TrustKit

@interface TrustKit : NSObject

TrustKit is the main class for configuring an SSL pinning policy within an App.

For most Apps, TrustKit should be used as a singleton, where a global SSL pinning policy is configured for the App. In singleton mode, the policy can be set either:

In singleton mode, TrustKit can only be initialized once so only one of the two techniques should be used.

For more complex Apps where multiple SSL pinning policies need to be used independently (for example within different frameworks), TrustKit can be used in multi-instance mode by leveraging the -initWithConfiguration: method described at the end of this page.

A TrustKit pinning policy is a dictionary which contains some global, App-wide settings (of type TSKGlobalConfigurationKey) as well as domain-specific configuration keys (of type TSKDomainConfigurationKey) to be defined under the kTSKPinnedDomains entry. The following table shows the keys and the types of the corresponding values, and uses indentation to indicate structure:

| Key                                          | Type       |
|----------------------------------------------|------------|
| TSKSwizzleNetworkDelegates                   | Boolean    |
| TSKIgnorePinningForUserDefinedTrustAnchors   | Boolean    |
| TSKPinnedDomains                             | Dictionary |
| __ <domain-name-to-pin-as-string>            | Dictionary |
| ____ TSKPublicKeyHashes                      | Array      |
| ____ TSKIncludeSubdomains                    | Boolean    |
| ____ TSKExcludeSubdomainFromParentPolicy     | Boolean    |
| ____ TSKEnforcePinning                       | Boolean    |
| ____ TSKReportUris                           | Array      |
| ____ TSKDisableDefaultReportUri              | Boolean    |

When setting the pinning policy programmatically, it has to be supplied to the initSharedInstanceWithConfiguration: method as a dictionary in order to initialize TrustKit. For example:

   NSDictionary *trustKitConfig =
 @{
   kTSKPinnedDomains : @{
           @"www.datatheorem.com" : @{
                   kTSKExpirationDate: @"2017-12-01",
                   kTSKPublicKeyHashes : @[
                           @"HXXQgxueCIU5TTLHob/bPbwcKOKw6DkfsTWYHbxbqTY=",
                           @"0SDf3cRToyZJaMsoS17oF72VMavLxj/N7WBNasNuiR8="
                           ],
                   kTSKEnforcePinning : @NO,
                   kTSKReportUris : @[@"http://report.datatheorem.com/log_report"],
                   },
           @"yahoo.com" : @{
                   kTSKPublicKeyHashes : @[
                           @"TQEtdMbmwFgYUifM4LDF+xgEtd0z69mPGmkp014d6ZY=",
                           @"rFjc3wG7lTZe43zeYTvPq8k4xdDEutCmIhI5dn4oCeE=",
                           ],
                   kTSKIncludeSubdomains : @YES
                   }
           }};

   [TrustKit initSharedInstanceWithConfiguration:trustKitConfig];
   trustKit = [TrustKit sharedInstance];

Similarly, the TrustKit singleton can be initialized in Swift:

       let trustKitConfig = [
           kTSKSwizzleNetworkDelegates: false,
           kTSKPinnedDomains: [
               "yahoo.com": [
                   kTSKExpirationDate: "2017-12-01",
                   kTSKPublicKeyHashes: [
                       "JbQbUG5JMJUoI6brnx0x3vZF6jilxsapbXGVfjhN8Fg=",
                       "WoiWRyIOVNa9ihaBciRSC7XHjliYS9VwUGOIud4PB18="
                   ],]]] as [String : Any]

       TrustKit.initSharedInstance(withConfiguration:trustKitConfig)

After initialization, the TrustKit instance’s pinningValidator should be used to implement pinning validation within the App’s network authentication handlers.

  • Retrieve the validator instance conforming to the pinning policy of this TrustKit instance.

    The validator should be used to implement pinning validation within the App’s network authentication handlers.

    Declaration

    Objective-C

    @property (assign, readwrite, nonatomic, nonnull)
        TSKPinningValidator *pinningValidator;

    Swift

    var pinningValidator: TSKPinningValidator { get set }
  • Declaration

    Objective-C

    - (nonnull instancetype)initWithConfiguration:
        (nonnull NSDictionary<TSKGlobalConfigurationKey, id> *)trustKitConfig;

    Swift

    init(configuration trustKitConfig: [String : Any])

    Parameters

    trustKitConfig

    A dictionary containing various keys for configuring the SSL pinning policy.

  • Initialize a local TrustKit instance with the supplied SSL pinning policy configuration.

    This method is useful in scenarios where the TrustKit singleton cannot be used, for example within larger Apps that have split some of their functionality into multiple framework/SDK. Each framework can initialize its own instance of TrustKit and use it for pinning validation independently of the App’s other components.

    Declaration

    Objective-C

    - (nonnull instancetype)
            initWithConfiguration:
                (nonnull NSDictionary<TSKGlobalConfigurationKey, id> *)
                    trustKitConfig
        sharedContainerIdentifier:(nullable NSString *)sharedContainerIdentifier;

    Swift

    init(configuration trustKitConfig: [String : Any], sharedContainerIdentifier: String?)

    Parameters

    trustKitConfig

    A dictionary containing various keys for configuring the SSL pinning policy.

    sharedContainerIdentifier

    The container identifier for an app extension. This must be set in order for reports to be sent from an app extension. See https://developer.apple.com/documentation/foundation/nsurlsessionconfiguration/1409450-sharedcontaineridentifier

  • Set the global logger.

    This method sets the global logger, used when any TrustKit instance needs to display a message to the developer.

    If a global logger is not set, the default logger will be used, which will only print TrustKit log messages (using NSLog()) when the App is built in Debug mode. If the App was built for Release, the default logger will not print any messages at all.

    Declaration

    Objective-C

    + (void)setLoggerBlock:(nonnull void (^)(NSString *_Nonnull))block;

    Swift

    class func setLoggerBlock(_ block: @escaping (String) -> Void)