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.

2 files changed, 8 insertions, 21 deletions

diff --git a/accounts/abi/bind/auth.go b/accounts/abi/bind/auth.go
index a20852fca..dbb235c14 100644
--- a/accounts/abi/bind/auth.go
+++ b/accounts/abi/bind/auth.go
@@ -52,7 +52,7 @@ func NewKeyedTransactor(key *ecdsa.PrivateKey) *TransactOpts {
 			if address != keyAddr {
 				return nil, errors.New("not authorized to sign this account")
 			}
-			signature, err := crypto.SignEthereum(signer.Hash(tx).Bytes(), key)
+			signature, err := crypto.Sign(signer.Hash(tx).Bytes(), key)
 			if err != nil {
 				return nil, err
 			}
diff --git a/accounts/account_manager.go b/accounts/account_manager.go
index abe442388..12ff30bca 100644
--- a/accounts/account_manager.go
+++ b/accounts/account_manager.go
@@ -136,42 +136,29 @@ func (am *Manager) DeleteAccount(a Account, passphrase string) error {
 	return err
 }
 
-// Sign calculates a ECDSA signature for the given hash.
-// Note, Ethereum signatures have a particular format as described in the
-// yellow paper. Use the SignEthereum function to calculate a signature
-// in Ethereum format.
+// Sign calculates a ECDSA signature for the given hash. The produced signature
+// is in the [R || S || V] format where V is 0 or 1.
 func (am *Manager) Sign(addr common.Address, hash []byte) ([]byte, error) {
 	am.mu.RLock()
 	defer am.mu.RUnlock()
-	unlockedKey, found := am.unlocked[addr]
-	if !found {
-		return nil, ErrLocked
-	}
-	return crypto.Sign(hash, unlockedKey.PrivateKey)
-}
 
-// SignEthereum calculates a ECDSA signature for the given hash.
-// The signature has the format as described in the Ethereum yellow paper.
-func (am *Manager) SignEthereum(addr common.Address, hash []byte) ([]byte, error) {
-	am.mu.RLock()
-	defer am.mu.RUnlock()
 	unlockedKey, found := am.unlocked[addr]
 	if !found {
 		return nil, ErrLocked
 	}
-	return crypto.SignEthereum(hash, unlockedKey.PrivateKey)
+	return crypto.Sign(hash, unlockedKey.PrivateKey)
 }
 
-// SignWithPassphrase signs hash if the private key matching the given
-// address can be decrypted with the given passphrase.
+// SignWithPassphrase signs hash if the private key matching the given address
+// can be decrypted with the given passphrase. The produced signature is in the
+// [R || S || V] format where V is 0 or 1.
 func (am *Manager) SignWithPassphrase(addr common.Address, passphrase string, hash []byte) (signature []byte, err error) {
 	_, key, err := am.getDecryptedKey(Account{Address: addr}, passphrase)
 	if err != nil {
 		return nil, err
 	}
-
 	defer zeroKey(key.PrivateKey)
-	return crypto.SignEthereum(hash, key.PrivateKey)
+	return crypto.Sign(hash, key.PrivateKey)
 }
 
 // Unlock unlocks the given account indefinitely.