From 87adff7e189ee0a1fd50a3ef30ba22482e60f314 Mon Sep 17 00:00:00 2001
From: obscuren <geffobscura@gmail.com>
Date: Wed, 10 Dec 2014 00:03:21 +0100
Subject: Added Encrypt & Decrypt using the ECIES w/ tests
---
crypto/crypto.go | 42 ++++++++++++++++++++++++++++++++++++++++++
crypto/encrypt_decrypt_test.go | 40 ++++++++++++++++++++++++++++++++++++++++
2 files changed, 82 insertions(+)
create mode 100644 crypto/encrypt_decrypt_test.go
diff --git a/crypto/crypto.go b/crypto/crypto.go
index e10a9e81f..87dd72dc7 100644
--- a/crypto/crypto.go
+++ b/crypto/crypto.go
@@ -1,14 +1,35 @@
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 ToECDSA(prv []byte) *ecdsa.PrivateKey {
+ 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 {
+ return prv.D.Bytes()
+}
+
// TODO refactor, remove (bin)
func Sha3(data []byte) []byte {
d := sha3.NewKeccak256()
@@ -45,3 +66,24 @@ func Ecrecover(data []byte) []byte {
return r
}
+
+func SigToPub(hash, sig []byte) []byte {
+ return Ecrecover(append(hash, sig...))
+}
+
+func Sign(hash, prv []byte) (sig []byte, err error) {
+ sig, err = secp256k1.Sign(hash, prv)
+ return
+}
+
+func Encrypt(pub, message []byte) ([]byte, error) {
+ x, y := elliptic.Unmarshal(S256(), pub)
+ epub := &ecdsa.PublicKey{S256(), x, y}
+
+ return ecies.Encrypt(rand.Reader, ecies.ImportECDSAPublic(epub), message, nil, nil)
+}
+
+func Decrypt(prv, ct []byte) ([]byte, error) {
+ key := ecies.ImportECDSA(ToECDSA(prv))
+ return key.Decrypt(rand.Reader, ct, nil, nil)
+}
diff --git a/crypto/encrypt_decrypt_test.go b/crypto/encrypt_decrypt_test.go
new file mode 100644
index 000000000..44bb26f47
--- /dev/null
+++ b/crypto/encrypt_decrypt_test.go
@@ -0,0 +1,40 @@
+package crypto
+
+import (
+ "bytes"
+ "fmt"
+ "testing"
+
+ "github.com/ethereum/go-ethereum/ethutil"
+)
+
+func TestBox(t *testing.T) {
+ prv1 := ethutil.Hex2Bytes("4b50fa71f5c3eeb8fdc452224b2395af2fcc3d125e06c32c82e048c0559db03f")
+ prv2 := ethutil.Hex2Bytes("d0b043b4c5d657670778242d82d68a29d25d7d711127d17b8e299f156dad361a")
+ pub2 := ethutil.Hex2Bytes("04bd27a63c91fe3233c5777e6d3d7b39204d398c8f92655947eb5a373d46e1688f022a1632d264725cbc7dc43ee1cfebde42fa0a86d08b55d2acfbb5e9b3b48dc5")
+
+ message := []byte("Hello, world.")
+ ct, err := Encrypt(pub2, message)
+ if err != nil {
+ fmt.Println(err.Error())
+ t.FailNow()
+ }
+
+ pt, err := Decrypt(prv2, ct)
+ if err != nil {
+ fmt.Println(err.Error())
+ t.FailNow()
+ }
+
+ if !bytes.Equal(pt, message) {
+ fmt.Println("ecies: plaintext doesn't match message")
+ t.FailNow()
+ }
+
+ _, err = Decrypt(prv1, pt)
+ if err == nil {
+ fmt.Println("ecies: encryption should not have succeeded")
+ t.FailNow()
+ }
+
+}
--
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