/**
 * EncodingDetector
 *
 * Detects and blocks encoding-based bypass attempts:
 * - Base64 encoded payloads
 * - URL encoded attacks
 * - Unicode/punycode obfuscation
 * - Hex encoding
 * - HTML entity encoding
 * - Mixed encoding attacks
 */
import { GuardLogger } from "../types";
export interface EncodingDetectorConfig {
    detectBase64?: boolean;
    detectURLEncoding?: boolean;
    detectUnicode?: boolean;
    detectHex?: boolean;
    detectHTMLEntities?: boolean;
    detectMixedEncoding?: boolean;
    detectROT13?: boolean;
    detectOctal?: boolean;
    detectBase32?: boolean;
    maxDecodingDepth?: number;
    threatPatterns?: ThreatPattern[];
    maxEncodedRatio?: number;
    logger?: GuardLogger;
}
export interface ThreatPattern {
    name: string;
    pattern: RegExp;
    severity: "low" | "medium" | "high" | "critical";
}
export interface EncodingDetectorResult {
    allowed: boolean;
    reason?: string;
    violations: string[];
    encoding_analysis: {
        encodings_detected: EncodingDetection[];
        decoded_content?: string;
        threats_found: ThreatFound[];
        obfuscation_score: number;
    };
}
export interface EncodingDetection {
    type: string;
    count: number;
    locations: string[];
    decoded_sample?: string;
}
export interface ThreatFound {
    pattern_name: string;
    severity: string;
    in_layer: string;
}
export declare class EncodingDetector {
    private config;
    private logger;
    private defaultThreatPatterns;
    constructor(config?: EncodingDetectorConfig);
    /**
     * Detect encoding and analyze for threats
     */
    detect(input: string, requestId?: string): EncodingDetectorResult;
    /**
     * Quick check if input contains encoded threats
     */
    containsEncodedThreat(input: string): boolean;
    private detectBase64;
    private detectURLEncoding;
    private detectUnicode;
    private detectHex;
    private detectHTMLEntities;
    private detectROT13;
    private detectOctal;
    private detectBase32;
    private checkThreats;
    private fullyDecode;
}