Last Updated: 03 Dec 2020 | 10 min read
SSL is an abbreviated term that stands for Secure Socket Layer. SSL certification lays the foundation of trust by establishing secure connections. These connections ensure that all the data passing between the web server and browsers remain private and integral. Here you’ll learn everything associated with SSL pinning and how you can use it to make both Android and iOS apps secure.
Whenever an individual steps out of his/her front door, he/she embarks upon a journey in search of Wi-Fi networks that are open to all. It’s a relatively new phenomenon that started with the arrival and ensuing popularity of smartphones, tablets, and other mobile devices. They do it while waiting for their flight or sitting at a café and working on a college or office project. The ultimate objective of this person is to find one such Wi-Fi connection.
Unfortunately, hackers and other web-based perpetrators want you to use these public Wi-Fi systems. They wait for you to establish a connection on that particular device. The moment to make the connection, hackers make their move. They steal confidential data and sometimes they even manage to find a backdoor to your bank account.
HTTPS can be effective but only to a certain extent, but SSL protocols are much more effective. It can keep you safe as it is extensively secure and it doesn’t yield to the tricks of hackers. Then again, MITM or Man-In-The-Middle attack managed to find ways to penetrate SSL protocols too.
It’s where SSL pinning enters the game as one the best security practices for mobile apps. In terms of platforms, SSL pinning is the perfect security solution for iOS and Android applications, and it handles the issue perfectly.
About SSL Pinning:
So, what is SSL pinning? Whenever a mobile application connects with a server, it relies on the technique of SSL pinning to protect the data it transmits against hackers who tamper with the same or keep tabs on it. In default, the implementations of SSL in applications trust only certified servers. The operating system’s trust store swears by these certifications.
Due to SSL pinning, an application rejects everything apart from the ones that have these certifications. As soon as the app establishes a connection with the server, it will compare the certificate against the pinned one. If the two certificates match, the app includes the server into the list of trustworthy servers and establishes an SSL connection. It’s one of the main reasons why SSL pinning is an excellent security measure. That’s why developers employ it for both Android and iOS apps.
How it works? Here’s a simplified explanation of how SSL works.
SSL pinning for iOS Applications:
An iOS application development company uses the following techniques to implement SSL pinning in an iOS application.
(1) NSURLSession: When it comes to NSURLSession, the most significant method of incorporating SSL pinning is about “URLSession:didReceiveChallenge:completionHandler:delegate.” The developers have to ascertain the class to confirm URLSessionDelegate and paste a specific function to the appropriate class. This function will request qualifications from the delegate as a response to a request for authentication from the remotely-based server. After that, they will check the server’s certificates against the app’s certificate. If these two appear identical, the authentication system will allow it to pass, and the user can establish a secure connection.
(2) Alamofire Certificate Pinning: Every iOS application development company is aware of Alamofire as it’s an incredibly popular library for HTTP networking, particularly in the Swift language. It has inbuilt systems for SSL pinning in Swift. It’s also worth mentioning here that using it is quite simple.
Implementation of SSL pinning in Android
Implementing SSL pinning in Android applications is also possible for the providers of Android app development services. Here are the procedures they follow.
(1) TrustManager: TrustManager decides whether the app should accept the credentials submitted by the host or not. Developers acquire the interface from the javax.net.ssl package. First, they add the certificate file to the app. After that, they load KeyStore with the certificate file as InputStream and create a KeyStore. Finally, they create the TrustManager along with an SSLContext that uses the same tell the URLConnection to use a SocketFactory from the SSLContext.
(2) OkHttp and CertificatePinner: Certificate pinning using OkHttp is quite simple as it requires creating an instance of CertificatePinner using a dedicated building with the corresponding fingerprints. The providers of android app development services hard-code the fingerprints into the app or inject specific keys during the building process using the buildConfigField method. After that, they create an OkHttpClient instance with the CertificatePinner.
(3) Pinning with Retrofit: Since the developers build Retrofit on top of OkHttp, configuring the same for pinning is as simple as setting up an OkHttpClient. They simply it to the Retrofit.Builder().
(4) Network Security Configuration: This feature has been available since the arrival of Android 7.0, and it has been the preferred method of implementing pinning. It lets developers customize the network security settings in a safe, declarative configuration file without modifying the app code. With Network Security Configuration, developers declare the communication methods, including Certificate Pinning, using XML files. They need to bind a configuration file with the AndroidManifest.xml file to enable the configuration.
Understanding SSL pinning isn’t going to be easy. That’s why it’s better to get in touch with an app development agency. The specialists there should be able to explain the intricacies associated with the subject in a much more simplified manner. They will also help you contemplate the requirements of your project.