From 0980a5b3e592de130ea2541ee9394229630c16c4 Mon Sep 17 00:00:00 2001
From: Arpit Temani <temaniarpit27@gmail.com>
Date: Thu, 30 Nov 2023 15:35:46 +0530
Subject: [PATCH] allow unprotected txns

---
 core/txpool/legacypool/legacypool.go | 16 +++++++++++--
 core/txpool/validation.go            |  4 +++-
 core/types/transaction_signing.go    | 35 ++++++++++++++++++++++++++++
 eth/backend.go                       |  2 --
 4 files changed, 52 insertions(+), 5 deletions(-)

diff --git a/core/txpool/legacypool/legacypool.go b/core/txpool/legacypool/legacypool.go
index bf179fe996..6a3005e5a1 100644
--- a/core/txpool/legacypool/legacypool.go
+++ b/core/txpool/legacypool/legacypool.go
@@ -155,7 +155,8 @@ var DefaultConfig = Config{
 	AccountQueue: 64,
 	GlobalQueue:  1024,
 
-	Lifetime: 3 * time.Hour,
+	Lifetime:            3 * time.Hour,
+	AllowUnprotectedTxs: false,
 }
 
 // sanitize checks the provided user configurations and changes anything that's
@@ -601,7 +602,8 @@ func (pool *LegacyPool) local() map[common.Address]types.Transactions {
 // and does not require the pool mutex to be held.
 func (pool *LegacyPool) validateTxBasics(tx *types.Transaction, local bool) error {
 	opts := &txpool.ValidationOptions{
-		Config: pool.chainconfig,
+		Config:              pool.chainconfig,
+		AllowUnprotectedTxs: pool.config.AllowUnprotectedTxs,
 		Accept: 0 |
 			1<<types.LegacyTxType |
 			1<<types.AccessListTxType |
@@ -671,6 +673,11 @@ func (pool *LegacyPool) add(tx *types.Transaction, local bool) (replaced bool, e
 		knownTxMeter.Mark(1)
 		return false, txpool.ErrAlreadyKnown
 	}
+
+	if pool.config.AllowUnprotectedTxs {
+		pool.signer = types.NewFakeSigner(tx.ChainId())
+	}
+
 	// Make the local flag. If it's from local source or it's from the network but
 	// the sender is marked as local previously, treat it as the local transaction.
 	isLocal := local || pool.locals.containsTx(tx)
@@ -984,6 +991,11 @@ func (pool *LegacyPool) Add(txs []*types.Transaction, local, sync bool) []error
 			knownTxMeter.Mark(1)
 			continue
 		}
+
+		if pool.config.AllowUnprotectedTxs {
+			pool.signer = types.NewFakeSigner(tx.ChainId())
+		}
+
 		// Exclude transactions with basic errors, e.g invalid signatures and
 		// insufficient intrinsic gas as soon as possible and cache senders
 		// in transactions before obtaining lock
diff --git a/core/txpool/validation.go b/core/txpool/validation.go
index 72921c6851..aa718ca7f9 100644
--- a/core/txpool/validation.go
+++ b/core/txpool/validation.go
@@ -35,6 +35,8 @@ import (
 type ValidationOptions struct {
 	Config *params.ChainConfig // Chain configuration to selectively validate based on current fork rules
 
+	AllowUnprotectedTxs bool // Whether to allow unprotected transactions in the pool
+
 	Accept  uint8    // Bitmap of transaction types that should be accepted for the calling pool
 	MaxSize uint64   // Maximum size of a transaction that the caller can meaningfully handle
 	MinTip  *big.Int // Minimum gas tip needed to allow a transaction into the caller pool
@@ -91,7 +93,7 @@ func ValidateTransaction(tx *types.Transaction, head *types.Header, signer types
 		return core.ErrTipAboveFeeCap
 	}
 	// Make sure the transaction is signed properly
-	if _, err := types.Sender(signer, tx); err != nil {
+	if _, err := types.Sender(signer, tx); err != nil || !opts.AllowUnprotectedTxs {
 		return ErrInvalidSender
 	}
 	// Ensure the transaction has more gas than the bare minimum needed to cover
diff --git a/core/types/transaction_signing.go b/core/types/transaction_signing.go
index 7d6ebe3686..98f7759c28 100644
--- a/core/types/transaction_signing.go
+++ b/core/types/transaction_signing.go
@@ -582,3 +582,38 @@ func deriveChainId(v *big.Int) *big.Int {
 	v = new(big.Int).Sub(v, big.NewInt(35))
 	return v.Div(v, big.NewInt(2))
 }
+
+// FakeSigner implements the Signer interface and accepts unprotected transactions
+type FakeSigner struct{ londonSigner }
+
+var _ Signer = FakeSigner{}
+
+func NewFakeSigner(chainId *big.Int) Signer {
+	signer := NewLondonSigner(chainId)
+	ls, _ := signer.(londonSigner)
+	return FakeSigner{londonSigner: ls}
+}
+
+func (f FakeSigner) Sender(tx *Transaction) (common.Address, error) {
+	return f.londonSigner.Sender(tx)
+}
+
+func (f FakeSigner) SignatureValues(tx *Transaction, sig []byte) (r, s, v *big.Int, err error) {
+	return f.londonSigner.SignatureValues(tx, sig)
+}
+
+func (f FakeSigner) ChainID() *big.Int {
+	return f.londonSigner.ChainID()
+}
+
+// Hash returns 'signature hash', i.e. the transaction hash that is signed by the
+// private key. This hash does not uniquely identify the transaction.
+func (f FakeSigner) Hash(tx *Transaction) common.Hash {
+	return f.londonSigner.Hash(tx)
+}
+
+// Equal returns true if the given signer is the same as the receiver.
+func (f FakeSigner) Equal(Signer) bool {
+	// Always return true
+	return true
+}
diff --git a/eth/backend.go b/eth/backend.go
index 3d18c71ac3..4787b56ed8 100644
--- a/eth/backend.go
+++ b/eth/backend.go
@@ -174,8 +174,6 @@ func New(stack *node.Node, config *ethconfig.Config) (*Ethereum, error) {
 
 	eth.APIBackend = &EthAPIBackend{stack.Config().ExtRPCEnabled(), stack.Config().AllowUnprotectedTxs, eth, nil}
 	if eth.APIBackend.allowUnprotectedTxs {
-		log.Debug(" ###########", "Unprotected transactions allowed")
-
 		config.TxPool.AllowUnprotectedTxs = true
 	}