Http Intercepter with CryptoJS

request-interceptor.ts

import { HttpEvent, HttpHandler, HttpInterceptor, HttpRequest, HttpResponse } from '@angular/common/http';
import { Observable } from 'rxjs/Observable';
import { map } from 'rxjs/operators';
import * as CryptoJS from 'crypto-js';

export class RequestInterceptor implements HttpInterceptor {  
  intercept(req: HttpRequest<any>, next: HttpHandler): Observable<HttpEvent<any>> {
    // Encrypt the body.
    
    const updatedReq = req.clone({
      body: this.updateBody(req),
    });
    
    // And then send out the request.
    return next.handle(updatedReq).pipe(map((event: HttpEvent<any>) => {
      // If the map event is not HttpResponse, ignore it.
      if (!(event instanceof HttpResponse)) {
        return event;
      }
      
      // If Http status code is not 200, ignore it.
      if (event.status !== 200) {
        return event;
      }
      
      // Decrypt the body of Http response.
      return this.updateResponse(event);
    }));
  }
  
  private updateBody(req: HttpRequest<any>) {
    const dateTime = new Date();
    const time = moment(dateTime).format('YYYY-MM-DD HH:mm:ss.SSS');
    const serviceName = req.headers.get('serviceName');

    let reqBy = '0.0.0.0';
    
    const encryptedRequestBody = JSON.stringify(CryptoJS.AES.encrypt(request.requestBody, 'abc').toString())

    const requestHeader = {
      'reqId': dateTime.getTime(),
      'reqChannel': 'WEB',
      'reqDtm': time,
      'reqBy': reqBy,
      'serviceName': serviceName,
      'instance': '00000'
    };

    return {
      requestHeader: requestHeader,
      requestBody: encryptedRequestBody,
    };
  }
  
  private updateResponse(res: HttpResponse) {
    const decryptedResponse = JSON.parse(CryptoJS.AES.decrypt(res.body.dataResp, 'abc').toString());
    
    return new HttpResponse({
      body: {..res, dataResp: decryptedResponse},
      headers: event.headers,
      status: event.status,
      statusText: event.statusText,
      url: event.url
    });
  }
}