/// <reference types="node" />
interface EncryptAes256CbcHmacRequest {
    payload: Buffer;
    /**
     * 64 bytes
     * 32 first bytes are used for encryption
     * 32 last bytes are used for MAC
     */
    combinedKey: Buffer;
    /**
     * uuid of the key used to encrypt the payload. This gives us the possibility to understand what
     * was used to encrypt and then debug encryption issue.
     */
    keyUuid: string;
}
export declare const encryptAes256CbcHmac: (params: EncryptAes256CbcHmacRequest) => Promise<string>;
interface DecryptAes256CbcHmacRequest {
    /**
     * Full encrypted string with possibly uuid%data, including the crypto identifier
     */
    encryptedData: string;
    /**
     * 64 bytes
     * 32 first bytes are used for encryption
     * 32 last bytes are used for MAC
     */
    combinedKey: Buffer;
}
export declare const decryptAes256CbcHmac: (params: DecryptAes256CbcHmacRequest) => Promise<string>;
/**
 * To identify the key used to encrypt a set of data, we concatenate key uuid with encrypted Data
 * The concatenation is done with "%"
 * @param keyUuid uuid of the key used to encrypt the data
 * @param encryptedData
 */
export declare const concatUuidWithEncryptedData: (keyUuid: string, encryptedData: string) => string;
/**
 * Check MAC in constant time, to avoid theorical timing attack
 */
export declare const safeCrytoEquals: (b1: Buffer, b2: Buffer) => boolean;
export {};