/**
 * The sealed cookie carries only what `verify()` reads back — the sid
 * is the store lookup key; everything else about the session (userId,
 * claims, freshAt, …) lives server-side in the {@link SessionRecord}
 * so it can never go stale inside an already-issued cookie.
 *
 * @typedef {object} SessionTokenPayload
 * @property {string} sid           Server-side session ID (opaque, from CSPRNG).
 * @property {number} iat           Issued-at (ms epoch).
 * @property {number} exp           Absolute expiry (ms epoch).
 * @property {string} [fp]          Fingerprint hash (IP + UA), when `bindTo` is enabled.
 * @property {string} [imp]         Admin user ID that started the impersonation.
 */
/**
 * Generate a fresh session ID — 128 bits of CSPRNG entropy, base64url.
 * Comfortably beyond the birthday-collision bound for any realistic
 * user base.
 *
 * @returns {string}
 */
export function generateSessionId(): string;
/**
 * Encode a session payload as a sealed (AES-256-GCM authenticated)
 * opaque token. Wraps `@exortek/crypto.seal` — the TTL of the seal
 * matches the payload's own `exp - now`, so the transport layer refuses
 * to open an expired token before we even parse it.
 *
 * @param {SessionTokenPayload} payload
 * @param {string | Buffer | Uint8Array} secret
 * @param {{ now?: number }} [options]
 * @returns {string}    base64url token.
 */
export function encodeToken(payload: SessionTokenPayload, secret: string | Buffer | Uint8Array, options?: {
    now?: number;
}): string;
/**
 * Decode + authenticate a session token. Returns the payload on
 * success, or a structured failure via {@link SessionError}. Callers
 * generally want to catch and translate to `null` — the manager does
 * this so `verify(req)` never throws for a wrong-shape stored value.
 *
 * `secret` may be a single key or an array `[newest, …older]` for
 * secret rotation. `crypto.unseal` walks the list; the first that
 * authenticates wins.
 *
 * @param {string} token
 * @param {string | Buffer | Uint8Array | Array<string | Buffer | Uint8Array>} secret
 * @param {{ now?: number }} [options]
 * @returns {SessionTokenPayload}
 * @throws {SessionError} — with `INVALID_TOKEN` / `EXPIRED` / `INVALID_ARGUMENT`.
 */
export function decodeToken(token: string, secret: string | Buffer | Uint8Array | Array<string | Buffer | Uint8Array>, options?: {
    now?: number;
}): SessionTokenPayload;
/**
 * The sealed cookie carries only what `verify()` reads back — the sid
 * is the store lookup key; everything else about the session (userId,
 * claims, freshAt, …) lives server-side in the {@link SessionRecord}
 * so it can never go stale inside an already-issued cookie.
 */
export type SessionTokenPayload = {
    /**
     * Server-side session ID (opaque, from CSPRNG).
     */
    sid: string;
    /**
     * Issued-at (ms epoch).
     */
    iat: number;
    /**
     * Absolute expiry (ms epoch).
     */
    exp: number;
    /**
     * Fingerprint hash (IP + UA), when `bindTo` is enabled.
     */
    fp?: string | undefined;
    /**
     * Admin user ID that started the impersonation.
     */
    imp?: string | undefined;
};