import { ConfigService } from '@nestjs/config';
export declare class InternalAppEnvCryptoService {
    private readonly config;
    private readonly logger;
    private readonly key;
    private readonly keyMissing;
    constructor(config: ConfigService);
    private assertKeyConfigured;
    encrypt(plaintext: string): {
        encrypted: Buffer;
        iv: Buffer;
        kmsKeyVersion: number;
    };
    decrypt(encrypted: Buffer, iv: Buffer, _kmsKeyVersion: number): string;
    maskValue(plaintext: string): string;
}