diff --git a/examples/2018.01.28-asymmetric-enc-dec/app.js b/examples/2018.01.28-asymmetric-enc-dec/app.js
index b024360..91a68b8 100644
--- a/examples/2018.01.28-asymmetric-enc-dec/app.js
+++ b/examples/2018.01.28-asymmetric-enc-dec/app.js
@@ -1,8 +1,21 @@
 const utils = require('./utils');
 const keys = require('./keys');
+const path = require('path');
+const fs = require('fs-extra');
 
 const plainText = '你好，我是程序猿小卡';
-const crypted = utils.encrypt(plainText, keys.pubKey);
-const decrypted = utils.decrypt(crypted, keys.privKey);
 
-console.log(decrypted.toString()); // 你好，我是程序猿小卡
\ No newline at end of file
+/**
+ * 新增两个通过 openssl 生成的密钥文件
+ * 必须是1024位长度 使用其他长度报错
+ * RSA_padding_add_PKCS1_OAEP_mgf1:data too large for key size
+ */
+(async function main() {
+  let pubKey = await fs.readFile(path.resolve(__dirname, './public_key.pem'));
+  let privKey = await fs.readFile(path.resolve(__dirname, './private_key.pem'));
+
+  let crypted = utils.encrypt(plainText, pubKey.toString());
+  let decrypted = utils.decrypt(crypted, privKey.toString());
+
+  console.log(decrypted.toString()); // 你好，我是程序员小卡
+})();
\ No newline at end of file
diff --git a/examples/2018.01.28-asymmetric-enc-dec/private_key.pem b/examples/2018.01.28-asymmetric-enc-dec/private_key.pem
new file mode 100644
index 0000000..566a0ca
--- /dev/null
+++ b/examples/2018.01.28-asymmetric-enc-dec/private_key.pem
@@ -0,0 +1,15 @@
+-----BEGIN RSA PRIVATE KEY-----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+-----END RSA PRIVATE KEY-----
diff --git a/examples/2018.01.28-asymmetric-enc-dec/public_key.pem b/examples/2018.01.28-asymmetric-enc-dec/public_key.pem
new file mode 100644
index 0000000..f98f2a6
--- /dev/null
+++ b/examples/2018.01.28-asymmetric-enc-dec/public_key.pem
@@ -0,0 +1,6 @@
+-----BEGIN PUBLIC KEY-----
+MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC7ikxFcifEdVZ7IxSvd65vUQKx
+xvYZRx+qSz0Cl1Xj+PwyT9hnw4M6rglvbjgpQhQnnumY/KkmI7CCglXVNjOI9zRA
+/IfSv3juPTEFItJUcnfOtgnzDgrzMvu9gP9nH45aD5mnZd+zWaK9BSJSuOk/D6rj
+Lts8Iykv1jpQ/KYFPwIDAQAB
+-----END PUBLIC KEY-----
diff --git a/package-lock.json b/package-lock.json
new file mode 100644
index 0000000..8e2b7ca
--- /dev/null
+++ b/package-lock.json
@@ -0,0 +1,36 @@
+{
+  "name": "nodejs-learning-guide",
+  "version": "1.0.0",
+  "lockfileVersion": 1,
+  "requires": true,
+  "dependencies": {
+    "fs-extra": {
+      "version": "5.0.0",
+      "resolved": "https://registry.npmjs.org/fs-extra/-/fs-extra-5.0.0.tgz",
+      "integrity": "sha512-66Pm4RYbjzdyeuqudYqhFiNBbCIuI9kgRqLPSHIlXHidW8NIQtVdkM1yeZ4lXwuhbTETv3EUGMNHAAw6hiundQ==",
+      "requires": {
+        "graceful-fs": "4.1.11",
+        "jsonfile": "4.0.0",
+        "universalify": "0.1.1"
+      }
+    },
+    "graceful-fs": {
+      "version": "4.1.11",
+      "resolved": "https://registry.npmjs.org/graceful-fs/-/graceful-fs-4.1.11.tgz",
+      "integrity": "sha1-Dovf5NHduIVNZOBOp8AOKgJuVlg="
+    },
+    "jsonfile": {
+      "version": "4.0.0",
+      "resolved": "https://registry.npmjs.org/jsonfile/-/jsonfile-4.0.0.tgz",
+      "integrity": "sha1-h3Gq4HmbZAdrdmQPygWPnBDjPss=",
+      "requires": {
+        "graceful-fs": "4.1.11"
+      }
+    },
+    "universalify": {
+      "version": "0.1.1",
+      "resolved": "https://registry.npmjs.org/universalify/-/universalify-0.1.1.tgz",
+      "integrity": "sha1-+nG63UQ3r0wUiEHjs7Fl+enlkLc="
+    }
+  }
+}
diff --git a/package.json b/package.json
index 26a5b2d..8d11f14 100644
--- a/package.json
+++ b/package.json
@@ -22,6 +22,7 @@
     "concat-stream": "^1.6.0",
     "content-type": "^1.0.2",
     "express": "^4.15.3",
+    "fs-extra": "^5.0.0",
     "iconv-lite": "^0.4.17",
     "through": "^2.3.8"
   }