# Comprehensive S/Kademlia Security Review & Production Readiness Plan

## Executive Summary

This plan ensures the saorsa-core S/Kademlia implementation is production-ready with:
- Full EigenTrust/geographic blocking integration
- Complete close group validation during routing table refresh
- Comprehensive metrics for security, node health, and data integrity
- All recorded security measures operational

---

## PART 1: AUDIT FINDINGS SUMMARY

### Current Security Architecture Status

| Component | Status | Production Ready |
|-----------|--------|-----------------|
| S/Kademlia Core | Implemented | Yes |
| Close Group Validator | Implemented | Needs Integration |
| EigenTrust++ | Implemented | Yes |
| IP Diversity (IPv4+IPv6) | Implemented | Yes |
| Geographic Blocking | Implemented | Yes |
| Sybil Detection | Implemented | Yes |
| Collusion Detection | Implemented | Yes |
| Witness Protocol | Implemented | Yes |
| Data Integrity Monitor | Implemented | Needs Integration |
| Security Metrics | Partial | Needs Enhancement |

### Critical Gap Identified

**Close Group Validation During Routing Table Refresh:**
- Validator EXISTS in `close_group_validator.rs` (1,122 lines)
- Refresh logic EXISTS in `refresh.rs` (29,862 bytes)
- **INTEGRATION NOT VERIFIED** - Need to ensure validator is called during refresh

---

## PART 2: IMPLEMENTATION PHASES

### Phase 1: Verify Close Group Validation Integration
**Priority: CRITICAL**

#### 1.1 Audit Routing Table Refresh Flow
**Files to Review:**
- `src/dht/routing_maintenance/refresh.rs` - Refresh orchestration
- `src/dht/routing_maintenance/close_group_validator.rs` - Validation logic
- `src/dht/routing_maintenance/security_coordinator.rs` - Security orchestration

**Verification Checklist:**
- [ ] Each node discovered during refresh is validated via `CloseGroupValidator`
- [ ] Validation uses hybrid approach (trust-weighted + BFT when under attack)
- [ ] Failed validations trigger node eviction
- [ ] Metrics track validation success/failure rates

#### 1.2 Close Group Agreement Verification
**Requirement:** During routing table refresh, verify each close node is:
1. Confirmed by peers as belonging to the close group
2. Not evicted from its own close group
3. Has valid EigenTrust score above threshold

**Implementation Verification:**
```rust
// Expected flow in refresh.rs:
async fn refresh_node(&self, node: &NodeInfo) -> Result<RefreshResult> {
    // 1. Validate node still in close group
    let validation = self.close_group_validator
        .validate_membership(node.id, &self.attack_indicators)
        .await?;

    // 2. Check validation result
    if !validation.is_valid {
        self.evict_node(node.id, EvictionReason::FailedCloseGroupValidation)?;
        return Ok(RefreshResult::Evicted);
    }

    // 3. Verify trust score
    if self.trust_engine.get_trust(&node.id) < MIN_TRUST_THRESHOLD {
        self.evict_node(node.id, EvictionReason::LowTrust)?;
        return Ok(RefreshResult::Evicted);
    }

    // 4. Continue with normal refresh
    Ok(RefreshResult::Refreshed)
}
```

#### 1.3 Add Missing Integration Points
**If not present, add:**
- Validation call during bucket refresh
- BFT escalation triggers
- Eviction enforcement
- Metric recording

---

### Phase 2: EigenTrust Integration Verification
**Priority: HIGH**

#### 2.1 Audit Trust Score Usage
**Files to Review:**
- `src/adaptive/trust.rs` - EigenTrust++ engine (871 lines)
- `src/dht/witness_selection.rs` - Witness selection with trust
- `src/placement/algorithms.rs` - Placement with trust weighting

**Verification Checklist:**
- [ ] Trust scores are updated on successful/failed interactions
- [ ] Trust scores influence routing decisions
- [ ] Trust scores influence witness selection (50% weight)
- [ ] Trust scores influence placement decisions
- [ ] Pre-trusted nodes are configured for bootstrap

#### 2.2 Trust Thresholds
**Current Configuration:**
```rust
min_trust_threshold: 0.15     // Minimum for routing table
min_witness_trust: 0.3        // Minimum for witness selection
trust_weighted_threshold: 0.7  // For close group validation
```

**Verification:**
- [ ] Thresholds are enforced at all decision points
- [ ] Nodes below threshold are evicted/excluded
- [ ] Trust decay is applied over time

---

### Phase 3: Geographic Blocking Verification
**Priority: HIGH**

#### 3.1 Audit IP Diversity Enforcement
**Files to Review:**
- `src/security.rs` - IP diversity enforcer (1,915 lines)
- `src/bgp_geo_provider.rs` - GeoIP provider (636 lines)
- `src/dht/ipv4_identity.rs` - IPv4 identity binding
- `src/dht/ipv6_identity.rs` - IPv6 identity binding

**Current Limits:**
```rust
// IPv6
max_nodes_per_64: 1      // Per host (/64)
max_nodes_per_48: 3      // Per site (/48)
max_nodes_per_32: 10     // Per ISP (/32)
max_nodes_per_asn: 20    // Per ASN

// IPv4
max_nodes_per_ipv4_32: 1   // Per IP
max_nodes_per_ipv4_24: 3   // Per /24
max_nodes_per_ipv4_16: 10  // Per /16
max_per_ip_cap: 50         // Hard limit
max_network_fraction: 0.005 // 0.5% of network
```

**Verification Checklist:**
- [ ] IPv4 diversity is enforced (recently added)
- [ ] IPv6 diversity is enforced
- [ ] ASN limits are enforced
- [ ] Geographic diversity minimum (3 regions) is enforced
- [ ] Hosting/VPN provider detection works

#### 3.2 Geographic Diversity in Routing Table
**Verification:**
- [ ] Routing table maintains geographic diversity
- [ ] Close group includes nodes from multiple regions
- [ ] Witness selection requires min 2 distinct regions

---

### Phase 4: Data Integrity Verification
**Priority: HIGH**

#### 4.1 Audit Data Integrity Monitor
**File:** `src/dht/routing_maintenance/data_integrity_monitor.rs` (1,321 lines)

**Verification Checklist:**
- [ ] Attestation challenges are issued periodically (every 5 min)
- [ ] Challenge-response protocol verifies data presence
- [ ] Health status tracks replica counts
- [ ] Degraded/AtRisk/Critical statuses trigger repair
- [ ] Storage node trust is verified (min 0.3)

#### 4.2 Data Health States
```rust
enum DataHealthStatus {
    Healthy,    // All replicas above minimum (3)
    Degraded,   // Some failed, above minimum
    AtRisk,     // Below minimum
    Critical,   // Immediate action needed
    Unknown,    // No verification
}
```

**Verification:**
- [ ] Each state triggers appropriate action
- [ ] Metrics track health distribution
- [ ] Repair recommendations are generated

---

### Phase 5: Security Metrics Enhancement
**Priority: HIGH**

#### 5.1 Audit Current Metrics
**File:** `src/dht/metrics/security_metrics.rs` (598 lines)

**Current Metrics:**
- `eclipse_score`, `sybil_score`, `collusion_score`
- `eclipse_attempts_total`, `sybil_nodes_detected_total`
- `close_group_validations_total`, `consensus_failures_total`
- `nodes_evicted_total`, `eviction_by_reason`
- `ip_diversity_rejections_total`, `nodes_per_region`

#### 5.2 Required Additional Metrics

**Node Health Metrics:**
```rust
// Add to security_metrics.rs
pub struct NodeHealthMetrics {
    // Trust distribution
    trust_score_histogram: Histogram,  // Distribution of trust scores
    trust_score_by_region: GaugeVec,   // Average trust per region

    // Routing table health
    routing_table_size: Gauge,
    stale_nodes_count: Gauge,
    validation_latency_ms: Histogram,

    // Connection health
    active_connections: Gauge,
    connection_failures_total: Counter,
    keepalive_timeouts_total: Counter,
}
```

**Data Health Metrics:**
```rust
pub struct DataHealthMetrics {
    // Replication health
    data_items_total: Gauge,
    healthy_items: Gauge,
    degraded_items: Gauge,
    at_risk_items: Gauge,
    critical_items: Gauge,

    // Attestation metrics
    attestation_challenges_issued: Counter,
    attestation_challenges_passed: Counter,
    attestation_challenges_failed: Counter,
    attestation_latency_ms: Histogram,

    // Repair metrics
    repairs_initiated: Counter,
    repairs_completed: Counter,
    repairs_failed: Counter,
}
```

**Routing Table Refresh Metrics:**
```rust
pub struct RefreshMetrics {
    // Refresh operations
    refreshes_initiated: Counter,
    refreshes_completed: Counter,
    refreshes_failed: Counter,

    // Per-tier tracking
    critical_tier_refreshes: Counter,    // 60s interval
    important_tier_refreshes: Counter,   // 5min interval
    standard_tier_refreshes: Counter,    // 15min interval
    background_tier_refreshes: Counter,  // 60min interval

    // Validation during refresh
    nodes_validated_during_refresh: Counter,
    nodes_evicted_during_refresh: Counter,
    bft_escalations_during_refresh: Counter,
}
```

---

### Phase 6: Comprehensive Testing
**Priority: HIGH**

#### 6.1 Integration Tests Required
**File:** `tests/security_comprehensive_test.rs`

```rust
// Tests to add/verify
#[tokio::test]
async fn test_close_group_validation_during_refresh() {
    // Setup routing table with known nodes
    // Trigger refresh
    // Verify each node was validated
    // Verify invalid nodes were evicted
}

#[tokio::test]
async fn test_bft_escalation_under_attack() {
    // Setup routing table
    // Inject attack indicators
    // Verify BFT mode is activated
    // Verify stricter thresholds apply
}

#[tokio::test]
async fn test_eigentrust_integration() {
    // Create nodes with varying trust scores
    // Verify low-trust nodes are excluded from routing
    // Verify trust influences witness selection
}

#[tokio::test]
async fn test_geographic_diversity_enforcement() {
    // Add nodes from single region
    // Verify additional nodes from same region rejected after limit
    // Verify routing maintains diversity
}

#[tokio::test]
async fn test_data_integrity_attestation() {
    // Store data
    // Wait for attestation challenge
    // Verify challenge-response works
    // Verify health status is tracked
}

#[tokio::test]
async fn test_security_metrics_coverage() {
    // Perform various operations
    // Verify all metrics are populated
    // Verify metrics accurately reflect state
}
```

---

## PART 3: IMPLEMENTATION TASKS

### Task List

1. **Verify Close Group Validation Integration**
   - [ ] Read `refresh.rs` to confirm validator is called
   - [ ] Trace validation flow from refresh to eviction
   - [ ] Add integration if missing

2. **Verify EigenTrust Integration**
   - [ ] Trace trust score usage in routing decisions
   - [ ] Verify trust thresholds are enforced
   - [ ] Confirm trust decay is applied

3. **Verify Geographic Blocking**
   - [ ] Test IPv4 diversity enforcement
   - [ ] Test IPv6 diversity enforcement
   - [ ] Verify ASN limits work

4. **Enhance Security Metrics**
   - [ ] Add NodeHealthMetrics
   - [ ] Add DataHealthMetrics
   - [ ] Add RefreshMetrics
   - [ ] Wire metrics into operations

5. **Add Missing Integration Tests**
   - [ ] Close group validation during refresh
   - [ ] BFT escalation under attack
   - [ ] EigenTrust integration
   - [ ] Geographic diversity enforcement
   - [ ] Data integrity attestation

6. **Documentation Update**
   - [ ] Update CLAUDE.md with security architecture
   - [ ] Document all metrics
   - [ ] Document configuration options

---

## PART 4: PRODUCTION CONFIGURATION

### Recommended Settings

```rust
// Close Group Validator
CloseGroupValidatorConfig {
    enforcement_mode: CloseGroupEnforcementMode::Strict,
    min_peers_to_query: 5,
    max_peers_to_query: 10,
    trust_weighted_threshold: 0.7,
    bft_threshold: 0.71,  // 5/7 for f=2
    min_witness_trust: 0.3,
    min_regions: 3,
    auto_escalate: true,
}

// IP Diversity
IPDiversityConfig {
    max_nodes_per_64: 1,
    max_nodes_per_48: 3,
    max_nodes_per_32: 10,
    max_nodes_per_ipv4_32: 1,
    max_nodes_per_ipv4_24: 3,
    max_nodes_per_ipv4_16: 10,
    max_per_ip_cap: 50,
    max_network_fraction: 0.005,
    max_nodes_per_asn: 20,
    enable_geolocation_check: true,
    min_geographic_diversity: 3,
}

// Data Integrity
DataIntegrityConfig {
    check_interval: Duration::from_secs(300),
    min_healthy_replicas: 3,
    attestation_success_threshold: 0.9,
    stale_data_threshold: Duration::from_secs(3600),
    min_storage_trust: 0.3,
}

// Maintenance
MaintenanceConfig {
    bucket_refresh_interval: Duration::from_secs(3600),
    bft_fault_tolerance: 2,
    min_trust_threshold: 0.15,
}
```

---

## PART 5: SUCCESS CRITERIA

### Production Readiness Checklist

- [ ] All routing table refresh operations validate nodes
- [ ] Invalid/evicted nodes are detected and removed
- [ ] EigenTrust scores influence all routing decisions
- [ ] Geographic diversity is enforced in routing table
- [ ] IPv4 and IPv6 diversity limits are enforced
- [ ] Data integrity is continuously monitored
- [ ] All security metrics are populated
- [ ] Integration tests pass for all security scenarios
- [ ] Zero compilation warnings
- [ ] Zero clippy warnings
- [ ] Documentation is complete

---

## PART 6: NEXT STEPS

1. **Begin with Phase 1** - Verify close group validation integration
2. **Run existing tests** to establish baseline
3. **Add missing integration** where gaps found
4. **Enhance metrics** for full observability
5. **Add integration tests** for complete coverage
6. **Document** all changes
