add middleware for koa 2

add back prepublish script and exclude csrf-koa from coverage

add example for koa 2 to readme

README.md

@@ -2,7 +2,7 @@
 
 [![NPM version][npm-image]][npm-url] [![Build Status][travis-image]][travis-url] [![Dependency Status][daviddm-image]][daviddm-url]
 
-An electrode plugin that enables stateless CSRF protection using [JWT](https://github.com/auth0/node-jsonwebtoken) in Electrode, Express, or Hapi applications.
+An electrode plugin that enables stateless CSRF protection using [JWT](https://github.com/auth0/node-jsonwebtoken) in Electrode, Express, Hapi, or Koa 2 applications.
 
 ## Why do we need this module?
 
@@ -55,7 +55,7 @@ Others are optional and follow the [same usage as jsonwebtoken](https://github.c
 * `noTimestamp`
 * `headers`
 
-This module can be used with either [Electrode](#electrode), [Express](#express), or [Hapi](#hapi).
+This module can be used with either [Electrode](#electrode), [Express](#express), [Hapi](#hapi), or [Koa 2](#koa-2).
 
 ### Electrode
 
@@ -113,6 +113,24 @@ server.register({register: csrfPlugin, options}, (err) => {
 });
 ```
 
+### Koa 2
+
+#### Example `app.js` configuration
+
+```js
+const csrfMiddleware = require("electrode-csrf-jwt").koaMiddleware;
+const Koa = require("koa");
+
+const app = new Koa();
+
+const options = {
+  secret: "shhhhh",
+  expiresIn: 60
+};
+
+app.use(csrfMiddleware(options));
+```
+
 Built with :heart: by [Team Electrode](https://github.com/orgs/electrode-io/people) @WalmartLabs.
 
 [npm-image]: https://badge.fury.io/js/electrode-csrf-jwt.svg

lib/csrf-koa.js

@@ -0,0 +1,61 @@
+"use strict";
+
+const Promise = require("bluebird");
+const uuid = require("uuid");
+const csrf = require("./csrf");
+
+const MISSING_SECRET = "MISSING_SECRET";
+const INVALID_JWT = "INVALID_JWT";
+
+function csrfMiddleware(options) {
+  if (!options || !options.secret) {
+    throw new Error(MISSING_SECRET);
+  }
+
+  function middleware(ctx, next) {
+
+    function createToken() {
+      const id = uuid.v4();
+      const headerPayload = {type: "header", uuid: id};
+      const cookiePayload = {type: "cookie", uuid: id};
+
+      return Promise.all([
+        csrf.create(headerPayload, options),
+        csrf.create(cookiePayload, options)
+      ]).spread((headerToken, cookieToken) => {
+        ctx.set("x-csrf-jwt", headerToken);
+        ctx.cookies.set("x-csrf-jwt", cookieToken);
+        return next();
+      });
+    }
+
+    function verifyAndCreateToken() {
+      const headerPayload = {token: ctx.headers["x-csrf-jwt"], secret: options.secret};
+      const cookiePayload = {token: ctx.cookies.get("x-csrf-jwt"), secret: options.secret};
+
+      return Promise.all([
+        csrf.verify(headerPayload),
+        csrf.verify(cookiePayload)
+      ]).spread((headerToken, cookieToken) => {
+        if (headerToken.uuid === cookieToken.uuid &&
+          headerToken.type === "header" && cookieToken.type === "cookie") {
+          return createToken();
+        }
+        ctx.throw(new Error(INVALID_JWT));
+      }).catch((err) => {
+        ctx.throw(err);
+      });
+    }
+
+    const method = ctx.method.toUpperCase();
+    if (method !== "GET" && method !== "HEAD") {
+      return verifyAndCreateToken();
+    }
+
+    return createToken();
+  }
+
+  return middleware;
+}
+
+module.exports = csrfMiddleware;

lib/index.js

@@ -2,8 +2,10 @@
 
 const csrfHapi = require("./csrf-hapi");
 const csrfExpress = require("./csrf-express");
+const csrfKoa = require("./csrf-koa");
 
 module.exports = {
   register: csrfHapi,
-  expressMiddleware: csrfExpress
+  expressMiddleware: csrfExpress,
+  koaMiddleware: csrfKoa
 };

package.json

@@ -6,7 +6,7 @@
   "scripts": {
     "lint": "gulp lint",
     "test": "npm run lint && gulp test",
-    "coverage": "istanbul cover -x lib/csrf-express.js node_modules/.bin/_mocha",
+    "coverage": "istanbul cover -x lib/csrf-express.js lib/csrf-koa.js node_modules/.bin/_mocha",
     "prepublish": "npm test"
   },
   "repository": {
@@ -41,6 +41,9 @@
     "hapi": "^14.2.0",
     "isomorphic-fetch": "^2.2.1",
     "istanbul": "^0.4.5",
+    "koa": "^2.0.0",
+    "koa-bodyparser": "^3.2.0",
+    "koa-router": "^7.0.1",
     "mocha": "^3.0.2",
     "vision": "^4.0.1"
   }

test/spec/csrf-koa-test.js

@@ -0,0 +1,130 @@
+"use strict";
+
+const bodyParser = require("koa-bodyparser");
+const Router = require("koa-router");
+const Koa = require("koa");
+const csrfMiddleware = require("../../lib/index").koaMiddleware;
+const jwt = require("jsonwebtoken");
+
+const fetch = require("isomorphic-fetch");
+
+const secret = "test";
+const url = "http://localhost:4000";
+let server;
+
+describe("test register", () => {
+  it("should fail with bad options", () => {
+    const app = new Koa();
+    try {
+      app.use(csrfMiddleware());
+    } catch (e) {
+      expect(e.message).to.equal("MISSING_SECRET");
+    }
+  });
+});
+
+describe("test csrf-jwt koa middleware", () => {
+  before(() => {
+    const app = new Koa();
+    const router = new Router();
+
+    app.use(bodyParser());
+
+    const options = {
+      secret,
+      expiresIn: "2d",
+      ignoreThisParam: "ignore"
+    };
+    app.use(csrfMiddleware(options));
+
+    router.get("/1", (ctx) => {
+      ctx.body = "valid";
+    });
+
+    router.post("/2", (ctx) => {
+      expect(ctx.request.body.message).to.equal("hello");
+      ctx.body = "valid";
+    });
+
+    app.use(router.routes());
+
+    server = require("http").createServer(app.callback());
+    server.listen(4000);
+  });
+
+  after(() => {
+    server.close();
+  });
+
+  it("should return success", () => {
+    return fetch(`${url}/1`)
+      .then((res) => {
+        expect(res.status).to.equal(200);
+        const csrfHeader = res.headers.get("x-csrf-jwt");
+        const csrfCookie = res.headers.get("set-cookie");
+        expect(csrfHeader).to.exist;
+        expect(csrfCookie).to.contain("x-csrf-jwt=");
+
+        return fetch(`${url}/2`, {
+          method: "POST",
+          headers: {
+            "Accept": "application/json",
+            "Content-Type": "application/json",
+            "x-csrf-jwt": csrfHeader,
+            "Cookie": csrfCookie
+          },
+          body: JSON.stringify({message: "hello"})
+        }).then((res) => {
+          expect(res.status).to.equal(200);
+          expect(res.headers.get("x-csrf-jwt")).to.exist;
+          expect(res.headers.get("set-cookie")).to.contain("x-csrf-jwt=");
+        });
+      });
+  });
+
+  it("should return 500 for missing jwt", () => {
+    return fetch(`${url}/2`, {
+      method: "POST",
+      headers: {
+        "Accept": "application/json",
+        "Content-Type": "application/json"
+      },
+      body: JSON.stringify({message: "hello"})
+    }).then((res) => {
+      expect(res.status).to.equal(500);
+      expect(res.headers.get("x-csrf-jwt")).to.not.exist;
+      expect(res.headers.get("set-cookie")).to.not.exist;
+    });
+  });
+
+  it("should return 500 for invalid jwt", () => {
+    return fetch(`${url}/1`)
+      .then(() => {
+        const token = jwt.sign({uuid: "1"}, secret, {});
+        return fetch(`${url}/2`, {
+          method: "POST",
+          headers: {
+            "Accept": "application/json",
+            "Content-Type": "application/json",
+            "x-csrf-jwt": token,
+            "Cookie": `x-csrf-jwt=${token}`
+          },
+          body: JSON.stringify({message: "hello"})
+        }).then((res) => {
+          expect(res.status).to.equal(500);
+          return fetch(`${url}/2`, {
+            method: "POST",
+            headers: {
+              "Accept": "application/json",
+              "Content-Type": "application/json",
+              "x-csrf-jwt": "invalid",
+              "Cookie": `x-csrf-jwt=${token}`
+            },
+            body: JSON.stringify({message: "hello"})
+          }).then((res) => {
+            expect(res.status).to.equal(500);
+          });
+        });
+      });
+  });
+});