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Cleanup.

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This commit is contained in:
obscuren
2015-03-29 15:02:49 +02:00
parent af153e7884
commit 61c5edcb57
2 changed files with 20 additions and 19 deletions
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23
core/vm/address.go
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@ -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)
}