[Csharp] AES Galois Counter Mode Compliant Cipher Text Wrapper Example (plaintext or generated key)

AESGCM_on_PlainText.cs

public class AESGCMBytes { //AES-GCM Core wrapper class starts here.
   //auto-properties for internal values store
   public byte[] tempKey {get; set;}
   public byte[] tempTag {get; set;}
   public byte[] cipherText {get; set;}
   public byte[] tempNonce{get; set;}


public string Encrypt(string plainTextinput) {

var key = new byte[16]; //MaxSize of plaintext input Key = 16 characters
RandomNumberGenerator.Fill(Encoding.UTF8.GetBytes("Test1NG12456O@K!"));
Console.WriteLine("Default key length ="+key.Length);
this.tempKey = key;

using var aes = new AesGcm(key);

var nonce = new byte[AesGcm.NonceByteSizes.MaxSize]; // MaxSize = 12
RandomNumberGenerator.Fill(nonce);

var plaintextBytes = Encoding.UTF8.GetBytes(plainTextinput);
var ciphertext = new byte[plaintextBytes.Length];
var tag = new byte[AesGcm.TagByteSizes.MaxSize]; // MaxSize = 16

aes.Encrypt(nonce, plaintextBytes, ciphertext, tag);

this.cipherText = ciphertext;
this.tempNonce = nonce;
this.tempTag = tag;

 return Encoding.UTF8.GetString(ciphertext);  //Convert.ToBase64String(ciphertext); ///Use Base64 for network based transmissions , web
}

public string Decrypt(byte[] ciphertext, byte[] nonce, byte[] tag, byte[] key)
{
    using (var aes = new AesGcm(key))
    {
        var plaintextBytes = new byte[ciphertext.Length];

        aes.Decrypt(nonce, ciphertext, tag, plaintextBytes);

        return Encoding.UTF8.GetString(plaintextBytes); //Use Base64 for network based transmissions , web
    }
 }
} // Core wrapper AES-GCM class end here..

void Main()
{
AESGCMBytes EncrDecrClass = new AESGCMBytes();
string strinput =  "t/f90j230-k23fm\"''3'2";
string cipherCopy = EncrDecrClass.Encrypt(strinput);

Console.WriteLine("Encrypted resulting GCM string = "+EncrDecrClass.Encrypt(strinput));
Console.WriteLine("Key = "+Encoding.UTF8.GetString(EncrDecrClass.tempKey));

 Console.WriteLine("Decrypted resulting GCM string = "+EncrDecrClass.Decrypt(EncrDecrClass.cipherText,
                                                                             EncrDecrClass.tempNonce,
                															 EncrDecrClass.tempTag,
															                 EncrDecrClass.tempKey));
}