init commit

output/Libraries/BouncyCastle.Crypto/Org/BouncyCastle/Crypto/Tls/TlsNullCipher.cs

@@ -0,0 +1,99 @@
+using System;
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Crypto.Tls;
+
+public class TlsNullCipher : TlsCipher
+{
+	protected readonly TlsContext context;
+
+	protected readonly TlsMac writeMac;
+
+	protected readonly TlsMac readMac;
+
+	public TlsNullCipher(TlsContext context)
+	{
+		this.context = context;
+		writeMac = null;
+		readMac = null;
+	}
+
+	public TlsNullCipher(TlsContext context, IDigest clientWriteDigest, IDigest serverWriteDigest)
+	{
+		if (clientWriteDigest == null != (serverWriteDigest == null))
+		{
+			throw new TlsFatalAlert(80);
+		}
+		this.context = context;
+		TlsMac tlsMac = null;
+		TlsMac tlsMac2 = null;
+		if (clientWriteDigest != null)
+		{
+			int num = clientWriteDigest.GetDigestSize() + serverWriteDigest.GetDigestSize();
+			byte[] key = TlsUtilities.CalculateKeyBlock(context, num);
+			int num2 = 0;
+			tlsMac = new TlsMac(context, clientWriteDigest, key, num2, clientWriteDigest.GetDigestSize());
+			num2 += clientWriteDigest.GetDigestSize();
+			tlsMac2 = new TlsMac(context, serverWriteDigest, key, num2, serverWriteDigest.GetDigestSize());
+			num2 += serverWriteDigest.GetDigestSize();
+			if (num2 != num)
+			{
+				throw new TlsFatalAlert(80);
+			}
+		}
+		if (context.IsServer)
+		{
+			writeMac = tlsMac2;
+			readMac = tlsMac;
+		}
+		else
+		{
+			writeMac = tlsMac;
+			readMac = tlsMac2;
+		}
+	}
+
+	public virtual int GetPlaintextLimit(int ciphertextLimit)
+	{
+		int num = ciphertextLimit;
+		if (writeMac != null)
+		{
+			num -= writeMac.Size;
+		}
+		return num;
+	}
+
+	public virtual byte[] EncodePlaintext(long seqNo, byte type, byte[] plaintext, int offset, int len)
+	{
+		if (writeMac == null)
+		{
+			return Arrays.CopyOfRange(plaintext, offset, offset + len);
+		}
+		byte[] array = writeMac.CalculateMac(seqNo, type, plaintext, offset, len);
+		byte[] array2 = new byte[len + array.Length];
+		Array.Copy(plaintext, offset, array2, 0, len);
+		Array.Copy(array, 0, array2, len, array.Length);
+		return array2;
+	}
+
+	public virtual byte[] DecodeCiphertext(long seqNo, byte type, byte[] ciphertext, int offset, int len)
+	{
+		if (readMac == null)
+		{
+			return Arrays.CopyOfRange(ciphertext, offset, offset + len);
+		}
+		int size = readMac.Size;
+		if (len < size)
+		{
+			throw new TlsFatalAlert(50);
+		}
+		int num = len - size;
+		byte[] a = Arrays.CopyOfRange(ciphertext, offset + num, offset + len);
+		byte[] b = readMac.CalculateMac(seqNo, type, ciphertext, offset, num);
+		if (!Arrays.ConstantTimeAreEqual(a, b))
+		{
+			throw new TlsFatalAlert(20);
+		}
+		return Arrays.CopyOfRange(ciphertext, offset, offset + num);
+	}
+}