feat(credentials): re-key team vaults, and reach sh1pt's vault as a provider (#117)

Two additions to Credential Sharing.

`logicsrc credentials rotate` (alias `logicsrc secrets rotate`) re-keys a
team vault: fresh DEK, re-sealed to the members who keep access, every
secret re-encrypted under it. Values do not change, so nothing that
consumes them breaks; what changes is that every wrapped key issued
before the rotation is dead. --active (the default) keeps only active
members and revokes the rest -- the "someone left" rotation. --all keeps
everyone who holds access, for plain hygiene. Dry run by default, like
`sync`.

The DEK is recoverable ONLY through the grants, so a half-applied
rotation makes a vault permanently unreadable by everyone. The whole next
state therefore goes to the server in one request and commits in one
transaction (new db.batch helper). The server also requires every
submitted fingerprint to equal the stored one: it cannot see values, but
it can prove a re-key did not swap any. Rotations that would leave the
caller ungranted, grant nobody, or cover the wrong secret count are
rejected before anything is written. GET /vaults/:id/grants now returns
publicKey and status so a client can re-seal in one pass instead of N+1
user lookups, and revocation finally deletes the grant row rather than
leaving one that reports access it no longer confers.

The sh1pt adapter is the fifth provider. It is the only one driven
through a CLI rather than HTTP, because sh1pt publishes
`sh1pt secret set|get|list|rm` as the interface to its vault and
documents no REST endpoint. Values go over the child's stdin, never argv
-- a secret in argv is readable by any user on the host via ps. Since
`sh1pt secret get` needs interactive confirmation it cannot be scripted,
so the adapter is write-only for values like github-secrets: a sync
target, never a source, no value-restoring rollback.

Tests drive a real fake sh1pt binary rather than a mocked execFile, which
is how the hang surfaced: with nothing to pipe, stdin was left open and
any subcommand that reads it would wait forever. It is now always closed.

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

apps/pwa/src/db.mjs

@@ -27,3 +27,11 @@ export async function all(sql, args = []) {
   const r = await db.execute({ sql, args });
   return r.rows;
 }
+
+/**
+ * Run many statements in ONE write transaction — all of them commit, or none
+ * do. Needed anywhere a partial write would leave unrecoverable state, e.g.
+ * re-keying a vault, where new grants over old ciphertext locks out every
+ * member permanently.
+ */
+export const batch = (statements) => db.batch(statements, "write");

apps/pwa/src/routes/credshare.mjs

@@ -6,7 +6,7 @@
 // Auth: the acting user comes from a browser session (req.user) OR a
 // `Bearer lsk_…` API key (the logicsrc CLI). Mounted at /api/credshare.
 import { Router } from "express";
-import { get, all, run } from "../db.mjs";
+import { get, all, run, batch } from "../db.mjs";
 import { id, token, sha256 } from "../lib/crypto.mjs";
 import { bearer, userForApiKey } from "../lib/apikey.mjs";
 import { config } from "../config.mjs";
@@ -200,10 +200,117 @@ credshareRouter.get("/api/credshare/vaults/:id/grants", api(async (req, res, use
   const granted = new Set((await all(`SELECT user_id FROM credshare_vault_grants WHERE vault_id = ?`, [vault.id])).map((r) => r.user_id));
   const members = await all(`SELECT * FROM credshare_members WHERE team_id = ?`, [vault.team_id]);
   const grants = [];
-  for (const m of members) grants.push({ email: m.email, hasPublicKey: m.user_id ? Boolean(await publicKeyFor(m.user_id)) : false, hasAccess: Boolean(m.user_id && granted.has(m.user_id)) });
+  for (const m of members) {
+    // The public key is included so a client can re-seal the vault key to every
+    // member in one pass (see rekey). Public keys are public by construction --
+    // they exist to be sealed against -- and this route is already member-only.
+    const publicKey = m.user_id ? await publicKeyFor(m.user_id) : null;
+    grants.push({
+      email: m.email,
+      publicKey,
+      status: m.status,
+      hasPublicKey: Boolean(publicKey),
+      hasAccess: Boolean(m.user_id && granted.has(m.user_id))
+    });
+  }
   res.json({ grants });
 }));
 
+// Re-key a vault: swap in a fresh DEK, re-seal it to the members who keep
+// access, and re-encrypt every secret under it. Values do not change, which the
+// server enforces by requiring each submitted fingerprint to equal the stored
+// one -- it cannot see values, but it can prove they were not swapped.
+//
+// This is ONE transaction on purpose. The DEK is recoverable only through the
+// grants, so a half-applied rotation (new grants over old ciphertext, or the
+// reverse) would make the vault permanently unreadable by everyone.
+credshareRouter.post("/api/credshare/vaults/:id/rekey", api(async (req, res, user) => {
+  const vault = await vaultCtx(res, req.params.id, user.id); if (!vault) return;
+  const iHold = await get(`SELECT 1 FROM credshare_vault_grants WHERE vault_id = ? AND user_id = ?`, [vault.id, user.id]);
+  if (!iHold) return res.status(403).json({ error: "Only a member with vault access can re-key it." });
+
+  const grants = Array.isArray(req.body?.grants) ? req.body.grants : null;
+  const secrets = Array.isArray(req.body?.secrets) ? req.body.secrets : null;
+  const revoke = Array.isArray(req.body?.revoke) ? req.body.revoke.map(norm) : [];
+  if (!grants || !secrets) return res.status(422).json({ error: "Expected { grants, secrets, revoke? }." });
+  if (grants.length === 0) return res.status(422).json({ error: "A re-key must keep at least one member, or the vault becomes unreadable." });
+
+  // The caller must keep their own access; otherwise they lock themselves out
+  // the moment the transaction commits.
+  const me = await get(`SELECT email FROM users WHERE id = ?`, [user.id]);
+  if (!grants.some((g) => norm(g?.email) === norm(me?.email))) {
+    return res.status(422).json({ error: "A re-key must include your own grant." });
+  }
+
+  // Every secret must be accounted for, with an unchanged fingerprint. This is
+  // what makes "re-key" distinct from "write": no value may change here.
+  const stored = await all(`SELECT name, fingerprint FROM credshare_secrets WHERE vault_id = ?`, [vault.id]);
+  const storedByName = new Map(stored.map((s) => [s.name, s.fingerprint]));
+  if (secrets.length !== stored.length) {
+    return res.status(409).json({ error: `Re-key covers ${secrets.length} secret(s) but the vault holds ${stored.length}. Re-read the vault and retry.` });
+  }
+  for (const s of secrets) {
+    if (!s || typeof s.name !== "string" || typeof s.nonce !== "string" || typeof s.ciphertext !== "string" || typeof s.fingerprint !== "string") {
+      return res.status(422).json({ error: "Each secret needs { name, nonce, ciphertext, fingerprint }." });
+    }
+    if (!storedByName.has(s.name)) {
+      return res.status(409).json({ error: `"${s.name}" is not in this vault. Re-read the vault and retry.` });
+    }
+    if (storedByName.get(s.name) !== s.fingerprint) {
+      return res.status(409).json({ error: `Re-key would change the value of "${s.name}". A re-key re-encrypts; it never changes values.` });
+    }
+  }
+
+  // Resolve grant targets before writing anything.
+  const resolved = [];
+  for (const g of grants) {
+    const email = norm(g?.email);
+    if (!email || typeof g?.wrappedDek !== "string" || !g.wrappedDek) {
+      return res.status(422).json({ error: "Each grant needs { email, wrappedDek }." });
+    }
+    const target = await get(`SELECT id FROM users WHERE email = ?`, [email]);
+    if (!target) return res.status(409).json({ error: `${email} has not logged in yet, so the vault key cannot be sealed to them.` });
+    resolved.push({ email, userId: target.id, wrappedDek: g.wrappedDek });
+  }
+
+  const revokedUsers = [];
+  for (const email of revoke) {
+    const target = await get(`SELECT id FROM users WHERE email = ?`, [email]);
+    if (target) revokedUsers.push({ email, userId: target.id });
+  }
+
+  const now = Date.now();
+  const statements = [];
+  for (const s of secrets) {
+    statements.push({
+      sql: `UPDATE credshare_secrets SET nonce = ?, ciphertext = ?, version = version + 1, updated_by = ?, updated_at = ? WHERE vault_id = ? AND name = ?`,
+      args: [s.nonce, s.ciphertext, user.id, now, vault.id, s.name]
+    });
+  }
+  for (const g of resolved) {
+    statements.push({
+      sql: `INSERT INTO credshare_vault_grants (vault_id, user_id, wrapped_dek, granted_by, created_at) VALUES (?,?,?,?,?) ON CONFLICT(vault_id, user_id) DO UPDATE SET wrapped_dek = excluded.wrapped_dek, granted_by = excluded.granted_by, created_at = excluded.created_at`,
+      args: [vault.id, g.userId, g.wrappedDek, user.id, now]
+    });
+  }
+  for (const r of revokedUsers) {
+    statements.push({ sql: `DELETE FROM credshare_vault_grants WHERE vault_id = ? AND user_id = ?`, args: [vault.id, r.userId] });
+  }
+  statements.push({
+    sql: `INSERT INTO credshare_audit (id, team_id, vault_id, actor_user_id, action, key_name, fingerprint, created_at) VALUES (?,?,?,?,?,?,?,?)`,
+    args: [id(), vault.team_id, vault.id, user.id, "vault:rekey", null, null, now]
+  });
+  for (const r of revokedUsers) {
+    statements.push({
+      sql: `INSERT INTO credshare_audit (id, team_id, vault_id, actor_user_id, action, key_name, fingerprint, created_at) VALUES (?,?,?,?,?,?,?,?)`,
+      args: [id(), vault.team_id, vault.id, user.id, "vault:revoke", r.email, null, now]
+    });
+  }
+
+  await batch(statements);
+  res.json({ ok: true, rekeyed: secrets.length, granted: resolved.map((g) => g.email), revoked: revokedUsers.map((r) => r.email) });
+}));
+
 credshareRouter.post("/api/credshare/vaults/:id/grants", api(async (req, res, user) => {
   const vault = await vaultCtx(res, req.params.id, user.id); if (!vault) return;
   const iHold = await get(`SELECT 1 FROM credshare_vault_grants WHERE vault_id = ? AND user_id = ?`, [vault.id, user.id]);