System.Security.Cryptography.RSAPKCS1SignatureFormatter.CreateSignature C# (CSharp) Method

		public override byte[] CreateSignature (byte[] rgbHash) 
		{
			if (rsa == null) {
				throw new CryptographicUnexpectedOperationException (
					Locale.GetText ("No key pair available."));
			}
			if (hash == null) {
				throw new CryptographicUnexpectedOperationException (
					Locale.GetText ("Missing hash algorithm."));
			}
			if (rgbHash == null)
				throw new ArgumentNullException ("rgbHash");

			return PKCS1.Sign_v15 (rsa, hash, rgbHash);
		}
	

 public static void Signature(Stream input, Stream output, string privateKey)
 {
     using (var sha = new SHA256CryptoServiceProvider())
     using (var rsa = new RSACryptoServiceProvider())
     {
         // Compute hash
         var buffer = ReadAllBytes(input);
         var hash = sha.ComputeHash(buffer);
         // RSA Initialize
         rsa.FromXmlString(privateKey);
         // format
         var formatter = new RSAPKCS1SignatureFormatter(rsa);
         formatter.SetHashAlgorithm("SHA256");
         var signature = formatter.CreateSignature(hash);
         // Krile Signature Package
         var magic = MagicStr + ":" + signature.Length + ":";
         var magicbytes = Encoding.UTF8.GetBytes(magic);
         if (magicbytes.Length > 64)
             throw new Exception("Magic bits too long.");
         output.Write(magicbytes, 0, magicbytes.Length);
         var padding = new byte[64 - magicbytes.Length];
         output.Write(padding, 0, padding.Length);
         output.Write(signature, 0, signature.Length);
         output.Write(buffer, 0, buffer.Length);
     }
 }