From 61c5edcb57a200764bfa37e3a7da909727a7852b Mon Sep 17 00:00:00 2001 From: obscuren Date: Sun, 29 Mar 2015 15:02:49 +0200 Subject: Cleanup. --- core/vm/address.go | 23 +++++++++++++---------- 1 file changed, 13 insertions(+), 10 deletions(-) (limited to 'core') diff --git a/core/vm/address.go b/core/vm/address.go index e4c33ec80..0b3a95dd0 100644 --- a/core/vm/address.go +++ b/core/vm/address.go @@ -61,27 +61,30 @@ func ripemd160Func(in []byte) []byte { return common.LeftPadBytes(crypto.Ripemd160(in), 32) } -const EcRecoverInputLength = 128 +const ecRecoverInputLength = 128 func ecrecoverFunc(in []byte) []byte { // "in" is (hash, v, r, s), each 32 bytes // but for ecrecover we want (r, s, v) - if len(in) < EcRecoverInputLength { + if len(in) < ecRecoverInputLength { return nil } - hash := in[:32] - // v is only a bit, but comes as 32 bytes from vm. We only need least significant byte - encodedV := in[32:64] - v := encodedV[31] - 27 - if !(v == 0 || v == 1) { + + // Treat V as a 256bit integer + v := new(big.Int).Sub(common.Bytes2Big(in[32:64]), big.NewInt(27)) + // Ethereum requires V to be either 0 or 1 => (27 || 28) + if !(v.Cmp(Zero) == 0 || v.Cmp(One) == 0) { return nil } - sig := append(in[64:], v) - pubKey := crypto.Ecrecover(append(hash, sig...)) - // secp256.go returns either nil or 65 bytes + + // v needs to be moved to the end + rsv := append(in[64:128], byte(v.Uint64())) + pubKey := crypto.Ecrecover(in[:32], rsv) + // make sure the public key is a valid one if pubKey == nil || len(pubKey) != 65 { return nil } + // the first byte of pubkey is bitcoin heritage return common.LeftPadBytes(crypto.Sha3(pubKey[1:])[12:], 32) } -- cgit v1.2.3