SecureChannel

internal final class SecureChannel

Represents a secure communication channel with cryptographic parameters.

This class defines a secure communication channel with encryption keys (KSenc, KSmac) and a Send Sequence Counter (SSC) for secure messaging during a session. The SSC is an unsigned integer and its bit size matches the block size of the block cipher used for secure messaging, which is 64 bits for 3DES and 128 bits for AES.

See also

NFCSecureSession, SecurityConfiguration, SecureMessaging and SessionKeyGenerator

  • The encryption key for data confidentiality.

    Declaration

    Swift

    private(set) var KSenc: [UInt8] { get }

  • The key for message authentication.

    Declaration

    Swift

    private(set) var KSmac: [UInt8] { get }
  • ssc

    The Send Sequence Counter (SSC) for secure messaging.

    The SSC is an unsigned integer and its bit size matches the block size of the block cipher used for secure messaging. It should be incremented before generating a command or response APDU. For the first command, the SSC is incremented from the starting value x to x+1, and for the first response, it becomes x+2.

    Declaration

    Swift

    private(set) var ssc: [UInt8] { get }

  • Initializes a secure channel with the provided encryption keys and SSC.

    Declaration

    Swift

    internal init(KSenc: [UInt8], KSmac: [UInt8], ssc: [UInt8])

    Parameters

    KSenc

    The encryption key for data confidentiality.
    KSmac

    The key for message authentication.
    ssc

    The Send Sequence Counter (SSC) for secure messaging.

  • Increment the Send Sequence Counter (SSC).

    The SSC should be incremented before generating a command or response APDU. For the first command, the value of SSC is increased from the starting value x to x+1. For the first response, it becomes x+2.

    Declaration

    Swift

    internal func incrementSSC()