init: v1.0.0

tpc/sm2/sm2a/enc_server.go

@@ -0,0 +1,26 @@
+package sm2a
+
+import (
+	"math/big"
+
+	"xdx.jelly/xgcl/gmath"
+	"xdx.jelly/xgcl/sm/sm2"
+)
+
+// ServerDecrypt 服务端协同计算，返回[d_s]·C1给客户端
+func ServerDecrypt(in []byte, ds *sm2.PrivateKey) ([]byte, error) {
+	x := new(big.Int)
+	y := new(big.Int)
+	x.SetBytes(in[:sm2.ByteSize()])
+	y.SetBytes(in[sm2.ByteSize() : 2*sm2.ByteSize()])
+
+	x, y = sm2.Curve256.ScalarMult(x, y, ds.D.Bytes())
+	out := make([]byte, 0, 2*sm2.ByteSize())
+	out = append(out, gmath.BigIntToNByte(x, sm2.ByteSize())...)
+	out = append(out, gmath.BigIntToNByte(y, sm2.ByteSize())...)
+	// 中间变量内存置0
+	gmath.ClearBigInt(x)
+	gmath.ClearBigInt(y)
+	return out, nil
+
+}