feat: crypto

crypto/aes.go

@@ -0,0 +1,74 @@
+package crypto
+
+import (
+	"bytes"
+	"fmt"
+
+	"crypto/aes"
+	"crypto/cipher"
+
+	"math/rand/v2"
+)
+
+// DefaultAESKey 默认AES密钥(16字节)
+var DefaultAESKey = []byte("f51d66a73d8a0927")
+
+// GenerateAESKey 生成AES密钥
+func GenerateAESKey(length int) ([]byte, error) {
+	if length != 16 && length != 24 && length != 32 {
+		return nil, fmt.Errorf("invalid key length: %d, must be 16, 24, or 32 bytes", length)
+	}
+	key := make([]byte, length)
+	src := rand.ChaCha8{}
+	_, err := src.Read(key)
+	if err != nil {
+		return nil, err
+	}
+	return key, nil
+}
+
+// PKCS5Padding 填充明文
+func PKCS5Padding(plaintext []byte, blockSize int) []byte {
+	padding := blockSize - len(plaintext)%blockSize
+	padText := bytes.Repeat([]byte{byte(padding)}, padding)
+	return append(plaintext, padText...)
+}
+
+// PKCS5UnPadding 去除填充数据
+func PKCS5UnPadding(origData []byte) []byte {
+	length := len(origData)
+	unpadding := int(origData[length-1])
+	return origData[:(length - unpadding)]
+}
+
+// AesEncrypt AES加密
+func AesEncrypt(origData, key []byte) ([]byte, error) {
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+
+	//AES分组长度为128位，所以blockSize=16，单位字节
+	blockSize := block.BlockSize()
+	origData = PKCS5Padding(origData, blockSize)
+	blockMode := cipher.NewCBCEncrypter(block, key[:blockSize]) //初始向量的长度必须等于块block的长度16字节
+	crypted := make([]byte, len(origData))
+	blockMode.CryptBlocks(crypted, origData)
+	return crypted, nil
+}
+
+// AesDecrypt AES解密
+func AesDecrypt(crypted, key []byte) ([]byte, error) {
+	block, err := aes.NewCipher(key)
+	if err != nil {
+		return nil, err
+	}
+
+	//AES分组长度为128位，所以blockSize=16，单位字节
+	blockSize := block.BlockSize()
+	blockMode := cipher.NewCBCDecrypter(block, key[:blockSize]) //初始向量的长度必须等于块block的长度16字节
+	origData := make([]byte, len(crypted))
+	blockMode.CryptBlocks(origData, crypted)
+	origData = PKCS5UnPadding(origData)
+	return origData, nil
+}