# Other Constants

The following constants are available globally.

- `TrustKitVersion`

  The version of TrustKit, such as 1.4.0.

  #### Declaration

  Objective-C

      extern NSString *const TrustKitVersion

  Swift

      let TrustKitVersion: String

### Domain-Specific Configuration Keys - Required

- `kTSKPublicKeyAlgorithms`

  Deprecated

  Starting with TrustKit 1.6.0, key algorithms no longer need to be specified; remove TSKPublicKeyAlgorithms from your configuration.

  DEPRECATED since 1.6.0: this configuration key is no longer needed.

  An array of `TSKSupportedAlgorithm` constants to specify the public key algorithms for the keys to be pinned.

  TrustKit requires this information in order to compute SSL pins when validating a server’s certificate chain, because the `Security` framework does not provide APIs to extract the key’s algorithm from an SSL certificate. To minimize the performance impact of Trustkit, only one algorithm should be enabled.

  #### Declaration

  Objective-C

      extern const TSKDomainConfigurationKey kTSKPublicKeyAlgorithms

  Swift

      let kTSKPublicKeyAlgorithms: String

### DEPRECATED - Supported Public Key Algorithm Keys

- `kTSKAlgorithmRsa2048`

  Deprecated

  Starting with TrustKit 1.6.0, key algorithms no longer need to be specified; remove TSKPublicKeyAlgorithms from your configuration.

  RSA 2048.

  #### Declaration

  Objective-C

      extern const TSKSupportedAlgorithm kTSKAlgorithmRsa2048

  Swift

      let kTSKAlgorithmRsa2048: String

- `kTSKAlgorithmRsa4096`

  Deprecated

  Starting with TrustKit 1.6.0, key algorithms no longer need to be specified; remove TSKPublicKeyAlgorithms from your configuration.

  RSA 4096.

  #### Declaration

  Objective-C

      extern const TSKSupportedAlgorithm kTSKAlgorithmRsa4096

  Swift

      let kTSKAlgorithmRsa4096: String

- `kTSKAlgorithmEcDsaSecp256r1`

  Deprecated

  Starting with TrustKit 1.6.0, key algorithms no longer need to be specified; remove TSKPublicKeyAlgorithms from your configuration.

  ECDSA with secp256r1 curve.

  #### Declaration

  Objective-C

      extern const TSKSupportedAlgorithm kTSKAlgorithmEcDsaSecp256r1

  Swift

      let kTSKAlgorithmEcDsaSecp256r1: String

- `kTSKAlgorithmEcDsaSecp384r1`

  Deprecated

  Starting with TrustKit 1.6.0, key algorithms no longer need to be specified; remove TSKPublicKeyAlgorithms from your configuration.

  ECDSA with secp384r1 curve.

  #### Declaration

  Objective-C

      extern const TSKSupportedAlgorithm kTSKAlgorithmEcDsaSecp384r1

  Swift

      let kTSKAlgorithmEcDsaSecp384r1: String