fix small error

Sources/Keycard/APDUResponse.swift

@@ -16,7 +16,7 @@ public struct APDUResponse {
         precondition(rawData.count >= 2, "rawData must contain at least the Status Word (2 bytes)")
         self.sw1 = rawData[rawData.count - 2]
         self.sw2 = rawData[rawData.count - 1]
-        self.data = rawData.count > 2 ? Array(rawData[0..<(rawData.count - 3)]) : []
+        self.data = rawData.count > 2 ? Array(rawData.prefix(upTo: rawData.count - 2)) : []
     }
     
     public init(sw1: UInt8, sw2: UInt8, data: [UInt8]) {

Sources/Keycard/CardError.swift

@@ -1,3 +1,5 @@
+import Foundation
+
 public enum CardError: Error {
     case wrongPIN(retryCounter: Int)
     case unrecoverableSignature
@@ -8,3 +10,22 @@ public enum CardError: Error {
     case invalidMac
     case communicationError
 }
+
+extension CardError: Equatable {
+
+    public static func ==(lhs: CardError, rhs: CardError) -> Bool {
+        switch (lhs, rhs) {
+        case (.wrongPIN(let lattempt), .wrongPIN(let rattempt)): return lattempt == rattempt
+        case (.unrecoverableSignature, .unrecoverableSignature),
+             (.invalidState, .invalidState),
+             (.notPaired, .notPaired),
+             (.pinBlocked, .pinBlocked),
+             (.invalidAuthData, .invalidAuthData),
+             (.invalidMac, .invalidMac),
+             (.communicationError, .communicationError):
+            return true
+        default: return false
+        }
+    }
+
+}

Sources/Keycard/KeycardController.swift

@@ -107,8 +107,7 @@ extension KeycardController: NFCTagReaderSessionDelegate {
         }
         session.connect(to: first) { [weak self] error in
             guard let `self` = self else { return }
-            if let error = error {
-                // TODO: should I call onFailure() explicitly here?
+            if error != nil {
                 self.stop(errorMessage: self.alertMessages.tagConnectionError)
                 return
             }

Sources/Keycard/SecureChannel.swift

@@ -123,6 +123,7 @@ class SecureChannel {
         let finalData: [UInt8];
         
         if open {
+            Logger.shared.log("SecureChannel: ==> protected: (cla=\(String(cla, radix:16)) ins=\(String(ins, radix:16)) p1=\(String(p1, radix:16)) p2=\(String(p2, radix:16)) data:\(Data(data).toHexString()))")
             let encrypted = encryptAPDU(data);
             let meta: [UInt8] = [cla, ins, p1, p2, UInt8(encrypted.count + SecureChannel.blockLength), 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
             updateIV(meta: meta, data: encrypted);
@@ -153,8 +154,9 @@ class SecureChannel {
             if self.iv != mac {
                 throw CardError.invalidMac
             }
-            
-            return APDUResponse(rawData: plainData)
+            let result = APDUResponse(rawData: plainData)
+            Logger.shared.log("SecureChannel: <== decrypted: (data=\(Data(result.data).toHexString()) sw1=\(String(result.sw1, radix:16)) sw2=\(String(result.sw2, radix:16)))")
+            return result
         } else {
             return rsp;
         }