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TypeScript

/**
* secret-storage-policy.ts
*
* Single owner of the "do we use the OS keychain at all?" decision for
* desktop-stored secrets (remote gateway tokens, CF Access headers, native
* OAuth token sets).
*
* Why this exists: Electron safeStorage on macOS parks a per-app key
* ("Hermes Key") in the login keychain. On machines with a locked, missing,
* or corrupted default keychain, ANY safeStorage touch — including
* isEncryptionAvailable() — makes macOS throw a blocking "Keychain Not
* Found" / password dialog on every launch. That is an unacceptable default
* for a chat app, so keychain-backed encryption is OPT-IN:
*
* - Setting OFF (default): secrets are written with encoding 'plain' and
* NO safeStorage API is ever called. decryptDesktopSecret already
* returns non-safeStorage encodings verbatim, so reads need no change.
* - Setting ON: the previous behavior — strict safeStorage encryption,
* loud failure when the keychain is unavailable, per-save plain-text
* confirm dialog as the escape hatch.
*
* Legacy blobs written before the flag existed are safeStorage-encoded on
* disk. With the setting OFF we attempt ONE migration pass (decrypt →
* rewrite as plain). The pass is recorded in the same settings file whether
* or not it succeeds, so a broken keychain costs at most one prompt on the
* first post-update launch — never one per launch.
*
* Kept standalone (no `import 'electron'`) so it unit-tests under the
* electron vitest project, same pattern as native-token-store.ts. main.ts
* injects the file path and fs.
*/
export interface SecretStoragePolicy {
/** Keychain-backed encryption enabled (explicit user opt-in). */
on: boolean
/** One-shot legacy-blob migration already attempted. */
migrated: boolean
}
export const SECRET_STORAGE_POLICY_FILE = 'secure-token-storage.json'
export interface SecretStoragePolicyIo {
readText: () => string
writeText: (text: string) => void
}
/**
* Normalize whatever is on disk into a policy. Anything unreadable,
* unparseable, or hand-mangled is the default: encryption OFF, migration
* not yet attempted. `on` uses strict `=== true` — a truthy-but-not-true
* value must not silently enable keychain prompts (mirrors the
* allowPlainText coercion rule in hardening.ts).
*/
export function readSecretStoragePolicy(io: SecretStoragePolicyIo): SecretStoragePolicy {
try {
const parsed = JSON.parse(io.readText())
if (parsed && typeof parsed === 'object' && !Array.isArray(parsed)) {
return { on: parsed.on === true, migrated: parsed.migrated === true }
}
} catch {
// fall through to default
}
return { on: false, migrated: false }
}
export function writeSecretStoragePolicy(policy: SecretStoragePolicy, io: SecretStoragePolicyIo): void {
io.writeText(JSON.stringify({ on: policy.on === true, migrated: policy.migrated === true }))
}
/** One stored secret blob as it appears on disk. */
interface StoredSecret {
encoding?: string
value?: string
}
/**
* Decide what to do with one stored blob under the current policy.
*
* - 'keep' — blob is fine as-is under this policy.
* - 'migrate' — safeStorage blob while encryption is OFF and migration has
* not run: caller should decrypt once and rewrite as plain.
* - 'drop' — safeStorage blob while encryption is OFF and the migration
* pass already ran (i.e. it could not be decrypted last
* time): treat as absent WITHOUT touching safeStorage, so a
* dead keychain never prompts again.
*/
export function classifyStoredSecret(
secret: StoredSecret | null | undefined,
policy: SecretStoragePolicy
): 'keep' | 'migrate' | 'drop' {
if (!secret || typeof secret !== 'object' || secret.encoding !== 'safeStorage') {
return 'keep'
}
if (policy.on) {
return 'keep'
}
return policy.migrated ? 'drop' : 'migrate'
}