials: authToken },
        data: {
            id,
-            iv: b64(encMsg.iv),
-            ciphertext: b64(encMsg.ciphertext),
-            iv2: b64(wrap.iv),
-            wrappedMk: b64(wrap.ciphertext),
-            salt: b64(wkSalt)
+            ...encrypted
        }
    } as DMEditRequest);
 }
@@ -189,6 +150,4 @@ export async function markRead(id: number, authToken: string): Promise<void> {
 }

 // Re-export user functions for convenience
-export { fetchUsers, searchUsers, fetchUserPublicKey };
-
-
+export { fetchUsers, searchUsers, fetchUserPublicKey };
@@ -1,12 +1,12 @@
 import { API_BASE_URL } from "@/core/config";
-import { getAuthHeaders } from "../user/auth";
 import type { BackupBlob } from "@/core/types";
+import api from "@/core/api";

 /**
 * Fetches the current user's backup blob
 */
 export async function fetchBackupBlob(token: string): Promise<string | null> {
-    const headers = getAuthHeaders(token, true);
+    const headers = api.user.auth.getAuthHeaders(token, true);
    const res = await fetch(`${API_BASE_URL}/crypto/backup`, {
        method: "GET",
        headers
@@ -25,7 +25,7 @@ export async function fetchBackupBlob(token: string): Promise<string | null> {
 export async function uploadBackupBlob(blobJson: string, token: string): Promise<void> {
    const payload: BackupBlob = { blob: blobJson }

-    const headers = getAuthHeaders(token, true);
+    const headers = api.user.auth.getAuthHeaders(token, true);
    const res = await fetch(`${API_BASE_URL}/crypto/backup`, {
        method: "POST",
        headers,
@@ -1,8 +1,6 @@
 import { API_BASE_URL } from "@/core/config";
 import { getAuthHeaders } from "./account";
-import { ecdhSharedSecret, deriveWrappingKey } from "@/utils/crypto/asymmetric";
-import { importAesGcmKey, aesGcmEncrypt, aesGcmDecrypt } from "@/utils/crypto/symmetric";
-import { randomBytes } from "@/utils/crypto/kdf";
+import { ecdhSharedSecret, deriveWrappingKey, importAesGcmKey, aesGcmEncrypt, aesGcmDecrypt, randomBytes } from "@fromchat/protocol";
 import { getCurrentKeys } from "./account";
 import { request } from "@/core/websocket";
 import type { SendDMRequest, DmEnvelope, DMEditRequest, DmEncryptedJSON, BaseDmEnvelope, User } from "@/core/types";
@@ -1,8 +1,6 @@
 import { API_BASE_URL } from "@/core/config";
 import { getAuthHeaders } from "./account";
-import { ecdhSharedSecret, deriveWrappingKey } from "@/utils/crypto/asymmetric";
-import { importAesGcmKey, aesGcmEncrypt, aesGcmDecrypt } from "@/utils/crypto/symmetric";
-import { randomBytes } from "@/utils/crypto/kdf";
+import { ecdhSharedSecret, deriveWrappingKey, importAesGcmKey, aesGcmEncrypt, aesGcmDecrypt, randomBytes } from "@fromchat/protocol";
 import { getCurrentKeys } from "./account";
 import { request } from "@/core/websocket";
 import type { SendDMRequest, DmEnvelope, DMEditRequest, DmEncryptedJSON, BaseDmEnvelope, User } from "@/core/types";
@@ -1,9 +1,7 @@
 import { API_BASE_URL } from "@/core/config";
 import type { LoginRequest, RegisterRequest, LoginResponse, Headers } from "@/core/types";
-import { generateX25519KeyPair } from "@/utils/crypto/asymmetric";
-import { encodeBlob, encryptBackupWithPassword, decryptBackupWithPassword, decodeBlob } from "@/utils/crypto/backup";
+import { generateX25519KeyPair, hkdfExtractAndExpand, encodeBlob, encryptBackupWithPassword, decryptBackupWithPassword, decodeBlob } from "@fromchat/protocol";
 import { b64, ub64 } from "@/utils/utils";
-import { hkdfExtractAndExpand } from "@/utils/crypto/kdf";
 import { fetchPublicKey, uploadPublicKey } from "../crypto/identity";
 import { fetchBackupBlob, uploadBackupBlob } from "../crypto/backup";

@@ -1,7 +1,5 @@
-import { importAesGcmKey, aesGcmEncrypt, aesGcmDecrypt } from "@/utils/crypto/symmetric";
-import { randomBytes } from "@/utils/crypto/kdf";
+import { importAesGcmKey, aesGcmEncrypt, aesGcmDecrypt, randomBytes, ecdhSharedSecret, deriveWrappingKey } from "@fromchat/protocol";
 import { b64, ub64 } from "@/utils/utils";
-import { ecdhSharedSecret, deriveWrappingKey } from "@/utils/crypto/asymmetric";
 import api from "@/core/api";
 import type { WrappedSessionKeyPayload } from "@/core/types";

@@ -2,7 +2,7 @@ import api from "@/core/api";
 import type { CallSignalingMessage, WrappedSessionKeyPayload } from "@/core/types";
 import { request } from "@/core/websocket";
 import { wrapCallSessionKeyForRecipient, unwrapCallSessionKeyFromSender, rotateCallSessionKey } from "./encryption";
-import { importAesGcmKey } from "@/utils/crypto/symmetric";
+import { importAesGcmKey } from "@fromchat/protocol";
 import E2EEWorker from "./e2eeWorker?worker";
 import { delay } from "@/utils/utils";

@@ -6,8 +6,7 @@ import { parse } from "marked";
 import { escape as escapeHtml } from "he";
 import { useEffect, useState, useRef, useMemo } from "react";
 import api from "@/core/api";
-import { ecdhSharedSecret, deriveWrappingKey } from "@/utils/crypto/asymmetric";
-import { importAesGcmKey, aesGcmDecrypt } from "@/utils/crypto/symmetric";
+import { ecdhSharedSecret, deriveWrappingKey, importAesGcmKey, aesGcmDecrypt } from "@fromchat/protocol";
 import { useUserStore } from "@/state/user";
 import { useProfileStore } from "@/state/profile";
 import { StatusBadge } from "@/core/components/StatusBadge";
@@ -0,0 +1,26 @@
+import { FromChatProtocol } from "@fromchat/protocol";
+import { getCurrentKeys } from "@/core/api/user/auth";
+
+let protocolInstance: FromChatProtocol | null = null;
+
+export function getFromChatProtocol(): FromChatProtocol | null {
+	return protocolInstance;
+}
+
+export function initializeFromChatProtocol(privateKey: Uint8Array): FromChatProtocol {
+	protocolInstance = new FromChatProtocol(privateKey);
+	return protocolInstance;
+}
+
+export function getOrInitProtocol(): FromChatProtocol {
+	if (protocolInstance) {
+		return protocolInstance;
+	}
+	
+	const keys = getCurrentKeys();
+	if (!keys) {
+		throw new Error("Keys not initialized");
+	}
+	
+	return initializeFromChatProtocol(keys.privateKey);
+}
@@ -14,10 +14,11 @@
        "noEmit": true,

        /* Path mapping */
-        "baseUrl": ".",
-        "paths": {
-            "@/*": ["src/*"]
-        },
+          "baseUrl": ".",
+          "paths": {
+              "@/*": ["src/*"],
+              "@fromchat/protocol": ["./packages/fromchat-protocol/src"]
+          },

        /* Linting */
        "strict": true,
@@ -31,6 +32,6 @@
        "jsx": "react-jsx",
        "jsxImportSource": "react"
    },
-    "include": ["src", "electron.d.ts"],
+      "include": ["src", "electron.d.ts", "packages/fromchat-protocol/src"],
    "exclude": ["**/__*/**", "__*"]
 }
@@ -70,7 +70,8 @@ export default defineConfig({
    plugins: plugins,
    resolve: {
        alias: {
-            "@": path.resolve(__dirname, "./src")
+            "@": path.resolve(__dirname, "./src"),
+            "@fromchat/protocol": path.resolve(__dirname, "./packages/fromchat-protocol/src/index.ts")
        }
    },
    server: {
@@ -89,6 +90,7 @@ export default defineConfig({
    },
    appType: "spa",
    optimizeDeps: {
+        exclude: ["@fromchat/protocol"],
        esbuildOptions: {
            target: "es2022"
        }
@@ -67,7 +67,11 @@
        "vite-plugin-html": "^3.2.2",
        "vite-plugin-sass-dts": "^1.3.34"
    },
+    "workspaces": [
+        "frontend/packages/fromchat-protocol"
+    ],
    "dependencies": {
+        "@fromchat/protocol": "workspace:*",
        "electron-squirrel-startup": "^1.0.1",
        "escape-string-regexp": "^5.0.0",
        "he": "^1.2.0",