/// <reference types="express" />
import { Request } from '@loopback/rest';
import { FileUploadConfig } from '../types';
import { SecurityLogger } from '../utils/security-logger';
/**
 * File upload handler that validates file uploads for security
 */
export declare class FileUploadHandler {
    private config?;
    private logger?;
    private readonly allowedMimeTypes;
    private readonly allowedExtensions;
    private readonly dangerousExtensions;
    constructor(config?: FileUploadConfig | undefined, logger?: SecurityLogger | undefined);
    /**
     * Validate file uploads in the request
     */
    validateFileUploads(req: Request): Promise<void>;
    /**
     * Extract files from request (simplified - depends on middleware used)
     */
    private extractFiles;
    /**
     * Validate a single file
     */
    private validateSingleFile;
    /**
     * Validate file content matches declared type
     */
    private validateFileContent;
    /**
     * Get file signature from buffer
     */
    private getFileSignature;
    /**
     * Detect file type from signature
     */
    private detectFileType;
    /**
     * Get expected MIME types for a detected file signature
     */
    private getMimeTypesForSignature;
    /**
     * Check for suspicious content in file
     */
    private containsSuspiciousContent;
    /**
     * Scan file for malware (placeholder implementation)
     */
    private scanForMalware;
    /**
     * Get upload statistics
     */
    getStats(): {
        maxFileSize: number;
        maxFiles: number;
        allowedMimeTypes: string[];
        allowedExtensions: string[];
        validateContent: boolean;
        scanForMalware: boolean;
        allowExecutables: boolean;
    };
    /**
     * Add allowed MIME type
     */
    addAllowedMimeType(mimeType: string): void;
    /**
     * Remove allowed MIME type
     */
    removeAllowedMimeType(mimeType: string): void;
    /**
     * Add allowed file extension
     */
    addAllowedExtension(extension: string): void;
    /**
     * Remove allowed file extension
     */
    removeAllowedExtension(extension: string): void;
    /**
     * Update configuration
     */
    updateConfig(config: Partial<FileUploadConfig>): void;
}