Feat/auth token middleware

package.json

@@ -23,10 +23,12 @@
     "cors": "^2.8.5",
     "express": "^4.18.2",
     "graphql": "^16.8.1",
-    "graphql-tag": "^2.12.6"
+    "graphql-tag": "^2.12.6",
+    "jsonwebtoken": "^9.0.2"
   },
   "devDependencies": {
     "@types/cors": "^2.8.17",
+    "@types/jsonwebtoken": "^9.0.6",
     "@types/node": "^20.11.21",
     "@typescript-eslint/parser": "^7.1.0",
     "eslint": "^8.54.0",

src/util/authToken.ts

@@ -0,0 +1,129 @@
+/**
+ * Express.js middleware for authentication token verification.
+ * Retrieves token from cookies, verifies it, and sends authentication context.
+ */
+import express from "express";
+import jwt from "jsonwebtoken";
+
+// Configuration
+const secretKey = "top secret"; // Secret key for JWT signing and verification
+
+/**
+ * Represents an optional value of type T.
+ */
+export type Optional<T> = T | null | undefined;
+
+/**
+ * Represents a JWT token.
+ */
+export type Token = string;
+
+/**
+ * Represents a decoded JWT token.
+ */
+export type DecodedToken = any;
+
+/**
+ * Represents the response from a token creation operation.
+ */
+export type CreateTokenResponse = {
+  /** Indicates whether the token creation was successful. */
+  ok: boolean;
+  /** The body of the token if creation was successful. */
+  body: Optional<Token>;
+  /** An error object if an error occurred during token creation. */
+  error: Optional<Error>;
+};
+
+/**
+ * Represents the response from a token verification operation.
+ */
+export type VerifyTokenResponse = {
+  /** Indicates whether the token verification was successful. */
+  ok: boolean;
+  /** The decoded body of the token if verification was successful. */
+  body: Optional<DecodedToken>;
+  /** An error object if an error occurred during token verification. */
+  error: Optional<Error>;
+};
+
+/**
+ * Represents the context for authentication operations.
+ */
+export type Context = {
+  /** The authentication verification response. */
+  auth: VerifyTokenResponse;
+};
+
+/**
+ * Creates a JWT token with the provided data.
+ * @param data - The data to be encoded into the token.
+ * @param durationOfToken - Optional. Duration for which the token will be valid (default is "1h").
+ * @returns The response indicating the success or failure of token creation.
+ */
+export function createToken(data: any, durationOfToken: string = "1h"): CreateTokenResponse {
+  const token = jwt.sign(data, secretKey, {
+    expiresIn: durationOfToken,
+  });
+
+  return {
+    ok: true,
+    body: token,
+    error: undefined,
+  };
+}
+
+/**
+ * Verifies the authenticity of a JWT token.
+ * @param token - The token to be verified.
+ * @returns The response indicating the success or failure of token verification.
+ */
+export function verifyToken(token: Token): VerifyTokenResponse {
+  try {
+    const decodedToken: DecodedToken = jwt.verify(token, secretKey);
+    return {
+      ok: true,
+      body: decodedToken,
+      error: undefined,
+    };
+  } catch (e) {
+    return {
+      ok: false,
+      body: undefined,
+      error: e,
+    };
+  }
+}
+
+/**
+ * Express router for token authentication
+ */
+export const authTokenRouter = express.Router();
+
+/**
+ * Middleware function to handle token authentication.
+ * Retrieves token from cookies, verifies it, and sends authentication context.
+ * @param req - The Express request object. Assumes that there exists req.cookies.token
+ * @param res - The Express response object.
+ * @param next - The next middleware function in the request-response cycle.
+ */
+authTokenRouter.use((req, res, next) => {
+  try {
+    const { token } = req.cookies; // Retrieve token from cookies
+    const context: Context = {
+      auth: verifyToken(token), // Verify token and create authentication context
+    };
+    res.send(context); // Send authentication context in the response
+    next();
+  } catch (e) {
+    const context: Context = {
+      auth: {
+        ok: false,
+        body: undefined,
+        error: e,
+      } as VerifyTokenResponse,
+    };
+    res.send(context); // Send error authentication context in case of exceptions
+    next();
+  }
+});