/**
 * STUN message codec (RFC 5389 + parts of 5766 for TURN integration).
 *
 * Supports the subset we need:
 *  - Binding Request / Binding Success Response (RFC 5389) for SRFLX
 *    discovery and ICE connectivity checks.
 *  - Long-term credential MESSAGE-INTEGRITY (HMAC-SHA1) and FINGERPRINT,
 *    needed by the bootnode TURN servers (coturn).
 *  - XOR-MAPPED-ADDRESS decoding.
 *  - USERNAME, REALM, NONCE, ERROR-CODE attributes (TURN auth dance).
 *  - SOFTWARE / FINGERPRINT attributes for being polite.
 *
 * Wire format:
 *
 *   0                   1                   2                   3
 *   0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |0 0|     STUN Message Type     |         Message Length        |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |                         Magic Cookie                          |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *  |                                                               |
 *  |                     Transaction ID (96 bits)                  |
 *  |                                                               |
 *  +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
 *
 * Attributes follow as { type: u16, length: u16, value: bytes, pad to 4 }.
 *
 * MESSAGE-INTEGRITY is HMAC-SHA1 over the entire message up to (not
 * including) the MESSAGE-INTEGRITY attribute itself, with the message
 * length pre-adjusted as if MESSAGE-INTEGRITY were present.
 */
export declare const STUN_MAGIC_COOKIE = 554869826;
export declare const STUN_BINDING_REQUEST = 1;
export declare const STUN_BINDING_SUCCESS = 257;
export declare const STUN_BINDING_ERROR = 273;
export declare const TURN_ALLOCATE_REQUEST = 3;
export declare const TURN_ALLOCATE_SUCCESS = 259;
export declare const TURN_ALLOCATE_ERROR = 275;
export declare const TURN_REFRESH_REQUEST = 4;
export declare const TURN_REFRESH_SUCCESS = 260;
export declare const TURN_CREATE_PERMISSION_REQUEST = 8;
export declare const TURN_CREATE_PERMISSION_SUCCESS = 264;
export declare const TURN_SEND_INDICATION = 22;
export declare const TURN_DATA_INDICATION = 23;
export declare const STUN_ATTR_MAPPED_ADDRESS = 1;
export declare const STUN_ATTR_USERNAME = 6;
export declare const STUN_ATTR_MESSAGE_INTEGRITY = 8;
export declare const STUN_ATTR_ERROR_CODE = 9;
export declare const STUN_ATTR_REALM = 20;
export declare const STUN_ATTR_NONCE = 21;
export declare const STUN_ATTR_XOR_MAPPED_ADDRESS = 32;
export declare const STUN_ATTR_SOFTWARE = 32802;
export declare const STUN_ATTR_FINGERPRINT = 32808;
export declare const STUN_ATTR_CHANNEL_NUMBER = 12;
export declare const STUN_ATTR_LIFETIME = 13;
export declare const STUN_ATTR_XOR_PEER_ADDRESS = 18;
export declare const STUN_ATTR_DATA = 19;
export declare const STUN_ATTR_XOR_RELAYED_ADDRESS = 22;
export declare const STUN_ATTR_REQUESTED_TRANSPORT = 25;
export declare const STUN_ATTR_DONT_FRAGMENT = 26;
export interface StunAttribute {
    type: number;
    value: Uint8Array;
}
export interface StunMessage {
    type: number;
    transactionId: Uint8Array;
    attributes: StunAttribute[];
}
export interface AddressValue {
    family: 4 | 6;
    address: string;
    port: number;
}
export declare function newTransactionId(): Uint8Array;
/**
 * Encode a STUN message. If `integrityKey` is provided, a
 * MESSAGE-INTEGRITY attribute (HMAC-SHA1) is appended. If `fingerprint`
 * is true, a FINGERPRINT (CRC32 XOR 0x5354554e) is appended last.
 *
 * The order matters because MESSAGE-INTEGRITY must be computed over
 * the message *as if* it were the last attribute (with length already
 * adjusted), and FINGERPRINT must be computed over the message
 * including MESSAGE-INTEGRITY.
 */
export declare function encodeStun(message: StunMessage, opts?: {
    integrityKey?: Uint8Array;
    fingerprint?: boolean;
}): Uint8Array;
export declare function decodeStun(data: Uint8Array): StunMessage | undefined;
export declare function findAttr(message: StunMessage, type: number): Uint8Array | undefined;
/**
 * Decode XOR-MAPPED-ADDRESS (RFC 5389 §15.2). The high bits of the
 * port and the address are XORed with the magic cookie + transactionId.
 */
export declare function decodeXorMappedAddress(value: Uint8Array, transactionId: Uint8Array): AddressValue | undefined;
/** Encode XOR-MAPPED-ADDRESS for outgoing STUN responses (TURN, conn check). */
export declare function encodeXorMappedAddress(addr: AddressValue, transactionId: Uint8Array): Uint8Array;
export declare function encodeErrorCode(code: number, reason: string): Uint8Array;
export declare function decodeErrorCode(value: Uint8Array): {
    code: number;
    reason: string;
} | undefined;
/**
 * Long-term-credential integrity key: MD5("username:realm:password").
 * RFC 5389 §15.4. coturn uses this.
 */
export declare function longTermIntegrityKey(username: string, realm: string, password: string): Uint8Array;
/** Short-term-credential integrity key: just the password as UTF-8. */
export declare function shortTermIntegrityKey(password: string): Uint8Array;
export declare function buildBindingRequest(transactionId?: Uint8Array): Uint8Array;
export declare function buildBindingRequestWithIntegrity(opts: {
    username: string;
    password: string;
    transactionId?: Uint8Array;
}): Uint8Array;