iOS

1. Choose the correct forum for your message. Posting a VB.NET question in the C++ forum will end in tears.
   
   
2. Be specific! Don't ask "can someone send me the code to create an application that does 'X'. Pinpoint exactly what it is you need help with.
   
   
3. Keep the subject line brief, but descriptive. eg "File Serialization problem"
   
   
4. Keep the question as brief as possible. If you have to include code, include the smallest snippet of code you can.
   
   
5. Be careful when including code that you haven't made a typo. Typing mistakes can become the focal point instead of the actual question you asked.
   
   
6. Do not remove or empty a message if others have replied. Keep the thread intact and available for others to search and read. If your problem was answered then edit your message and add "[Solved]" to the subject line of the original post, and cast an approval vote to the one or several answers that really helped you.
   
   
7. If you are posting source code with your question, place it inside <pre></pre> tags. We advise you also check the "Encode "<" (and other HTML) characters when pasting" checkbox before pasting anything inside the PRE block, and make sure "Use HTML in this post" check box is checked.
   
   
8. Be courteous and DON'T SHOUT. Everyone here helps because they enjoy helping others, not because it's their job.
   
   
9. Please do not post links to your question into an unrelated forum such as the lounge. It will be deleted. Likewise, do not post the same question in more than one forum.
   
   
10. Do not be abusive, offensive, inappropriate or harass anyone on the boards. Doing so will get you kicked off and banned. Play nice.
    
    
11. If you have a school or university assignment, assume that your teacher or lecturer is also reading these forums.
    
    
12. No advertising or soliciting.
    
    
13. We reserve the right to move your posts to a more appropriate forum or to delete anything deemed inappropriate or illegal.

I want to use AES-GCM encryption of a plaintext with 'key' only. The 'key' will be received from backend (.net), in webservice response. The same key will be used later in backend as well to decrypt the encrypted value.

I have used extension as follwoing

To generate string to Symetric key

extension SymmetricKey {
init(string keyString: String, size: SymmetricKeySize = .bits256) throws {
guard var keyData = keyString.data(using: .utf8) else {
  print("Could not create base64 encoded Data from String.")
  throw CryptoKitError.incorrectParameterSize
}

let keySizeBytes = size.bitCount / 8
keyData = keyData.subdata(in: 0..<keySizeBytes)

guard keyData.count >= keySizeBytes else { throw CryptoKitError.incorrectKeySize }
self.init(data: keyData)
} }

Encryption & Decryption code snipet:

func aesgcmEncryptDecrypt() {
        let str : String = "FwhXRYJ$xLf?^Kh6_&YfTJ%RuG+EqcTY"    
        var key : SymmetricKey = SymmetricKey(size: .bits256)
        do{
            key = try SymmetricKey(string: str)
        }catch{        
        }
        let plain = "HOW ARE YOU?"
        let nonce = try! AES.GCM.Nonce(data: Data(base64Encoded: "fv1nixTVoYpSvpdA")!)
        let tag = Data(base64Encoded: "e1eIgoB4+lA/j3KDHhY4BQ==")!
        // Encrypt
        let sealedBox = try! AES.GCM.seal(plain.data(using: .utf8)!, using: key, 
        nonce: nonce, authenticating: tag)
        // Decrypt
        let sealedBoxRestored = try! AES.GCM.SealedBox(combined: sealedBox.combined!)
        let decrypted = try! AES.GCM.open(sealedBoxRestored, using: key, 
        authenticating: tag)
        Swift.print("Combined:\n\(sealedBox.combined!.base64EncodedString())\n")
        Swift.print("Cipher:\n\(sealedBox.ciphertext.base64EncodedString())\n")
        Swift.print("Nonce:\n\(nonce.withUnsafeBytes { 
            Data(Array($0)).base64EncodedString() })\n")
        Swift.print("Tag:\n\(tag.base64EncodedString())\n")
        Swift.print("Decrypted:\n\(String(data: decrypted, encoding: .utf8)!)\n")
    }
Our(generated from this code & .Net code) encrypted text is not matching. Anyone can help me, what I am doing wrong, detailing will be more helpful. Basically I was looking for saloution in Objective-C but I did not get any supported library for Objective-C.

if (device.platform.toLowerCase() == "android") {
                window.resolveLocalFileSystemURL(cordova.file.externalRootDirectory, onFileSystemSuccess, onError);
            } else {
                window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, onFileSystemSuccess, onError);
            }



function onFileSystemSuccess(fileSystem) {
            var entry = "";
            if (device.platform.toLowerCase() == "android") {
                entry = fileSystem;
            } else {
                entry = fileSystem.root;
            }
            entry.getDirectory("FT2019", {
                create: true,
                exclusive: false
            }, onGetDirectorySuccess, onGetDirectoryFail);
        };



        function onError(e) {
            alert("Fail to get folder");
        };




        function onGetDirectorySuccess(dir) {
            dummyFilePath = dir.toURL();
        };


        function onGetDirectoryFail(dir) {
            alert("Fail to get folder");
        };

struct DatingProfile{
      var Name: String
      var Age: Int
      var City: String
      var FavoriteMovie: String? 
      var Hobbies: String?
     
    }
    
    let myDatingProfile = DatingProfile(Name: "William", Age: 30, City: "North Hollywood", FavoriteMovie: nil , Hobbies: "Basketball")
    
    if let myFavoriteMovie = FavoriteMovie = nil{
      print("\(Name) does not have a favorite movie")
       
    }else {
      
        print(myDatingProfile.FavoriteMovie)
      }
      
    }