/// <reference types="node" />
import { SupportedJsonWebEncryptionContentEncryptionAlgorithm } from './types/supported-jsonwebencryption-content-encryption-algorithm';
import { JsonWebEncryptionContentEncryptionAlgorithm } from './jsonwebencryption-content-encryption.algorithm';
/**
 * Implementation of the AES-GCM JSON Web Encryption Content Encryption Algorithm.
 *
 * @see https://www.rfc-editor.org/rfc/rfc7518.html#section-5.3
 */
declare class GcmAlgorithm extends JsonWebEncryptionContentEncryptionAlgorithm {
    /**
     * Size of the Authentication Tag in bytes.
     */
    private readonly authTagLength;
    /**
     * Name of the Cipher Algorithm.
     */
    private readonly cipher;
    /**
     * Instantiates a new AES-GCM JSON Web Encryption Content Encryption to Encrypt and Decrypt a Plaintext.
     *
     * @param algorithm Name of the JSON Web Encryption Content Encryption Algorithm.
     */
    constructor(algorithm: SupportedJsonWebEncryptionContentEncryptionAlgorithm);
    /**
     * Encrypts the provided Plaintext.
     *
     * @param plaintext Plaintext to be Cncrypted.
     * @param aad Additional Authenticated Data.
     * @param iv Initialization Vector.
     * @param key Content Encryption Key used to Encrypt the provided Plaintext.
     * @returns Resulting Ciphertext and Authentication Tag.
     */
    encrypt(plaintext: Buffer, aad: Buffer, iv: Buffer, key: Buffer): Promise<[Buffer, Buffer]>;
    /**
     * Decrypts the provided Ciphertext back to its original Plaintext.
     *
     * @param ciphertext Ciphertext to be Decrypted.
     * @param aad Additional Authenticated Data.
     * @param iv Initialization Vector.
     * @param tag Authentication Tag.
     * @param key Content Encryption Key used to Decrypt the provided Ciphertext.
     * @returns Resulting Plaintext.
     */
    decrypt(ciphertext: Buffer, aad: Buffer, iv: Buffer, tag: Buffer, key: Buffer): Promise<Buffer>;
}
/**
 * AES GCM using 128-bit key.
 */
export declare const A128GCM: GcmAlgorithm;
/**
 * AES GCM using 192-bit key.
 */
export declare const A192GCM: GcmAlgorithm;
/**
 * AES GCM using 256-bit key.
 */
export declare const A256GCM: GcmAlgorithm;
export {};