add security api class

src/api/Security.ts

@@ -0,0 +1,58 @@
+import crypto from 'crypto';
+import { Request } from 'express';
+import { Client } from '..';
+
+export default class Security {
+  public client: Client;
+
+  public keyPair: { publicKey: string, privateKey: string };
+
+  constructor(client: Client) {
+    this.client = client;
+    this.keyPair = client.config.keyPair;
+  }
+
+  /**
+   * Creates a new Bearer token.
+   * @param _id The Mongoose Document property labeled ._id
+   */
+  public async createBearer(_id: string): Promise<string> {
+    const account = await this.client.db.Account.findOne({ _id });
+    if (!account) throw new Error(`Account [${_id}] cannot be found.`);
+    const bearer = crypto.randomBytes(12);
+    const sign = crypto.createSign('sha3-224');
+    sign.update(bearer);
+    sign.end();
+    const signature = sign.sign(this.keyPair.privateKey, 'hex');
+    await account.updateOne({ bearerSignature: signature });
+    return bearer.toString('base64');
+  }
+
+  public async checkBearer(_id: string, bearer: string): Promise<boolean> {
+    const account = await this.client.db.Account.findOne({ _id });
+    if (!account) return false;
+    if (!account.bearerSignature) return false;
+    const verify = crypto.createVerify('sha3-224');
+    verify.update(bearer);
+    verify.end();
+    try {
+      return verify.verify(this.keyPair.publicKey, account.bearerSignature, 'base64');
+    } catch {
+      return false;
+    }
+  }
+
+  public extractBearer(req: Request): string {
+    const url = new URL(req.url);
+    if (req.headers.authorization && req.headers.authorization.split(' ')[0] === 'Bearer') {
+      return req.headers.authorization.split(' ')[1];
+    }
+    if (req.query && req.query.token) {
+      return req.query.token;
+    }
+    if (url.password) {
+      return url.password;
+    }
+    return 'null';
+  }
+}