init: v1.0.0

2026-05-27 23:03:00 +08:00
commit 8d97f750eb
466 changed files with 80067 additions and 0 deletions
@@ -0,0 +1,42 @@
+package sm2a
+
+import (
+	"math/big"
+
+	"xdx.jelly/xgcl/gmath"
+	"xdx.jelly/xgcl/sm/sm2"
+)
+
+type ClientDecContext struct {
+	cipher *sm2.Cipher
+}
+
+func NewClientDecContext() *ClientDecContext {
+	return &ClientDecContext{
+		cipher: sm2.NewCipher(),
+	}
+}
+
+// Decrypt_one 客户端协同解密第一步，输出cipher.C1并发送给服务端
+func (c *ClientDecContext) Decrypt_one(cipher *sm2.Cipher) ([]byte, error) {
+	out := make([]byte, 0, 2*sm2.ByteSize())
+	cipher.X.Mod(cipher.X, sm2.OrderN())
+	cipher.Y.Mod(cipher.Y, sm2.OrderN())
+	out = append(out, gmath.BigIntToNByte(cipher.X, sm2.ByteSize())...)
+	out = append(out, gmath.BigIntToNByte(cipher.Y, sm2.ByteSize())...)
+
+	c.cipher.Set(cipher)
+	return out, nil
+}
+
+// Decrypt_two 客户端协同解密第二步，收到服务端计算结果 [d_s]·C1,计算解密明文。
+func (c *ClientDecContext) Decrypt_two(in []byte, dc *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()])
+	xx, yy := sm2.Curve256.ScalarMult(c.cipher.X, c.cipher.Y, dc.D.Bytes())
+	x, y = sm2.Curve256.Add(x, y, xx, yy)
+	// (x,y) = d*C1, 后续解密同标准SM2解密一致
+	return sm2.Decrypt_aux(x, y, c.cipher)
+}