添加文件: xy_sh/pkg/crypto/crypto.go

xy_sh/pkg/crypto/crypto.go

@@ -0,0 +1,144 @@
+package crypto
+
+import (
+	"bytes"
+	"crypto/cipher"
+	"crypto/hmac"
+	"crypto/rand"
+	"encoding/base64"
+	"encoding/hex"
+	"errors"
+	"fmt"
+	"io"
+
+	"github.com/tjfoc/gmsm/sm3"
+	"github.com/tjfoc/gmsm/sm4"
+)
+
+var (
+	sm3Salt []byte
+	sm4Key  []byte
+)
+
+func InitCrypto(salt, key string) {
+	sm3Salt = []byte(salt)
+	keyBytes := []byte(key)
+	if len(keyBytes) < 16 {
+		padded := make([]byte, 16)
+		copy(padded, keyBytes)
+		sm4Key = padded
+	} else if len(keyBytes) > 16 {
+		sm4Key = keyBytes[:16]
+	} else {
+		sm4Key = keyBytes
+	}
+}
+
+func SM3Hash(data []byte) string {
+	h := sm3.New()
+	h.Write(data)
+	hashBytes := h.Sum(nil)
+	return hex.EncodeToString(hashBytes)
+}
+
+func SM3HashWithSalt(data string) string {
+	h := hmac.New(sm3.New, sm3Salt)
+	h.Write([]byte(data))
+	return hex.EncodeToString(h.Sum(nil))
+}
+
+func GenerateSign(timestamp, encryptedData string) string {
+	signStr := timestamp + encryptedData
+	return SM3HashWithSalt(signStr)
+}
+
+func VerifySign(timestamp, encryptedData, sign string) bool {
+	expectedSign := GenerateSign(timestamp, encryptedData)
+	return hmac.Equal([]byte(expectedSign), []byte(sign))
+}
+
+func SM4CBCEncrypt(plaintext []byte) (string, error) {
+	if len(sm4Key) != 16 {
+		return "", fmt.Errorf("SM4密钥长度必须为16字节")
+	}
+
+	block, err := sm4.NewCipher(sm4Key)
+	if err != nil {
+		return "", fmt.Errorf("创建SM4 cipher失败: %v", err)
+	}
+
+	padded := pkcs7Padding(plaintext, block.BlockSize())
+
+	iv := make([]byte, block.BlockSize())
+	if _, err := io.ReadFull(rand.Reader, iv); err != nil {
+		return "", fmt.Errorf("生成IV失败: %v", err)
+	}
+
+	mode := cipher.NewCBCEncrypter(block, iv)
+	ciphertext := make([]byte, len(padded))
+	mode.CryptBlocks(ciphertext, padded)
+
+	result := append(iv, ciphertext...)
+	return base64.StdEncoding.EncodeToString(result), nil
+}
+
+func SM4CBCDecrypt(encryptedData string) ([]byte, error) {
+	if len(sm4Key) != 16 {
+		return nil, fmt.Errorf("SM4密钥长度必须为16字节")
+	}
+
+	data, err := base64.StdEncoding.DecodeString(encryptedData)
+	if err != nil {
+		return nil, fmt.Errorf("base64解码失败: %v", err)
+	}
+
+	block, err := sm4.NewCipher(sm4Key)
+	if err != nil {
+		return nil, fmt.Errorf("创建SM4 cipher失败: %v", err)
+	}
+
+	blockSize := block.BlockSize()
+	if len(data) < blockSize {
+		return nil, errors.New("数据长度不足")
+	}
+	iv := data[:blockSize]
+	ciphertext := data[blockSize:]
+
+	if len(ciphertext)%blockSize != 0 {
+		return nil, errors.New("密文长度不是块大小的整数倍")
+	}
+
+	mode := cipher.NewCBCDecrypter(block, iv)
+	plaintext := make([]byte, len(ciphertext))
+	mode.CryptBlocks(plaintext, ciphertext)
+
+	plaintext, err = pkcs7UnPadding(plaintext)
+	if err != nil {
+		return nil, fmt.Errorf("去除填充失败: %v", err)
+	}
+
+	return plaintext, nil
+}
+
+func pkcs7Padding(data []byte, blockSize int) []byte {
+	padding := blockSize - len(data)%blockSize
+	padText := bytes.Repeat([]byte{byte(padding)}, padding)
+	return append(data, padText...)
+}
+
+func pkcs7UnPadding(data []byte) ([]byte, error) {
+	length := len(data)
+	if length == 0 {
+		return nil, errors.New("数据为空")
+	}
+	padding := int(data[length-1])
+	if padding > length || padding == 0 {
+		return nil, errors.New("无效的填充")
+	}
+	for i := length - padding; i < length; i++ {
+		if data[i] != byte(padding) {
+			return nil, errors.New("无效的填充")
+		}
+	}
+	return data[:length-padding], nil
+}