handshake

README

IFPS Handshake

The IPFS Protocol Handshake is divided into three sequential steps

1. Version Handshake (Hanshake1)
2. Secure Channel (NewSecureConn)
3. Services (Handshake3)

Currently these parts currently happen sequentially (costing an awful 5 RTT), but can be optimized to 2 RTT.

Version Handshake

The Version Handshake ensures that nodes speaking to each other can interoperate. They send each other protocol versions and ensure there is a match on the major version (semver).

Secure Channel

The second part exchanges keys and establishes a secure comm channel. This follows ECDHE TLS, but isn't TLS. (why will be written up elsewhere).

Services

The Services portion sends any additional information on nodes needed by the nodes, e.g. Listen Address (the received address could be a Dial addr), and later on can include Service listing (dht, exchange, ipns, etc).

Documentation

Overview

package handshake implements the ipfs handshake protocol

IPFS Handshake

The IPFS Protocol Handshake is divided into three sequential steps

1. Version Handshake (`Hanshake1`)

2. Secure Channel (`NewSecureConn`)

3. Services (`Handshake3`)

Currently these parts currently happen sequentially (costing an awful 5 RTT), but can be optimized to 2 RTT.

Version Handshake

The Version Handshake ensures that nodes speaking to each other can interoperate. They send each other protocol versions and ensure there is a match on the major version (semver).

Secure Channel

The second part exchanges keys and establishes a secure comm channel. This follows ECDHE TLS, but *isn't* TLS. (why will be written up elsewhere).

Services

The Services portion sends any additional information on nodes needed by the nodes, e.g. Listen Address (the received address could be a Dial addr), and later on can include Service listing (dht, exchange, ipns, etc).

Index

• Variables
• func Handshake1Compatible(handshakeA, handshakeB *pb.Handshake1) error
• func Handshake1Msg() *pb.Handshake1
• func Handshake3Msg(localPeer peer.Peer, remoteAddr ma.Multiaddr) *pb.Handshake3
• func NewHandshake1(protoVer, agentVer string) *pb.Handshake1
• type Handshake3Result
  • func Handshake3Update(lpeer, rpeer peer.Peer, msg *pb.Handshake3) (*Handshake3Result, error)

Variables

var ClientVersion = "go-ipfs/" + config.CurrentVersionNumber

var ErrVersionMismatch = errors.New("protocol missmatch")

ErrVersionMismatch is returned when two clients don't share a protocol version

var IpfsVersion *semver.Version

IpfsVersion holds the current protocol version for a client running this code

Functions

func Handshake1Compatible

func Handshake1Compatible(handshakeA, handshakeB *pb.Handshake1) error

Handshake1Compatible checks whether two versions are compatible returns nil if they are fine

func Handshake1Msg

func Handshake1Msg() *pb.Handshake1

Handshake1Msg returns the current protocol version as a protobuf message

func Handshake3Msg

func Handshake3Msg(localPeer peer.Peer, remoteAddr ma.Multiaddr) *pb.Handshake3

Handshake3Msg constructs a Handshake3 msg.

func NewHandshake1

func NewHandshake1(protoVer, agentVer string) *pb.Handshake1

NewHandshake1 creates a new Handshake1 from the two strings

Types

type Handshake3Result

type Handshake3Result struct {

	// The addresses reported by the remote client
	RemoteListenAddresses []ma.Multiaddr

	// The address of the remote client we observed in this connection
	RemoteObservedAddress ma.Multiaddr

	// The address the remote client observed from this connection
	LocalObservedAddress ma.Multiaddr
}

Handshake3Result collects the knowledge gained in Handshake3.

func Handshake3Update

func Handshake3Update(lpeer, rpeer peer.Peer, msg *pb.Handshake3) (*Handshake3Result, error)

Handshake3Update updates local knowledge with the information in the handshake3 msg we received from remote client.