go-i2p/common

A comprehensive Go library implementing I2P (Invisible Internet Project) network protocol common data structures and utilities. This library provides type-safe implementations of the I2P specification common structures, factored out from the main I2P router to enable reusable components for parsing, encoding, and manipulating I2P network data.

---

Installation

go mod init your-project
go get github.com/go-i2p/common

---

Usage

Basic Certificate Parsing

package main

import (
    "fmt"
    "github.com/go-i2p/common/certificate"
)

func main() {
    // Parse I2P certificate from binary data
    data := []byte{0x00, 0x00, 0x02, 0xff, 0xff}
    cert, remainder, err := certificate.ReadCertificate(data)
    if err != nil {
        fmt.Printf("Error: %v\n", err)
        return
    }
    
    fmt.Printf("Certificate type: %d\n", cert.Type())
    fmt.Printf("Certificate length: %d\n", cert.Length())
    fmt.Printf("Remaining bytes: %d\n", len(remainder))
}

Working with Destinations

package main

import (
    "fmt"
    "github.com/go-i2p/common/destination"
)

func main() {
    // Read destination from binary data
    data := []byte{/* destination bytes */}
    dest, remainder, err := destination.ReadDestination(data)
    if err != nil {
        fmt.Printf("Error: %v\n", err)
        return
    }
    
    // Generate I2P addresses
    base32Address := dest.Base32Address()
    base64Address := dest.Base64()
    
    fmt.Printf("Base32 address: %s\n", base32Address)
    fmt.Printf("Base64 address: %s\n", base64Address)
}

Parsing Router Information

package main

import (
    "fmt"
    "github.com/go-i2p/common/router_info"
)

func main() {
    // Read router info from binary data
    data := []byte{/* router info bytes */}
    routerInfo, remainder, err := router_info.ReadRouterInfo(data)
    if err != nil {
        fmt.Printf("Error: %v\n", err)
        return
    }
    
    // Access router information
    identity := routerInfo.RouterIdentity()
    addresses := routerInfo.RouterAddresses()
    capabilities := routerInfo.RouterCapabilities()
    
    fmt.Printf("Router identity: %v\n", identity)
    fmt.Printf("Router addresses: %d\n", len(addresses))
    fmt.Printf("Router capabilities: %s\n", capabilities)
}

Working with I2P Strings

package main

import (
    "fmt"
    "github.com/go-i2p/common/data"
)

func main() {
    // Parse I2P string from binary data
    stringData := []byte{0x05, 'h', 'e', 'l', 'l', 'o'}
    i2pString := data.I2PString(stringData)
    
    length, err := i2pString.Length()
    if err != nil {
        fmt.Printf("Error: %v\n", err)
        return
    }
    
    content, err := i2pString.Data()
    if err != nil {
        fmt.Printf("Error: %v\n", err)
        return
    }
    
    fmt.Printf("String length: %d\n", length)
    fmt.Printf("String content: %s\n", content)
}

---

Requirements

• Go Version: 1.24.2 or later
• Dependencies:
  • github.com/go-i2p/go-i2p - Core I2P library
  • github.com/go-i2p/logger - Structured logging wrapper
  • github.com/samber/oops - Enhanced error handling
  • github.com/sirupsen/logrus - Logging framework
  • github.com/stretchr/testify - Testing utilities

---

Testing

Run the comprehensive test suite:

# Run all tests
make test

# Run specific component tests
go test ./certificate/...
go test ./destination/...
go test ./router_info/...

# Run fuzz tests
go test -fuzz=FuzzCertificate ./certificate/

---

License

MIT License - see LICENSE file for details.

Copyright (c) 2025 I2P For Go