Implement keep: self-hosted E2E encrypted secrets sync

Server: Express + better-sqlite3 (WAL), multi-recipient key-wrapping
per IMPLEMENTATION.md's design — vaults/recipients/vault_grants/
access_log. Two auth paths: ADMIN_PASSWORD header for recipient
management and revoke (pure metadata operations), signed-request
auth (Ed25519 signature over method+path+timestamp+body-hash) for
push/pull/grant, mirroring the spirit of this project family's other
signed-handshake patterns without naming them.

CLI: identity init/show/set-id, push/pull/grant/log, admin recipient
add/list/remove and revoke. Grant is a client-side crypto operation
(the granter unwraps the vault's current key locally and reseals it
for the new recipient) rather than a server-side operation, since the
server never holds an unwrapped key to grant with.

Verified end-to-end with two independent local identities against a
live server and separately against the built Docker image: register,
push, pull (granted and ungranted), grant without re-pushing, admin
revoke, a subsequent rotation confirming the revoked recipient stays
excluded, and rejection of missing/malformed signed-request auth.

Two real bugs caught during verification, not just written up:
- libsodium-wrappers' published ESM build does a relative import only
  resolvable under bundler-style resolution — broken under plain Node
  ESM. Fixed via createRequire to force the CJS build.
- Express's req.path inside a sub-router is relative to the mount
  point, which would have silently mismatched a client signing the
  full request path. Fixed by verifying against req.originalUrl.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/cli/commands/identity.ts

@@ -0,0 +1,21 @@
+import { loadOrCreateIdentity, setRecipientId } from '../identityStore.js';
+
+export async function identityInit(): Promise<void> {
+  const { identity, created } = await loadOrCreateIdentity();
+  console.log(created ? 'identity created.' : 'identity already exists.');
+  console.log(`public key: ${identity.id}`);
+  console.log(`\nSend this public key to whoever runs 'keep recipient add' for this vault server.`);
+  console.log(`They'll give you back a recipient id — set it locally with:`);
+  console.log(`  keep identity set-id <recipient-id>`);
+}
+
+export async function identityShow(): Promise<void> {
+  const { identity, recipientId } = await loadOrCreateIdentity();
+  console.log(`public key:  ${identity.id}`);
+  console.log(`recipient id: ${recipientId ?? '(not set — see: keep identity set-id)'}`);
+}
+
+export function identitySetId(recipientId: string): void {
+  setRecipientId(recipientId);
+  console.log(`recipient id set to: ${recipientId}`);
+}

src/cli/commands/recipient.ts

@@ -0,0 +1,20 @@
+import { adminFetch, expectOk } from '../signedFetch.js';
+
+export async function recipientAdd(label: string, publicKey: string): Promise<void> {
+  const data = await expectOk(await adminFetch('POST', '/api/admin/recipients', { label, publicKey }));
+  console.log(`recipient created: ${data.recipientId}`);
+  console.log(`Give this id back to whoever owns this identity — they set it with 'keep identity set-id ${data.recipientId}'.`);
+}
+
+export async function recipientList(): Promise<void> {
+  const data = await expectOk(await adminFetch('GET', '/api/admin/recipients'));
+  if (!data.length) { console.log('no recipients yet.'); return; }
+  for (const r of data) {
+    console.log(`${r.recipientId}  ${r.label}  ${r.publicKey.slice(0, 16)}…`);
+  }
+}
+
+export async function recipientRemove(recipientId: string): Promise<void> {
+  await expectOk(await adminFetch('DELETE', `/api/admin/recipients/${encodeURIComponent(recipientId)}`));
+  console.log(`recipient removed: ${recipientId} (and all their vault grants)`);
+}

src/cli/commands/vault.ts

@@ -0,0 +1,110 @@
+import fs from 'node:fs';
+import { requireIdentityAndRecipientId } from '../identityStore.js';
+import { signedFetch, adminFetch, expectOk } from '../signedFetch.js';
+import { parseEnv, serializeEnv } from '../envFormat.js';
+import {
+  ready,
+  Identity,
+  generateSymmetricKey,
+  secretboxEncrypt,
+  secretboxDecrypt,
+  enc,
+} from '../../shared/crypto.js';
+
+export async function vaultPush(vaultKey: string, file: string): Promise<void> {
+  await ready();
+  const { identity, recipientId } = await requireIdentityAndRecipientId();
+
+  if (!fs.existsSync(file)) throw new Error(`file not found: ${file}`);
+  const values = parseEnv(fs.readFileSync(file, 'utf8'));
+  const payload = enc.fromUtf8(JSON.stringify(values));
+
+  const existsRes = await expectOk(await signedFetch(identity, recipientId, 'GET', `/api/vaults/${encodeURIComponent(vaultKey)}/exists`));
+
+  const wrapFor = new Map<string, string>(); // recipientId -> publicKey
+  wrapFor.set(recipientId, identity.id);
+
+  if (existsRes.exists) {
+    const recipientsRes = await signedFetch(identity, recipientId, 'GET', `/api/vaults/${encodeURIComponent(vaultKey)}/recipients`);
+    if (!recipientsRes.ok) {
+      const body = await recipientsRes.json().catch(() => ({}));
+      throw new Error(body.error ?? `no access to vault '${vaultKey}' — ask an existing grantee to run 'keep grant ${vaultKey} ${recipientId}'`);
+    }
+    const current = await recipientsRes.json() as { recipientId: string; publicKey: string }[];
+    for (const r of current) if (r.publicKey) wrapFor.set(r.recipientId, r.publicKey);
+  }
+
+  const symmetricKey = generateSymmetricKey();
+  const { nonce, ciphertext } = secretboxEncrypt(symmetricKey, payload);
+
+  const wrappedKeys: Record<string, string> = {};
+  for (const [rid, pubHex] of wrapFor) {
+    wrappedKeys[rid] = enc.toBase64(Identity.sealFor(pubHex, symmetricKey));
+  }
+
+  await expectOk(await signedFetch(identity, recipientId, 'POST', `/api/vaults/${encodeURIComponent(vaultKey)}/push`, {
+    ciphertext: enc.toBase64(ciphertext),
+    nonce: enc.toBase64(nonce),
+    wrappedKeys,
+  }));
+
+  console.log(`pushed '${vaultKey}' — ${Object.keys(values).length} key${Object.keys(values).length === 1 ? '' : 's'}, wrapped for ${wrapFor.size} recipient${wrapFor.size === 1 ? '' : 's'}.`);
+}
+
+export async function vaultPull(vaultKey: string, format: 'env' | 'json', outFile?: string): Promise<void> {
+  await ready();
+  const { identity, recipientId } = await requireIdentityAndRecipientId();
+
+  const data = await expectOk(await signedFetch(identity, recipientId, 'GET', `/api/vaults/${encodeURIComponent(vaultKey)}/pull`));
+
+  const symmetricKey = identity.openSealed(enc.fromBase64(data.wrappedKey));
+  if (!symmetricKey) throw new Error('failed to unwrap this vault\'s key — wrong identity, or the grant is stale');
+
+  const plaintext = secretboxDecrypt(symmetricKey, enc.fromBase64(data.nonce), enc.fromBase64(data.ciphertext));
+  const values = JSON.parse(enc.toUtf8(plaintext)) as Record<string, string>;
+
+  const out = format === 'json' ? JSON.stringify(values, null, 2) : serializeEnv(values);
+  if (outFile) {
+    fs.writeFileSync(outFile, out);
+    console.error(`wrote ${Object.keys(values).length} key(s) to ${outFile}`);
+  } else {
+    process.stdout.write(out);
+  }
+}
+
+export async function vaultGrant(vaultKey: string, targetRecipientId: string): Promise<void> {
+  await ready();
+  const { identity, recipientId } = await requireIdentityAndRecipientId();
+
+  const pullRes = await expectOk(await signedFetch(identity, recipientId, 'GET', `/api/vaults/${encodeURIComponent(vaultKey)}/pull`));
+  const symmetricKey = identity.openSealed(enc.fromBase64(pullRes.wrappedKey));
+  if (!symmetricKey) throw new Error("failed to unwrap this vault's key — can't grant access to someone else without it");
+
+  const recipientsRes = await expectOk(await signedFetch(identity, recipientId, 'GET', '/api/recipients'));
+  const target = (recipientsRes as { recipientId: string; publicKey: string }[]).find(r => r.recipientId === targetRecipientId);
+  if (!target) throw new Error(`unknown recipient id: ${targetRecipientId} (ask an admin to 'keep recipient add' them first)`);
+
+  const wrappedKey = enc.toBase64(Identity.sealFor(target.publicKey, symmetricKey));
+  await expectOk(await signedFetch(identity, recipientId, 'POST', `/api/vaults/${encodeURIComponent(vaultKey)}/grant`, {
+    recipientId: targetRecipientId,
+    wrappedKey,
+  }));
+
+  console.log(`granted '${vaultKey}' to ${targetRecipientId}.`);
+}
+
+export async function vaultRevoke(vaultKey: string, targetRecipientId: string): Promise<void> {
+  await expectOk(await adminFetch('DELETE', `/api/admin/vaults/${encodeURIComponent(vaultKey)}/grants/${encodeURIComponent(targetRecipientId)}`));
+  console.log(`revoked ${targetRecipientId}'s access to '${vaultKey}'.`);
+  console.log(`Note: this stops future pulls only. If this was a compromise response, also run 'keep push ${vaultKey}' with rotated values.`);
+}
+
+export async function vaultLog(vaultKey: string): Promise<void> {
+  await ready();
+  const { identity, recipientId } = await requireIdentityAndRecipientId();
+  const entries = await expectOk(await signedFetch(identity, recipientId, 'GET', `/api/vaults/${encodeURIComponent(vaultKey)}/log`));
+  if (!entries.length) { console.log('no access log entries yet.'); return; }
+  for (const e of entries as { recipient_id: string; action: string; accessed_at: number }[]) {
+    console.log(`${new Date(e.accessed_at * 1000).toISOString()}  ${e.action.padEnd(6)}  ${e.recipient_id}`);
+  }
+}

src/cli/envFormat.ts

@@ -0,0 +1,22 @@
+export function parseEnv(text: string): Record<string, string> {
+  const out: Record<string, string> = {};
+  for (const rawLine of text.split('\n')) {
+    const line = rawLine.trim();
+    if (!line || line.startsWith('#')) continue;
+    const eq = line.indexOf('=');
+    if (eq === -1) continue;
+    const key = line.slice(0, eq).trim();
+    let value = line.slice(eq + 1).trim();
+    if ((value.startsWith('"') && value.endsWith('"')) || (value.startsWith("'") && value.endsWith("'"))) {
+      value = value.slice(1, -1);
+    }
+    out[key] = value;
+  }
+  return out;
+}
+
+export function serializeEnv(values: Record<string, string>): string {
+  return Object.entries(values)
+    .map(([k, v]) => `${k}=${/[\s#"']/.test(v) ? JSON.stringify(v) : v}`)
+    .join('\n') + '\n';
+}

src/cli/identityStore.ts

@@ -0,0 +1,53 @@
+import fs from 'node:fs';
+import path from 'node:path';
+import os from 'node:os';
+import { Identity } from '../shared/crypto.js';
+
+const DIR = path.join(os.homedir(), '.keep');
+const FILE = path.join(DIR, 'identity.json');
+
+interface StoredIdentity {
+  seedHex: string;
+  // Assigned by whoever runs `keep recipient add` after registering this
+  // identity's public key — not derivable from the keypair itself, so it
+  // has to be stored once known via `keep identity set-id`.
+  recipientId?: string;
+}
+
+function readStored(): StoredIdentity | null {
+  if (!fs.existsSync(FILE)) return null;
+  return JSON.parse(fs.readFileSync(FILE, 'utf8')) as StoredIdentity;
+}
+
+function writeStored(data: StoredIdentity): void {
+  fs.mkdirSync(DIR, { recursive: true, mode: 0o700 });
+  fs.writeFileSync(FILE, JSON.stringify(data, null, 2), { mode: 0o600 });
+}
+
+export async function loadOrCreateIdentity(): Promise<{ identity: Identity; recipientId: string | null; created: boolean }> {
+  const stored = readStored();
+  if (stored) {
+    return { identity: await Identity.fromSeedHex(stored.seedHex), recipientId: stored.recipientId ?? null, created: false };
+  }
+  const identity = await Identity.generate();
+  writeStored({ seedHex: identity.seedHex });
+  return { identity, recipientId: null, created: true };
+}
+
+export function setRecipientId(recipientId: string): void {
+  const stored = readStored();
+  if (!stored) throw new Error("no local identity — run 'keep identity init' first");
+  writeStored({ ...stored, recipientId });
+}
+
+export async function requireIdentityAndRecipientId(): Promise<{ identity: Identity; recipientId: string }> {
+  const stored = readStored();
+  if (!stored) throw new Error("no local identity — run 'keep identity init' first");
+  if (!stored.recipientId) {
+    throw new Error(
+      "this identity has no recipient id set yet — after an admin registers your public key " +
+      "('keep identity show' to get it), run 'keep identity set-id <recipient-id>' with the id they give you back",
+    );
+  }
+  return { identity: await Identity.fromSeedHex(stored.seedHex), recipientId: stored.recipientId };
+}

src/cli/index.ts

@@ -0,0 +1,61 @@
+#!/usr/bin/env node
+import { identityInit, identityShow, identitySetId } from './commands/identity.js';
+import { recipientAdd, recipientList, recipientRemove } from './commands/recipient.js';
+import { vaultPush, vaultPull, vaultGrant, vaultRevoke, vaultLog } from './commands/vault.js';
+
+function flag(args: string[], name: string, fallback?: string): string | undefined {
+  const i = args.indexOf(`--${name}`);
+  return i !== -1 ? args[i + 1] : fallback;
+}
+
+async function main(): Promise<void> {
+  const [, , cmd, sub, ...rest] = process.argv;
+
+  try {
+    if (cmd === 'identity') {
+      if (sub === 'init') return await identityInit();
+      if (sub === 'show') return await identityShow();
+      if (sub === 'set-id') return identitySetId(rest[0]);
+    }
+
+    if (cmd === 'recipient') {
+      if (sub === 'add') return await recipientAdd(flag(rest, 'label')!, flag(rest, 'pubkey')!);
+      if (sub === 'list') return await recipientList();
+      if (sub === 'remove') return await recipientRemove(rest[0]);
+    }
+
+    if (cmd === 'push') return await vaultPush(sub, flag(rest, 'file', '.env')!);
+    if (cmd === 'pull') return await vaultPull(sub, (flag(rest, 'format', 'env') as 'env' | 'json'), flag(rest, 'out'));
+    if (cmd === 'grant') return await vaultGrant(sub, rest[0]);
+    if (cmd === 'revoke') return await vaultRevoke(sub, rest[0]);
+    if (cmd === 'log') return await vaultLog(sub);
+
+    printUsage();
+    process.exitCode = cmd ? 1 : 0;
+  } catch (err) {
+    console.error(`error: ${err instanceof Error ? err.message : err}`);
+    process.exitCode = 1;
+  }
+}
+
+function printUsage(): void {
+  console.log(`keep — self-hosted, end-to-end encrypted secrets sync
+
+  keep identity init
+  keep identity show
+  keep identity set-id <recipient-id>
+
+  keep push <vault> [--file .env]
+  keep pull <vault> [--format env|json] [--out <path>]
+  keep grant <vault> <recipient-id>
+  keep revoke <vault> <recipient-id>          (admin — needs KEEP_ADMIN_PASSWORD)
+  keep log <vault>
+
+  keep recipient add --label <label> --pubkey <hex>   (admin)
+  keep recipient list                                  (admin)
+  keep recipient remove <recipient-id>                 (admin)
+
+Env: KEEP_SERVER_URL (default http://localhost:3050), KEEP_ADMIN_PASSWORD (for admin commands)`);
+}
+
+main();

src/cli/signedFetch.ts

@@ -0,0 +1,48 @@
+import { Identity, signingString, enc } from '../shared/crypto.js';
+
+export function serverUrl(): string {
+  return process.env.KEEP_SERVER_URL ?? 'http://localhost:3050';
+}
+
+export async function signedFetch(
+  identity: Identity,
+  recipientId: string,
+  method: string,
+  path: string,
+  body?: unknown,
+): Promise<Response> {
+  const bodyBytes = body !== undefined ? enc.fromUtf8(JSON.stringify(body)) : new Uint8Array();
+  const timestamp = Math.floor(Date.now() / 1000);
+  const toSign = signingString(method, path, timestamp, bodyBytes);
+  const signature = enc.toHex(identity.sign(enc.fromUtf8(toSign)));
+
+  return fetch(`${serverUrl()}${path}`, {
+    method,
+    headers: {
+      'Content-Type': 'application/json',
+      'X-Recipient-Id': recipientId,
+      'X-Signature': signature,
+      'X-Timestamp': String(timestamp),
+    },
+    body: body !== undefined ? JSON.stringify(body) : undefined,
+  });
+}
+
+export async function adminFetch(method: string, path: string, body?: unknown): Promise<Response> {
+  const password = process.env.KEEP_ADMIN_PASSWORD;
+  if (!password) throw new Error('KEEP_ADMIN_PASSWORD is not set');
+  return fetch(`${serverUrl()}${path}`, {
+    method,
+    headers: {
+      'Content-Type': 'application/json',
+      'X-Admin-Password': password,
+    },
+    body: body !== undefined ? JSON.stringify(body) : undefined,
+  });
+}
+
+export async function expectOk(res: Response): Promise<any> {
+  const data = await res.json().catch(() => ({}));
+  if (!res.ok) throw new Error(data.error ?? `request failed: ${res.status}`);
+  return data;
+}