export declare const genAesCtrKey: (length?: number) => Promise<{
    privateKey: string;
}>;
export declare const encryptAesCtr: (keyStr: string, content: string, counter: ArrayBuffer, length?: number) => Promise<string>;
export declare const decryptAesCtr: (keyStr: string, encryptText: string, counter: ArrayBuffer, length?: number) => Promise<string>;