How to call spring security azure AD localhost:8080 from angular localhost:4200. Error in azure call

Question

package com.example.demo;

import java.util.Arrays;
import java.util.Collections;

import org.springframework.beans.factory.annotation.Configurable;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.security.config.annotation.method.configuration.EnableGlobalMethodSecurity;
import org.springframework.security.config.annotation.web.builders.HttpSecurity;
import org.springframework.security.config.annotation.web.configuration.EnableWebSecurity;
import org.springframework.security.config.annotation.web.configuration.WebSecurityConfigurerAdapter;
import org.springframework.security.config.http.SessionCreationPolicy;
import org.springframework.security.oauth2.client.oidc.userinfo.OidcUserRequest;
import org.springframework.security.oauth2.client.userinfo.OAuth2UserService;
import org.springframework.security.oauth2.core.oidc.user.OidcUser;
import org.springframework.web.bind.annotation.CrossOrigin;
import org.springframework.web.cors.CorsConfiguration;
import org.springframework.web.cors.CorsConfigurationSource;
import org.springframework.web.cors.UrlBasedCorsConfigurationSource;

@Configuration
@EnableWebSecurity
@EnableGlobalMethodSecurity(prePostEnabled = true)
public class SecurityConfiguration extends WebSecurityConfigurerAdapter {

private final OAuth2UserService<OidcUserRequest, OidcUser> oidcUserService;

public SecurityConfiguration(OAuth2UserService<OidcUserRequest, OidcUser> oidcUserService) {
    System.out.println("loading user:" + oidcUserService);
    this.oidcUserService = oidcUserService;
}

@Override
protected void configure(HttpSecurity http) throws Exception {
    http.cors()
    .and().authorizeRequests()
    .anyRequest()
    .authenticated()
    .and()
    .oauth2Login()
    .userInfoEndpoint().oidcUserService(oidcUserService);
}

 @Bean
    CorsConfigurationSource corsConfigurationSource() 
    {
    CorsConfiguration configuration = new CorsConfiguration();
    configuration.setAllowedOrigins(Arrays.asList("*"));
    configuration.setAllowedMethods(Arrays.asList("*"));
    configuration.setAllowedHeaders(Arrays.asList("*"));
    UrlBasedCorsConfigurationSource source = new UrlBasedCorsConfigurationSource();
    source.registerCorsConfiguration("/**", configuration);
    return source;
    }

API:

    package com.example.demo;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.web.bind.annotation.CrossOrigin;
    import org.springframework.web.bind.annotation.GetMapping;
    import org.springframework.web.bind.annotation.RestController;
    
    @RestController
    public class AccountResource {
    
        @Autowired
        AdUserInfo adUserInfo;
    
        @CrossOrigin(origins = "http://localhost:4200")
        @GetMapping("/account")
        public AdInfo getAccount() {
            adUserInfo.setEmail("[e-mail]");
            return new AdInfo();
        }
    }

Angular code:

        import { Injectable } from '@angular/core';
        import { HttpClient } from '@angular/common/http';
        import { Observable, Subject } from 'rxjs';
        import { AdInfo } from './ad-info';
        @Injectable({
          providedIn: 'root'
        })
        export class LoginService {
          private loginUrl: string;
          constructor(private http: HttpClient) {
            this.loginUrl = 'http://localhost:8080/account';
          }
        
          public login(): Observable<AdInfo> {
            return this.http.get<AdInfo>(this.loginUrl);
          }
        
        }

Angular class:

            export class AdInfo {
                id: string;
                name: string;
                email: string;
            }

Calling from http://localhost:8080 is working fine. It goes to azure and login . as per • https://docs.microsoft.com/en-us/azure/developer/java/spring-framework/configure-spring-boot-starter-java-app-with-azure-active-directory.

Now i want to call it from Angular UI. So Localhost:4200. made a login page. Onlick login button. It is calling localhost:8080. But error in showing to redirecting to azure ad login.

ERROR: Access to XMLHttpRequest at 'https://login.microsoftonline.com/common/oauth2/authorize?response_type=code&client_id=******&scope=openid%20https://graph.microsoft.com/user.read&state=a04QyhpKFkvGUvjUCRwZ834QhTgzTFYIu74M0768Co0%3D&redirect_uri=http://localhost:8080/login/oauth2/code/azure' (redirected from 'http://localhost:8080/account') from origin 'http://localhost:4200' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource

Access to XMLHttpRequest at 'https://login.microsoftonline.com/common/oauth2/authorize?response_type=code&client_id=******&scope=openid%20https://graph.microsoft.com/user.read&state=Du8JvHSEGdD3xcBft6B683mDrW8Zedppel1Xz6lBZwY%3D&redirect_uri=http://localhost:4200/login/oauth2/code/azure' (redirected from 'http://localhost:4200/account') from origin 'http://localhost:4200' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.

Answer 1

The issue that you might be facing is that spring security is not letting through the pre-flight checkup requests and failing them.

Add

configuration.setAllowedHeaders(Arrays.asList("Origin", "Content-Type", "Accept","Authorization"));
configuration.setAllowedMethods(Arrays.asList("GET","POST"));

and In Angular try adding Proxying to a backend server