#define TRACE
using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Globalization;
using System.IO;
using System.IO.Compression;
using System.Numerics;
using System.Security.Cryptography;
using System.Security.Cryptography.X509Certificates;
using System.Text;
using ArchestrAServices.Common;
using Invensys.Compression;

namespace ArchestrAServices.ASBContract;

public class SysAuthConnectionBase
{
	private static RandomNumberGenerator mRANDOM = RandomNumberGenerator.Create();

	private static readonly byte[] PASSWORDSALT = Encoding.ASCII.GetBytes("ArchestrAService");

	protected static string ASBAuthenticationVersion = "V2";

	protected static readonly object MessageNumberLock = new object();

	protected SysAuthParameters m_SolutionParameters;

	public Guid connectionID = Guid.Empty;

	protected byte[] m_PrivateKey;

	protected byte[] m_LocalPublicKey;

	protected byte[] m_RemotePublicKey;

	protected bool m_Authenticated;

	protected ulong m_NextMessageNumber = 1uL;

	private ulong m_HighestMessageNumberReceived;

	private List<ulong> m_OutOfSyncMessageNumbers = new List<ulong>();

	private byte[] SolutionPassphrase
	{
		get
		{
			byte[] result = null;
			if (m_SolutionParameters.ASBSolutionValid)
			{
				if (m_SolutionParameters.DH_passphrase != null && m_SolutionParameters.DH_passphrase.Length > 0)
				{
					result = Encoding.UTF8.GetBytes(m_SolutionParameters.DH_passphrase);
				}
				if (m_SolutionParameters.DH_certificate != null && m_SolutionParameters.DH_certificate.Length != 0)
				{
					result = new X509Certificate(m_SolutionParameters.DH_certificate).GetPublicKey();
				}
			}
			return result;
		}
	}

	private byte[] CryptoKey
	{
		get
		{
			List<byte> list = new List<byte>();
			list.AddRange(CalculateConnectionKey(m_RemotePublicKey, m_PrivateKey));
			byte[] solutionPassphrase = SolutionPassphrase;
			if (solutionPassphrase != null)
			{
				list.AddRange(solutionPassphrase);
			}
			return list.ToArray();
		}
	}

	public ConnectionValidator m_ConnectionValidator { get; protected set; }

	public bool SecureSessionEstablished
	{
		get
		{
			return m_Authenticated;
		}
		protected set
		{
			m_Authenticated = value;
		}
	}

	public string ReasonSecureSessionNotEstablished { get; protected set; }

	public string DH_passphrase
	{
		get
		{
			return m_SolutionParameters.DH_passphrase;
		}
		set
		{
			m_SolutionParameters.DH_passphrase = value;
		}
	}

	public string DH_hashAlgorithm => m_SolutionParameters.hashAlgorithm;

	public string DH_asbSolutionName => m_SolutionParameters.ASBSolutionName;

	public SigningMethod SignatureMethod { get; set; }

	public SysAuthConnectionBase(string asbSolutionName = null)
	{
		m_SolutionParameters = new SysAuthParameters(asbSolutionName);
		ReasonSecureSessionNotEstablished = "Constructed";
		Reset();
	}

	protected void Reset()
	{
		SecureSessionEstablished = false;
		ReasonSecureSessionNotEstablished = "Reset";
		SignatureMethod = SigningMethod.Baktun;
		connectionID = Guid.NewGuid();
		m_PrivateKey = GetPrivateKey(m_SolutionParameters.KeySize);
		m_LocalPublicKey = CalculatePublicKey(m_PrivateKey);
		m_Authenticated = false;
	}

	private byte[] GetPrivateKey(int length)
	{
		byte[] array = null;
		if (length > 0)
		{
			BigInteger bigInteger = m_SolutionParameters.DH_p - new BigInteger(1);
			BigInteger bigInteger2 = new BigInteger(0);
			while (bigInteger2 >= bigInteger || bigInteger2 <= 0L)
			{
				array = new byte[length / 8];
				mRANDOM.GetBytes(array);
				bigInteger2 = new BigInteger(array);
			}
		}
		return array;
	}

	protected byte[] CalculatePublicKey(byte[] privateKey)
	{
		BigInteger exponent = new BigInteger(privateKey);
		BigInteger dH_g = m_SolutionParameters.DH_g;
		BigInteger dH_p = m_SolutionParameters.DH_p;
		return BigInteger.ModPow(dH_g, exponent, dH_p).ToByteArray();
	}

	protected byte[] CalculateConnectionKey(byte[] remotePublicKey, byte[] localPrivateKey)
	{
		BigInteger value = new BigInteger(remotePublicKey);
		BigInteger exponent = new BigInteger(localPrivateKey);
		BigInteger dH_p = m_SolutionParameters.DH_p;
		return BigInteger.ModPow(value, exponent, dH_p).ToByteArray();
	}

	private HMAC NewSolutionHmac(bool ForceHMAC = false)
	{
		HMAC result;
		switch (DH_hashAlgorithm.ToLower())
		{
		case "md5":
			SvcTrace.DiagDiagnostics.TraceEvent(TraceEventType.Information, 0, "Solution HMAC is MD5");
			result = new HMACMD5(CryptoKey);
			break;
		case "sha1":
			SvcTrace.DiagDiagnostics.TraceEvent(TraceEventType.Information, 0, "Solution HMAC is SHA1");
			result = new HMACSHA1(CryptoKey);
			break;
		case "sha512":
			SvcTrace.DiagDiagnostics.TraceEvent(TraceEventType.Information, 0, "Solution HMAC is SHA512");
			result = new HMACSHA512(CryptoKey);
			break;
		default:
			SvcTrace.DiagDiagnostics.TraceEvent(TraceEventType.Information, 0, "Solution HMAC is NONE");
			result = null;
			if (ForceHMAC)
			{
				result = new HMACSHA1(CryptoKey);
			}
			break;
		}
		return result;
	}

	public bool ValidRequest(ConnectedRequest request, bool ForceHmac = false)
	{
		bool flag = false;
		if (request != null && request.ConnectionValidator != null)
		{
			ConnectionValidator connectionValidator = request.ConnectionValidator;
			byte[] messageAuthenticationCode = connectionValidator.MessageAuthenticationCode;
			byte[] signatureInitializationVector = connectionValidator.SignatureInitializationVector;
			byte[] array = null;
			using (HMAC hMAC = NewSolutionHmac(ForceHmac))
			{
				if (hMAC != null)
				{
					connectionValidator.MessageAuthenticationCode = new byte[0];
					connectionValidator.SignatureInitializationVector = new byte[0];
					byte[] bytes = Encoding.UTF8.GetBytes(request.ToXml());
					connectionValidator.MessageAuthenticationCode = messageAuthenticationCode;
					connectionValidator.SignatureInitializationVector = signatureInitializationVector;
					if (SignatureMethod == SigningMethod.Baktun)
					{
						array = EncypherBaktun(hMAC.ComputeHash(bytes), signatureInitializationVector);
					}
					else
					{
						byte[] array2 = hMAC.ComputeHash(bytes);
						byte[] array3 = DecypherApollo(messageAuthenticationCode, signatureInitializationVector);
						bool flag2 = false;
						if (array2 != null && array3 != null && array2.Length == array3.Length)
						{
							flag2 = true;
							for (int i = 0; i < array2.Length; i++)
							{
								if (array2[i] != array3[i])
								{
									flag2 = false;
									break;
								}
							}
						}
						array = ((!flag2) ? new byte[0] : messageAuthenticationCode);
					}
				}
			}
			if (array != null)
			{
				if (messageAuthenticationCode != null && array.Length == messageAuthenticationCode.Length)
				{
					flag = true;
					for (int j = 0; j < messageAuthenticationCode.Length; j++)
					{
						if (messageAuthenticationCode[j] != array[j])
						{
							if (string.IsNullOrEmpty(ReasonSecureSessionNotEstablished))
							{
								ReasonSecureSessionNotEstablished = string.Format(CultureInfo.CurrentCulture, "ValidRequest: Received message hmac correct length {0} but differs at byte {1}, cannot validate", new object[2] { messageAuthenticationCode.Length, j });
							}
							flag = false;
							break;
						}
					}
				}
				else if (messageAuthenticationCode == null)
				{
					if (string.IsNullOrEmpty(ReasonSecureSessionNotEstablished))
					{
						ReasonSecureSessionNotEstablished = "ValidRequest: Received message has null hmac, cannot validate";
					}
				}
				else if (string.IsNullOrEmpty(ReasonSecureSessionNotEstablished))
				{
					ReasonSecureSessionNotEstablished = string.Format(CultureInfo.CurrentCulture, "ValidRequest: Received message hmac wrong length, cannot validate (received {0}, computed {1})", new object[2] { messageAuthenticationCode.Length, array.Length });
				}
			}
			else
			{
				flag = true;
			}
			if (flag)
			{
				lock (this)
				{
					if (connectionValidator.MessageNumber <= m_HighestMessageNumberReceived)
					{
						ReasonSecureSessionNotEstablished = string.Format(CultureInfo.CurrentCulture, "ValidRequest: Received message out of sequence, cannot validate (current {0}, highest {1})", new object[2] { connectionValidator.MessageNumber, m_HighestMessageNumberReceived });
						flag = false;
					}
					else if (m_OutOfSyncMessageNumbers.Contains(connectionValidator.MessageNumber))
					{
						ReasonSecureSessionNotEstablished = string.Format(CultureInfo.CurrentCulture, "ValidRequest: Received message received late, cannot validate (current {0})", new object[1] { connectionValidator.MessageNumber });
						flag = false;
					}
					else if (connectionValidator.MessageNumber == m_HighestMessageNumberReceived + 1)
					{
						m_HighestMessageNumberReceived = connectionValidator.MessageNumber;
					}
					else
					{
						m_OutOfSyncMessageNumbers.Add(connectionValidator.MessageNumber);
					}
					m_OutOfSyncMessageNumbers.Sort();
					foreach (ulong outOfSyncMessageNumber in m_OutOfSyncMessageNumbers)
					{
						if (outOfSyncMessageNumber == m_HighestMessageNumberReceived + 1)
						{
							m_HighestMessageNumberReceived = outOfSyncMessageNumber;
						}
					}
					List<ulong> list = new List<ulong>();
					foreach (ulong outOfSyncMessageNumber2 in m_OutOfSyncMessageNumbers)
					{
						if (outOfSyncMessageNumber2 <= m_HighestMessageNumberReceived)
						{
							list.Add(outOfSyncMessageNumber2);
						}
					}
					foreach (ulong item in list)
					{
						m_OutOfSyncMessageNumbers.Remove(item);
					}
				}
			}
		}
		else
		{
			ReasonSecureSessionNotEstablished = "ValidRequest: Either the message or its ConnectionValidator field is null, cannot validate";
		}
		return flag;
	}

	public bool ValidResponse(ConnectedResponse response, bool ForceHmac = false)
	{
		if (response != null && response.Result.Success)
		{
			return ValidRequest(response, ForceHmac);
		}
		return false;
	}

	protected byte[] ReCalculateAuthenticationData(byte[] leftPart, byte[] rightPart, byte[] initializationVector)
	{
		List<byte> list = new List<byte>();
		if (leftPart != null)
		{
			list.AddRange(leftPart);
		}
		if (rightPart != null)
		{
			list.AddRange(rightPart);
		}
		return ReEncypher(list.ToArray(), initializationVector);
	}

	protected byte[] CalculateAuthenticationData(byte[] leftPart, byte[] rightPart, out byte[] initializationVector)
	{
		List<byte> list = new List<byte>();
		initializationVector = null;
		if (leftPart != null)
		{
			list.AddRange(leftPart);
		}
		if (rightPart != null)
		{
			list.AddRange(rightPart);
		}
		return Encypher(list.ToArray(), out initializationVector);
	}

	public ConnectionValidator MakeConnectionValidator()
	{
		lock (MessageNumberLock)
		{
			return new ConnectionValidator
			{
				ConnectionId = connectionID,
				MessageNumber = m_NextMessageNumber++,
				MessageAuthenticationCode = new byte[0],
				SignatureInitializationVector = new byte[0]
			};
		}
	}

	public void Sign(ConnectedRequest request, bool ForceHmac = false)
	{
		if (request == null)
		{
			return;
		}
		lock (MessageNumberLock)
		{
			ConnectionValidator connectionValidator = new ConnectionValidator();
			connectionValidator.ConnectionId = connectionID;
			connectionValidator.MessageNumber = m_NextMessageNumber++;
			connectionValidator.MessageAuthenticationCode = new byte[0];
			connectionValidator.SignatureInitializationVector = new byte[0];
			request.ConnectionValidator = connectionValidator;
			using HMAC hMAC = NewSolutionHmac(ForceHmac);
			if (hMAC != null)
			{
				byte[] bytes = Encoding.UTF8.GetBytes(request.ToXml());
				connectionValidator.MessageAuthenticationCode = Encypher(hMAC.ComputeHash(bytes), out var initializationVector);
				connectionValidator.SignatureInitializationVector = initializationVector;
			}
		}
	}

	public byte[] EncypherBaktun(byte[] clearData, byte[] initializationVector)
	{
		byte[] result = null;
		if (clearData != null)
		{
			using AesManaged aesManaged = new AesManaged();
			using Rfc2898DeriveBytes rfc2898DeriveBytes = new Rfc2898DeriveBytes(CryptoKey.ToBase64(), PASSWORDSALT);
			aesManaged.Key = rfc2898DeriveBytes.GetBytes(16);
			aesManaged.IV = initializationVector;
			using ICryptoTransform transform = aesManaged.CreateEncryptor();
			using MemoryStream memoryStream = new MemoryStream();
			using (CryptoStream stream = new CryptoStream(memoryStream, transform, CryptoStreamMode.Write))
			{
				using AADeflateStream aADeflateStream = new AADeflateStream(stream, CompressionMode.Compress);
				aADeflateStream.Write(clearData, 0, clearData.Length);
				aADeflateStream.Close();
			}
			result = memoryStream.ToArray();
		}
		return result;
	}

	public byte[] EncypherBaktun(byte[] clearData, out byte[] initializationVector)
	{
		byte[] result = null;
		initializationVector = null;
		if (clearData != null)
		{
			using AesManaged aesManaged = new AesManaged();
			using Rfc2898DeriveBytes rfc2898DeriveBytes = new Rfc2898DeriveBytes(CryptoKey.ToBase64(), PASSWORDSALT);
			aesManaged.Key = rfc2898DeriveBytes.GetBytes(16);
			initializationVector = aesManaged.IV;
			using ICryptoTransform transform = aesManaged.CreateEncryptor();
			using MemoryStream memoryStream = new MemoryStream();
			using (CryptoStream stream = new CryptoStream(memoryStream, transform, CryptoStreamMode.Write))
			{
				using AADeflateStream aADeflateStream = new AADeflateStream(stream, CompressionMode.Compress);
				aADeflateStream.Write(clearData, 0, clearData.Length);
				aADeflateStream.Close();
			}
			result = memoryStream.ToArray();
		}
		return result;
	}

	public string EncypherBaktun(string clearText, out byte[] initializationVector)
	{
		string result = string.Empty;
		initializationVector = null;
		if (!string.IsNullOrEmpty(clearText))
		{
			byte[] bytes = Encoding.UTF8.GetBytes(clearText);
			result = EncypherBaktun(bytes, out initializationVector).ToBase64();
		}
		return result;
	}

	public byte[] ReEncypherBaktun(byte[] clearData, byte[] initializationVector)
	{
		byte[] result = null;
		if (clearData != null)
		{
			using AesManaged aesManaged = new AesManaged();
			using Rfc2898DeriveBytes rfc2898DeriveBytes = new Rfc2898DeriveBytes(CryptoKey.ToBase64(), PASSWORDSALT);
			aesManaged.Key = rfc2898DeriveBytes.GetBytes(16);
			aesManaged.IV = initializationVector;
			using ICryptoTransform transform = aesManaged.CreateEncryptor();
			using MemoryStream memoryStream = new MemoryStream();
			using (CryptoStream stream = new CryptoStream(memoryStream, transform, CryptoStreamMode.Write))
			{
				using AADeflateStream aADeflateStream = new AADeflateStream(stream, CompressionMode.Compress);
				aADeflateStream.Write(clearData, 0, clearData.Length);
				aADeflateStream.Close();
			}
			result = memoryStream.ToArray();
		}
		return result;
	}

	public string ReEncypherBaktun(string clearText, byte[] initializationVector)
	{
		string result = string.Empty;
		if (!string.IsNullOrEmpty(clearText))
		{
			byte[] bytes = Encoding.UTF8.GetBytes(clearText);
			result = ReEncypherBaktun(bytes, initializationVector).ToBase64();
		}
		return result;
	}

	public byte[] DecypherBaktun(byte[] cypherData, byte[] initializationVector)
	{
		byte[] result = null;
		if (cypherData != null)
		{
			using AesManaged aesManaged = new AesManaged();
			using Rfc2898DeriveBytes rfc2898DeriveBytes = new Rfc2898DeriveBytes(CryptoKey.ToBase64(), PASSWORDSALT);
			aesManaged.Key = rfc2898DeriveBytes.GetBytes(16);
			aesManaged.IV = initializationVector;
			using ICryptoTransform transform = aesManaged.CreateDecryptor();
			using MemoryStream stream = new MemoryStream(cypherData);
			using CryptoStream stream2 = new CryptoStream(stream, transform, CryptoStreamMode.Read);
			using AADeflateStream aADeflateStream = new AADeflateStream(stream2, CompressionMode.Decompress);
			using MemoryStream memoryStream = new MemoryStream();
			aADeflateStream.CopyTo(memoryStream);
			result = memoryStream.ToArray();
		}
		return result;
	}

	public string DecypherBaktun(string cypherText, byte[] initializationVector)
	{
		string result = string.Empty;
		if (!string.IsNullOrEmpty(cypherText))
		{
			byte[] cypherData = cypherText.FromBase64ToByteArray();
			byte[] bytes = DecypherBaktun(cypherData, initializationVector);
			result = Encoding.UTF8.GetString(bytes);
		}
		return result;
	}

	public byte[] EncypherApollo(byte[] clearData, byte[] initializationVector)
	{
		byte[] result = null;
		if (clearData != null)
		{
			using AesManaged aesManaged = new AesManaged();
			using Rfc2898DeriveBytes rfc2898DeriveBytes = new Rfc2898DeriveBytes(CryptoKey.ToBase64(), PASSWORDSALT);
			aesManaged.Key = rfc2898DeriveBytes.GetBytes(16);
			aesManaged.IV = initializationVector;
			using ICryptoTransform transform = aesManaged.CreateEncryptor();
			using MemoryStream memoryStream = new MemoryStream();
			using (CryptoStream cryptoStream = new CryptoStream(memoryStream, transform, CryptoStreamMode.Write))
			{
				cryptoStream.Write(clearData, 0, clearData.Length);
				cryptoStream.Close();
			}
			result = memoryStream.ToArray();
		}
		return result;
	}

	public byte[] EncypherApollo(byte[] clearData, out byte[] initializationVector)
	{
		byte[] result = null;
		initializationVector = null;
		if (clearData != null)
		{
			using AesManaged aesManaged = new AesManaged();
			using Rfc2898DeriveBytes rfc2898DeriveBytes = new Rfc2898DeriveBytes(CryptoKey.ToBase64(), PASSWORDSALT);
			aesManaged.Key = rfc2898DeriveBytes.GetBytes(16);
			initializationVector = aesManaged.IV;
			using ICryptoTransform transform = aesManaged.CreateEncryptor();
			using MemoryStream memoryStream = new MemoryStream();
			using (CryptoStream cryptoStream = new CryptoStream(memoryStream, transform, CryptoStreamMode.Write))
			{
				cryptoStream.Write(clearData, 0, clearData.Length);
				cryptoStream.Close();
			}
			result = memoryStream.ToArray();
		}
		return result;
	}

	public string EncypherApollo(string clearText, out byte[] initializationVector)
	{
		string result = string.Empty;
		initializationVector = null;
		if (!string.IsNullOrEmpty(clearText))
		{
			byte[] bytes = Encoding.UTF8.GetBytes(clearText);
			result = EncypherApollo(bytes, out initializationVector).ToBase64();
		}
		return result;
	}

	public byte[] ReEncypherApollo(byte[] clearData, byte[] initializationVector)
	{
		byte[] result = null;
		if (clearData != null)
		{
			using AesManaged aesManaged = new AesManaged();
			using Rfc2898DeriveBytes rfc2898DeriveBytes = new Rfc2898DeriveBytes(CryptoKey.ToBase64(), PASSWORDSALT);
			aesManaged.Key = rfc2898DeriveBytes.GetBytes(16);
			aesManaged.IV = initializationVector;
			using ICryptoTransform transform = aesManaged.CreateEncryptor();
			using MemoryStream memoryStream = new MemoryStream();
			using (CryptoStream cryptoStream = new CryptoStream(memoryStream, transform, CryptoStreamMode.Write))
			{
				cryptoStream.Write(clearData, 0, clearData.Length);
				cryptoStream.Close();
			}
			result = memoryStream.ToArray();
		}
		return result;
	}

	public string ReEncypherApollo(string clearText, byte[] initializationVector)
	{
		string result = string.Empty;
		if (!string.IsNullOrEmpty(clearText))
		{
			byte[] bytes = Encoding.UTF8.GetBytes(clearText);
			result = ReEncypherApollo(bytes, initializationVector).ToBase64();
		}
		return result;
	}

	public byte[] DecypherApollo(byte[] cypherData, byte[] initializationVector)
	{
		byte[] result = null;
		if (cypherData != null)
		{
			using AesManaged aesManaged = new AesManaged();
			using Rfc2898DeriveBytes rfc2898DeriveBytes = new Rfc2898DeriveBytes(CryptoKey.ToBase64(), PASSWORDSALT);
			aesManaged.Key = rfc2898DeriveBytes.GetBytes(16);
			aesManaged.IV = initializationVector;
			using ICryptoTransform transform = aesManaged.CreateDecryptor();
			using MemoryStream stream = new MemoryStream(cypherData);
			using CryptoStream cryptoStream = new CryptoStream(stream, transform, CryptoStreamMode.Read);
			using MemoryStream memoryStream = new MemoryStream();
			cryptoStream.CopyTo(memoryStream);
			result = memoryStream.ToArray();
		}
		return result;
	}

	public string DecypherApollo(string cypherText, byte[] initializationVector)
	{
		string result = string.Empty;
		if (!string.IsNullOrEmpty(cypherText))
		{
			byte[] cypherData = cypherText.FromBase64ToByteArray();
			byte[] bytes = DecypherApollo(cypherData, initializationVector);
			result = Encoding.UTF8.GetString(bytes);
		}
		return result;
	}

	public byte[] Encypher(byte[] clearData, byte[] initializationVector)
	{
		if (SignatureMethod == SigningMethod.Baktun)
		{
			return EncypherBaktun(clearData, initializationVector);
		}
		return EncypherApollo(clearData, initializationVector);
	}

	public byte[] Encypher(byte[] clearData, out byte[] initializationVector)
	{
		if (SignatureMethod == SigningMethod.Baktun)
		{
			return EncypherBaktun(clearData, out initializationVector);
		}
		return EncypherApollo(clearData, out initializationVector);
	}

	public string Encypher(string clearText, out byte[] initializationVector)
	{
		if (SignatureMethod == SigningMethod.Baktun)
		{
			return EncypherBaktun(clearText, out initializationVector);
		}
		return EncypherApollo(clearText, out initializationVector);
	}

	public byte[] ReEncypher(byte[] clearData, byte[] initializationVector)
	{
		if (SignatureMethod == SigningMethod.Baktun)
		{
			return ReEncypherBaktun(clearData, initializationVector);
		}
		return ReEncypherApollo(clearData, initializationVector);
	}

	public string ReEncypher(string clearText, byte[] initializationVector)
	{
		if (SignatureMethod == SigningMethod.Baktun)
		{
			return ReEncypherBaktun(clearText, initializationVector);
		}
		return ReEncypherApollo(clearText, initializationVector);
	}

	public byte[] Decypher(byte[] cypherData, byte[] initializationVector)
	{
		if (SignatureMethod == SigningMethod.Baktun)
		{
			return DecypherBaktun(cypherData, initializationVector);
		}
		return DecypherApollo(cypherData, initializationVector);
	}

	public string Decypher(string cypherText, byte[] initializationVector)
	{
		if (SignatureMethod == SigningMethod.Baktun)
		{
			return DecypherBaktun(cypherText, initializationVector);
		}
		return DecypherApollo(cypherText, initializationVector);
	}
}