Harden CHORUS security and messaging stack

pkg/dht/real_dht.go

@@ -1,14 +1,117 @@
 package dht
 
 import (
+	"context"
+	"errors"
 	"fmt"
 
 	"chorus/pkg/config"
+	libp2p "github.com/libp2p/go-libp2p"
+	"github.com/libp2p/go-libp2p/core/host"
+	"github.com/libp2p/go-libp2p/core/peer"
+	"github.com/libp2p/go-libp2p/p2p/security/noise"
+	"github.com/libp2p/go-libp2p/p2p/transport/tcp"
+	"github.com/multiformats/go-multiaddr"
 )
 
-// NewRealDHT creates a new real DHT implementation
-func NewRealDHT(config *config.HybridConfig) (DHT, error) {
-	// TODO: Implement real DHT initialization
-	// For now, return an error to indicate it's not yet implemented
-	return nil, fmt.Errorf("real DHT implementation not yet available")
-}
+// RealDHT wraps a libp2p-based DHT to satisfy the generic DHT interface.
+type RealDHT struct {
+	cancel context.CancelFunc
+	host   host.Host
+	dht    *LibP2PDHT
+}
+
+// NewRealDHT creates a new real DHT implementation backed by libp2p.
+func NewRealDHT(cfg *config.HybridConfig) (DHT, error) {
+	if cfg == nil {
+		cfg = &config.HybridConfig{}
+	}
+
+	ctx, cancel := context.WithCancel(context.Background())
+
+	listenAddr, err := multiaddr.NewMultiaddr("/ip4/0.0.0.0/tcp/0")
+	if err != nil {
+		cancel()
+		return nil, fmt.Errorf("failed to create listen address: %w", err)
+	}
+
+	host, err := libp2p.New(
+		libp2p.ListenAddrs(listenAddr),
+		libp2p.Security(noise.ID, noise.New),
+		libp2p.Transport(tcp.NewTCPTransport),
+		libp2p.DefaultMuxers,
+		libp2p.EnableRelay(),
+	)
+	if err != nil {
+		cancel()
+		return nil, fmt.Errorf("failed to create libp2p host: %w", err)
+	}
+
+	opts := []Option{
+		WithProtocolPrefix("/CHORUS"),
+	}
+
+	if nodes := cfg.GetDHTBootstrapNodes(); len(nodes) > 0 {
+		opts = append(opts, WithBootstrapPeersFromStrings(nodes))
+	}
+
+	libp2pDHT, err := NewLibP2PDHT(ctx, host, opts...)
+	if err != nil {
+		host.Close()
+		cancel()
+		return nil, fmt.Errorf("failed to initialize libp2p DHT: %w", err)
+	}
+
+	if err := libp2pDHT.Bootstrap(); err != nil {
+		libp2pDHT.Close()
+		host.Close()
+		cancel()
+		return nil, fmt.Errorf("failed to bootstrap DHT: %w", err)
+	}
+
+	return &RealDHT{
+		cancel: cancel,
+		host:   host,
+		dht:    libp2pDHT,
+	}, nil
+}
+
+// PutValue stores a value in the DHT.
+func (r *RealDHT) PutValue(ctx context.Context, key string, value []byte) error {
+	return r.dht.PutValue(ctx, key, value)
+}
+
+// GetValue retrieves a value from the DHT.
+func (r *RealDHT) GetValue(ctx context.Context, key string) ([]byte, error) {
+	return r.dht.GetValue(ctx, key)
+}
+
+// Provide announces that this node can provide the given key.
+func (r *RealDHT) Provide(ctx context.Context, key string) error {
+	return r.dht.Provide(ctx, key)
+}
+
+// FindProviders locates peers that can provide the specified key.
+func (r *RealDHT) FindProviders(ctx context.Context, key string, limit int) ([]peer.AddrInfo, error) {
+	return r.dht.FindProviders(ctx, key, limit)
+}
+
+// GetStats exposes runtime metrics for the real DHT.
+func (r *RealDHT) GetStats() DHTStats {
+	return r.dht.GetStats()
+}
+
+// Close releases resources associated with the DHT.
+func (r *RealDHT) Close() error {
+	r.cancel()
+
+	var errs []error
+	if err := r.dht.Close(); err != nil {
+		errs = append(errs, err)
+	}
+	if err := r.host.Close(); err != nil {
+		errs = append(errs, err)
+	}
+
+	return errors.Join(errs...)
+}