From bb73b83edf481fd8c298b4255347c509f27cd80c Mon Sep 17 00:00:00 2001
From: N08I40K <nhomcencko1@gmail.com>
Date: Sun, 26 Jan 2025 19:20:16 +0400
Subject: [PATCH] Switch VK ID authentication to use JWT tokens

- Replace access token with JWT id token
- Add JWT public key for VK ID
- Implement JWT verification and decoding
- Validate JWT issuer and app ID
---
 src/auth/auth.service.ts | 44 +++++++++++++++++++++++-----------------
 src/contants.ts          | 15 ++++++++++++++
 src/vkid/vkid.service.ts |  8 ++++----
 3 files changed, 44 insertions(+), 23 deletions(-)

diff --git a/src/auth/auth.service.ts b/src/auth/auth.service.ts
index 1f7d26f..3f788fa 100644
--- a/src/auth/auth.service.ts
+++ b/src/auth/auth.service.ts
@@ -9,13 +9,14 @@ import { compare, genSalt, hash } from "bcrypt";
 import UserRole from "../users/user-role.enum";
 import User from "../users/entity/user.entity";
 import ChangePasswordDto from "./dto/change-password.dto";
-import axios from "axios";
 import SignInErrorDto, { SignInErrorCode } from "./dto/sign-in-error.dto";
 import { SignUpDto, SignUpVKDto } from "./dto/sign-up.dto";
 import SignUpErrorDto, { SignUpErrorCode } from "./dto/sign-up-error.dto";
 import { SignInDto, SignInVKDto } from "./dto/sign-in.dto";
 import ObjectID from "bson-objectid";
 import UserDto from "../users/dto/user.dto";
+import { decodeJwt, verifyJwtSignature } from "firebase-admin/lib/utils/jwt";
+import { vkIdConstants } from "../contants";
 
 @Injectable()
 export class AuthService {
@@ -123,7 +124,7 @@ export class AuthService {
 	/**
 	 * Парсит VK ID пользователя по access token
 	 *
-	 * @param accessToken - Access token пользователя VK
+	 * @param idToken - Access token пользователя VK
 	 * @returns Promise, который разрешается в VK ID пользователя или null в случае ошибки
 	 *
 	 * @example
@@ -134,26 +135,31 @@ export class AuthService {
 	 *   console.error('Ошибка при получении VK ID');
 	 * }
 	 */
-	private static async parseVKID(accessToken: string): Promise<number> {
-		const form = new FormData();
-		form.append("access_token", accessToken);
-		form.append("v", "5.199");
-
-		const response = await axios.post(
-			"https://api.vk.com/method/account.getProfileInfo",
-			form,
-			{ responseType: "json" },
-		);
-
-		const data: { error?: any; response?: { id: number } } =
-			response.data as object;
-
-		if (response.status !== 200 || data.error !== undefined) {
-			console.warn(data);
+	private static async parseVKID(idToken: string): Promise<number> {
+		try {
+			await verifyJwtSignature(idToken, vkIdConstants.jwtPubKey, {
+				issuer: "VK",
+				jwtid: "21",
+			});
+		} catch {
 			return null;
 		}
 
-		return data.response.id;
+		const decodedToken = await decodeJwt(idToken);
+		type TokenData = {
+			iis: string;
+			sub: number;
+			app: number;
+			exp: number;
+			iat: number;
+			jti: number;
+		};
+
+		const payload = decodedToken.payload as TokenData;
+
+		if (payload.app !== vkIdConstants.clientId) return null;
+
+		return payload.sub;
 	}
 
 	/**
diff --git a/src/contants.ts b/src/contants.ts
index d4b14db..32c4ab8 100644
--- a/src/contants.ts
+++ b/src/contants.ts
@@ -6,6 +6,21 @@ configDotenv();
 export const vkIdConstants = {
 	clientId: +process.env.VKID_CLIENT_ID,
 	redirectUri: process.env.VKID_REDIRECT_URI,
+	jwtPubKey:
+		"-----BEGIN PUBLIC KEY-----\n" +
+		"MIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEAvsvJlhFX9Ju/pvCz1frB\n" +
+		"DgJs592VjdwQuRAmnlJAItyHkoiDIOEocPzgcUBTbDf1plDcTyO2RCkUt0pz0WK6\n" +
+		"6HNhpJyIfARjaWHeUlv4TpuHXAJJsBKklkU2gf1cjID+40sWWYjtq5dAkXnSJUVA\n" +
+		"UR+sq0lJ7GmTdJtAr8hzESqGEcSP15PTs7VUdHZ1nkC2XgkuR8KmKAUb388ji1Q4\n" +
+		"n02rJNOPQgd9r0ac4N2v/yTAFPXumO78N25bpcuWf5vcL9e8THk/U2zt7wf+aAWL\n" +
+		"748e0pREqNluTBJNZfmhC79Xx6GHtwqHyyduiqfPmejmiujNM/rqnA4e30Tg86Yn\n" +
+		"cNZ6vLJyF72Eva1wXchukH/aLispbY+EqNPxxn4zzCWaLKHG87gaCxpVv9Tm0jSD\n" +
+		"2es22NjrUbtb+2pAGnXbyDp2eGUqw0RrTQFZqt/VcmmSCE45FlcZMT28otrwG1ZB\n" +
+		"kZAb5Js3wLEch3ZfYL8sjhyNRPBmJBrAvzrd8qa3rdUjkC9sKyjGAaHu2MNmFl1Y\n" +
+		"JFQ3J54tGpkGgJjD7Kz3w0K6OiPDlVCNQN5sqXm24fCw85Pbi8SJiaLTp/CImrs1\n" +
+		"Z3nHW5q8hljA7OGmqfOP0nZS/5zW9GHPyepsI1rW6CympYLJ15WeNzePxYS5KEX9\n" +
+		"EncmkSD9b45ge95hJeJZteUCAwEAAQ==\n" +
+		"-----END PUBLIC KEY-----",
 };
 
 export const jwtConstants = {
diff --git a/src/vkid/vkid.service.ts b/src/vkid/vkid.service.ts
index 06cc44d..5f312bc 100644
--- a/src/vkid/vkid.service.ts
+++ b/src/vkid/vkid.service.ts
@@ -21,16 +21,16 @@ export class VKIDService {
 				`redirect_uri=${vkIdConstants.redirectUri}`,
 		);
 
-		const accessToken: string = (response.data as { access_token: string })
-			.access_token;
+		const idToken: string = (response.data as { id_token: string })
+			.id_token;
 
-		if (!accessToken) {
+		if (!idToken) {
 			console.error(response.data);
 			return null;
 		}
 
 		return new OAuthResponseDto({
-			accessToken: accessToken,
+			accessToken: idToken,
 		});
 	}
 }