import { PkSigning } from "@matrix-org/olm";
import type { SignedValue } from "../e2ee/common";
import type * as OlmNamespace from "@matrix-org/olm";
type Olm = typeof OlmNamespace;
/**
 * Sign a JSON object using public key cryptography
 * @param obj - Object to sign.  The object will be modified to include
 *     the new signature
 * @param key - the signing object or the private key
 * seed
 * @param userId - The user ID who owns the signing key
 * @param pubKey - The public key (ignored if key is a seed)
 * @returns the signature for the object
 */
export declare function pkSign(olmUtil: Olm, obj: SignedValue, key: Uint8Array | PkSigning, userId: string, pubKey: string): string;
export {};