From 0fa1e17078f705ed84418d1e0043bd3474c79605 Mon Sep 17 00:00:00 2001
From: Kristof De Langhe <kristof.delanghe@atmire.com>
Date: Mon, 13 Jul 2020 15:47:59 +0200
Subject: [PATCH] 71809: ForwardClientIpInterceptor

---
 src/app/core/auth/server-auth.service.ts      |  3 --
 .../forward-client-ip.interceptor.spec.ts     | 44 +++++++++++++++++++
 .../forward-client-ip.interceptor.ts          | 23 ++++++++++
 src/modules/app/server-app.module.ts          | 10 ++++-
 4 files changed, 76 insertions(+), 4 deletions(-)
 create mode 100644 src/app/core/forward-client-ip/forward-client-ip.interceptor.spec.ts
 create mode 100644 src/app/core/forward-client-ip/forward-client-ip.interceptor.ts

diff --git a/src/app/core/auth/server-auth.service.ts b/src/app/core/auth/server-auth.service.ts
index 30767be85a..7b78255001 100644
--- a/src/app/core/auth/server-auth.service.ts
+++ b/src/app/core/auth/server-auth.service.ts
@@ -27,9 +27,6 @@ export class ServerAuthService extends AuthService {
 
     headers = headers.append('Accept', 'application/json');
     headers = headers.append('Authorization', `Bearer ${token.accessToken}`);
-    // NB this is used to pass server client IP check.
-    const clientIp = this.req.get('x-forwarded-for') || this.req.connection.remoteAddress;
-    headers = headers.append('X-Forwarded-For', clientIp);
 
     options.headers = headers;
     return this.authRequestService.getRequest('status', options).pipe(
diff --git a/src/app/core/forward-client-ip/forward-client-ip.interceptor.spec.ts b/src/app/core/forward-client-ip/forward-client-ip.interceptor.spec.ts
new file mode 100644
index 0000000000..49acd5b46d
--- /dev/null
+++ b/src/app/core/forward-client-ip/forward-client-ip.interceptor.spec.ts
@@ -0,0 +1,44 @@
+import { ForwardClientIpInterceptor } from './forward-client-ip.interceptor';
+import { DSpaceRESTv2Service } from '../dspace-rest-v2/dspace-rest-v2.service';
+import { TestBed } from '@angular/core/testing';
+import { HttpClientTestingModule, HttpTestingController } from '@angular/common/http/testing';
+import { HTTP_INTERCEPTORS, HttpRequest } from '@angular/common/http';
+import { REQUEST } from '@nguniversal/express-engine/tokens';
+
+describe('ForwardClientIpInterceptor', () => {
+  let service: DSpaceRESTv2Service;
+  let httpMock: HttpTestingController;
+
+  let requestUrl;
+  let clientIp;
+
+  beforeEach(() => {
+    requestUrl = 'test-url';
+    clientIp = '1.2.3.4';
+
+    TestBed.configureTestingModule({
+      imports: [HttpClientTestingModule],
+      providers: [
+        DSpaceRESTv2Service,
+        {
+          provide: HTTP_INTERCEPTORS,
+          useClass: ForwardClientIpInterceptor,
+          multi: true,
+        },
+        { provide: REQUEST, useValue: { get: () => undefined, connection: { remoteAddress: clientIp } }}
+      ],
+    });
+
+    service = TestBed.get(DSpaceRESTv2Service);
+    httpMock = TestBed.get(HttpTestingController);
+  });
+
+  it('should add an X-Forwarded-For header matching the client\'s IP', () => {
+    service.get(requestUrl).subscribe((response) => {
+      expect(response).toBeTruthy();
+    });
+
+    const httpRequest = httpMock.expectOne(requestUrl);
+    expect(httpRequest.request.headers.get('X-Forwarded-For')).toEqual(clientIp);
+  });
+});
diff --git a/src/app/core/forward-client-ip/forward-client-ip.interceptor.ts b/src/app/core/forward-client-ip/forward-client-ip.interceptor.ts
new file mode 100644
index 0000000000..2e1be09c96
--- /dev/null
+++ b/src/app/core/forward-client-ip/forward-client-ip.interceptor.ts
@@ -0,0 +1,23 @@
+import { HttpEvent, HttpHandler, HttpInterceptor, HttpRequest } from '@angular/common/http';
+import { Inject, Injectable } from '@angular/core';
+import { Observable } from 'rxjs/internal/Observable';
+import { REQUEST } from '@nguniversal/express-engine/tokens';
+
+@Injectable()
+/**
+ * Http Interceptor intercepting Http Requests, adding the client's IP to their X-Forwarded-For header
+ */
+export class ForwardClientIpInterceptor implements HttpInterceptor {
+  constructor(@Inject(REQUEST) protected req: any) {
+  }
+
+  /**
+   * Intercept http requests and add the client's IP to the X-Forwarded-For header
+   * @param httpRequest
+   * @param next
+   */
+  intercept(httpRequest: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
+    const clientIp = this.req.get('x-forwarded-for') || this.req.connection.remoteAddress;
+    return next.handle(httpRequest.clone({ setHeaders: { 'X-Forwarded-For': clientIp } }));
+  }
+}
diff --git a/src/modules/app/server-app.module.ts b/src/modules/app/server-app.module.ts
index 5abd8e3aa1..d46a013b3b 100644
--- a/src/modules/app/server-app.module.ts
+++ b/src/modules/app/server-app.module.ts
@@ -25,6 +25,8 @@ import { ServerSubmissionService } from '../../app/submission/server-submission.
 import { Angulartics2DSpace } from '../../app/statistics/angulartics/dspace-provider';
 import { Angulartics2RouterlessModule } from 'angulartics2/routerlessmodule';
 import { ModuleMapLoaderModule } from '@nguniversal/module-map-ngfactory-loader';
+import { HTTP_INTERCEPTORS } from '@angular/common/http';
+import { ForwardClientIpInterceptor } from '../../app/core/forward-client-ip/forward-client-ip.interceptor';
 
 export function createTranslateLoader() {
   return new TranslateJson5UniversalLoader('dist/server/assets/i18n/', '.json5');
@@ -73,7 +75,13 @@ export function createTranslateLoader() {
     {
       provide: SubmissionService,
       useClass: ServerSubmissionService
-    }
+    },
+    // register ForwardClientIpInterceptor as HttpInterceptor
+    {
+      provide: HTTP_INTERCEPTORS,
+      useClass: ForwardClientIpInterceptor,
+      multi: true
+    },
   ]
 })
 export class ServerAppModule {