client

Documentation

Overview

Package client makes it possible to encrypt and decrypt messages using a monolithic cryptographic protocol.

CLIENT MESSAGE PROTOCOL

Protocol participants:
	A - sender,
	B - receiver.

Steps of participant A:
1. 	K = G( N ), R = G( N ),
	where
		G - generator pseudo random bytes,
		N - count of bytes for generator,
		K - encryption session key,
		R - pseudo random bytes (salt).
2. 	HP = H( R || P || PubKA || PubKB ),
	where
		HP - message hash,
		H - hash function,
		P - plaintext,
		PubKX - public key of X participant.
3. 	CP = [ E( PubKB, K ), E( K, PubKA ), E( K, R ), E( K, P ), E( K, HP ), E( K, S( PrivKA, HP ) ) ],
	where
		CP - encrypted message,
		E - encryption function,
		S - sign function,
		PrivKX - private key of X participant.

Steps of participant B:
4. 	K = D( PrivKB, E( PubKB, K ) ),
	where
		D - decryption function.
	IF ≠, than protocol is interrupted.
5. 	PubKA = D( K, E( K, PubKA ) ).
	IF ≠, than protocol is interrupted.
6. 	HP = V( PubKA, D( K, E( K, S( PrivKA, D( K, E( K, HP) ) ) ) ) ),
	where
		V - signature verification function.
	IF ≠, than protocol is interrupted.
7. 	HP = H( D( K, E( K, R ) ) || D( K, E( K, P ) ) || PubKA || PubKB ),
	IF ≠, than protocol is interrupted.

More information in article: https://github.com/number571/go-peer/blob/master/docs/monolithic_cryptographic_protocol.pdf
Scheme: https://github.com/number571/go-peer/blob/master/images/go-peer_layer2_message.jpg

Index

• Variables
• type IClient
  • func NewClient(pPrivKey asymmetric.IPrivKey, pMessageSize uint64) IClient
• type SClientError
  • func (err *SClientError) Error() string

Variables

var (
	ErrLimitMessageSize     = &SClientError{"limit message size"}
	ErrInitCheckMessage     = &SClientError{"init check message"}
	ErrDecryptCipherKey     = &SClientError{"decrypt cipher key"}
	ErrDecodePublicKey      = &SClientError{"decode public key"}
	ErrDecodePayloadWrapper = &SClientError{"decode payload wrapper"}
	ErrInvalidDataHash      = &SClientError{"invalid data hash"}
	ErrInvalidHashSign      = &SClientError{"invalid hash sign"}
	ErrEncryptSymmetricKey  = &SClientError{"encrypt symmetric key"}
	ErrDecodeBytesJoiner    = &SClientError{"decode bytes joiner"}
)

Types

type IClient

type IClient interface {
	GetMessageSize() uint64
	GetPayloadLimit() uint64

	GetPrivKey() asymmetric.IPrivKey

	EncryptMessage(asymmetric.IPubKey, []byte) ([]byte, error)
	DecryptMessage(asymmetric.IMapPubKeys, []byte) (asymmetric.IPubKey, []byte, error)
}

func NewClient

func NewClient(pPrivKey asymmetric.IPrivKey, pMessageSize uint64) IClient

Create client by private key as identification. Handle function is used when the network exists.

type SClientError

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

func (*SClientError) Error

func (err *SClientError) Error() string