goprocrypt

Simple Go RSA Asymmetric Key Encryption for Protocol Buffers

dependency

dep ensure -add "github.com/Yomiji/goprocrypt"

protocol

Provided EncryptedMessage protocol buffer is returned from an encrypted message. The EncryptedMessage protocol buffer has the following configuration:

syntax = "proto3";
package goprocrypt;
option go_package = "goprocrypt";

message EncryptedMessage {
    bytes id = 1; //hash of type
    bytes signature = 3;
    bytes digest = 5;
}

The idea is that an application would encrypt, send and then decrypt an EncryptedMessage protocol buffer. An application could use the id parameter to hash the protocol buffer's specific type.

useage

import (
	"github.com/Yomiji/genrsa"
	"github.com/Yomiji/goprocrypt"
	"github.com/golang/protobuf/proto"
	"testing"
	"time"
)

var party1private, party1public = genrsa.MakeKeys(2048)
var party2private, party2public = genrsa.MakeKeys(2048)

var testMsg = &TestMsg{
  Time:time.Now().Unix(),
  TrialNo:0,
  Msgtext:"Some Text",
}

func TestEncrypt(t *testing.T) {
	// private key necessary for signature application from first party, encrypting for second party
	encMsg, err := goprocrypt.Encrypt([]byte("test"), testMsg, party2public, party1private)
	
	// do something with encrypted message
}

func TestDecrypt(t *testing.T) {
	decMsg := &TestMsg{}

	encMsg, err := goprocrypt.Encrypt([]byte("test"), testMsg, party2public, party1private)
	
	// first party's public key for verification of identity and second party key for decryption
	// directly modifies decMsg to fill it with the decrypted data, the type must match or an error
	// occurs
	err = goprocrypt.Decrypt([]byte("test"), encMsg, party2private, party1public, decMsg)
	
	// do something with decMsg, which now contains testMsg unencrypted
}

To change the encryption algorithm:

goprocrypt.Hash = crypto.SHA256

To change the verification algorithm:

goprocrypt.Sign = crypto.SHA512_256