/// <reference types="node" />
export type KeyVault = {
    signAsync(buffer: Buffer): Promise<Buffer>;
};
export type SignerOptions = {
    did: string;
    keyId: string;
    keyVault: KeyVault;
};
export default class Signer {
    private readonly _did;
    private readonly _keyId;
    private readonly _keyVault;
    /**
     * Construct a Signer based on the given options
     *
     * @param options auth service options
     */
    constructor(options: SignerOptions);
    fillSignature(jwtObject: any): Promise<void>;
    private sign;
}