i2plib

i2plib

Go library for working with I2P via the SAM v3.1 API.

What’s included

• SAM message helpers and I2P base64/base32 (sam.go)
• SAM client primitives (HELLO, DEST GENERATE, SESSION CREATE, NAMING LOOKUP, STREAM CONNECT/ACCEPT) (aiosam.go)
• Stream tunnels (client/server) (tunnel.go)

Install

go get github.com/svanichkin/i2plib

Configuration

The default SAM address is 127.0.0.1:7656.

You can override it via:

export I2P_SAM_ADDRESS=127.0.0.1:7656

Usage

Create destination + session

package main

import (
	"context"
	"log"
	"time"

	"github.com/svanichkin/i2plib"
)

func main() {
	ctx, cancel := context.WithTimeout(context.Background(), 5*time.Second)
	defer cancel()

	samAddr := i2plib.GetSAMAddress()
	sess, err := i2plib.CreateSession(ctx, "test", samAddr, "STREAM", i2plib.DefaultSigType, nil, nil)
	if err != nil {
		log.Fatal(err)
	}
	defer sess.Close()

	log.Printf("session=%s dest=%s.b32.i2p", sess.Name(), sess.Destination.Base32())
}

Client tunnel (local TCP -> remote I2P destination)

samAddr := i2plib.GetSAMAddress()
samClient := i2plib.NewDefaultSAMClient(samAddr)

tun := i2plib.NewClientTunnel(
	i2plib.Address{Host: "127.0.0.1", Port: 6668},
	"irc.echelon.i2p",
	samAddr,
	samClient,
	nil,    // destination (nil => create new)
	"",     // session name ("" => auto)
	nil,    // SAM options
)

ctx := context.Background()
if err := tun.Run(ctx); err != nil {
	log.Fatal(err)
}
defer tun.Stop()

Server tunnel (accept from I2P -> local TCP)

samAddr := i2plib.GetSAMAddress()
samClient := i2plib.NewDefaultSAMClient(samAddr)

tun := i2plib.NewServerTunnel(
	i2plib.Address{Host: "127.0.0.1", Port: 8080},
	samAddr,
	samClient,
	nil, // destination (nil => transient)
	"",
	nil,
)

ctx := context.Background()
if err := tun.Run(ctx); err != nil {
	log.Fatal(err)
}
defer tun.Stop()

Tests

GOCACHE="$PWD/.gocache" go test ./...

tunnel_mock_sam_test.go includes a mock SAM server. In restricted sandboxes that disallow listen(2), these tests will be skipped.