diff --git a/xy_sh/pkg/crypto/crypto.go b/xy_sh/pkg/crypto/crypto.go
new file mode 100644
index 0000000..6ac6aca
--- /dev/null
+++ b/xy_sh/pkg/crypto/crypto.go
@@ -0,0 +1,106 @@
+package crypto
+
+import (
+	"bytes"
+	"encoding/base64"
+	"encoding/hex"
+	"fmt"
+
+	"github.com/tjfoc/gmsm/sm3"
+	"github.com/tjfoc/gmsm/sm4"
+)
+
+// SM4ECBEncrypt SM4-ECB模式加密
+func SM4ECBEncrypt(plaintext []byte, key []byte) (string, error) {
+	if len(key) != 16 {
+		return "", fmt.Errorf("SM4密钥长度必须为16字节")
+	}
+
+	block, err := sm4.NewCipher(key)
+	if err != nil {
+		return "", fmt.Errorf("创建SM4 cipher失败: %v", err)
+	}
+
+	padded := pkcs7Padding(plaintext, block.BlockSize())
+
+	ciphertext := make([]byte, len(padded))
+	for i := 0; i < len(padded); i += block.BlockSize() {
+		block.Encrypt(ciphertext[i:i+block.BlockSize()], padded[i:i+block.BlockSize()])
+	}
+
+	return base64.StdEncoding.EncodeToString(ciphertext), nil
+}
+
+// SM4ECBDecrypt SM4-ECB模式解密
+func SM4ECBDecrypt(encryptedData string, key []byte) ([]byte, error) {
+	if len(key) != 16 {
+		return nil, fmt.Errorf("SM4密钥长度必须为16字节")
+	}
+
+	ciphertext, err := base64.StdEncoding.DecodeString(encryptedData)
+	if err != nil {
+		return nil, fmt.Errorf("base64解码失败: %v", err)
+	}
+
+	block, err := sm4.NewCipher(key)
+	if err != nil {
+		return nil, fmt.Errorf("创建SM4 cipher失败: %v", err)
+	}
+
+	blockSize := block.BlockSize()
+	if len(ciphertext)%blockSize != 0 {
+		return nil, fmt.Errorf("密文长度不是块大小的整数倍")
+	}
+
+	plaintext := make([]byte, len(ciphertext))
+	for i := 0; i < len(ciphertext); i += blockSize {
+		block.Decrypt(plaintext[i:i+blockSize], ciphertext[i:i+blockSize])
+	}
+
+	plaintext, err = pkcs7UnPadding(plaintext)
+	if err != nil {
+		return nil, fmt.Errorf("去除填充失败: %v", err)
+	}
+
+	return plaintext, nil
+}
+
+// SM3WithSalt 带盐的SM3哈希计算
+// 对应Java的 SmUtil.sm3WithSalt(saltBytes).digestHex(data)
+// 实现方式：SM3(salt + data)，输出十六进制字符串
+func SM3WithSalt(data string, salt string) string {
+	h := sm3.New()
+	h.Write([]byte(salt))
+	h.Write([]byte(data))
+	return hex.EncodeToString(h.Sum(nil))
+}
+
+// SM3Hash 计算SM3哈希值
+func SM3Hash(data []byte) string {
+	return hex.EncodeToString(sm3.Sm3Sum(data))
+}
+
+// pkcs7Padding PKCS7填充
+func pkcs7Padding(data []byte, blockSize int) []byte {
+	padding := blockSize - len(data)%blockSize
+	padText := bytes.Repeat([]byte{byte(padding)}, padding)
+	return append(data, padText...)
+}
+
+// pkcs7UnPadding 去除PKCS7填充
+func pkcs7UnPadding(data []byte) ([]byte, error) {
+	length := len(data)
+	if length == 0 {
+		return nil, fmt.Errorf("数据为空")
+	}
+	padding := int(data[length-1])
+	if padding > length || padding == 0 {
+		return nil, fmt.Errorf("无效的填充")
+	}
+	for i := length - padding; i < length; i++ {
+		if data[i] != byte(padding) {
+			return nil, fmt.Errorf("无效的填充")
+		}
+	}
+	return data[:length-padding], nil
+}
\ No newline at end of file