declare const otpDigitLength: readonly [6, 8, 10];
type OtpSecret = string | Buffer;
type OtpHashAlgorithm = "sha1" | "sha256" | "sha512";
type OtpSecretStringEncoding = "base32" | BufferEncoding;
type OtpDigitLength = (typeof otpDigitLength)[number];
interface TotpOptions {
	addChecksum?: boolean;
	algorithm?: OtpHashAlgorithm;
	digits?: OtpDigitLength;
	interval?: number;
	secretEncoding?: OtpSecretStringEncoding;
	t0?: number;
	time?: number;
	truncationOffset?: number;
}
interface TotpBufferSecretOptions extends Omit<TotpOptions, "secretEncoding"> {}
interface TotpStringSecretOptions extends TotpOptions {}
interface TotpSpecificOptions extends Omit<TotpOptions, "algorithm"> {}
interface TotpSpecificBufferSecretOptions extends Omit<TotpSpecificOptions, "secretEncoding"> {}
interface TotpSpecificStringSecretOptions extends TotpSpecificOptions {}
declare function generateTotp(secret: Buffer, options?: TotpBufferSecretOptions): string;
declare function generateTotp(secret: string, options?: TotpStringSecretOptions): string;
declare function generateTotp(secret: OtpSecret, options?: TotpOptions): string;
declare function generateTotpSha1(secret: Buffer, options?: TotpSpecificBufferSecretOptions): string;
declare function generateTotpSha1(secret: string, options?: TotpSpecificStringSecretOptions): string;
declare function generateTotpSha256(secret: Buffer, options?: TotpSpecificBufferSecretOptions): string;
declare function generateTotpSha256(secret: string, options?: TotpSpecificStringSecretOptions): string;
declare function generateTotpSha512(secret: Buffer, options?: TotpSpecificBufferSecretOptions): string;
declare function generateTotpSha512(secret: string, options?: TotpSpecificStringSecretOptions): string;
export { generateTotpSha512, generateTotpSha256, generateTotpSha1, generateTotp };