feat: 初始化配置中心项目

go-client/crypto.go

@@ -0,0 +1,62 @@
+package client
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/md5"
+	"encoding/base64"
+	"encoding/hex"
+	"fmt"
+	"strings"
+)
+
+const CryptPrefix = "{Cipher}"
+
+func decryptConfig(secret string, data string) (string, error) {
+	if !strings.HasPrefix(data, CryptPrefix) {
+		return data, nil
+	}
+	encrypted := strings.TrimPrefix(data, CryptPrefix)
+	return decryptWithAES(secret, encrypted)
+}
+
+func decryptWithAES(key string, data string) (string, error) {
+	secretKey := md5.Sum([]byte(key))
+	aesKey := hex.EncodeToString(secretKey[:])[16:]
+
+	cipherText, err := base64.StdEncoding.DecodeString(data)
+	if err != nil {
+		return "", err
+	}
+
+	block, err := aes.NewCipher([]byte(aesKey))
+	if err != nil {
+		return "", err
+	}
+
+	if len(cipherText)%aes.BlockSize != 0 {
+		return "", fmt.Errorf("ciphertext is not a multiple of block size")
+	}
+
+	plainText := make([]byte, len(cipherText))
+	mode := cipher.NewCBCDecrypter(block, make([]byte, aes.BlockSize))
+	mode.CryptBlocks(plainText, cipherText)
+
+	plainText, err = pkcs7Unpad(plainText, aes.BlockSize)
+	if err != nil {
+		return "", err
+	}
+
+	return string(plainText), nil
+}
+
+func pkcs7Unpad(data []byte, blockSize int) ([]byte, error) {
+	if len(data) == 0 {
+		return nil, fmt.Errorf("empty data")
+	}
+	padding := int(data[len(data)-1])
+	if padding > blockSize || padding == 0 {
+		return nil, fmt.Errorf("invalid padding")
+	}
+	return data[:len(data)-padding], nil
+}