After unlocking a saved nsec key the user had to re-enter the PIN on every reload,
because the key is only passphrase-encrypted and the in-memory signer is lost on
refresh. Add an opt-in unlocked-key cache with two tiers (maintainer's choice):
- session (default, always): sessionStorage — survives refresh/navigation, cleared
when the tab/browser closes. Same rough exposure as the in-memory signer.
- persistent (opt-in): the unlock prompt now shows a "Keep me unlocked on this
device" checkbox with an inline unencrypted-at-rest warning; when checked the key
is also written to localStorage and survives until site data is cleared.
client.restoreUnlockedSigner(pubkey) re-registers the signer from the cache WITHOUT
a passphrase — it verifies the cached key derives to that pubkey and forgets a
mismatch, so it never adopts another account. It runs proactively from
ensureActiveSignerForPubkey (auto-login/refresh) and lazily from
ensureEncryptionCapableSigner before any prompt, so after a reload the signer is
restored silently and storage/hashtags/DMs/reactions/blocks/subs all just work.
Logout and remove-saved-profile forget the cached key (forgetUnlockedSigner).
SECURITY: while cached, the key is stored decrypted — the passphrase no longer
protects it at rest. Session tier is the default; persistence is opt-in + warned.
Tests: tests/unlocked-key-cache.test.mjs (8 — session vs persistent tiers, promote
persistent->session on read, reject non-hex, forget one, clear all, missing-storage
degrade). Related unlock/switch/session-actor suites green. Lint + build green.
Co-Authored-By: Claude Opus 4.8 <[email protected]>
