release: prepare v4.8.5 security hardening release

doc/CONFIGURATION.md

@@ -0,0 +1,63 @@
+# Configuration Guide
+
+## Requirements
+
+- modern browser with WebRTC and Web Crypto support
+- Node.js 18+ for local development
+- TURN service only when relay-only privacy mode is required
+
+## Local setup
+
+```bash
+npm install
+npm run build
+npm run serve
+```
+
+## ICE server configuration
+
+SecureBit.chat keeps existing STUN support for ordinary WebRTC connectivity. Deployments that require relay-only privacy must provide their own TURN service credentials through deployment configuration; public TURN credentials are intentionally not bundled.
+
+### Privacy modes
+
+| Mode | Behavior | IP privacy |
+| --- | --- | --- |
+| default | standard WebRTC candidate gathering | direct candidates may expose IP addresses |
+| relay-only | `iceTransportPolicy: "relay"` | requires TURN and avoids direct peer candidates when configured correctly |
+
+### Operational rules
+
+- STUN is not a privacy substitute for TURN.
+- Relay-only mode without TURN cannot establish a working relay connection.
+- The UI warns users when TURN is missing.
+- Validate TURN deployment with browser WebRTC diagnostics before production rollout.
+
+## Verification flow
+
+Protocol `4.1` requires interactive SAS verification:
+
+1. both peers derive the same SAS from shared session material
+2. users compare the code out of band
+3. each user enters the matching code manually
+4. the chat unlocks only after both confirmations succeed
+
+Three failed local attempts disconnect the session.
+
+## File-transfer policy
+
+Incoming file requests are validated before the consent prompt and require explicit user approval.
+
+Allowed categories:
+
+- common raster images
+- PDF
+- plain text
+- ZIP archives
+
+Blocked examples:
+
+- `.exe`, `.bat`, `.cmd`, `.sh`, `.js`
+- `.msi`, `.dmg`, `.app`, `.jar`, `.scr`
+- `.ps1`, `.vbs`, `.html`, `.svg`
+
+Both MIME type and extension must be acceptable. Missing or unknown MIME types are treated as unsafe unless explicitly covered by policy.

doc/SECURITY-ARCHITECTURE.md

@@ -1,774 +1,53 @@
-# SecureBit.chat Security Architecture v4.02.985
+# Security Architecture
 
-## 🛡️ Overview
+## Current baseline
 
-SecureBit.chat implements a revolutionary **18-layer security architecture** with ECDH + DTLS + SAS authentication that provides military-grade protection for peer-to-peer communications. This document details the technical implementation of our security system, which exceeds most government and enterprise communication standards.
+| Area | Current behavior |
+| --- | --- |
+| Protocol | `4.1` with mismatch rejection |
+| Peer verification | mandatory manual SAS entry |
+| Transport | WebRTC over DTLS |
+| Privacy mode | optional TURN relay-only mode |
+| Message UI safety | incoming decrypted text sanitized before display |
+| File transfer | validated metadata, explicit consent, allowlist policy |
+| Local metadata | encrypted IndexedDB envelopes with migration |
+| Lifecycle | unified disconnect cleanup and bounded resource retention |
 
-**Current Implementation:** Stage 5 - Maximum Security  
-**Security Rating:** Maximum (ECDH + DTLS + SAS)  
-**Active Layers:** 18/18  
-**Threat Protection:** Comprehensive (MITM, Traffic Analysis, Replay Attacks, Session Hijacking, Race Conditions, Key Exposure, DTLS Race Conditions, Memory Safety, Use-After-Free, Key Structure Manipulation)
+## Verification state machine
 
----
-
-## 📋 Table of Contents
-
-1. [Security Architecture Overview](#security-architecture-overview)
-2. [Layer-by-Layer Analysis](#layer-by-layer-analysis)
-3. [Cryptographic Specifications](#cryptographic-specifications)
-4. [Threat Model](#threat-model)
-5. [Implementation Details](#implementation-details)
-6. [Security Verification](#security-verification)
-7. [Performance Impact](#performance-impact)
-8. [Compliance Standards](#compliance-standards)
-9. [ASN.1 Validation Framework](#asn1-validation-framework)
-
----
-
-## 🏗️ Security Architecture Overview
-
-### 19-Layer Defense System
-
-```
-┌─────────────────────────────────────────────────────────────┐
-│                    APPLICATION LAYER                        │
-├─────────────────────────────────────────────────────────────┤
-│ Layer 19: HKDF Key Derivation (RFC 5869 Compliant)         │
-│ Layer 18: EC Point Validation (Format & Structure)         │
-│ Layer 17: OID Validation (Algorithm & Curve Verification)  │
-│ Layer 16: ASN.1 Validation (Complete Key Structure)        │
-│ Layer 15: Production Security Logging (Data Sanitization)  │
-│ Layer 14: Secure Key Storage (WeakMap Isolation)           │
-│ Layer 13: Mutex Framework (Race Condition Protection)      │
-├─────────────────────────────────────────────────────────────┤
-│                   CRYPTOGRAPHIC LAYER                      │
-├─────────────────────────────────────────────────────────────┤
-│ Layer 12: Perfect Forward Secrecy (Key Rotation)           │
-│ Layer 11: Enhanced Rate Limiting (DDoS Protection)         │
-│ Layer 10: Fake Traffic Generation (Traffic Analysis)       │
-│ Layer 9:  Message Chunking (Timing Analysis Protection)    │
-│ Layer 8:  Packet Reordering Protection (Sequence Security) │
-├─────────────────────────────────────────────────────────────┤
-│                   OBFUSCATION LAYER                        │
-├─────────────────────────────────────────────────────────────┤
-│ Layer 7:  Anti-Fingerprinting (Pattern Obfuscation)       │
-│ Layer 6:  Packet Padding (Size Obfuscation)               │
-│ Layer 5:  Nested Encryption (Additional AES-GCM)          │
-├─────────────────────────────────────────────────────────────┤
-│                   ENCRYPTION LAYER                         │
-├─────────────────────────────────────────────────────────────┤
-│ Layer 4:  Message Encryption (Enhanced AES-GCM)           │
-│ Layer 3:  Metadata Protection (Separate AES-GCM)          │
-│ Layer 2:  Key Exchange (ECDH P-384)                       │
-│ Layer 1:  Enhanced Authentication (ECDSA P-384)           │
-├─────────────────────────────────────────────────────────────┤
-│                    TRANSPORT LAYER                         │
-│                   (WebRTC/ICE/DTLS)                        │
-└─────────────────────────────────────────────────────────────┘
+```text
+connection established
+        ↓
+shared keys derived
+        ↓
+deterministic SAS displayed
+        ↓
+manual out-of-band comparison
+        ↓
+local input validated
+        ↓
+peer confirmation received
+        ↓
+verified session
 ```
 
-### Security Progression Stages
+The verified state is reached only when both local and remote confirmation flags are true.
 
-| Stage | Layers Active | Security Level | Target Threats |
-|-------|---------------|----------------|-----------------|
-| 1     | 1-5          | Basic Enhanced | Basic attacks, MITM |
-| 2     | 1-7          | Medium         | + Traffic analysis |
-| 3     | 1-9          | High           | + Timing attacks |
-| 4     | 1-12         | High Enhanced  | + Advanced persistent threats |
-| 5     | 1-15         | Military-Grade | + Race conditions, Key exposure |
-| 6     | 1-19         | Maximum        | + DTLS race conditions, Memory safety, Key structure validation, HKDF compliance |
+## File-transfer architecture
 
----
+1. sender emits metadata
+2. receiver validates name, size, type, and abuse limits
+3. receiver sees Accept / Reject prompt
+4. no receive buffers are allocated before acceptance
+5. sender transmits chunks only after acceptance
+6. completed received buffers are retained within a bounded window
 
-## 🔍 Layer-by-Layer Analysis
+## Disconnect cleanup
 
-### Layer 1: Enhanced Authentication (ECDSA P-384)
-**Purpose:** Cryptographic proof of message authenticity and sender verification
+The canonical disconnect path clears:
 
-**Technical Specifications:**
-- **Algorithm:** ECDSA with P-384 curve
-- **Hash Function:** SHA-384 (primary), SHA-256 (fallback)
-- **Key Size:** 384-bit (equivalent to 7680-bit RSA)
-- **Signature Size:** 96 bytes
-- **Key Properties:** Non-extractable, hardware-protected
-
-**Implementation:**
-```javascript
-// Self-signed key package for MITM protection
-const keyPackage = {
-    keyType: 'ECDSA',
-    keyData: exported384BitKey,
-    timestamp: Date.now(),
-    version: '4.02',
-    signature: ecdsaSignature
-};
-```
-
-### Layer 16: ASN.1 Validation (Complete Key Structure)
-**Purpose:** Complete structural validation of all cryptographic keys according to PKCS standards
-
-**Technical Specifications:**
-- **Parser:** Complete ASN.1 DER parser
-- **Validation Scope:** Full key structure verification
-- **Standards:** RFC 5280, RFC 5480, PKCS compliance
-- **Performance:** < 10ms validation time
-- **Coverage:** All cryptographic operations
-
-**Implementation:**
-```javascript
-// Complete ASN.1 DER parsing and validation
-const validateKeyStructure = (keyData) => {
-    const asn1Parser = new ASN1Validator();
-    const parsed = asn1Parser.parseDER(keyData);
-    
-    // Validate complete structure
-    if (!asn1Parser.validateSPKI(parsed)) {
-        throw new Error('Invalid SPKI structure');
-    }
-    
-    // Validate OID and curves
-    if (!asn1Parser.validateOID(parsed)) {
-        throw new Error('Invalid algorithm OID');
-    }
-    
-    // Validate EC point format
-    if (!asn1Parser.validateECPoint(parsed)) {
-        throw new Error('Invalid EC point format');
-    }
-    
-    return true;
-};
-```
-
-### Layer 17: OID Validation (Algorithm & Curve Verification)
-**Purpose:** Verification of cryptographic algorithms and elliptic curves
-
-**Technical Specifications:**
-- **Supported Curves:** P-256, P-384 only
-- **Algorithm Validation:** Complete OID verification
-- **Fallback Support:** P-384 to P-256 compatibility
-- **Security:** Prevents algorithm substitution attacks
-
-**Implementation:**
-```javascript
-// OID validation for algorithms and curves
-const validateOID = (parsed) => {
-    const validOIDs = {
-        '1.2.840.10045.3.1.7': 'P-256',  // secp256r1
-        '1.3.132.0.34': 'P-384'          // secp384r1
-    };
-    
-    const oid = parsed.algorithm.algorithm;
-    if (!validOIDs[oid]) {
-        throw new Error(`Unsupported curve: ${oid}`);
-    }
-    
-    return validOIDs[oid];
-};
-```
-
-### Layer 19: HKDF Key Derivation (RFC 5869 Compliant)
-**Purpose:** RFC 5869 compliant key derivation with proper key separation and cryptographic security
-
-**Technical Specifications:**
-- **Standard:** RFC 5869 HMAC-based Extract-and-Expand Key Derivation Function
-- **Hash Function:** SHA-256 for optimal compatibility and performance
-- **Salt Security:** 64-byte cryptographically secure salt for each derivation
-- **Key Separation:** Unique `info` parameters for each derived key type
-- **Non-Extractable Keys:** Hardware-protected keys for enhanced security
-
-**Implementation:**
-```javascript
-// HKDF key derivation with proper separation
-const deriveSharedKeys = async (privateKey, publicKey, salt) => {
-    // Step 1: Pure ECDH derivation
-    const rawKeyMaterial = await crypto.subtle.deriveKey(
-        { name: 'ECDH', public: publicKey },
-        privateKey,
-        { name: 'AES-GCM', length: 256 },
-        true, // Extractable for HKDF processing
-        ['encrypt', 'decrypt']
-    );
-    
-    // Export and import for HKDF
-    const rawKeyData = await crypto.subtle.exportKey('raw', rawKeyMaterial);
-    const rawSharedSecret = await crypto.subtle.importKey(
-        'raw', rawKeyData,
-        { name: 'HKDF', hash: 'SHA-256' },
-        false, ['deriveKey']
-    );
-    
-    // Step 2: Derive specific keys with unique info parameters
-    const messageKey = await crypto.subtle.deriveKey(
-        {
-            name: 'HKDF',
-            hash: 'SHA-256',
-            salt: saltBytes,
-            info: encoder.encode('message-encryption-v4')
-        },
-        rawSharedSecret,
-        { name: 'AES-GCM', length: 256 },
-        false, ['encrypt', 'decrypt']
-    );
-    
-    // Additional keys derived with unique info parameters...
-    return { messageKey, macKey, pfsKey, metadataKey, fingerprint };
-};
-```
-
-### Layer 18: EC Point Validation (Format & Structure Verification)
-**Purpose:** Verification of elliptic curve point format and structure
-
-**Technical Specifications:**
-- **Format:** Uncompressed format 0x04 only
-- **Structure:** Complete point coordinate validation
-- **Size Limits:** 50-2000 bytes to prevent DoS attacks
-- **BIT STRING:** Unused bits must be 0
-
-**Implementation:**
-```javascript
-// EC point format and structure validation
-const validateECPoint = (parsed) => {
-    const publicKey = parsed.subjectPublicKey;
-    
-    // Check format (uncompressed 0x04)
-    if (publicKey[0] !== 0x04) {
-        throw new Error('Only uncompressed EC point format supported');
-    }
-    
-    // Validate size limits
-    if (publicKey.length < 50 || publicKey.length > 2000) {
-        throw new Error('Key size outside allowed range (50-2000 bytes)');
-    }
-    
-    // Validate BIT STRING unused bits
-    if (parsed.unusedBits !== 0) {
-        throw new Error('BIT STRING unused bits must be 0');
-    }
-    
-    return true;
-};
-```
-
----
-
-## 🔐 Cryptographic Specifications
-
-### Algorithm Selection Rationale
-
-| Component | Algorithm | Key Size | Rationale |
-|-----------|-----------|----------|-----------|
-| Key Exchange | ECDH P-384 | 384-bit | NSA Suite B, quantum-resistant timeline |
-| Signatures | ECDSA P-384 | 384-bit | Matches key exchange, proven security |
-| Encryption | AES-256-GCM | 256-bit | NIST recommended, authenticated encryption |
-| Hashing | SHA-384 | 384-bit | Matches curve size, collision resistant |
-| MAC | HMAC-SHA-384 | 384-bit | Proven security, matches hash function |
-
-### Security Strengths
-
-- **ECDH P-384:** Equivalent to 7680-bit RSA
-- **AES-256:** Quantum computer resistant until 2040+
-- **SHA-384:** 192-bit security level (collision resistance)
-- **Combined Security:** Exceeds 256-bit security level
-
-### Cryptographic Operations Performance
-
-| Operation | Time (ms) | CPU Usage | Memory Usage |
-|-----------|-----------|-----------|--------------|
-| Key Generation | 10-50 | Medium | Low |
-| ECDH Agreement | 5-15 | Low | Low |
-| AES Encryption | 0.1-1 | Very Low | Very Low |
-| ECDSA Signing | 2-8 | Low | Low |
-| Message Processing | 1-5 | Low | Low |
-
----
-
-## 🎯 Threat Model
-
-### Threat Classifications
-
-#### **🔴 Critical Threats (Fully Mitigated)**
-- **Nation-State Attacks:** Advanced persistent threats
-- **MITM Attacks:** Certificate pinning bypass attempts
-- **Cryptographic Attacks:** Implementation vulnerabilities
-- **Traffic Analysis:** Deep packet inspection and metadata analysis
-
-#### **🟡 High Threats (Substantially Mitigated)**
-- **Side-Channel Attacks:** Timing and power analysis
-- **Social Engineering:** User manipulation (partially mitigated)
-- **Endpoint Compromise:** Device-level attacks
-- **Quantum Computing:** Future quantum attacks (timeline > 15 years)
-
-#### **🟢 Medium Threats (Completely Mitigated)**
-- **Passive Eavesdropping:** Network traffic interception
-- **Replay Attacks:** Message reuse attempts
-- **DDoS Attacks:** Service disruption attempts
-- **Protocol Downgrade:** Forced weak encryption
-
-### Attack Scenarios and Defenses
-
-#### Scenario 1: Government Surveillance
-**Attack:** Comprehensive traffic monitoring and analysis
-**Defense Layers:** 6, 7, 10, 12 (traffic obfuscation)
-**Result:** Encrypted traffic indistinguishable from noise
-
-#### Scenario 2: Corporate Espionage
-**Attack:** Targeted interception with advanced tools
-**Defense Layers:** 1, 2, 3, 4, 5 (cryptographic protection)
-**Result:** Computationally infeasible to decrypt
-
-#### Scenario 3: ISP-Level Monitoring
-**Attack:** Deep packet inspection and metadata collection
-**Defense Layers:** 6, 7, 8, 9, 10 (pattern obfuscation)
-**Result:** No useful metadata or patterns extractable
-
-#### Scenario 4: Academic Cryptanalysis
-**Attack:** Advanced mathematical attacks on crypto
-**Defense Layers:** 2, 4, 5 (multiple algorithms)
-**Result:** Multiple independent cryptographic barriers
-
----
-
-## 🔧 Implementation Details
-
-### Message Flow Through Security Layers
-
-```
-┌─────────────────┐
-│ User Message    │
-└─────────┬───────┘
-          │
-┌─────────▼───────┐    ┌──────────────────┐
-│ Layer 7: Anti  │    │ Outbound Process │
-│ Fingerprinting │◄───┤ (Sending)        │
-└─────────┬───────┘    └──────────────────┘
-          │
-┌─────────▼───────┐
-│ Layer 6: Packet│
-│ Padding        │
-└─────────┬───────┘
-          │
-┌─────────▼───────┐
-│ Layer 8: Packet│
-│ Reordering     │
-└─────────┬───────┘
-          │
-┌─────────▼───────┐
-│ Layer 5: Nested│
-│ Encryption     │
-└─────────┬───────┘
-          │
-┌─────────▼───────┐
-│ Layer 4: Message│
-│ Encryption     │
-└─────────┬───────┘
-          │
-┌─────────▼───────┐
-│ WebRTC Channel │
-└─────────────────┘
-```
-
-### Security Layer Configuration
-
-```javascript
-// Production configuration for maximum security
-const securityConfig = {
-    // Stage 4 - Maximum Security
-    features: {
-        hasEncryption: true,
-        hasECDH: true,
-        hasECDSA: true,
-        hasMutualAuth: true,
-        hasMetadataProtection: true,
-        hasEnhancedReplayProtection: true,
-        hasNonExtractableKeys: true,
-        hasRateLimiting: true,
-        hasEnhancedValidation: true,
-        hasPFS: true,
-        hasNestedEncryption: true,
-        hasPacketPadding: true,
-        hasFakeTraffic: true,
-        hasMessageChunking: true,
-        hasDecoyChannels: true,
-        hasPacketReordering: true,
-        hasAntiFingerprinting: true
-    },
-    
-    // Performance optimizations
-    performance: {
-        paddingRange: [64, 512], // Reduced for efficiency
-        chunkSize: 2048, // Larger chunks
-        fakeTrafficInterval: [10000, 30000], // Less frequent
-        keyRotation: 300000 // 5 minutes
-    }
-};
-```
-
----
-
-## ✅ Security Verification
-
-### Automated Testing
-
-```javascript
-// Security layer verification
-async function verifySecurityLayers() {
-    const tests = [
-        verifyEncryption(),
-        verifyECDHKeyExchange(),
-        verifyECDSASignatures(),
-        verifyMutualAuth(),
-        verifyMetadataProtection(),
-        verifyReplayProtection(),
-        verifyNonExtractableKeys(),
-        verifyRateLimiting(),
-        verifyEnhancedValidation(),
-        verifyPFS(),
-        verifyNestedEncryption(),
-        verifyPacketPadding()
-    ];
-    
-    const results = await Promise.all(tests);
-    return results.every(result => result === true);
-}
-```
-
-### Manual Verification Commands
-
-```javascript
-// Check security status
-webrtcManager.getSecurityStatus()
-// Expected: { stage: 4, securityLevel: 'MAXIMUM', activeFeatures: 12 }
-
-// Verify cryptographic implementation
-webrtcManager.calculateSecurityLevel()
-// Expected: { level: 'HIGH', score: 80+, verificationResults: {...} }
-
-// Test fake traffic filtering
-webrtcManager.checkFakeTrafficStatus()
-// Expected: { fakeTrafficEnabled: true, timerActive: true }
-```
-
-### Security Metrics Dashboard
-
-| Metric | Target | Current | Status |
-|--------|---------|---------|---------|
-| Active Security Layers | 19 | 19 | ✅ |
-| Encryption Strength | 256-bit | 256-bit | ✅ |
-| Key Exchange Security | P-384 | P-384 | ✅ |
-| Forward Secrecy | Complete | Complete | ✅ |
-| Traffic Obfuscation | Maximum | Maximum | ✅ |
-| Attack Surface | Minimal | Minimal | ✅ |
-| HKDF Compliance | RFC 5869 | RFC 5869 | ✅ |
-
----
-
-## 🔒 Layer 13: Mutex Framework (Race Condition Protection)
-
-### Purpose
-Prevents race conditions during connection establishment and cryptographic operations through advanced mutex coordination system.
-
-### Technical Implementation
-- **Custom Mutex System:** `_withMutex('connectionOperation')` with 15-second timeout
-- **Atomic Operations:** Serialized connection operations to prevent conflicts
-- **Deadlock Prevention:** Emergency recovery mechanisms with automatic cleanup
-- **Operation Tracking:** Unique `operationId` for comprehensive diagnostics
-
-### Security Benefits
-- **Race Condition Prevention:** Eliminates timing-based attacks during key generation
-- **Connection Integrity:** Ensures atomic connection establishment
-- **Error Recovery:** Automatic rollback via `_cleanupFailedOfferCreation()` on failures
-- **Diagnostic Capability:** Phase tracking for precise error identification
-
-### Implementation Details
-```javascript
-// Mutex-protected connection operations
-await this._withMutex('connectionOperation', async () => {
-    const operationId = this._generateOperationId();
-    try {
-        await this._generateEncryptionKeys();
-        await this._validateConnectionParameters();
-        await this._establishSecureChannel();
-    } catch (error) {
-        await this._cleanupFailedOfferCreation(operationId);
-        throw error;
-    }
-});
-```
-
----
-
-## 🔐 Layer 14: Secure Key Storage (WeakMap Isolation)
-
-### Purpose
-Replaces public key properties with private WeakMap-based storage to prevent unauthorized access and memory exposure.
-
-### Technical Implementation
-- **WeakMap Storage:** `_secureKeyStorage` for all cryptographic keys
-- **Private Access Methods:** `_getSecureKey()`, `_setSecureKey()`, `_initializeSecureKeyStorage()`
-- **Key Validation:** `_validateKeyValue()` with type and format checking
-- **Key Rotation:** `_rotateKeys()` with secure key replacement
-- **Emergency Wipe:** `_emergencyKeyWipe()` for threat response
-
-### Security Benefits
-- **Memory Protection:** Keys inaccessible via direct property access or debugger
-- **Access Control:** Secure getters/setters with validation
-- **Key Lifetime Management:** Automatic rotation and expiration
-- **Threat Response:** Immediate key destruction capabilities
-
-### Implementation Details
-```javascript
-// Secure key storage initialization
-this._initializeSecureKeyStorage();
-
-// Secure key access
-const encryptionKey = this._getSecureKey('encryptionKey');
-this._setSecureKey('encryptionKey', newKey, { validate: true });
-
-// Emergency key wipe
-this._emergencyKeyWipe();
-```
-
----
-
-## 🛡️ Layer 15: Production Security Logging (Data Sanitization)
-
-### Purpose
-Implements environment-aware logging system that prevents sensitive data exposure while maintaining useful diagnostics.
-
-### Technical Implementation
-- **Environment Detection:** Automatic production vs development mode detection
-- **Data Sanitization:** `_secureLog()` replacing `console.log` with sanitization
-- **Log Level Control:** Production (warn+error only), Development (debug+)
-- **Rate Limiting:** Automatic log spam prevention and cleanup
-- **Memory Management:** Automatic cleanup for log counters
-
-### Security Benefits
-- **Data Protection:** Encryption keys, message content, and tokens are sanitized
-- **Privacy Preservation:** User privacy maintained in production logs
-- **Debugging Support:** Safe debugging information without sensitive content
-- **Compliance:** Meets privacy regulations and security standards
-
-### Implementation Details
-```javascript
-// Secure logging with data sanitization
-this._secureLog('debug', 'Connection established', {
-    userId: '[REDACTED]',
-    encryptionKey: '[REDACTED]',
-    messageContent: '[REDACTED]'
-});
-
-// Environment-aware logging
-if (this._isProductionMode()) {
-    // Only critical errors and warnings
-} else {
-    // Full debugging information (sanitized)
-}
-```
-
----
-
-## 🛡️ Layer 16: Atomic Operations (Race Condition Prevention)
-
-### Purpose
-Prevents race conditions in critical security operations through atomic lock-based mechanisms.
-
-### Technical Implementation
-- **Lock Management:** Map-based lock system with unique keys
-- **Atomic Operations:** `withLock()` wrapper for critical sections
-- **Timeout Protection:** Configurable lock timeouts (default: 5 seconds)
-- **Automatic Cleanup:** Lock removal after operation completion
-- **Error Handling:** Graceful fallback on lock failures
-
-### Security Benefits
-- **Race Condition Prevention:** Eliminates concurrent access vulnerabilities
-- **Data Integrity:** Ensures consistent state during operations
-- **Critical Section Protection:** Secures file transfer and cryptographic operations
-- **Deadlock Prevention:** Automatic cleanup prevents resource exhaustion
-
-### Implementation Details
-```javascript
-// Atomic operation wrapper
-return this.atomicOps.withLock(
-    `chunk-${chunkMessage.fileId}`, 
-    async () => {
-        // Critical section protected by lock
-        // File chunk processing logic
-    }
-);
-```
-
----
-
-## 🛡️ Layer 17: DTLS Race Condition Protection (WebRTC Security)
-
-### Purpose
-Advanced protection against October 2024 WebRTC DTLS ClientHello race condition vulnerabilities.
-
-### Technical Implementation
-- **ICE Endpoint Verification:** Secure validation before DTLS establishment
-- **ClientHello Validation:** TLS cipher suite and version verification
-- **Source Authentication:** Cryptographic verification of DTLS packet sources
-- **Queue Management:** DTLS message queuing during ICE verification
-- **Timeout Protection:** Configurable verification timeouts
-
-### Security Benefits
-- **DTLS Vulnerability Mitigation:** Protects against race condition attacks
-- **WebRTC Security Enhancement:** Comprehensive transport layer protection
-- **Endpoint Validation:** Ensures legitimate connection sources
-- **Protocol Security:** TLS version and cipher suite validation
-
-### Implementation Details
-```javascript
-// DTLS source validation
-await this.validateDTLSSource(clientHelloData, expectedSource);
-
-// ICE endpoint verification
-this.addVerifiedICEEndpoint(endpoint);
-
-// DTLS message handling
-await this.handleDTLSClientHello(clientHelloData, sourceEndpoint);
-```
-
----
-
-## 🛡️ Layer 18: Memory Safety Protection (Use-After-Free)
-
-### Purpose
-Advanced memory safety mechanisms to prevent use-after-free vulnerabilities and ensure secure data cleanup.
-
-### Technical Implementation
-- **Secure Memory Wiping:** Advanced buffer wiping with zero-filling
-- **Context Isolation:** Symbol-based private instance management
-- **Memory Cleanup:** Comprehensive cleanup of sensitive data structures
-- **Error Handling:** Secure error handling without information leakage
-- **Garbage Collection:** Optional forced GC for critical operations
-
-### Security Benefits
-- **Use-After-Free Prevention:** Eliminates memory safety vulnerabilities
-- **Data Leakage Prevention:** Secure cleanup of sensitive information
-- **Context Security:** Isolated instance management prevents tampering
-- **Error Security:** Sanitized error messages prevent information disclosure
-
-### Implementation Details
-```javascript
-// Secure memory wiping
-SecureMemoryManager.secureWipe(buffer);
-
-// Context isolation
-SecureFileTransferContext.getInstance().setFileTransferSystem(this);
-
-// Enhanced memory cleanup
-for (const [key, value] of Object.entries(receivingState)) {
-    if (value instanceof ArrayBuffer || value instanceof Uint8Array) {
-        SecureMemoryManager.secureWipe(value);
-    }
-}
-```
-
----
-
-## ⚡ Performance Impact
-
-### Latency Analysis
-
-| Security Layer | Added Latency | Justification |
-|----------------|---------------|---------------|
-| Authentication | ~5ms | Necessary for MITM protection |
-| Key Exchange | ~10ms | One-time cost per session |
-| Metadata Protection | ~1ms | Minimal overhead |
-| Message Encryption | ~2ms | Standard AES-GCM performance |
-| Nested Encryption | ~2ms | Additional security layer |
-| Packet Padding | ~0.5ms | Simple padding operation |
-| Anti-Fingerprinting | ~3ms | Pattern obfuscation |
-| Reordering Protection | ~1ms | Header processing |
-| Message Chunking | ~50ms | Intentional delay for security |
-| Fake Traffic | 0ms | Background operation |
-| Rate Limiting | ~0.1ms | Memory lookup |
-| PFS Key Rotation | ~10ms | Every 5 minutes |
-| Mutex Framework | ~2ms | Race condition protection |
-| Secure Key Storage | ~0.5ms | WeakMap access overhead |
-| Production Logging | ~1ms | Data sanitization processing |
-| Atomic Operations | ~2ms | Race condition protection |
-| DTLS Protection | ~3ms | WebRTC security enhancement |
-| Memory Safety | ~1ms | Secure cleanup operations |
-
-**Total Average Latency:** ~84.5ms per message (acceptable for secure communications)
-
-### Throughput Impact
-
-- **Without Security:** ~1000 messages/second
-- **With Stage 4 Security:** ~500 messages/second
-- **Efficiency:** 50% (excellent for security level provided)
-
-### Memory Usage
-
-- **Base Memory:** ~2MB
-- **Security Layers:** ~3MB additional
-- **Cryptographic Keys:** ~1MB
-- **Total:** ~6MB (minimal for modern devices)
-
----
-
-## 📊 Compliance Standards
-
-### Industry Standards Met
-
-- ✅ **NIST SP 800-57:** Key management best practices
-- ✅ **FIPS 140-2 Level 2:** Cryptographic module security
-- ✅ **NSA Suite B:** Cryptographic algorithms (P-384, AES-256)
-- ✅ **RFC 7748:** Elliptic curve cryptography standards
-- ✅ **RFC 5869:** HKDF key derivation
-- ✅ **RFC 3394:** AES key wrap specifications
-
-### Regulatory Compliance
-
-- ✅ **GDPR:** Privacy by design, data minimization
-- ✅ **CCPA:** California privacy protection
-- ✅ **HIPAA:** Healthcare data protection (suitable for)
-- ✅ **SOX:** Financial data protection (suitable for)
-- ✅ **ITAR:** International traffic in arms regulations (crypto export)
-
-### Security Certifications (Pending)
-
-- 🔄 **Common Criteria EAL4+:** Security functionality evaluation
-- 🔄 **FIPS 140-3:** Next-generation cryptographic validation
-- 🔄 **ISO 27001:** Information security management
-
----
-
-## 🚀 Future Enhancements
-
-### Quantum-Resistant Cryptography (2026)
-- **Post-Quantum Key Exchange:** CRYSTALS-Kyber
-- **Post-Quantum Signatures:** CRYSTALS-Dilithium
-- **Hybrid Classical/Quantum:** Dual algorithm support
-
-### Advanced Traffic Obfuscation (2025)
-- **AI-Powered Pattern Generation:** Machine learning fake traffic
-- **Protocol Mimicry:** Disguise as common protocols (HTTP, DNS)
-- **Adaptive Obfuscation:** Real-time pattern adjustment
-
-### Enhanced Perfect Forward Secrecy (2025)
-- **Automatic Key Rotation:** Every 1 minute
-- **Group Key Management:** Multi-party key rotation
-- **Quantum Key Distribution:** Hardware-based key generation
-
----
-
-## 📞 Technical Support
-
-For technical questions about the security architecture:
-
-- **Security Team:** security@SecureBit.chat
-- **Technical Documentation:** docs@SecureBit.chat
-- **GitHub Issues:** [Security Architecture Issues](https://github.com/SecureBitChat/securebit-chat/issues?q=label%3Asecurity-architecture)
-
----
-
-*This document is updated with each major security enhancement. Current version reflects Stage 5 Military-Grade Security implementation with comprehensive connection security overhaul.*
-
-**Last Updated:** January 15, 2025  
-**Document Version:** 4.1  
-**Security Implementation:** Stage 5 - Military-Grade Security  
-**Review Status:** ✅ Verified and Tested
+- WebRTC channels and peer connection handles
+- timers, deferred retries, fake traffic, and decoy traffic
+- pending transfer state and consent waits
+- verification state and crypto/PFS state
+- React file-transfer callbacks and stale UI transfer state