A security in mind file uploading web app

This a proof-of-concept project to show how to implement a secure file uploading web app using open source software & libraries:
Build/Deploy
Java 8 : http://openjdk.java.net/ | http://www.oracle.com/technetwork/java/index.html
Maven : https://maven.apache.org/
Web app
Spring Boot: http://projects.spring.io/spring-boot/
Twitter Bootstrap: http://v4-alpha.getbootstrap.com/
jQuery : http://jquery.com/
WebJars : http://www.webjars.org/
Antivirus
ClamAv : http://www.clamav.net/
clamav-client : https://github.com/cdarras/clamav-client
Content-Type Detection
Apache Tika : https://tika.apache.org/
Helper libraries
Google Guava : https://github.com/google/guava
Apache Commons-IO : https://commons.apache.org/proper/commons-io/
Testing
JUnit : http://junit.org/junit4/
Docker : https://www.docker.com/
ClamAV Docker Image : https://hub.docker.com/r/mkodockx/docker-clamav/
Documentation/Guidelines
OWASP - Unrestricted File Upload : https://www.owasp.org/index.php/Unrestricted_File_Upload
SANS - 8 Basic Rules to Implement Secure File Uploads : https://software-security.sans.org/blog/2009/12/28/8-basic-rules-to-implement-secure-file-uploads

Settings

1.- If you haven't already done, please clone this repository

git clone https://github.com/immontilla/file-uploading-web-app.git

2.- An available and updated ClamAV daemon is necessary to run this app. Every candidate file has to be scanned for virus to be accepted as an uploaded file. Fortunately, there is a docker image to help you out. You need to name it av and add it to the net host. Also, you need to add 127.0.0.1 av to /etc/hosts file.

docker pull mkodockx/docker-clamav
docker run -d --name av --net=host -p 3310:3310 mkodockx/docker-clamav

3.- Review src/main/resources/application.properties file before building

server.port=8090
spring.http.multipart.max-file-size=3MB
spring.http.multipart.max-request-size=3MB
temp.path=/tmp/unsafe
file.path=/tmp/safe
clam.av.server.host=av
clam.av.server.port=3310
clam.av.server.platform=UNIX
logging.level.org.springframework=INFO
logging.level.eu.immontilla.poc=DEBUG
where:

• server.port is the port number the embedded Tomcat server will be listening on.
• spring.http.multipart.max-file-size and spring.http.multipart.max-request-size set the maximum accepted file size.
• temp.path and file.path are the locations paths where uploaded files will be stored. Important If you are planning to run this web app in a Windows machine, the back-slash \ has to be escaped with double slashes //
• clam.av.server.host, clam.av.server.port and clam.av.server.platform are the host and port the ClamAV daemon is listening on whereas platform is its operating system type. Platform could it be: UNIX, WINDOWS or JVM_PLATFORM. Default values belong to a local Linux installation.
• logging.level.org.springframework and logging.level.eu.immontilla.poc are just logback levels.

4.- Run a mvn clean install to see if everything is OK including the tests.

mvn clean install

Run & Deploy

mvn spring-boot:run

Additional Testing

Use the /src/test/resources files to perform some curl back-end testing

curl -i -X POST -F file=@fake-csv-it-is-a-png-file.csv http://localhost:8090/upload

produces a 400 Bad Request response because fake-csv-it-is-a-png-file.csv is a PNG image file with a fake extension:

HTTP/1.1 100

HTTP/1.1 400
Content-Type: application/json;charset=UTF-8
Transfer-Encoding: chunked
Date: Thu, 27 Jul 2017 19:11:03 GMT
Connection: close

{"virusFree":true,"failed":true,"validFileExtension":true,"validContentType":false}

curl -i -X POST http://localhost:8090/upload

produces a 415 Unsupported media type because there is no file:

HTTP/1.1 415
Accept: multipart/form-data
Content-Length: 0
Date: Thu, 27 Jul 2017 19:13:29 GMT

curl -i -X POST -F file=@libre-office-csv-file.csv http://localhost:8090/upload

produces a 200 OK response code because libre-office-csv-file.csv is a valid virus-free file:

HTTP/1.1 100

HTTP/1.1 200
Content-Type: application/json;charset=UTF-8
Transfer-Encoding: chunked
Date: Thu, 27 Jul 2017 19:17:36 GMT

{"virusFree":true,"failed":false,"validFileExtension":true,"validContentType":true}

curl -i -X POST -F file=@FL_insurance_sample.csv http://localhost:8090/upload

produces a 413 Payload too large response code because FL_insurance_sample.csv size' is bigger than 3Mb:

HTTP/1.1 100

HTTP/1.1 413
Content-Type: application/json;charset=UTF-8
Transfer-Encoding: chunked
Date: Thu, 27 Jul 2017 19:18:52 GMT
Connection: close

{"validFileSize":false,"failed":true}

Open the web app in your browser

http://localhost:8090/