/**
 * RFC5054 SRP group parameters.
 * These must match the server-side implementation exactly.
 */
import { SRPGroup } from './types';
/**
 * Get the SRP group parameters for the specified group ID.
 *
 * @param groupID - Group ID (3, 4, or 5)
 * @returns SRP group parameters
 * @throws Error if group ID is invalid
 *
 * @risk Spoofing: Weak group parameters allow offline attacks.
 * Always use RFC5054 standard groups.
 */
export declare function getGroup(groupID: number): SRPGroup;
/**
 * Compute the SRP multiplier parameter k = H(N | g).
 *
 * @param group - SRP group parameters
 * @returns Multiplier k
 *
 * @mitigation Tampering: Correct k computation per RFC5054/SRP-6a.
 */
export declare function computeK(group: SRPGroup): Promise<bigint>;
/**
 * Convert a bigint to a Uint8Array (big-endian).
 */
export declare function bigIntToBytes(value: bigint): Uint8Array;
/**
 * Convert a Uint8Array to a bigint (big-endian).
 */
export declare function bytesToBigInt(bytes: Uint8Array): bigint;
/**
 * Pad bytes to a specific length with leading zeros.
 */
export declare function padBytes(bytes: Uint8Array, length: number): Uint8Array;