import { isInitialized } from '../init.js';
import type { WasmSource } from '../wasm-source.js';
import type { X25519KeyPair } from './types.js';
/**
 * Initialise the curve25519 WASM module under the `x25519` alias.
 * Equivalent to `ed25519Init(source)`; both target the same WASM module
 * and the init layer de-dupes when given identical sources.
 */
export declare function x25519Init(source: WasmSource): Promise<void>;
export type { WasmSource };
export type { X25519KeyPair, X25519Exports } from './types.js';
export { isInitialized };
export declare class X25519 {
    constructor();
    private get mx();
    /**
     * Deterministic X25519 key generation from a 32-byte secret per
     * RFC 7748 §6. Clamping is applied internally on every WASM call;
     * the returned secretKey is a fresh copy of the supplied sk bytes
     * (NOT pre-clamped).
     */
    keygenDerand(sk: Uint8Array): X25519KeyPair;
    /** Random X25519 key generation, wraps `keygenDerand` with `randomBytes(32)`. */
    keygen(): X25519KeyPair;
    /**
     * X25519 Diffie-Hellman, RFC 7748 §6.
     *
     * Computes the shared u-coordinate from the local secret and the
     * peer's public key. If the resulting shared secret is all-zero
     * (peer public key is a small-order point per RFC 7748 §7), throws
     * `KeyAgreementError` rather than returning the degenerate value.
     * The all-zero scan accumulates via OR across all 32 output bytes
     * before comparing to zero, so the success path is constant-time;
     * the throw branches off only after a known-bad outcome is observed.
     *
     * @param sk     32-byte local secret (NOT pre-clamped, clamped internally)
     * @param peerPk 32-byte peer public key (u-coordinate)
     * @returns 32-byte shared u-coordinate
     * @throws KeyAgreementError on all-zero shared secret
     */
    dh(sk: Uint8Array, peerPk: Uint8Array): Uint8Array;
    dispose(): void;
}