using System.Collections;
using System.IO;
using Org.BouncyCastle.Crypto.Agreement;
using Org.BouncyCastle.Crypto.Generators;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Math;
using Org.BouncyCastle.Security;
using Org.BouncyCastle.Utilities;
using Org.BouncyCastle.Utilities.Encoders;

namespace Org.BouncyCastle.Crypto.Tls;

public abstract class TlsDHUtilities
{
	internal static readonly BigInteger Two = BigInteger.Two;

	private static readonly string draft_ffdhe2432_p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

	internal static readonly DHParameters draft_ffdhe2432 = FromSafeP(draft_ffdhe2432_p);

	private static readonly string draft_ffdhe3072_p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

	internal static readonly DHParameters draft_ffdhe3072 = FromSafeP(draft_ffdhe3072_p);

	private static readonly string draft_ffdhe4096_p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

	internal static readonly DHParameters draft_ffdhe4096 = FromSafeP(draft_ffdhe4096_p);

	private static readonly string draft_ffdhe6144_p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

	internal static readonly DHParameters draft_ffdhe6144 = FromSafeP(draft_ffdhe6144_p);

	private static readonly string draft_ffdhe8192_p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

	internal static readonly DHParameters draft_ffdhe8192 = FromSafeP(draft_ffdhe8192_p);

	private static BigInteger FromHex(string hex)
	{
		return new BigInteger(1, Hex.Decode(hex));
	}

	private static DHParameters FromSafeP(string hexP)
	{
		BigInteger bigInteger = FromHex(hexP);
		BigInteger q = bigInteger.ShiftRight(1);
		return new DHParameters(bigInteger, Two, q);
	}

	public static void AddNegotiatedDheGroupsClientExtension(IDictionary extensions, byte[] dheGroups)
	{
		extensions[ExtensionType.negotiated_ff_dhe_groups] = CreateNegotiatedDheGroupsClientExtension(dheGroups);
	}

	public static void AddNegotiatedDheGroupsServerExtension(IDictionary extensions, byte dheGroup)
	{
		extensions[ExtensionType.negotiated_ff_dhe_groups] = CreateNegotiatedDheGroupsServerExtension(dheGroup);
	}

	public static byte[] GetNegotiatedDheGroupsClientExtension(IDictionary extensions)
	{
		byte[] extensionData = TlsUtilities.GetExtensionData(extensions, ExtensionType.negotiated_ff_dhe_groups);
		if (extensionData != null)
		{
			return ReadNegotiatedDheGroupsClientExtension(extensionData);
		}
		return null;
	}

	public static short GetNegotiatedDheGroupsServerExtension(IDictionary extensions)
	{
		byte[] extensionData = TlsUtilities.GetExtensionData(extensions, ExtensionType.negotiated_ff_dhe_groups);
		if (extensionData != null)
		{
			return ReadNegotiatedDheGroupsServerExtension(extensionData);
		}
		return -1;
	}

	public static byte[] CreateNegotiatedDheGroupsClientExtension(byte[] dheGroups)
	{
		if (dheGroups == null || dheGroups.Length < 1 || dheGroups.Length > 255)
		{
			throw new TlsFatalAlert(80);
		}
		return TlsUtilities.EncodeUint8ArrayWithUint8Length(dheGroups);
	}

	public static byte[] CreateNegotiatedDheGroupsServerExtension(byte dheGroup)
	{
		return TlsUtilities.EncodeUint8(dheGroup);
	}

	public static byte[] ReadNegotiatedDheGroupsClientExtension(byte[] extensionData)
	{
		byte[] array = TlsUtilities.DecodeUint8ArrayWithUint8Length(extensionData);
		if (array.Length < 1)
		{
			throw new TlsFatalAlert(50);
		}
		return array;
	}

	public static byte ReadNegotiatedDheGroupsServerExtension(byte[] extensionData)
	{
		return TlsUtilities.DecodeUint8(extensionData);
	}

	public static DHParameters GetParametersForDHEGroup(short dheGroup)
	{
		return dheGroup switch
		{
			0 => draft_ffdhe2432, 
			1 => draft_ffdhe3072, 
			2 => draft_ffdhe4096, 
			3 => draft_ffdhe6144, 
			4 => draft_ffdhe8192, 
			_ => null, 
		};
	}

	public static bool ContainsDheCipherSuites(int[] cipherSuites)
	{
		for (int i = 0; i < cipherSuites.Length; i++)
		{
			if (IsDheCipherSuite(cipherSuites[i]))
			{
				return true;
			}
		}
		return false;
	}

	public static bool IsDheCipherSuite(int cipherSuite)
	{
		switch (cipherSuite)
		{
		case 17:
		case 18:
		case 19:
		case 20:
		case 21:
		case 22:
		case 24:
		case 27:
		case 45:
		case 50:
		case 51:
		case 52:
		case 56:
		case 57:
		case 58:
		case 64:
		case 68:
		case 69:
		case 70:
		case 103:
		case 106:
		case 107:
		case 108:
		case 109:
		case 135:
		case 136:
		case 137:
		case 142:
		case 143:
		case 144:
		case 145:
		case 153:
		case 154:
		case 155:
		case 158:
		case 159:
		case 162:
		case 163:
		case 166:
		case 167:
		case 170:
		case 171:
		case 178:
		case 179:
		case 180:
		case 181:
		case 189:
		case 190:
		case 191:
		case 195:
		case 196:
		case 197:
		case 49276:
		case 49277:
		case 49280:
		case 49281:
		case 49284:
		case 49285:
		case 49296:
		case 49297:
		case 49302:
		case 49303:
		case 49310:
		case 49311:
		case 49314:
		case 49315:
		case 49318:
		case 49319:
		case 49322:
		case 49323:
		case 52394:
		case 52397:
		case 65280:
		case 65281:
		case 65298:
		case 65299:
			return true;
		default:
			return false;
		}
	}

	public static bool AreCompatibleParameters(DHParameters a, DHParameters b)
	{
		if (a.P.Equals(b.P) && a.G.Equals(b.G))
		{
			if (a.Q != null && b.Q != null)
			{
				return a.Q.Equals(b.Q);
			}
			return true;
		}
		return false;
	}

	public static byte[] CalculateDHBasicAgreement(DHPublicKeyParameters publicKey, DHPrivateKeyParameters privateKey)
	{
		DHBasicAgreement dHBasicAgreement = new DHBasicAgreement();
		dHBasicAgreement.Init(privateKey);
		BigInteger n = dHBasicAgreement.CalculateAgreement(publicKey);
		return BigIntegers.AsUnsignedByteArray(n);
	}

	public static AsymmetricCipherKeyPair GenerateDHKeyPair(SecureRandom random, DHParameters dhParams)
	{
		DHBasicKeyPairGenerator dHBasicKeyPairGenerator = new DHBasicKeyPairGenerator();
		dHBasicKeyPairGenerator.Init(new DHKeyGenerationParameters(random, dhParams));
		return dHBasicKeyPairGenerator.GenerateKeyPair();
	}

	public static DHPrivateKeyParameters GenerateEphemeralClientKeyExchange(SecureRandom random, DHParameters dhParams, Stream output)
	{
		AsymmetricCipherKeyPair asymmetricCipherKeyPair = GenerateDHKeyPair(random, dhParams);
		DHPublicKeyParameters dHPublicKeyParameters = (DHPublicKeyParameters)asymmetricCipherKeyPair.Public;
		WriteDHParameter(dHPublicKeyParameters.Y, output);
		return (DHPrivateKeyParameters)asymmetricCipherKeyPair.Private;
	}

	public static DHPrivateKeyParameters GenerateEphemeralServerKeyExchange(SecureRandom random, DHParameters dhParams, Stream output)
	{
		AsymmetricCipherKeyPair asymmetricCipherKeyPair = GenerateDHKeyPair(random, dhParams);
		DHPublicKeyParameters dHPublicKeyParameters = (DHPublicKeyParameters)asymmetricCipherKeyPair.Public;
		WriteDHParameters(dhParams, output);
		WriteDHParameter(dHPublicKeyParameters.Y, output);
		return (DHPrivateKeyParameters)asymmetricCipherKeyPair.Private;
	}

	public static BigInteger ReadDHParameter(Stream input)
	{
		return new BigInteger(1, TlsUtilities.ReadOpaque16(input));
	}

	public static DHParameters ReadDHParameters(Stream input)
	{
		BigInteger p = ReadDHParameter(input);
		BigInteger g = ReadDHParameter(input);
		return new DHParameters(p, g);
	}

	public static DHParameters ReceiveDHParameters(TlsDHVerifier dhVerifier, Stream input)
	{
		DHParameters dHParameters = ReadDHParameters(input);
		if (!dhVerifier.Accept(dHParameters))
		{
			throw new TlsFatalAlert(71);
		}
		return dHParameters;
	}

	public static void WriteDHParameter(BigInteger x, Stream output)
	{
		TlsUtilities.WriteOpaque16(BigIntegers.AsUnsignedByteArray(x), output);
	}

	public static void WriteDHParameters(DHParameters dhParameters, Stream output)
	{
		WriteDHParameter(dhParameters.P, output);
		WriteDHParameter(dhParameters.G, output);
	}
}