Dec2017-Script-Dump/Photon3Unity3D/Photon/SocketServer/Security/DiffieHellmanCryptoProvider.cs

using System;
using System.Security.Cryptography;
using Photon.SocketServer.Numeric;

namespace Photon.SocketServer.Security
{
	// Token: 0x02000004 RID: 4
	internal class DiffieHellmanCryptoProvider : ICryptoProvider, IDisposable
	{
		// Token: 0x06000009 RID: 9 RVA: 0x000020AF File Offset: 0x000002AF
		public DiffieHellmanCryptoProvider()
		{
			this.prime = new BigInteger(OakleyGroups.OakleyPrime768);
			this.secret = this.GenerateRandomSecret(160);
			this.publicKey = this.CalculatePublicKey();
		}

		// Token: 0x0600000A RID: 10 RVA: 0x000020E8 File Offset: 0x000002E8
		public DiffieHellmanCryptoProvider(byte[] sharedSecretHash)
		{
			this.crypto = new RijndaelManaged();
			this.crypto.Key = sharedSecretHash;
			this.crypto.IV = new byte[16];
			this.crypto.Padding = PaddingMode.PKCS7;
		}

		// Token: 0x17000003 RID: 3
		// (get) Token: 0x0600000B RID: 11 RVA: 0x00002138 File Offset: 0x00000338
		public bool IsInitialized
		{
			get
			{
				return this.crypto != null;
			}
		}

		// Token: 0x17000004 RID: 4
		// (get) Token: 0x0600000C RID: 12 RVA: 0x00002154 File Offset: 0x00000354
		public byte[] PublicKey
		{
			get
			{
				return this.publicKey.GetBytes();
			}
		}

		// Token: 0x0600000D RID: 13 RVA: 0x00002174 File Offset: 0x00000374
		public void DeriveSharedKey(byte[] otherPartyPublicKey)
		{
			BigInteger bigInteger = new BigInteger(otherPartyPublicKey);
			BigInteger bigInteger2 = this.CalculateSharedKey(bigInteger);
			this.sharedKey = bigInteger2.GetBytes();
			byte[] array;
			using (SHA256 sha = new SHA256Managed())
			{
				array = sha.ComputeHash(this.sharedKey);
			}
			this.crypto = new RijndaelManaged();
			this.crypto.Key = array;
			this.crypto.IV = new byte[16];
			this.crypto.Padding = PaddingMode.PKCS7;
		}

		// Token: 0x0600000E RID: 14 RVA: 0x00002208 File Offset: 0x00000408
		public byte[] Encrypt(byte[] data)
		{
			return this.Encrypt(data, 0, data.Length);
		}

		// Token: 0x0600000F RID: 15 RVA: 0x00002228 File Offset: 0x00000428
		public byte[] Encrypt(byte[] data, int offset, int count)
		{
			byte[] array;
			using (ICryptoTransform cryptoTransform = this.crypto.CreateEncryptor())
			{
				array = cryptoTransform.TransformFinalBlock(data, offset, count);
			}
			return array;
		}

		// Token: 0x06000010 RID: 16 RVA: 0x0000226C File Offset: 0x0000046C
		public byte[] Decrypt(byte[] data)
		{
			return this.Decrypt(data, 0, data.Length);
		}

		// Token: 0x06000011 RID: 17 RVA: 0x0000228C File Offset: 0x0000048C
		public byte[] Decrypt(byte[] data, int offset, int count)
		{
			byte[] array;
			using (ICryptoTransform cryptoTransform = this.crypto.CreateDecryptor())
			{
				array = cryptoTransform.TransformFinalBlock(data, offset, count);
			}
			return array;
		}

		// Token: 0x06000012 RID: 18 RVA: 0x000022D0 File Offset: 0x000004D0
		public void Dispose()
		{
			this.Dispose(true);
			GC.SuppressFinalize(this);
		}

		// Token: 0x06000013 RID: 19 RVA: 0x000022E4 File Offset: 0x000004E4
		protected void Dispose(bool disposing)
		{
			bool flag = !disposing;
			if (flag)
			{
			}
		}

		// Token: 0x06000014 RID: 20 RVA: 0x00002300 File Offset: 0x00000500
		private BigInteger CalculatePublicKey()
		{
			return DiffieHellmanCryptoProvider.primeRoot.ModPow(this.secret, this.prime);
		}

		// Token: 0x06000015 RID: 21 RVA: 0x00002328 File Offset: 0x00000528
		private BigInteger CalculateSharedKey(BigInteger otherPartyPublicKey)
		{
			return otherPartyPublicKey.ModPow(this.secret, this.prime);
		}

		// Token: 0x06000016 RID: 22 RVA: 0x0000234C File Offset: 0x0000054C
		private BigInteger GenerateRandomSecret(int secretLength)
		{
			BigInteger bigInteger;
			do
			{
				bigInteger = BigInteger.GenerateRandom(secretLength);
			}
			while (bigInteger >= this.prime - 1 || bigInteger == 0);
			return bigInteger;
		}

		// Token: 0x04000005 RID: 5
		private static readonly BigInteger primeRoot = new BigInteger((long)OakleyGroups.Generator);

		// Token: 0x04000006 RID: 6
		private readonly BigInteger prime;

		// Token: 0x04000007 RID: 7
		private readonly BigInteger secret;

		// Token: 0x04000008 RID: 8
		private readonly BigInteger publicKey;

		// Token: 0x04000009 RID: 9
		private Rijndael crypto;

		// Token: 0x0400000A RID: 10
		private byte[] sharedKey;
	}
}