init: v1.0.0

tpc/sm9/sm9m/decapsulate.go

@@ -0,0 +1,77 @@
+package sm9m
+
+import (
+	"encoding"
+
+	"xdx.jelly/xgcl/sm/sm9"
+)
+
+// SM9协同密钥解封装
+
+type ClientDecapsulateContext struct {
+	pack *sm9.KeyPackage
+}
+
+type ClientDecapsulateParam struct {
+	c sm9.G1
+}
+
+type ServerDecapsulateParam struct {
+	e sm9.GT // e(C, Ks)
+}
+
+func (ctx *ClientDecapsulateContext) GenerateParam(pack *sm9.KeyPackage) (*ClientDecapsulateParam, error) {
+	if !pack.G1.IsValid() {
+		return nil, ErrInvalidCipherC1
+	}
+	ctx.pack = pack
+	param := &ClientDecapsulateParam{}
+	param.c.Set(&pack.G1)
+	return param, nil
+}
+
+func (ctx *ClientDecapsulateContext) DecapsulateFinal(id []byte, keylen int, clientEncKey *EncKeyClient, param *ServerDecapsulateParam) ([]byte, error) {
+	w := sm9.Pairing(&ctx.pack.G1, &clientEncKey.p)
+	w.Mul(w, &param.e) // e = e(C1, de)
+
+	key := make([]byte, keylen)
+	_ = sm9.Kdf(key, ctx.pack.G1.Marshal(), w.Marshal(), id)
+	return key, nil
+}
+
+func ServerDecapsulate(clientParam *ClientDecapsulateParam, serverEncKey *EncKeyServer) (*ServerDecapsulateParam, error) {
+	if !clientParam.c.IsValid() {
+		return nil, ErrInvalidCipherC1
+	}
+
+	w := sm9.Pairing(&clientParam.c, &serverEncKey.p)
+	return &ServerDecapsulateParam{e: *w}, nil
+}
+
+var _ encoding.BinaryMarshaler = &ClientDecapsulateParam{}
+var _ encoding.BinaryUnmarshaler = &ClientDecapsulateParam{}
+
+var _ encoding.BinaryMarshaler = &ServerDecapsulateParam{}
+var _ encoding.BinaryUnmarshaler = &ServerDecapsulateParam{}
+
+// MarshalBinary implements encoding.BinaryMarshaler
+func (p *ClientDecapsulateParam) MarshalBinary() (data []byte, err error) {
+	return p.c.Marshal(), nil
+}
+
+// UnmarshalBinary implements encoding.BinaryUnmarshaler
+func (p *ClientDecapsulateParam) UnmarshalBinary(data []byte) error {
+	_, err := p.c.Unmarshal(data)
+	return err
+}
+
+// MarshalBinary implements encoding.BinaryMarshaler
+func (p *ServerDecapsulateParam) MarshalBinary() (data []byte, err error) {
+	return p.e.Marshal(), nil
+}
+
+// UnmarshalBinary implements encoding.BinaryUnmarshaler
+func (p *ServerDecapsulateParam) UnmarshalBinary(data []byte) error {
+	_, err := p.e.Unmarshal(data)
+	return err
+}