# NimPak Security and Verification System

## Overview

The NimPak Security and Verification System provides military-grade package integrity monitoring, provenance tracking, and trust management for NexusOS. This comprehensive system ensures package authenticity, maintains audit trails, and enforces security policies throughout the package lifecycle.

## Architecture

The security system consists of several interconnected components:

```
┌─────────────────────────────────────────────────────────────┐
│                    NimPak Security System                   │
├─────────────────────────────────────────────────────────────┤
│  ┌─────────────────┐  ┌─────────────────┐  ┌──────────────┐ │
│  │ Integrity       │  │ Provenance      │  │ Trust Policy │ │
│  │ Monitor         │  │ Tracker         │  │ Manager      │ │
│  │                 │  │                 │  │              │ │
│  │ • Hash Verify   │  │ • Chain Track   │  │ • Reputation │ │
│  │ • Signature     │  │ • Trust Score   │  │ • Policies   │ │
│  │ • Real-time     │  │ • Audit Trail   │  │ • Enforcement│ │
│  │ • Health Checks │  │ • Verification  │  │ • Community  │ │
│  └─────────────────┘  └─────────────────┘  └──────────────┘ │
├─────────────────────────────────────────────────────────────┤
│  ┌─────────────────┐  ┌─────────────────┐  ┌──────────────┐ │
│  │ Hash Verifier   │  │ Signature       │  │ Keyring      │ │
│  │                 │  │ Verifier        │  │ Manager      │ │
│  │ • BLAKE2b/3     │  │ • Ed25519       │  │ • Key Store  │ │
│  │ • Streaming     │  │ • Dilithium     │  │ • Revocation │ │
│  │ • Batch Verify  │  │ • Hybrid Sigs   │  │ • Trust Web  │ │
│  └─────────────────┘  └─────────────────┘  └──────────────┘ │
├─────────────────────────────────────────────────────────────┤
│  ┌─────────────────┐  ┌─────────────────┐  ┌──────────────┐ │
│  │ Event Logger    │  │ Periodic        │  │ CLI Commands │ │
│  │                 │  │ Scanner         │  │              │ │
│  │ • Audit Trail   │  │ • Scheduled     │  │ • nip verify │ │
│  │ • Security Log  │  │ • Incremental   │  │ • nip doctor │ │
│  │ • Compliance    │  │ • Full Scans    │  │ • nip track  │ │
│  └─────────────────┘  └─────────────────┘  └──────────────┘ │
└─────────────────────────────────────────────────────────────┘
```

## Core Components

### 1. Integrity Monitor (`integrity_monitor.nim`)

The Integrity Monitor provides comprehensive package integrity verification and real-time monitoring.

**Key Features:**
- **Hash Verification**: BLAKE2b/BLAKE3 streaming hash verification for packages of any size
- **Signature Verification**: Ed25519 digital signature verification with post-quantum hooks
- **Real-time Monitoring**: Filesystem watcher for immediate tamper detection
- **Health Check Integration**: Pluggable health checks with the framework
- **Quarantine System**: Automatic quarantine of corrupted files
- **Alert Management**: Comprehensive alerting with severity levels

**Usage:**
```bash
# Verify all packages
nip verify --all

# Verify specific package with auto-repair
nip verify htop --auto-repair

# Run integrity health check
nip doctor --integrity

# Start real-time monitoring
nip verify --all --watch
```

### 2. Provenance Tracker (`provenance_tracker.nim`)

The Provenance Tracker maintains complete package source attribution with cryptographic proof.

**Key Features:**
- **Complete Chain Tracking**: From source to installation with cryptographic proof
- **Trust Score Calculation**: Multi-factor trust scoring based on provenance quality
- **Chain Verification**: Cryptographic verification of provenance steps
- **Graft Preservation**: Maintains provenance during external package grafting
- **Audit Trail Integration**: Complete audit trails for compliance

**Provenance Chain Structure:**
```nim
ProvenanceChain:
  - packageId: string
  - version: string
  - source: ProvenanceSource (original, grafted, converted, rebuilt, mirrored)
  - steps: seq[ProvenanceStep]
  - trustScore: float (0.0-1.0)
  - verificationErrors: seq[string]
```

**Usage:**
```bash
# Track package provenance
nip track htop

# Show detailed trust scoring
nip track htop --trust-score

# Show verification details
nip track htop --verification

# Output structured data
nip track htop --output json
```

### 3. Trust Policy Manager (`trust_policy.nim`)

The Trust Policy Manager enforces security policies and manages community reputation.

**Key Features:**
- **Policy-Based Security**: Configurable trust policies with rule-based evaluation
- **Community Reputation**: Actor reputation system with verification history
- **Dynamic Trust Scoring**: Multi-factor trust calculation with community input
- **Policy Enforcement**: Automatic policy enforcement during package operations
- **Reputation Tracking**: Long-term reputation tracking for package maintainers

**Trust Policy Rules:**
```nim
TrustPolicyRule:
  - condition: "trust_score >= 0.8"
  - action: "allow" | "deny" | "warn" | "require_approval"
  - priority: int
```

**Usage:**
```bash
# List available trust policies
nip trust policy list

# Set active trust policy
nip trust policy set strict

# Show community actors
nip trust actor list

# Show actor details
nip trust actor show nexusos-build-farm
```

### 4. Periodic Scanner (`periodic_scanner.nim`)

The Periodic Scanner provides automated integrity scanning with configurable scheduling.

**Key Features:**
- **Scheduled Scanning**: Configurable full and incremental scans
- **Scan Types**: Full system, incremental (recent changes), and targeted scans
- **Performance Optimization**: Efficient scanning with minimal system impact
- **Scan History**: Complete scan history with statistics and reporting
- **Integration**: Seamless integration with integrity monitoring

**Usage:**
```bash
# Manual full scan
nip scan full

# Manual incremental scan
nip scan incremental

# Targeted scan of specific packages
nip scan targeted htop vim git

# Show scan statistics
nip scan status

# Show scan history
nip scan history
```

## CLI Commands

### `nip verify` - Package Verification

Comprehensive package integrity verification with multiple options.

```bash
# Basic usage
nip verify <package|--all> [options]

# Options
--no-signatures      # Skip signature verification
--no-hashes          # Skip hash verification
--signatures-only    # Only verify signatures
--hashes-only        # Only verify hashes
--verbose, -v        # Verbose output
--details            # Show detailed verification info
--auto-repair        # Attempt automatic repair
--watch              # Enable real-time monitoring
--periodic           # Enable periodic scanning
--output <format>    # Output format (json, yaml, kdl)

# Examples
nip verify --all --verbose
nip verify htop --auto-repair
nip verify --all --watch --periodic
```

### `nip doctor --integrity` - Health Checks

System integrity health checks with comprehensive reporting.

```bash
# Basic usage
nip doctor --integrity [options]

# Options
--auto-repair        # Attempt automatic repair
--verbose, -v        # Verbose output
--no-recommendations # Hide repair recommendations
--output <format>    # Output format (json, yaml, kdl)

# Examples
nip doctor --integrity
nip doctor --integrity --auto-repair --verbose
```

### `nip track` - Provenance Tracking

Package provenance tracking with trust scoring and verification.

```bash
# Basic usage
nip track <package> [options]

# Options
--version <version>  # Specific version
--trust-score        # Show detailed trust scoring
--verification       # Show verification details
--no-steps          # Hide individual provenance steps
--no-validation     # Skip chain validation
--verbose, -v       # Verbose output
--output <format>   # Output format (json, yaml, kdl)

# Examples
nip track htop
nip track htop --trust-score --verification
nip track htop --output json
```

### `nip trust` - Trust Policy Management

Trust policy and community reputation management.

```bash
# Policy management
nip trust policy list
nip trust policy set <policy_id>
nip trust policy show [policy_id]

# Actor management
nip trust actor list
nip trust actor show <actor_id>

# Examples
nip trust policy list
nip trust policy set strict
nip trust actor show nexusos-build-farm
```

### `nip scan` - Manual Scanning

Manual integrity scanning with different scope options.

```bash
# Scan types
nip scan full                    # Full system scan
nip scan incremental            # Incremental scan (recent changes)
nip scan targeted <packages...> # Targeted scan

# Status and history
nip scan status                 # Show scan statistics
nip scan history [limit]        # Show scan history

# Examples
nip scan full
nip scan targeted htop vim git
nip scan history 10
```

## Configuration

### Integrity Monitor Configuration

```kdl
integrity {
  enable_realtime_watcher true
  scan_interval 3600              // 1 hour
  watch_paths "/Programs" "/System/Index" "/System/Generations"
  alert_threshold 5
  auto_repair false
  quarantine_corrupted true
}
```

### Provenance Tracker Configuration

```kdl
provenance {
  enable_tracking true
  store_location "/var/lib/nimpak/provenance"
  verification_interval 24        // 24 hours
  auto_verify_on_install true
  require_provenance_for_install false
}
```

### Trust Policy Configuration

```kdl
trust_policy {
  enable_policy_enforcement true
  policy_store_path "/etc/nimpak/trust-policies"
  reputation_store_path "/var/lib/nimpak/reputation"
  auto_update_reputation true
  require_approval_threshold 0.5
}
```

### Periodic Scanner Configuration

```kdl
periodic_scanner {
  enabled true
  full_scan_interval 24           // Hours between full scans
  incremental_interval 15         // Minutes between incremental scans
  full_scan_hour 2               // Hour of day for full scan (0-23)
  max_concurrent_scans 2
  scan_timeout 3600              // Timeout for individual scans (seconds)
}
```

## Security Features

### Cryptographic Verification

- **Hash Algorithms**: BLAKE2b (primary), BLAKE3 (future), SHA256 (legacy)
- **Signature Algorithms**: Ed25519 (primary), Dilithium (post-quantum future)
- **Hybrid Signatures**: Support for classical + post-quantum signature combinations
- **Streaming Verification**: Memory-efficient verification for large packages

### Real-time Monitoring

- **Filesystem Watcher**: Real-time monitoring of critical paths
- **Tamper Detection**: Immediate detection of unauthorized modifications
- **Quarantine System**: Automatic isolation of corrupted files
- **Alert Generation**: Comprehensive alerting with severity classification

### Trust Management

- **Multi-factor Trust Scoring**: Based on provenance, signatures, reputation, and age
- **Community Reputation**: Long-term reputation tracking for package maintainers
- **Policy Enforcement**: Configurable trust policies with rule-based evaluation
- **Audit Trails**: Complete audit trails for compliance and forensics

## Integration Points

### Health Check Framework

The security system integrates with the existing health check framework:

```nim
# Register integrity health checks
registerIntegrityHealthChecks()

# Run all health checks
let results = runHealthChecks()

# Start health check daemon
startHealthCheckDaemon(monitor)
```

### Security Event Logging

All security events are logged for audit and compliance:

```nim
# Log security events
logGlobalSecurityEvent(EventPackageVerification, SeverityInfo, "nip-verify",
  "Package verification completed successfully")

# Event types
EventPackageVerification
EventSecurityIncident
EventSystemHealthCheck
EventFileSystemChange
```

### Grafting Integration

Provenance is preserved during grafting operations:

```nim
# Preserve provenance during graft
let preservedChain = preserveProvenanceDuringGraft(originalChain,
  graftedPackageName, graftedVersion, sourceEcosystem)

# Preserve provenance during conversion
let convertedChain = preserveProvenanceDuringConvert(graftedChain, convertedHash)
```

## Performance Characteristics

### Hash Verification Performance

- **BLAKE2b**: ~1.5 GB/s on modern hardware
- **Streaming**: Constant memory usage regardless of file size
- **Batch Processing**: Optimized for multiple file verification
- **Chunk Size Optimization**: Adaptive chunk sizes for different file sizes

### Monitoring Overhead

- **Real-time Monitoring**: <1% CPU overhead
- **Periodic Scanning**: Configurable to minimize system impact
- **Incremental Scans**: Only check recently modified packages
- **Background Processing**: Non-blocking operations with async I/O

### Storage Requirements

- **Provenance Data**: ~1KB per package per version
- **Scan History**: ~100 bytes per scan result
- **Event Logs**: ~200 bytes per security event
- **Trust Data**: ~500 bytes per community actor

## Compliance and Auditing

### ACUL Compliance

The security system supports ACUL (Auditable Compute Use License) compliance:

- **Reproducible Builds**: Verification of build reproducibility
- **License Tracking**: License compliance verification
- **Audit Trails**: Complete audit trails for all operations
- **Signature Requirements**: Configurable signature requirements

### Security Standards

- **NIST Guidelines**: Follows NIST cybersecurity framework
- **Cryptographic Standards**: Uses approved cryptographic algorithms
- **Audit Requirements**: Comprehensive logging for security audits
- **Incident Response**: Automated incident detection and response

## Troubleshooting

### Common Issues

1. **Hash Verification Failures**
   - Check file integrity
   - Verify expected hash values
   - Check for file corruption

2. **Signature Verification Failures**
   - Verify key availability
   - Check key revocation status
   - Validate signature format

3. **Trust Policy Violations**
   - Review active trust policy
   - Check package trust score
   - Verify actor reputation

4. **Performance Issues**
   - Adjust scan intervals
   - Optimize chunk sizes
   - Check system resources

### Debug Commands

```bash
# Enable verbose logging
nip verify --all --verbose

# Show detailed trust breakdown
nip track <package> --trust-score --verification

# Check system health
nip doctor --integrity --verbose

# Show scan statistics
nip scan status
```

## Future Enhancements

### Post-Quantum Cryptography

- **Dilithium Signatures**: Post-quantum signature algorithm support
- **Hybrid Signatures**: Classical + post-quantum signature combinations
- **Migration Tools**: Smooth transition to post-quantum algorithms

### Advanced Analytics

- **Machine Learning**: Anomaly detection using ML algorithms
- **Behavioral Analysis**: Package behavior analysis for threat detection
- **Predictive Security**: Predictive security threat identification

### Distributed Trust

- **Blockchain Integration**: Distributed trust verification
- **Consensus Mechanisms**: Multi-party trust consensus
- **Decentralized Reputation**: Distributed reputation management

---

This comprehensive security and verification system provides NimPak with enterprise-grade security capabilities, ensuring package integrity, maintaining complete audit trails, and enforcing configurable trust policies throughout the package lifecycle.