import * as lambda from 'aws-cdk-lib/aws-lambda';
import { Construct } from 'constructs';
/**
 * Properties for the DataMaskingLayerConstruct
 */
export interface DataMaskingLayerProps {
    /**
     * Description for the Lambda layer
     * @default 'Lambda layer for masking sensitive data in document processing'
     */
    description?: string;
    /**
     * Custom masking patterns to add to the default ones
     * @default {}
     */
    customPatterns?: Record<string, {
        /**
         * Regular expression pattern as string
         */
        regex: string;
        /**
         * Mask to apply (string or function name)
         */
        mask: string;
    }>;
}
/**
 * Construct that creates a Lambda layer for data masking
 */
export declare class DataMaskingLayerConstruct extends Construct {
    /**
     * The Lambda layer containing masking utilities
     */
    readonly layer: lambda.LayerVersion;
    constructor(scope: Construct, id: string, props?: DataMaskingLayerProps);
    /**
     * Adds the masking layer to a Lambda function
     * @param fn Lambda function to add the layer to
     * @param maskingConfig Optional masking configuration to add as environment variable
     */
    addToFunction(fn: lambda.Function, maskingConfig?: Record<string, string[]>): void;
}