init: v1.0.0

sm/sm2/sm2.go

@@ -0,0 +1,90 @@
+package sm2
+
+import (
+	"crypto/elliptic"
+	"math/big"
+
+	"xdx.jelly/xgcl/gmath"
+	"xdx.jelly/xgcl/internal/kdf"
+	"xdx.jelly/xgcl/sm/sm2/ec256"
+)
+
+const (
+	// ECCRefMaxBits c.f. GMT 0018
+	ECCRefMaxBits = 512
+	// ECCRefMaxLen c.f. GMT 0018
+	ECCRefMaxLen = (ECCRefMaxBits + 7) >> 3
+
+	// ECCStrict UnmarshalBinary的时候是否要求数据严格遵循GMT0018格式, 也就是要求
+	// bits按大端存储，并且等于密钥长度即256
+	ECCStrict = false
+)
+
+var one = new(big.Int).SetInt64(1)
+
+var (
+	sm2Curve elliptic.Curve
+
+	// byteSize is the Bytes of prime, module...
+	byteSize int
+
+	// orderN the order of Group of points on the curve
+	orderN *big.Int
+
+	// byteOfN is the ByteSize - long of N of byte slice
+	byteOfN []byte
+
+	// nMinusOne N-1
+	nMinusOne *big.Int
+
+	// Curve256 export the curve param.
+	Curve256 = ec256.Curve256
+)
+
+func init() {
+	// Choose the curve
+	// if the curve changed to a 384-bits curve,
+	// just sm2Curve = ec.EC384()
+	sm2Curve = ec256.CurveSM2()
+	byteSize = (sm2Curve.Params().BitSize + 7) / 8
+	orderN = new(big.Int).Set(sm2Curve.Params().N)
+	byteOfN = gmath.BigIntToNByte(orderN, byteSize)
+	nMinusOne = new(big.Int).Sub(orderN, gmath.BigInt1)
+	// must after sm2Curve and byteSize
+	initPrecompute()
+	// for key exchange constants
+	initKeyExchange()
+
+}
+
+// ByteSize 返回SM2的密钥大小
+func ByteSize() int {
+	return byteSize
+}
+
+// OrderN return the order of point group
+func OrderN() *big.Int {
+	return orderN
+}
+
+// Curve return the sm2 curve (interface)
+func Curve() elliptic.Curve {
+	return sm2Curve
+}
+
+// Prime return the p of field charactor
+func Prime() *big.Int {
+	return sm2Curve.Params().P
+}
+
+// BaseX return the x of base point
+func BaseX() *big.Int {
+	return sm2Curve.Params().Gx
+}
+
+// BaseY return the y of base point
+func BaseY() *big.Int {
+	return sm2Curve.Params().Gy
+}
+
+var Kdf = kdf.SMKDF.Kdf