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