package crypto
import (
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"crypto/sha256"
"code.google.com/p/go.crypto/ripemd160"
"github.com/ethereum/go-ethereum/ethutil"
"github.com/obscuren/ecies"
"github.com/obscuren/secp256k1-go"
"github.com/obscuren/sha3"
)
func init() {
// specify the params for the s256 curve
ecies.AddParamsForCurve(S256(), ecies.ECIES_AES128_SHA256)
}
func Sha3(data []byte) []byte {
d := sha3.NewKeccak256()
d.Write(data)
return d.Sum(nil)
}
// Creates an ethereum address given the bytes and the nonce
func CreateAddress(b []byte, nonce uint64) []byte {
return Sha3(ethutil.NewValue([]interface{}{b, nonce}).Encode())[12:]
}
func Sha256(data []byte) []byte {
hash := sha256.Sum256(data)
return hash[:]
}
func Ripemd160(data []byte) []byte {
ripemd := ripemd160.New()
ripemd.Write(data)
return ripemd.Sum(nil)
}
func Ecrecover(data []byte) []byte {
var in = struct {
hash []byte
sig []byte
}{data[:32], data[32:]}
r, _ := secp256k1.RecoverPubkey(in.hash, in.sig)
return r
}
// New methods using proper ecdsa keys from the stdlib
func ToECDSA(prv []byte) *ecdsa.PrivateKey {
if len(prv) == 0 {
return nil
}
priv := new(ecdsa.PrivateKey)
priv.PublicKey.Curve = S256()
priv.D = ethutil.BigD(prv)
priv.PublicKey.X, priv.PublicKey.Y = S256().ScalarBaseMult(prv)
return priv
}
func FromECDSA(prv *ecdsa.PrivateKey) []byte {
if prv == nil {
return nil
}
return prv.D.Bytes()
}
func ToECDSAPub(pub []byte) *ecdsa.PublicKey {
if len(pub) == 0 {
return nil
}
x, y := elliptic.Unmarshal(S256(), pub)
return &ecdsa.PublicKey{S256(), x, y}
}
func FromECDSAPub(pub *ecdsa.PublicKey) []byte {
if pub == nil {
return nil
}
return elliptic.Marshal(S256(), pub.X, pub.Y)
}
func GenerateKey() (*ecdsa.PrivateKey, error) {
return ecdsa.GenerateKey(S256(), rand.Reader)
}
func SigToPub(hash, sig []byte) *ecdsa.PublicKey {
s := Ecrecover(append(hash, sig...))
x, y := elliptic.Unmarshal(S256(), s)
return &ecdsa.PublicKey{S256(), x, y}
}
func Sign(hash []byte, prv *ecdsa.PrivateKey) (sig []byte, err error) {
sig, err = secp256k1.Sign(hash, prv.D.Bytes())
return
}
func Encrypt(pub *ecdsa.PublicKey, message []byte) ([]byte, error) {
return ecies.Encrypt(rand.Reader, ecies.ImportECDSAPublic(pub), message, nil, nil)
}
func Decrypt(prv *ecdsa.PrivateKey, ct []byte) ([]byte, error) {
key := ecies.ImportECDSA(prv)
return key.Decrypt(rand.Reader, ct, nil, nil)
}
