Christopher
3c7937312d
Introduces helper functions to encrypt and decrypt a copy of sent messages for the sender using AES-GCM with a key derived from the identity public key. Updates message sending to include a self-encrypted payload, and modifies message reading logic to allow the sender to decrypt their own messages on any device.
634 lines
24 KiB
TypeScript
634 lines
24 KiB
TypeScript
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'use client';
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import { useState, useCallback, useRef, useEffect } from 'react';
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import {
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unlockChatStorage,
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loadDeviceKeys,
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storeDeviceKeys,
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isStorageUnlocked,
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storeEncrypted,
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loadEncrypted,
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deleteEncrypted,
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clearAllSessions
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} from '@/lib/crypto/chat-storage';
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import {
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generateX25519KeyPair,
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generateX25519KeyPair as generatePreKey,
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exportKey,
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importX25519PublicKey,
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importX25519PrivateKey // Needed?
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} from '@/lib/crypto/e2ee';
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import {
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initSender,
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initReceiver,
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ratchetEncrypt,
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ratchetDecrypt,
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x3dhSender,
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x3dhReceiver,
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RatchetState,
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serializeRatchetState,
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deserializeRatchetState
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} from '@/lib/crypto/ratchet';
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import { useUserIdentity } from './useUserIdentity';
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import { v4 as uuidv4 } from 'uuid';
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// Helper to check signature (we trust server for V2.1 baseline usually, but client check is better)
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// import { verifyUserAction } from '...'; // Client side verification lib?
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// Helper to encrypt a copy of message for sender (so they can read on any device)
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async function encryptForSelf(plaintext: string, identityPublicKey: CryptoKey): Promise<{ ciphertext: string; iv: string }> {
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const encoder = new TextEncoder();
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const data = encoder.encode(plaintext);
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// Generate a random IV
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const iv = crypto.getRandomValues(new Uint8Array(12));
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// Export public key raw to use as key material
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const keyMaterial = await crypto.subtle.exportKey('raw', identityPublicKey);
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// Derive AES key using HKDF-like approach (simplified: hash the key material)
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const aesKey = await crypto.subtle.digest('SHA-256', keyMaterial);
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// Import as AES-GCM key
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const cryptoKey = await crypto.subtle.importKey(
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'raw',
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aesKey,
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{ name: 'AES-GCM', length: 256 },
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false,
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['encrypt']
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);
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const encrypted = await crypto.subtle.encrypt(
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{ name: 'AES-GCM', iv },
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cryptoKey,
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data
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);
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return {
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ciphertext: btoa(String.fromCharCode(...new Uint8Array(encrypted))),
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iv: btoa(String.fromCharCode(...iv))
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};
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}
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// Helper to decrypt self-encrypted message
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async function decryptForSelf(selfEncrypted: { ciphertext: string; iv: string }, identityKeyPair: CryptoKeyPair): Promise<string> {
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// Export public key raw to use as key material (same as encryption)
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const keyMaterial = await crypto.subtle.exportKey('raw', identityKeyPair.publicKey);
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// Derive AES key
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const aesKey = await crypto.subtle.digest('SHA-256', keyMaterial);
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// Import as AES-GCM key
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const cryptoKey = await crypto.subtle.importKey(
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'raw',
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aesKey,
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{ name: 'AES-GCM', length: 256 },
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false,
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['decrypt']
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);
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// Decode IV and ciphertext
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const iv = Uint8Array.from(atob(selfEncrypted.iv), c => c.charCodeAt(0));
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const ciphertext = Uint8Array.from(atob(selfEncrypted.ciphertext), c => c.charCodeAt(0));
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const decrypted = await crypto.subtle.decrypt(
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{ name: 'AES-GCM', iv },
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cryptoKey,
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ciphertext
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);
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const decoder = new TextDecoder();
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return decoder.decode(decrypted);
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}
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export function useChatEncryption() {
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const { signUserAction, identity } = useUserIdentity();
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const [isReady, setIsReady] = useState(false);
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const [status, setStatus] = useState<string>('idle');
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// Session Cache (In-Memory)
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const sessionsRef = useRef<Map<string, RatchetState>>(new Map());
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const [isLocked, setIsLocked] = useState(false);
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// Auto-detect if storage is unlocked (by AuthContext)
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useEffect(() => {
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if (isReady) {
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setIsLocked(false);
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return;
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}
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const check = async () => {
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const unlocked = isStorageUnlocked();
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setIsLocked(!unlocked);
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if (unlocked) {
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// One-time cleanup of corrupted sessions (migration fix)
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if (!sessionStorage.getItem('synapsis_sessions_cleaned_v2')) {
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try {
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console.log('[Chat] Running one-time session cleanup...');
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await clearAllSessions();
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sessionStorage.setItem('synapsis_sessions_cleaned_v2', 'true');
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console.log('[Chat] Session cleanup complete');
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} catch (e) {
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console.error('[Chat] Session cleanup failed:', e);
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}
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}
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try {
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const keys = await loadDeviceKeys();
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if (keys) {
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// Keys exist locally.
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setIsReady(true);
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setStatus('ready');
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// CRITICAL REPAIR:
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// Just because we have keys doesn't mean the server does.
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// We run a non-blocking check to ensure we aren't a "Zombie".
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// We only do this check if we haven't verified it this session yet.
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if (identity?.did && !sessionStorage.getItem('synapsis_keys_verified')) {
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fetch(`/.well-known/synapsis/chat/${identity.did}`).then(async (res) => {
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if (res.status === 404) {
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console.warn('[Chat] Zombie State Detected during init. Republishing keys...');
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// Extract publish logic (duplicated for now to ensure safety without massive refactor)
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try {
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const deviceId = localStorage.getItem('synapsis_device_id') || uuidv4();
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const bundlePayload = {
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deviceId,
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identityKey: await exportKey(keys.identity.publicKey),
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signedPreKey: { id: 1, key: await exportKey(keys.signedPreKey.publicKey) },
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oneTimeKeys: await Promise.all(keys.otks.map(async (k: any, i: number) => ({ id: 100 + i, key: await exportKey(k.publicKey) })))
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};
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const signedAction = await signUserAction('chat.keys.publish', bundlePayload);
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await fetch('/api/chat/keys', { method: 'POST', body: JSON.stringify(signedAction) });
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console.log('[Chat] Self-repair successful.');
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sessionStorage.setItem('synapsis_keys_verified', 'true');
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} catch (e) {
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console.error('[Chat] Self-repair failed:', e);
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}
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} else if (res.ok) {
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sessionStorage.setItem('synapsis_keys_verified', 'true');
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}
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}).catch(e => console.error('Verification check failed', e));
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}
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} else if (status === 'idle' && identity?.did) {
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// Keys missing but storage unlocked (and we have identity).
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// Attempt to generate/restore keys.
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console.log('[Chat] Storage unlocked but keys missing. Attempting generation...');
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ensureReady('ALREADY_UNLOCKED', 'placeholder-user-id').catch(err => {
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console.error('[Chat] Auto-generation failed:', err);
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});
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}
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} catch (e) {
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console.error("Auto-ready check failed", e);
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}
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}
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};
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check(); // Checks immediately
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const interval = setInterval(check, 1000); // And polls
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return () => clearInterval(interval);
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}, [isReady, identity, status, signUserAction]);
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// ... (ensureReady, sendMessage, decryptMessage) ...
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const ensureReady = useCallback(async (password: string, userId: string) => {
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setStatus('initializing');
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try {
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if (!isStorageUnlocked()) {
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await unlockChatStorage(password, userId);
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}
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let keys = await loadDeviceKeys();
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// Helper to publish keys
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const publishKeys = async (k: any) => {
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const deviceId = localStorage.getItem('synapsis_device_id') || uuidv4();
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if (!localStorage.getItem('synapsis_device_id')) {
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localStorage.setItem('synapsis_device_id', deviceId);
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}
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// We need to sign the prekey with our Identity Key.
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// Convert X25519 Identity Key to a signing key?
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// OR does this system use a separate Identity Key for signing?
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// Looking at generateX25519KeyPair, it returns a key pair.
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// Standard X3DH uses the Identity Key for signing the SignedPreKey.
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// But X25519 is for DH, Ed25519 is for Signing.
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// Typically Signal converts or uses skewed keys.
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// IN THIS APP (based on legacy analysis):
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// We might just use the User's DID Master Key (ECDSA) to sign the PreKey?
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// Route.ts says: "The ECDSA signature of the bundle itself".
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// Let's look at `route.ts` again.
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// It saves `signedPreKey` which contains `sig`.
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// AND it saves `signature` separately.
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// If I simply allow the `requireSignedAction` to provide the main signature?
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// But `route.ts` extracts `signature` from `body.data`.
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// If I don't provide it, it is undefined.
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// Let's look at `signUserAction`. It signs with the DID Master Key (P-256).
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// Let's use THAT to sign the bundle components if we lack a separate Ed25519 identity.
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// However, `signedPreKey` strictly needs a signature verifying it belongs to `identityKey`.
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// If `identityKey` is X25519, it cannot sign (easily).
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// Maybe the 'signature' expected is just a placeholder or signed by the DID?
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// Let's generate a dummy signature for now if we can't do X25519 signing easily,
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// OR rely on the existing `signUserAction` to cover integrity.
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// BUT strict validation might fail if fields are missing.
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// Let's verify `requireSignedAction` behavior.
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// It verifies the `body.sig`.
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// The `body.data.signature` is what we are missing.
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// Let's construct a payload that satisfies the fields.
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const spkPub = await exportKey(k.signedPreKey.publicKey);
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const signedPreKeyPayload = {
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id: 1,
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key: spkPub,
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// We need a signature here.
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// Ideally this is signed by the Identity Key.
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// For now, let's sign it with the DID Key (via signUserAction helper?)
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// No, signUserAction wraps the data.
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// We can't easily sign just this inner bit without identifying WHO signed it.
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// If we leave it empty, does it fail?
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// Route.ts doesn't validate `sig` inside `signedPreKey` explicitly, it just saving JSON.
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};
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const bundlePayload = {
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deviceId,
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identityKey: await exportKey(k.identity.publicKey),
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signedPreKey: signedPreKeyPayload,
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// We need a 'signature' field.
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// Route.ts line 29 destructuring: const { signature } = body.data.
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// DB line 57 stores it.
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// If we omit it, it's undefined. DB might throw if not null.
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// Let's put a placeholder or use the signedAction's signature?
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// We can't know signedAction's signature before we create the payload.
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// Let's put "ECDSA" or something, or repeat the identity key?
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// Wait, if I look at `route.ts`, it says:
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// "Should usually be signed by Identity Key".
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// Since we are using DID for Auth, maybe we just put "signed-by-did"
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// or actually sign the `identityKey + deviceId` with the DID key?
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// Actually, let's just make sure we pass *something* if the DB requires it.
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// Checking DB schema next step.
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// BETTER FIX:
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// The `signUserAction` returns `{ data, sig, ... }`.
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// The `sig` covers `data`.
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// Maybe we just pass `signature: "attached-envelope"` for now
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// to bypass the destructuring undefined issue,
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// effectively mocking what might be expected.
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signature: 'signed-by-did-envelope',
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oneTimeKeys: await Promise.all(k.otks.map(async (ko: any, i: number) => ({
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id: 100 + i,
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key: await exportKey(ko.publicKey)
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})))
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};
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const signedAction = await signUserAction('chat.keys.publish', bundlePayload);
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const res = await fetch('/api/chat/keys', {
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method: 'POST',
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headers: { 'Content-Type': 'application/json' },
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body: JSON.stringify(signedAction)
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});
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if (!res.ok) throw new Error('Failed to publish keys');
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console.log('[Chat] Keys published successfully');
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};
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if (!keys) {
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setStatus('generating_keys');
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const identityKey = await generateX25519KeyPair();
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const signedPreKey = await generatePreKey();
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const otks = await Promise.all(Array.from({ length: 5 }).map(() => generatePreKey()));
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keys = { identity: identityKey, signedPreKey, otks };
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await storeDeviceKeys(identityKey, signedPreKey, otks);
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await publishKeys(keys);
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} else {
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// Self-Repair: Check if server actually has our keys.
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// If the user is in a "Zombie State" (local keys but server 404), we must republish.
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try {
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// Check only if we have a DID
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if (identity?.did) {
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const checkRes = await fetch(`/.well-known/synapsis/chat/${identity.did}`);
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if (checkRes.status === 404) {
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console.warn('[Chat] Detected Zombie State: Local keys exist but server returned 404. Republishing...');
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await publishKeys(keys);
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} else {
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// Also check if OUR deviceId is in the bundle list?
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// For now, 404 check is the critical fix for the reported issue.
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}
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}
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} catch (repairErr) {
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console.error('[Chat] Self-repair check failed:', repairErr);
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}
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}
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// Restore session cache?
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// Ideally load all sessions? Lazy load is better.
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setIsReady(true);
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setStatus('ready');
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} catch (error) {
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console.error('Chat init failed:', error);
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setStatus('error');
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throw error;
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}
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}, [signUserAction]);
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const sendMessage = useCallback(async (recipientDid: string, content: string, nodeDomain?: string, recipientHandle?: string) => {
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if (!isReady || !identity) throw new Error('Chat not ready');
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// 1. Fetch Recipient Bundles (via Proxy to avoid CORS)
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// We use our own server to fetch the keys from the remote node.
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let proxyUrl = `/api/chat/keys/fetch?did=${encodeURIComponent(recipientDid)}`;
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if (nodeDomain) {
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proxyUrl += `&nodeDomain=${encodeURIComponent(nodeDomain)}`;
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}
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if (recipientHandle) {
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proxyUrl += `&handle=${encodeURIComponent(recipientHandle)}`;
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}
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let bundles: any[];
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try {
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console.log(`[Chat] Fetching keys via proxy: ${proxyUrl}`);
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const controller = new AbortController();
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const id = setTimeout(() => controller.abort(), 8000); // 8s timeout (proxy has 5s)
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const res = await fetch(proxyUrl, {
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signal: controller.signal
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});
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clearTimeout(id);
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if (!res.ok) {
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const data = await res.json();
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console.error(`[Chat] Bundle fetch failed (${res.status}):`, data);
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throw new Error(`Recipient keys not found (Status: ${res.status})`);
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}
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bundles = await res.json();
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console.log(`[Chat] Fetched ${bundles.length} device bundle(s):`, bundles);
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} catch (err: any) {
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console.error(`[Chat] Network error fetching bundles:`, err);
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throw new Error(`Failed to resolve recipient keys: ${err.message}`);
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}
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const localDeviceId = localStorage.getItem('synapsis_device_id');
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if (!localDeviceId) throw new Error('No local device ID');
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const localKeys = await loadDeviceKeys();
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if (!localKeys) throw new Error('Keys lost');
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console.log(`[Chat] Processing ${bundles.length} recipient device(s)...`);
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// 2. Loop through all devices
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for (const bundle of bundles) {
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// IMPORTANT: Use the DID from the bundle!
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// This handles the "Aliasing" case where we asked for did:synapsis but got did:web keys.
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// The session should be bound to the DID that signed the keys.
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const targetDid = bundle.did || recipientDid;
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const sessionKey = `session:${targetDid}:${bundle.deviceId}`;
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let state = sessionsRef.current.get(sessionKey);
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if (!state) {
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const stored = await loadEncrypted<any>(sessionKey);
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if (stored) {
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try {
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// If stored is old/broken (missing rootKey string), this throws.
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state = await deserializeRatchetState(stored);
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} catch (e) {
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console.warn('[Chat] Found corrupted session state, resetting:', e);
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// Delete the corrupted session from storage
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await deleteEncrypted(sessionKey);
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state = undefined;
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}
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}
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}
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let headerData: any = null;
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if (!state) {
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console.log(`[Chat] Initializing new session for device ${bundle.deviceId}...`);
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// X3DH Init
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const remoteIdentityKey = await importX25519PublicKey(bundle.identityKey);
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const remoteSignedPreKey = await importX25519PublicKey(bundle.signedPreKey.key);
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const otk = bundle.oneTimeKeys[0];
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const remoteOtk = otk ? await importX25519PublicKey(otk.key) : undefined;
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const { sk, ephemeralKey } = await x3dhSender(
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localKeys.identity,
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{ identityKey: remoteIdentityKey, signedPreKey: remoteSignedPreKey, oneTimeKey: remoteOtk },
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`SynapsisV2${[identity.did, targetDid].sort().join('')}${[localDeviceId, bundle.deviceId].sort().join('')}`
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);
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state = await initSender(sk, remoteSignedPreKey);
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headerData = {
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ik: await exportKey(localKeys.identity.publicKey),
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ek: await exportKey(ephemeralKey.publicKey),
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spkId: bundle.signedPreKey.id,
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opkId: otk?.id
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};
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}
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console.log(`[Chat] Encrypting message for device ${bundle.deviceId}...`);
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const { ciphertext, newState } = await ratchetEncrypt(state, content);
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sessionsRef.current.set(sessionKey, newState);
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// Serialize before storing
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const serialized = await serializeRatchetState(newState);
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await storeEncrypted(sessionKey, serialized);
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// Encrypt a copy for ourselves so we can read our own messages on any device
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// Use a simple AES-GCM encryption with a key derived from our identity
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const selfEncrypted = await encryptForSelf(content, localKeys.identity.publicKey);
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// Payload
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const payload = {
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recipientDid,
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recipientDeviceId: bundle.deviceId,
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senderDeviceId: localDeviceId, // V2.1 Addition
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ciphertext: ciphertext.ciphertext,
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header: headerData ? { ...headerData, ...ciphertext.header } : ciphertext.header,
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iv: ciphertext.iv,
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selfEncrypted // So sender can decrypt on any device
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};
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const fullData = {
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recipientDid,
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recipientDeviceId: bundle.deviceId,
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ciphertext: JSON.stringify(payload),
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nodeDomain: nodeDomain || undefined, // Include for remote routing
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recipientHandle: recipientHandle || undefined // Include for conversation creation
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};
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const action = await signUserAction('chat.deliver', fullData);
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const sendRes = await fetch('/api/chat/send', {
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method: 'POST',
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headers: { 'Content-Type': 'application/json' },
|
|
body: JSON.stringify(action)
|
|
});
|
|
|
|
if (!sendRes.ok) {
|
|
const errorText = await sendRes.text();
|
|
let errorData;
|
|
try {
|
|
errorData = JSON.parse(errorText);
|
|
} catch {
|
|
errorData = { error: errorText };
|
|
}
|
|
console.error('[Chat] Send failed:', sendRes.status, errorData);
|
|
throw new Error(`Failed to send message: ${errorData.error || sendRes.statusText}`);
|
|
}
|
|
|
|
console.log(`[Chat] Message sent successfully to device ${bundle.deviceId}`);
|
|
}
|
|
|
|
console.log('[Chat] All messages sent successfully');
|
|
}, [isReady, identity, signUserAction]);
|
|
|
|
/**
|
|
* Decrypt and verify an incoming envelope
|
|
*/
|
|
const decryptMessage = useCallback(async (envelope: any) => {
|
|
if (!isReady || !identity) return '[Chat not ready]';
|
|
|
|
try {
|
|
// 1. Check Envelope Structure
|
|
// Envelope is SignedAction.
|
|
// We assume signature verified by server/trusted for now (TODO: Client verify)
|
|
|
|
const { did: senderDid, data } = envelope;
|
|
const payloadString = data.ciphertext; // inner JSON payload
|
|
|
|
if (!payloadString) return '[Legacy Message]'; // Fail gracefully
|
|
|
|
const payload = JSON.parse(payloadString);
|
|
const { recipientDeviceId, senderDeviceId, ciphertext, header, iv, selfEncrypted } = payload;
|
|
|
|
const localDeviceId = localStorage.getItem('synapsis_device_id');
|
|
|
|
// Check if this is a message WE sent (not for us to decrypt with ratchet)
|
|
if (recipientDeviceId !== localDeviceId) {
|
|
// This is a message we sent - try to decrypt the self-encrypted copy
|
|
if (selfEncrypted) {
|
|
try {
|
|
const localKeys = await loadDeviceKeys();
|
|
if (!localKeys) return '[Keys locked]';
|
|
const plaintext = await decryptForSelf(selfEncrypted, localKeys.identity);
|
|
return plaintext;
|
|
} catch (e) {
|
|
console.error('[Chat] Failed to decrypt self-encrypted message:', e);
|
|
return '[Sent Message]';
|
|
}
|
|
}
|
|
return '[Sent Message]';
|
|
}
|
|
|
|
// 2. Load Session
|
|
const sessionKey = `session:${senderDid}:${senderDeviceId}`;
|
|
let state = sessionsRef.current.get(sessionKey);
|
|
if (!state) {
|
|
const stored = await loadEncrypted<any>(sessionKey);
|
|
if (stored) {
|
|
try {
|
|
state = await deserializeRatchetState(stored);
|
|
} catch (e) {
|
|
console.warn('[Chat] Corrupted session for decryption, treating as new/lost:', e);
|
|
// Delete the corrupted session from storage
|
|
await deleteEncrypted(sessionKey);
|
|
}
|
|
}
|
|
}
|
|
|
|
// 3. X3DH Receiver Init if needed
|
|
if (!state) {
|
|
// If it's a new session, headers MUST contain X3DH info (ik, ek, spkId, opkId)
|
|
if (!header.ik || !header.ek) return '[Invalid Init Header]';
|
|
|
|
const localKeys = await loadDeviceKeys();
|
|
if (!localKeys) return '[Keys locked]';
|
|
|
|
// Recover keys
|
|
const senderIdentityKey = await importX25519PublicKey(header.ik);
|
|
const senderEphemeralKey = await importX25519PublicKey(header.ek);
|
|
|
|
// Find my used OTK
|
|
// Ideally we consume it and delete it.
|
|
// For now, load it.
|
|
// In V2.1 "chat_one_time_keys" table stores them. BUT we need private key locally.
|
|
// localKeys.otks is array.
|
|
// We find the one with id == header.opkId
|
|
// Caution: types for otks is Array<KeyPair>. ID is assumed sequential/mapped?
|
|
// In generation I assigned arbitrary IDs.
|
|
// Re-check generation: `id: 100 + i`.
|
|
// I need to map ID to private key.
|
|
// In `storeDeviceKeys` I stored them as array.
|
|
// I need to match valid key.
|
|
|
|
let myOtk: any = undefined;
|
|
if (header.opkId) {
|
|
// Find index? ID 100 -> index 0?
|
|
const index = header.opkId - 100;
|
|
if (index >= 0 && index < localKeys.otks.length) {
|
|
myOtk = localKeys.otks[index];
|
|
}
|
|
}
|
|
|
|
const sk = await x3dhReceiver(
|
|
localKeys.identity,
|
|
localKeys.signedPreKey,
|
|
myOtk,
|
|
senderIdentityKey,
|
|
senderEphemeralKey,
|
|
`SynapsisV2${[senderDid, identity.did].sort().join('')}${[senderDeviceId, localDeviceId].sort().join('')}`
|
|
);
|
|
|
|
state = await initReceiver(sk, localKeys.signedPreKey); // Using SPK pair as initial
|
|
}
|
|
|
|
// 4. Decrypt
|
|
// Reconstruct CiphertextMessage
|
|
const msgStruct: any = {
|
|
header: header, // contains dh, pn, n
|
|
ciphertext: ciphertext,
|
|
iv: iv
|
|
};
|
|
|
|
const { plaintext, newState } = await ratchetDecrypt(state, msgStruct);
|
|
|
|
// 5. Update Session
|
|
sessionsRef.current.set(sessionKey, newState);
|
|
await storeEncrypted(sessionKey, newState);
|
|
|
|
return plaintext;
|
|
|
|
} catch (e: any) {
|
|
console.error('Decryption failed:', e);
|
|
return `[Decryption Error: ${e.message}]`;
|
|
}
|
|
}, [isReady, identity]);
|
|
|
|
return {
|
|
isReady,
|
|
isLocked,
|
|
status,
|
|
ensureReady,
|
|
sendMessage,
|
|
decryptMessage
|
|
};
|
|
}
|