How to Block Non-SSL Connections in iOS Apps

Last updated November 23, 2023 by Appdome

Learn to Block Non-SSL Connections in iOS apps, in mobile CI/CD with a Data-Driven DevSecOps™ build system.

What is a Non-SSL Connection?

Non-SSL connections are connections that do not use SSL/TLS encryption and usually use the HTTP protocol. Packets in connections that are being sent through this protocol contain clear text, which makes these packets insecure and prone to vulnerabilities. Examples of such vulnerabilities are man-in-the-middle attacks, which allow eavesdropping and tampering with the content. While nowadays most sites already switched to HTTPS protocol that uses SSL/TLS, some are still using regular HTTP to take advantage of the initial connection speed. When connection is established via HTTP, it does not perform an SSL handshake to begin the connection. The use of HTTP is mainly common in connections where the performance and the user experience is the most important, while the outgoing contents of the connection packets do not contain sensitive data like ads.

Why Block Non-SSL Connections?

Non-SSL connections are unencrypted and are easy to read. This is unsafe, as the contained data can be tampered and listened to during a man-in-the-middle attack. The data in Non-SSL connections may contain sensitive data, such as tokens and cookies related to user logins, device info, user input, and passwords. Blocking all non-SSL connections by enabling the iOS MiTM Prevention feature is important even if the app only accesses SSL/TLS based URLs. The reason is that even then these URLs could contain content that is being loaded through plain HTTP requests, and this content can be tampered, thereby making the app endanger your user; For example: request sensitive user data from a database. Additionally, URLs without the secured TLS/SSL extension are not authenticated by a certificate. This allows potential attackers to create URLs that only seem valid but return malicious answers to requests submitted from the app.

Prerequisites for Using iOS MiTM Prevention:

To use Appdome’s mobile app security build system to Block Non-SSL Connections , you’ll need:

Block Non-SSL Connections on iOS apps using Appdome

On Appdome, follow these 3 simple steps to create self-defending iOS Apps that Block Non-SSL Connections without an SDK or gateway:

  1. Upload the Mobile App to Appdome.

    1. Upload an app to Appdome’s Mobile App Security Build System

    2. Upload Method: Appdome Console or DEV-API
    3. iOS Formats: .ipa
    4. iOS MiTM Prevention Compatible With: Obj-C, C+, Java, Swift, Flutter, React Native, Unity, Xamarin, Cordova and more
  2. Build the feature: iOS MiTM Prevention.

    1. Building iOS MiTM Prevention by using Appdome’s DEV-API:

      1. Create and name the Fusion Set (security template) that will contain the iOS MiTM Prevention feature as shown below:
      2. fusion set that contains iOS MiTM Prevention

        Figure 1: Fusion Set that will contain the iOS MiTM Prevention feature
        Note: Naming the Fusion Set to correspond to the protection(s) selected is for illustration purposes only (not required).

      3. Follow the steps in Sections 2.2.1-2.2.2 of this article, Building the iOS MiTM Prevention feature via Appdome Console, to add the iOS MiTM Prevention feature to this Fusion Set.

      4. Open the Fusion Set Detail Summary by clicking the “...” symbol on the far-right corner of the Fusion Set, as shown in Figure 1 above, and get the Fusion Set ID from the Fusion Set Detail Summary (as shown below): fusion Set Detail Summary image

        Figure 2: Fusion Set Detail Summary
        Note: Annotating the Fusion Set to identify the protection(s) selected is optional only (not mandatory).

      5. Follow the instructions below to use the Fusion Set ID inside any standard mobile DevOps or CI/CD toolkit like Bitrise, App Center, Jenkins, Travis, Team City, Cirlce CI or other system:
        1. Build an API for the app – for instructions, see the tasks under Appdome API Reference Guide
        2. Look for sample APIs in Appdome’s GitHub Repository
    2. Building the iOS MiTM Prevention feature via Appdome Console

      To build the iOS MiTM Prevention protection by using Appdome Console, follow the instructions below.

      1. Where: Inside the Appdome Console, go to Build > Security Tab > Secure Communication section.
      2. When you select the iOS MiTM Prevention you'll notice that your Fusion Set you created in step 2.1.1 now bears the icon of the protection category that contains iOS MiTM Prevention

        Fusion Set applied iOS MiTM Prevention

        Figure 4: Fusion Set that displays the newly added iOS MiTM Prevention protection

      3. Select the Threat-Event™ in-app mobile Threat Defense and Intelligence policy for iOS MiTM Prevention:
        1. Threat-Events™ OFF > In-App Defense

          If the Threat-Events™ setting is cleared (not selected). Appdome will detect and defend the user and app by enforcing Block Non-SSL Connections.

        2. Threat-Events™ ON > In-App Detection

          When this setting is used, Appdome detects a non-secure connection (connection over HTTP) and passes Appdome’s Threat-Event™ attack intelligence to the app’s business logic for processing, enforcement, and user notification. For more information on consuming and using Appdome Threat-Events™ in the app, see section Using Threat-Events™ for iOS MiTM Prevention Intelligence and Control in Mobile Apps.

        3. Threat-Events™ ON > In-App Defense

          When this setting is used, Appdome detects and defends against Non-SSL Connections (same as Appdome Enforce) and passes Appdome’s Threat-Event™ attack intelligence the app’s business logic for processing. For more information on consuming and using Appdome Threat-Events™ in the app, see section Using Threat-Events™ for iOS MiTM Prevention Intelligence and Control in Mobile Apps.

      4. Click Build My App at the bottom of the Build Workflow (shown in Figure 3).
    Congratulations!  The iOS MiTM Prevention protection is now added to the mobile app

Using Threat-Events™ for Non-SSL Connections Intelligence and Control in iOS Apps

Appdome Threat-Events™ provides consumable in-app mobile app attack intelligence and defense control when Non-SSL Connections is detected. To consume and use Threat-Events™ for Non-SSL Connections in iOS Apps, use AddObserverForName in Notification Center, and the code samples for Threat-Events™ for Non-SSL Connections shown below.

The specifications and options for Threat-Events™ for Non-SSL Connections are:

Threat-Event™ Elements Block Non-SSL Connections Method Detail
Appdome Feature Name iOS MiTM Prevention
Threat-Event Mode
OFF, IN-APP DEFENSE Appdome detects, defends and notifies user (standard OS dialog) using customizable messaging.
ON, IN-APP DETECTION Appdome detects the attack or threat and passes the event in a standard format to the app for processing (app chooses how and when to enforce).
ON, IN-APP DEFENSE Uses Appdome Enforce mode for any attack or threat and passes the event in a standard format to the app for processing (gather intel on attacks and threats without losing any protection).
Certified Secure™ Threat Event Check
Visible in ThreatScope™
Developer Parameters for Blocking Non-SSL Connections Threat-Event™
Threat-Event NAME SslNonSslConnection
Threat-Event DATA reasonData
Threat-Event CODE reasonCode
Threat-Event REF 6500-1
Threat-Event SCORE
currentThreatEventScore Current Threat-Event score
threatEventsScore Total Threat-events score
Threat-Event Context Keys
message Message displayed for the user on event
externalID The external ID of the event which can be listened via Threat Events
osVersion OS version of the current device
deviceModel Current device model
deviceManufacturer The manufacturer of the current device
fusedAppToken The task ID of the Appdome fusion of the currently running app
kernelInfo Info about the kernel: system name, node name, release, version and machine.
carrierPlmn PLMN of the device
deviceID Current device ID
reasonCode Reason code of the occured event
buildDate Appdome fusion date of the current application
devicePlatform OS name of the current device
carrierName Carrier name of the current device
updatedOSVersion Is the OS version up to date
timeZone Time zone
deviceFaceDown Is the device face down
locationLong Location longitude conditioned by location permission
locationLat Location latitude conditioned by location permission
locationState Location state conditioned by location permission
wifiSsid Wifi SSID
wifiSsidPermissionStatus Wifi SSID permission status
host The host identified using non-TLS connections
DeveventDetailedErrorMessage Error message
extendedMessageText Extended message

With Threat-Events™ enabled (turned ON), iOS developers can get detailed attack intelligence and granular defense control in iOS applications and create amazing user experiences for all mobile end users when Non-SSL Connections is detected.

The following is a code sample for native iOS apps, which uses all values in the specification above for iOS MiTM Prevention:


Using Appdome, there are no development or coding prerequisites to build secured iOS Apps by using iOS MiTM Prevention. There is no SDK and no library to code or implement in the app and no gateway to deploy in your network. All protections are built into each app and the resulting app is self-defending and self-protecting.

Releasing and Publishing Mobile Apps with iOS MiTM Prevention

After successfully securing your app by using Appdome, there are several available options to complete your project, depending on your app lifecycle or workflow. These include:

Related Articles:

If you have any questions, please send them our way at support.appdome.com or via the chat window on the Appdome platform.

Thank you!

Thanks for visiting Appdome! Our mission is to secure every app on the planet by making mobile app security easy. We hope we’re living up to the mission with your project.

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