import { type SrtpKeyingMaterial } from '@zapo-js/voip-media';
/**
 * Derives the end-to-end SRTP keying material of one device from the call key.
 *
 * The whole 32-byte call key is the HKDF input, the salt is empty, and the
 * device jid is the info string. The 46 bytes out split into a 16-byte master
 * key and a 14-byte master salt.
 *
 * The call key is **not** split into a 16-byte input plus a 16-byte salt. That
 * split belongs to the SFrame key derivation, which is a different function,
 * and applying it here yields a key no WhatsApp peer agrees with: this
 * derivation is what decrypts real media today.
 */
export declare function derivePerJidSrtpKey(callKey: Uint8Array, deviceJid: string): SrtpKeyingMaterial;
export declare function generateCallKey(): Uint8Array;