diff --git a/imgdec.js b/imgdec.js
new file mode 100644
index 0000000..bb05c91
--- /dev/null
+++ b/imgdec.js
@@ -0,0 +1,55 @@
+
+let 图片解密 = function(key,iv,kiType,mode) {
+    function hexStringToBytes(cipherText) {
+        cipherText = String(cipherText);
+        let str = cipherText.toLowerCase();
+        let length = str.length;
+        let bArr = java.lang.reflect.Array.newInstance(java.lang.Byte.TYPE, length / 2);
+        for (let i = 0, o = 0; i < length; i += 2, o++) {
+            let a = str[i + 1],
+                b = str[i];
+            if (b != "0") {
+                a = b + a;
+            }
+            let hexInt = java.lang.Integer.parseInt(new java.lang.String(a), 16);
+            let inty = hexInt > 127 ? hexInt - 255 - 1 : hexInt;
+            bArr[o] = inty;
+        }
+        return bArr;
+    }
+    let javaImport = new JavaImporter();
+    javaImport.importPackage(
+        Packages.com.example.hikerview.utils,
+        Packages.java.lang,
+        Packages.java.security,
+        Packages.javax.crypto,
+        Packages.javax.crypto.spec
+    );
+    with(javaImport) {
+        function getBytes(str) {
+            let bytes;
+            if (kiType === "Base64") {
+                bytes = _base64.decode(str, _base64.NO_WRAP);
+            } else if (kiType === "Hex") {
+                bytes = hexStringToBytes(str);
+            } else {
+                bytes = String(str).getBytes("UTF-8");
+            }
+            return bytes;
+        }
+        kiType = kiType || "String";
+        mode = mode || 'AES/CBC/PKCS5Padding';
+        key = getBytes(key);
+        iv = getBytes(iv);
+        function decryptData(cipherText) {
+            let secretKeySpec = new SecretKeySpec(key, "AES");
+            let ivParameterSpec = new IvParameterSpec(iv);
+            let cipher = Cipher.getInstance(mode);
+            cipher.init(2, secretKeySpec, ivParameterSpec);
+            return cipher.doFinal(cipherText);
+        }
+        let bytes = FileUtil.toBytes(input);
+        bytes = decryptData(bytes);
+        return FileUtil.toInputStream(bytes);
+    }
+}