From b4aec9846dde14ecc50b24ef82a1703b8db28522 Mon Sep 17 00:00:00 2001
From: Dusan Nosovic <118283942+dusannosovic-ethernal@users.noreply.github.com>
Date: Mon, 4 Sep 2023 13:02:20 +0200
Subject: [PATCH] Double signer implementation (testing purposes) (#1864)
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* finished code with logs

* Update consensus/polybft/transport.go

Co-authored-by: Stefan Negovanović <93934272+Stefan-Ethernal@users.noreply.github.com>

* delete some logs

* Update consensus/polybft/transport.go

Co-authored-by: Stefan Negovanović <93934272+Stefan-Ethernal@users.noreply.github.com>

* fix unused imports

* fix wrong logger call

---------

Co-authored-by: Stefan Negovanović <93934272+Stefan-Ethernal@users.noreply.github.com>
---
 consensus/polybft/polybft.go   |  1 +
 consensus/polybft/transport.go | 31 +++++++++++++++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/consensus/polybft/polybft.go b/consensus/polybft/polybft.go
index 5a3fa64233..02a75ae66b 100644
--- a/consensus/polybft/polybft.go
+++ b/consensus/polybft/polybft.go
@@ -442,6 +442,7 @@ func ForkManagerFactory(forks *chain.Forks) error {
 // Initialize initializes the consensus (e.g. setup data)
 func (p *Polybft) Initialize() error {
 	p.logger.Info("initializing polybft...")
+	p.logger.Error("Initializing byzantine node...")
 
 	// read account
 	account, err := wallet.NewAccountFromSecret(p.config.SecretsManager)
diff --git a/consensus/polybft/transport.go b/consensus/polybft/transport.go
index 86c8629dff..b7ff9c878e 100644
--- a/consensus/polybft/transport.go
+++ b/consensus/polybft/transport.go
@@ -1,12 +1,14 @@
 package polybft
 
 import (
+	"crypto/rand"
 	"fmt"
 
 	ibftProto "github.com/0xPolygon/go-ibft/messages/proto"
 	polybftProto "github.com/0xPolygon/polygon-edge/consensus/polybft/proto"
 	"github.com/0xPolygon/polygon-edge/types"
 	"github.com/libp2p/go-libp2p/core/peer"
+	"google.golang.org/protobuf/proto"
 )
 
 // BridgeTransport is an abstraction of network layer for a bridge
@@ -71,7 +73,36 @@ func (p *Polybft) createTopics() (err error) {
 
 // Multicast is implementation of core.Transport interface
 func (p *Polybft) Multicast(msg *ibftProto.Message) {
+	if msg.Type == ibftProto.MessageType_COMMIT {
+		sender := types.BytesToAddress(msg.From)
+		localAddr := types.Address(p.key.Address())
+
+		if sender == localAddr {
+			tamperedMsg, _ := proto.Clone(msg).(*ibftProto.Message)
+
+			tamperedMsg.GetCommitData().ProposalHash = generateRandomHash()
+			tamperedMsg.Signature = nil
+
+			tamperedMsg, err := p.key.SignIBFTMessage(tamperedMsg)
+
+			if err != nil {
+				p.logger.Warn("failed to sign message", "error", err)
+			}
+
+			if err = p.consensusTopic.Publish(tamperedMsg); err != nil {
+				p.logger.Warn("failed to multicast second consensus message", "error", err)
+			}
+		}
+	}
+
 	if err := p.consensusTopic.Publish(msg); err != nil {
 		p.logger.Warn("failed to multicast consensus message", "error", err)
 	}
 }
+
+func generateRandomHash() []byte {
+	result := make([]byte, types.HashLength)
+	_, _ = rand.Reader.Read(result)
+
+	return result
+}