add

pkg/captcha/encrypt_scene.go

@@ -0,0 +1,28 @@
+package captcha
+
+import (
+	"encoding/base64"
+	"fmt"
+	"time"
+
+	lzcrypto "tyass-server/pkg/lzkit/crypto"
+)
+
+func GenerateEncryptedSceneID(sceneId, ekey string, expireSeconds int) (string, error) {
+	if expireSeconds <= 0 || expireSeconds > 86400 {
+		expireSeconds = 3600
+	}
+
+	ts := time.Now().Unix()
+	plaintext := fmt.Sprintf("%s&%d&%d", sceneId, ts, expireSeconds)
+
+	keyBytes, err := base64.StdEncoding.DecodeString(ekey)
+	if err != nil {
+		return "", fmt.Errorf("decode ekey error: %w", err)
+	}
+	if len(keyBytes) != 32 {
+		return "", fmt.Errorf("invalid ekey length, need 32 bytes after base64 decode, got %d", len(keyBytes))
+	}
+
+	return lzcrypto.AesEncrypt([]byte(plaintext), keyBytes)
+}