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output/Libraries/BouncyCastle.Crypto/Org/BouncyCastle/Crypto/Signers/GenericSigner.cs

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+using System;
+using Org.BouncyCastle.Crypto.Parameters;
+using Org.BouncyCastle.Security;
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Crypto.Signers;
+
+public class GenericSigner : ISigner
+{
+	private readonly IAsymmetricBlockCipher engine;
+
+	private readonly IDigest digest;
+
+	private bool forSigning;
+
+	public virtual string AlgorithmName => "Generic(" + engine.AlgorithmName + "/" + digest.AlgorithmName + ")";
+
+	public GenericSigner(IAsymmetricBlockCipher engine, IDigest digest)
+	{
+		this.engine = engine;
+		this.digest = digest;
+	}
+
+	public virtual void Init(bool forSigning, ICipherParameters parameters)
+	{
+		this.forSigning = forSigning;
+		AsymmetricKeyParameter asymmetricKeyParameter = ((!(parameters is ParametersWithRandom)) ? ((AsymmetricKeyParameter)parameters) : ((AsymmetricKeyParameter)((ParametersWithRandom)parameters).Parameters));
+		if (forSigning && !asymmetricKeyParameter.IsPrivate)
+		{
+			throw new InvalidKeyException("Signing requires private key.");
+		}
+		if (!forSigning && asymmetricKeyParameter.IsPrivate)
+		{
+			throw new InvalidKeyException("Verification requires public key.");
+		}
+		Reset();
+		engine.Init(forSigning, parameters);
+	}
+
+	public virtual void Update(byte input)
+	{
+		digest.Update(input);
+	}
+
+	public virtual void BlockUpdate(byte[] input, int inOff, int length)
+	{
+		digest.BlockUpdate(input, inOff, length);
+	}
+
+	public virtual byte[] GenerateSignature()
+	{
+		if (!forSigning)
+		{
+			throw new InvalidOperationException("GenericSigner not initialised for signature generation.");
+		}
+		byte[] array = new byte[digest.GetDigestSize()];
+		digest.DoFinal(array, 0);
+		return engine.ProcessBlock(array, 0, array.Length);
+	}
+
+	public virtual bool VerifySignature(byte[] signature)
+	{
+		if (forSigning)
+		{
+			throw new InvalidOperationException("GenericSigner not initialised for verification");
+		}
+		byte[] array = new byte[digest.GetDigestSize()];
+		digest.DoFinal(array, 0);
+		try
+		{
+			byte[] array2 = engine.ProcessBlock(signature, 0, signature.Length);
+			if (array2.Length < array.Length)
+			{
+				byte[] array3 = new byte[array.Length];
+				Array.Copy(array2, 0, array3, array3.Length - array2.Length, array2.Length);
+				array2 = array3;
+			}
+			return Arrays.ConstantTimeAreEqual(array2, array);
+		}
+		catch (Exception)
+		{
+			return false;
+		}
+	}
+
+	public virtual void Reset()
+	{
+		digest.Reset();
+	}
+}