feat(hardening): M-Hard 1-5 — crypto, auth, rate limit, fingerprints, rotation

M-Hard 1: Cryptographic Hardening
- constantTimeEqual, zeroize, randomUint32 on CryptoProvider
- Fix Math.random() → crypto.randomUint32() for registrationId
- Zero message keys and chain keys after use in ratchet.ts
- Constant-time trust comparison in MemoryStorage + SQLiteStorage
- Timing variance test catches early-exit regressions

M-Hard 2: Self-Authenticated Prekey Server
- Ed25519 signature verification on all write routes
- signPayload/verifyPayload with canonical JSON, ±5 min replay window
- Address validation (NFKC, alphanumeric + :_-.)
- Global ShadeError → HTTP status mapping
- ShadeFetchTransport signs requests when signingPrivateKey provided
- Anonymous bundle fetches still allowed (read-only)

M-Hard 3: Rate Limiting + DoS Protection
- Token bucket rate limiter with pluggable store
- Per-route limits: register 5/h/IP, fetch 60/min/IP, replenish 10/min/id
- 64KB body size limit on POST
- Retry-After header on 429 responses

M-Hard 4: Auto-replenish + Fingerprints + Session Reset
- Safety numbers (12 groups × 5 digits, Signal-style)
- ensurePreKeyStock, resetSession, acceptIdentityChange
- verifyRemoteIdentity for out-of-band comparison

M-Hard 5: Identity Rotation with Grace Period
- rotateIdentity archives old identity, generates fresh signed prekey
- RetiredIdentity storage with addRetired/getRetired/pruneRetired
- 7-day default grace period for decrypting old sessions
- pruneExpiredIdentities for cleanup

M-Hard 8: Error Hierarchy
- New error types: Network, Storage, Validation, Timeout, RateLimit,
  Configuration, Unauthorized, Replay, IdentityRotation
- All errors have stable SHADE_* codes
- errorToHttpStatus for consistent HTTP mapping
- toJSON() for network serialization

188 tests passing, zero failures.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
This commit is contained in:
2026-04-10 17:45:34 +02:00
parent 7d214dc614
commit 96a8c210b2
25 changed files with 1835 additions and 257 deletions

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@@ -1,25 +1,55 @@
import type { PreKeyBundle, OneTimePreKey } from '@shade/core';
import type { PreKeyBundle, OneTimePreKey, CryptoProvider } from '@shade/core';
import { fromBase64, NetworkError } from '@shade/core';
/**
* HTTP transport client for the Shade Prekey Server.
*
* Signing: write operations (register, replenish, delete) are signed with
* the caller's Ed25519 identity signing key. The caller must provide a
* signing function via the constructor.
*
* Usage:
* ```ts
* const transport = new ShadeFetchTransport('https://shade.example.com');
* await transport.register('alice', bundle, oneTimePreKeys);
* const bundle = await transport.fetchBundle('bob');
* const transport = new ShadeFetchTransport({
* baseUrl: 'https://shade.example.com',
* crypto,
* signingKey: identity.signingPrivateKey,
* });
* await transport.register('alice', identity, signedPreKey, oneTimePreKeys);
* const bundle = await transport.fetchBundle('bob'); // anonymous
* ```
*/
export class ShadeFetchTransport {
constructor(
private readonly baseUrl: string,
private readonly authToken?: string,
) {}
private readonly baseUrl: string;
private readonly crypto: CryptoProvider;
private readonly signingPrivateKey?: Uint8Array;
constructor(options: { baseUrl: string; crypto: CryptoProvider; signingPrivateKey?: Uint8Array }) {
this.baseUrl = options.baseUrl;
this.crypto = options.crypto;
this.signingPrivateKey = options.signingPrivateKey;
}
private headers(): Record<string, string> {
const h: Record<string, string> = { 'Content-Type': 'application/json' };
if (this.authToken) h['Authorization'] = `Bearer ${this.authToken}`;
return h;
return { 'Content-Type': 'application/json' };
}
/** Sign a payload using the configured signing key */
private async sign<T extends Record<string, unknown>>(payload: T): Promise<T & { signedAt: number; signature: string }> {
if (!this.signingPrivateKey) {
throw new Error('ShadeFetchTransport: signingPrivateKey is required for write operations');
}
const signedAt = Date.now();
const withTs = { ...payload, signedAt, signature: '' };
// Canonicalize: sort keys, omit signature
const { signature, ...rest } = withTs;
const sorted = Object.keys(rest).sort().reduce<Record<string, unknown>>((acc, k) => {
acc[k] = (rest as Record<string, unknown>)[k];
return acc;
}, {});
const bytes = new TextEncoder().encode(JSON.stringify(sorted));
const sig = await this.crypto.sign(this.signingPrivateKey, bytes);
return { ...payload, signedAt, signature: Buffer.from(sig).toString('base64') };
}
/** Register identity and upload prekey bundle + one-time prekeys */
@@ -47,20 +77,22 @@ export class ShadeFetchTransport {
}));
}
const signed = await this.sign(body);
const res = await fetch(`${this.baseUrl}/v1/keys/register`, {
method: 'POST',
headers: this.headers(),
body: JSON.stringify(body),
body: JSON.stringify(signed),
});
if (!res.ok) throw new Error(`Register failed: ${res.status}`);
if (!res.ok) throw new NetworkError(`Register failed: ${res.status}`, res.status);
}
/** Fetch a prekey bundle for a peer (consumes one one-time prekey) */
/** Fetch a prekey bundle for a peer (anonymous, consumes one one-time prekey) */
async fetchBundle(address: string): Promise<PreKeyBundle> {
const res = await fetch(`${this.baseUrl}/v1/keys/bundle/${encodeURIComponent(address)}`, {
headers: this.headers(),
});
if (!res.ok) throw new Error(`Fetch bundle failed: ${res.status}`);
if (!res.ok) throw new NetworkError(`Fetch bundle failed: ${res.status}`, res.status);
const data = await res.json();
return {
@@ -81,36 +113,50 @@ export class ShadeFetchTransport {
};
}
/** Upload additional one-time prekeys */
/** Upload additional one-time prekeys (signed) */
async replenish(
address: string,
keys: Array<{ keyId: number; publicKey: Uint8Array }>,
): Promise<number> {
const body = {
address,
oneTimePreKeys: keys.map((k) => ({
keyId: k.keyId,
publicKey: toB64(k.publicKey),
})),
};
const signed = await this.sign(body);
const res = await fetch(`${this.baseUrl}/v1/keys/replenish`, {
method: 'POST',
headers: this.headers(),
body: JSON.stringify({
address,
oneTimePreKeys: keys.map((k) => ({
keyId: k.keyId,
publicKey: toB64(k.publicKey),
})),
}),
body: JSON.stringify(signed),
});
if (!res.ok) throw new Error(`Replenish failed: ${res.status}`);
if (!res.ok) throw new NetworkError(`Replenish failed: ${res.status}`, res.status);
const data = await res.json();
return data.remaining;
}
/** Get remaining one-time prekey count */
/** Get remaining one-time prekey count (anonymous) */
async getKeyCount(address: string): Promise<number> {
const res = await fetch(`${this.baseUrl}/v1/keys/count/${encodeURIComponent(address)}`, {
headers: this.headers(),
});
if (!res.ok) throw new Error(`Count failed: ${res.status}`);
if (!res.ok) throw new NetworkError(`Count failed: ${res.status}`, res.status);
const data = await res.json();
return data.count;
}
/** Delete all keys for this identity (signed) */
async unregister(address: string): Promise<void> {
const signed = await this.sign({ address });
const res = await fetch(`${this.baseUrl}/v1/keys/${encodeURIComponent(address)}`, {
method: 'DELETE',
headers: this.headers(),
body: JSON.stringify(signed),
});
if (!res.ok) throw new NetworkError(`Unregister failed: ${res.status}`, res.status);
}
}
function toB64(bytes: Uint8Array): string {

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@@ -8,55 +8,55 @@ const crypto = new SubtleCryptoProvider();
describe('ShadeFetchTransport', () => {
test('full flow: register → fetch bundle → establish session → talk', async () => {
// Start in-process prekey server
const store = new MemoryPrekeyStore();
const server = createPrekeyServer({ store });
const server = createPrekeyServer({ crypto, store, disableRateLimit: true });
// We'll use Hono's request() method directly instead of actual HTTP
// But ShadeFetchTransport uses fetch(), so let's start a real server
const port = 19000 + Math.floor(Math.random() * 1000);
const handle = Bun.serve({ port, fetch: server.fetch });
try {
const baseUrl = `http://localhost:${port}`;
const transport = new ShadeFetchTransport(baseUrl);
// ─── Bob: register with prekey server ────────────────
// ─── Bob: set up session manager, register with transport ──
const bobStorage = new MemoryStorage();
const bobManager = new ShadeSessionManager(crypto, bobStorage);
await bobManager.initialize();
const bobIdentity = await bobStorage.getIdentityKeyPair();
const bobTransport = new ShadeFetchTransport({
baseUrl,
crypto,
signingPrivateKey: bobIdentity!.signingPrivateKey,
});
const bobOTPKs = await bobManager.generateOneTimePreKeys(5);
const bobBundle = await bobManager.createPreKeyBundle();
await transport.register(
await bobTransport.register(
'bob',
bobManager.getPublicIdentity(),
bobBundle.signedPreKey,
bobOTPKs,
);
// Verify count
const count = await transport.getKeyCount('bob');
expect(count).toBe(5);
expect(await bobTransport.getKeyCount('bob')).toBe(5);
// ─── Alice: fetch bundle and establish session ───────
// ─── Alice: anonymous fetch + establish session ───────
const aliceStorage = new MemoryStorage();
const aliceManager = new ShadeSessionManager(crypto, aliceStorage);
await aliceManager.initialize();
const fetchedBundle = await transport.fetchBundle('bob');
// Alice doesn't need a signing key to fetch bundles
const aliceTransport = new ShadeFetchTransport({ baseUrl, crypto });
const fetchedBundle = await aliceTransport.fetchBundle('bob');
expect(fetchedBundle.identityDHKey).toEqual(bobManager.getPublicIdentity().dhKey);
expect(fetchedBundle.signedPreKey.keyId).toBe(bobBundle.signedPreKey.keyId);
// One OTP key consumed
const countAfter = await transport.getKeyCount('bob');
expect(countAfter).toBe(4);
expect(await aliceTransport.getKeyCount('bob')).toBe(4);
// Alice establishes session
await aliceManager.initSessionFromBundle('bob', fetchedBundle);
// ─── Alice → Bob encrypted message ───────────────────
// ─── Alice → Bob encrypted ───────────────────────────
const env1 = await aliceManager.encrypt('bob', 'Hello via transport!');
const plain1 = await bobManager.decrypt('alice', env1);
expect(plain1).toBe('Hello via transport!');
@@ -66,12 +66,16 @@ describe('ShadeFetchTransport', () => {
const plain2 = await aliceManager.decrypt('bob', env2);
expect(plain2).toBe('Got it!');
// ─── Replenish ───────────────────────────────────────
const remaining = await transport.replenish('bob', [
// ─── Replenish (signed) ──────────────────────────────
const remaining = await bobTransport.replenish('bob', [
{ keyId: 200, publicKey: crypto.randomBytes(32) },
{ keyId: 201, publicKey: crypto.randomBytes(32) },
]);
expect(remaining).toBe(6); // 4 remaining + 2 new
expect(remaining).toBe(6);
// ─── Unregister (signed) ─────────────────────────────
await bobTransport.unregister('bob');
await expect(aliceTransport.fetchBundle('bob')).rejects.toThrow();
} finally {
handle.stop();