negotiation

README

Negotiation

Decentralised communication channel requires a pre-negotiation where both of the nodes don't trust each other but the communication is possible.

For this, I added a negotiation package where users try to validate each other before exchanging certificates and uplifting communication to the actual gossip channel.

Structures

For this nodes share some pre-shared knowledge with each other:

• A RSA Private Key
• A RSA Public Key
• A byte array prefix

This pre-shared data is called PredefinedKey in negotiation package.

Negotiation is handled with three phase handshake so a negotiation session is created.

NegotiationSession has two parameter in negotiation package:

• A PredefinedKey
• A byte array message

Assuming Node 1 and Node 2 has the same PredefinedKey.

• Node 1 creates a NegotiationSession with random test as session message.
• Node 1 encrypts and sends as message 1.
• Node 2 decrypts message 1, add prefix to the session message and send it back as message 2.
• Node 1 decrypts message 2 and compares the result to prefix prepended to the session message.

Security:

• All messages are encrypted with random data, so it is not possible to crack the communication with brute force attack.
• Each session has a different session message so communication is totally different.
• Request and response has different data inside so it is not possible to create, even if the node 2 is a fake server, node 2 can not try replaying the first message to another node.

Documentation

Index

• func RandomBytes(n int) []byte
• type NegotiationSession
  • func (ns *NegotiationSession) Get() ([]byte, error)
  • func (ns *NegotiationSession) Validate(message []byte) (bool, error)
  • func (ns *NegotiationSession) ValidateWithPrefix(prefix []byte, message []byte) (bool, error)
• type PredefinedKey
  • func NewPredefinedKey(private *rsa.PrivateKey, prefix []byte) *PredefinedKey
  • func NewRandomPredefinedKey() *PredefinedKey
  • func (pk *PredefinedKey) CreateNegotiationSession() *NegotiationSession
  • func (pk *PredefinedKey) Decrypt(encrypted []byte) ([]byte, error)
  • func (pk *PredefinedKey) Encrypt(message []byte) ([]byte, error)
  • func (pk *PredefinedKey) EncryptWithPrefix(message []byte) ([]byte, error)

Functions

func RandomBytes

func RandomBytes(n int) []byte

RandomBytes generates cryptographically secure pseudorandom numbers byte array

Types

type NegotiationSession

type NegotiationSession struct {
	// contains filtered or unexported fields
}

func (*NegotiationSession) Get

func (ns *NegotiationSession) Get() ([]byte, error)

func (*NegotiationSession) Validate

func (ns *NegotiationSession) Validate(message []byte) (bool, error)

func (*NegotiationSession) ValidateWithPrefix

func (ns *NegotiationSession) ValidateWithPrefix(prefix []byte, message []byte) (bool, error)

type PredefinedKey

type PredefinedKey struct {
	// contains filtered or unexported fields
}

func NewPredefinedKey

func NewPredefinedKey(private *rsa.PrivateKey, prefix []byte) *PredefinedKey

func NewRandomPredefinedKey

func NewRandomPredefinedKey() *PredefinedKey

func (*PredefinedKey) CreateNegotiationSession

func (pk *PredefinedKey) CreateNegotiationSession() *NegotiationSession

func (*PredefinedKey) Decrypt

func (pk *PredefinedKey) Decrypt(encrypted []byte) ([]byte, error)

func (*PredefinedKey) Encrypt

func (pk *PredefinedKey) Encrypt(message []byte) ([]byte, error)

func (*PredefinedKey) EncryptWithPrefix

func (pk *PredefinedKey) EncryptWithPrefix(message []byte) ([]byte, error)