go-i2ptunnel-config/lib/sam.go

package i2pconv

import (
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"github.com/go-i2p/i2pkeys"
)

// SAMTunnel returns the I2P keys and SAM options for this tunnel configuration.
// If PersistentKeys is true, keys will be stored in a SAMv3 compatible format.
func (c *TunnelConfig) SAMTunnel() (*i2pkeys.I2PKeys, []string, error) {
	var keys *i2pkeys.I2PKeys

	if c.PersistentKey {
		// Get default I2P keystore path
		keystore, err := os.Getwd()
		if err != nil {
			return nil, nil, err
		}

		// Load or create keys for this tunnel
		keypath := filepath.Join(keystore, c.Name+".keys")
		loadedKeys, err := i2pkeys.LoadKeys(keypath)
		if err == nil {
			keys = &loadedKeys
		} else {
			// Create new keys if none exist
			newKeys, err := i2pkeys.NewDestination()
			if err != nil {
				return nil, nil, err
			}
			keys = newKeys
			// Store the new
			keyFile, err := os.Open(keypath)
			if err != nil {
				return nil, nil, err
			}
			if err := i2pkeys.StoreKeysIncompat(*newKeys, keyFile); err != nil {
				return nil, nil, err
			}
		}
	}

	// Generate SAM options from config
	var opts []string

	// Process I2CP options
	for k, v := range c.I2CP {
		opts = append(opts, "i2cp."+k+"="+fmt.Sprint(v))
	}

	// Process tunnel options
	for k, v := range c.Tunnel {
		opts = append(opts, k+"="+fmt.Sprint(v))
	}

	// Process inbound/outbound options
	for k, v := range c.Inbound {
		opts = append(opts, "inbound."+k+"="+fmt.Sprint(v))
	}
	for k, v := range c.Outbound {
		opts = append(opts, "outbound."+k+"="+fmt.Sprint(v))
	}

	// Ensure lease set encryption
	if !hasOption(opts, "i2cp.leaseSetEncType") {
		opts = append(opts, "i2cp.leaseSetEncType=4,0")
	}

	return keys, opts, nil
}

func hasOption(opts []string, prefix string) bool {
	for _, opt := range opts {
		if strings.HasPrefix(opt, prefix) {
			return true
		}
	}
	return false
}