feat: add secret feature

internal/utils/crypto.go

@@ -0,0 +1,114 @@
+package utils
+
+import (
+	"crypto/aes"
+	"crypto/cipher"
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/base64"
+	"errors"
+	"io"
+	"os"
+	"strings"
+)
+
+var (
+	masterSecretKey []byte
+	ErrKeyNotSet    = errors.New("加密秘钥未配置，请按照文档使用 BAIHU_SECRET_KEY 环境变量启动服务配置秘钥")
+)
+
+// InitSecretKey initialized the master secret key from the environment and unsets it
+func InitSecretKey() {
+	key := os.Getenv("BAIHU_SECRET_KEY")
+	if key != "" {
+		hash := sha256.Sum256([]byte(key))
+		masterSecretKey = hash[:]
+		// Ensure it's only in memory by unsetting the environment variable
+		os.Unsetenv("BAIHU_SECRET_KEY")
+	}
+}
+
+// IsSecretKeySet returns true if the master secret key is configured
+func IsSecretKeySet() bool {
+	return len(masterSecretKey) > 0
+}
+
+// Encrypt encrypts a plaintext string using AES-GCM
+func Encrypt(plaintext string) (string, error) {
+	if plaintext == "" {
+		return "", nil
+	}
+	if !IsSecretKeySet() {
+		return "", ErrKeyNotSet
+	}
+	
+	block, err := aes.NewCipher(masterSecretKey)
+	if err != nil {
+		return "", err
+	}
+
+	aesGCM, err := cipher.NewGCM(block)
+	if err != nil {
+		return "", err
+	}
+
+	nonce := make([]byte, aesGCM.NonceSize())
+	if _, err = io.ReadFull(rand.Reader, nonce); err != nil {
+		return "", err
+	}
+
+	ciphertext := aesGCM.Seal(nonce, nonce, []byte(plaintext), nil)
+	return base64.StdEncoding.EncodeToString(ciphertext), nil
+}
+
+// Decrypt decrypts a ciphertext string using AES-GCM
+// Returns the original string if decryption fails or if it wasn't encrypted
+func Decrypt(ciphertext string) (string, error) {
+	if ciphertext == "" {
+		return "", nil
+	}
+	if !IsSecretKeySet() {
+		return ciphertext, ErrKeyNotSet
+	}
+
+	data, err := base64.StdEncoding.DecodeString(ciphertext)
+	if err != nil {
+		return ciphertext, err
+	}
+
+	block, err := aes.NewCipher(masterSecretKey)
+	if err != nil {
+		return ciphertext, err
+	}
+
+	aesGCM, err := cipher.NewGCM(block)
+	if err != nil {
+		return ciphertext, err
+	}
+
+	nonceSize := aesGCM.NonceSize()
+	if len(data) < nonceSize {
+		return ciphertext, errors.New("ciphertext too short")
+	}
+
+	nonce, ciphertextBytes := data[:nonceSize], data[nonceSize:]
+	plaintext, err := aesGCM.Open(nil, nonce, ciphertextBytes, nil)
+	if err != nil {
+		return ciphertext, err
+	}
+
+	return string(plaintext), nil
+}
+
+// MaskSecrets 将文本中的所有敏感机密值替换为脱敏字符串 "********"
+func MaskSecrets(text string, secrets []string) string {
+	if len(secrets) == 0 || text == "" {
+		return text
+	}
+	for _, mask := range secrets {
+		if mask != "" {
+			text = strings.ReplaceAll(text, mask, "********")
+		}
+	}
+	return text
+}