From 08eea0f0e417c5f6ff864ae4633cc3e0a12aa405 Mon Sep 17 00:00:00 2001
From: Péter Szilágyi <peterke@gmail.com>
Date: Thu, 5 Jan 2017 12:35:23 +0200
Subject: accounts, core, crypto, internal: use normalised V during signature
 handling (#3455)

To address increasing complexity in code that handles signatures, this PR
discards all notion of "different" signature types at the library level. Both
the crypto and accounts package is reduced to only be able to produce plain
canonical secp256k1 signatures. This makes the crpyto APIs much cleaner,
simpler and harder to abuse.
---
 core/types/transaction.go | 49 ++---------------------------------------------
 1 file changed, 2 insertions(+), 47 deletions(-)

(limited to 'core/types/transaction.go')

diff --git a/core/types/transaction.go b/core/types/transaction.go
index f566dc365..87b54ab30 100644
--- a/core/types/transaction.go
+++ b/core/types/transaction.go
@@ -199,9 +199,9 @@ func (tx *Transaction) UnmarshalJSON(input []byte) error {
 
 	var V byte
 	if isProtectedV((*big.Int)(dec.V)) {
-		V = normaliseV(NewEIP155Signer(deriveChainId((*big.Int)(dec.V))), (*big.Int)(dec.V))
+		V = byte((new(big.Int).Sub((*big.Int)(dec.V), deriveChainId((*big.Int)(dec.V))).Uint64()) - 35)
 	} else {
-		V = byte(((*big.Int)(dec.V)).Uint64())
+		V = byte(((*big.Int)(dec.V)).Uint64() - 27)
 	}
 	if !crypto.ValidateSignatureValues(V, (*big.Int)(dec.R), (*big.Int)(dec.S), false) {
 		return ErrInvalidSig
@@ -272,51 +272,6 @@ func (tx *Transaction) Size() common.StorageSize {
 	return common.StorageSize(c)
 }
 
-/*
-// From returns the address derived from the signature (V, R, S) using secp256k1
-// elliptic curve and an error if it failed deriving or upon an incorrect
-// signature.
-//
-// From Uses the homestead consensus rules to determine whether the signature is
-// valid.
-//
-// From caches the address, allowing it to be used regardless of
-// Frontier / Homestead. however, the first time called it runs
-// signature validations, so we need two versions. This makes it
-// easier to ensure backwards compatibility of things like package rpc
-// where eth_getblockbynumber uses tx.From() and needs to work for
-// both txs before and after the first homestead block. Signatures
-// valid in homestead are a subset of valid ones in Frontier)
-func (tx *Transaction) From() (common.Address, error) {
-	if tx.signer == nil {
-		return common.Address{}, errNoSigner
-	}
-
-	if from := tx.from.Load(); from != nil {
-		return from.(common.Address), nil
-	}
-
-	pubkey, err := tx.signer.PublicKey(tx)
-	if err != nil {
-		return common.Address{}, err
-	}
-	var addr common.Address
-	copy(addr[:], crypto.Keccak256(pubkey[1:])[12:])
-	tx.from.Store(addr)
-	return addr, nil
-}
-
-// SignatureValues returns the ECDSA signature values contained in the transaction.
-func (tx *Transaction) SignatureValues() (v byte, r *big.Int, s *big.Int, err error) {
-	if tx.signer == nil {
-		return 0, nil, nil,errNoSigner
-	}
-
-	return normaliseV(tx.signer, tx.data.V), new(big.Int).Set(tx.data.R),new(big.Int).Set(tx.data.S), nil
-}
-
-*/
-
 // AsMessage returns the transaction as a core.Message.
 //
 // AsMessage requires a signer to derive the sender.
-- 
cgit