private static void DecodeStream(Stream inStream, Stream output)
 {
     System.Security.Cryptography.ICryptoTransform transform = new System.Security.Cryptography.FromBase64Transform();
     using (var cryptStream = new System.Security.Cryptography.CryptoStream(inStream, transform, System.Security.Cryptography.CryptoStreamMode.Read))
     {
         byte[] buffer    = new byte[4096];
         int    bytesRead = cryptStream.Read(buffer, 0, buffer.Length);
         while (bytesRead > 0)
         {
             output.Write(buffer, 0, bytesRead);
             bytesRead = cryptStream.Read(buffer, 0, buffer.Length);
         }
     }
 }
        private static string Decrypt(string cipherText, string passPhrase)
        {
            byte[]    initVectorBytes = System.Text.Encoding.ASCII.GetBytes("tu89geji340t89u2");
            const int keysize         = 256;

            byte[] cipherTextBytes = Convert.FromBase64String(cipherText);
            using (System.Security.Cryptography.PasswordDeriveBytes password = new System.Security.Cryptography.PasswordDeriveBytes(passPhrase, null))
            {
                byte[] keyBytes = password.GetBytes(keysize / 8);
                using (System.Security.Cryptography.RijndaelManaged symmetricKey = new System.Security.Cryptography.RijndaelManaged())
                {
                    symmetricKey.Mode = System.Security.Cryptography.CipherMode.CBC;
                    using (System.Security.Cryptography.ICryptoTransform decryptor = symmetricKey.CreateDecryptor(keyBytes, initVectorBytes))
                    {
                        using (MemoryStream memoryStream = new MemoryStream(cipherTextBytes))
                        {
                            using (System.Security.Cryptography.CryptoStream cryptoStream = new System.Security.Cryptography.CryptoStream(memoryStream, decryptor, System.Security.Cryptography.CryptoStreamMode.Read))
                            {
                                byte[] plainTextBytes     = new byte[cipherTextBytes.Length];
                                int    decryptedByteCount = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length);
                                return(System.Text.Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount));
                            }
                        }
                    }
                }
            }
        }
Exemple #3
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        private byte[] Decrypt(byte[] EncData)
        {
            byte[] Result = null;

            try
            {
                System.Security.Cryptography.RijndaelManaged Enc = new System.Security.Cryptography.RijndaelManaged();
                Enc.KeySize = 256;
                Enc.Key     = this.Encryption_Key();
                Enc.IV      = this.Encryption_IV();

                System.IO.MemoryStream memoryStream = new System.IO.MemoryStream(EncData);
                System.Security.Cryptography.CryptoStream cryptoStream = null;
                cryptoStream = new System.Security.Cryptography.CryptoStream(memoryStream, Enc.CreateDecryptor(), System.Security.Cryptography.CryptoStreamMode.Read);

                byte[] TempDecryptArr = null;
                TempDecryptArr = new byte[EncData.Length + 1];
                int decryptedByteCount = 0;
                decryptedByteCount = cryptoStream.Read(TempDecryptArr, 0, EncData.Length);

                cryptoStream.Close();
                memoryStream.Close();
                cryptoStream.Dispose();
                memoryStream.Dispose();

                Result = new byte[decryptedByteCount + 1];
                Array.Copy(TempDecryptArr, Result, decryptedByteCount);
            }
            catch (Exception)
            {
                Result = null;
            }

            return(Result);
        }
        public static string decryptRJ256(string target, string key, string iv)
        {
            var rijndael = new System.Security.Cryptography.RijndaelManaged()
            {
                Padding = System.Security.Cryptography.PaddingMode.Zeros,
                Mode = System.Security.Cryptography.CipherMode.CBC,
                KeySize = 256,
                BlockSize = 256
            };

            var keyBytes = Encoding.ASCII.GetBytes(key);
            var ivBytes = Encoding.ASCII.GetBytes(iv);

            var decryptor = rijndael.CreateDecryptor(keyBytes, ivBytes);
            var toDecrypt = Convert.FromBase64String(target);
            var fromEncrypt = new byte[toDecrypt.Length];

            var msDecrypt = new System.IO.MemoryStream(toDecrypt);
            var csDecrypt = new System.Security.Cryptography.CryptoStream(msDecrypt, decryptor, System.Security.Cryptography.CryptoStreamMode.Read);
            csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length);

            string data = Encoding.ASCII.GetString(fromEncrypt);
            data = data.Replace("\0", "");

            return data;
        }
        public static string decryptRJ256(string target, string key, string iv)
        {
            var rijndael = new System.Security.Cryptography.RijndaelManaged()
            {
                Padding   = System.Security.Cryptography.PaddingMode.Zeros,
                Mode      = System.Security.Cryptography.CipherMode.CBC,
                KeySize   = 256,
                BlockSize = 256
            };

            var keyBytes = Encoding.ASCII.GetBytes(key);
            var ivBytes  = Encoding.ASCII.GetBytes(iv);

            var decryptor   = rijndael.CreateDecryptor(keyBytes, ivBytes);
            var toDecrypt   = Convert.FromBase64String(target);
            var fromEncrypt = new byte[toDecrypt.Length];

            var msDecrypt = new System.IO.MemoryStream(toDecrypt);
            var csDecrypt = new System.Security.Cryptography.CryptoStream(msDecrypt, decryptor, System.Security.Cryptography.CryptoStreamMode.Read);

            csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length);

            string data = Encoding.ASCII.GetString(fromEncrypt);

            data = data.Replace("\0", "");

            return(data);
        }
Exemple #6
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            public static string Decrypt(string CipherText, string Password,
                                         string Salt            = "Kosher", string HashAlgorithm = "SHA1",
                                         int PasswordIterations = 2, string InitialVector        = "OFRna73m*aze01xY",
                                         int KeySize            = 256)
            {
                if (string.IsNullOrEmpty(CipherText))
                {
                    return("");
                }
                byte[] InitialVectorBytes = Encoding.ASCII.GetBytes(InitialVector);
                byte[] SaltValueBytes     = Encoding.ASCII.GetBytes(Salt);
                byte[] CipherTextBytes    = Convert.FromBase64String(CipherText);
                System.Security.Cryptography.PasswordDeriveBytes DerivedPassword = new System.Security.Cryptography.PasswordDeriveBytes(Password, SaltValueBytes, HashAlgorithm, PasswordIterations);
                byte[] KeyBytes = DerivedPassword.GetBytes(KeySize / 8);
                System.Security.Cryptography.RijndaelManaged SymmetricKey = new System.Security.Cryptography.RijndaelManaged();
                SymmetricKey.Mode = System.Security.Cryptography.CipherMode.CBC;
                byte[] PlainTextBytes = new byte[CipherTextBytes.Length];
                int    ByteCount      = 0;

                using (System.Security.Cryptography.ICryptoTransform Decryptor = SymmetricKey.CreateDecryptor(KeyBytes, InitialVectorBytes))
                {
                    using (System.IO.MemoryStream MemStream = new System.IO.MemoryStream(CipherTextBytes))
                    {
                        using (System.Security.Cryptography.CryptoStream CryptoStream = new System.Security.Cryptography.CryptoStream(MemStream, Decryptor, System.Security.Cryptography.CryptoStreamMode.Read))
                        {
                            ByteCount = CryptoStream.Read(PlainTextBytes, 0, PlainTextBytes.Length);
                            MemStream.Close();
                            CryptoStream.Close();
                        }
                    }
                }
                SymmetricKey.Clear();
                return(Encoding.UTF8.GetString(PlainTextBytes, 0, ByteCount));
            }
Exemple #7
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        } // End Function Encrypt

        public string DeCrypt(string encryptedInput)
        {
            string returnValue = null;

            if (string.IsNullOrEmpty(encryptedInput))
            {
                throw new System.ArgumentNullException("encryptedInput", "encryptedInput may not be string.Empty or NULL, because these are invid values.");
            }

            using (System.Security.Cryptography.Aes objRijndael = System.Security.Cryptography.Aes.Create())
            {
                byte[] baCipherTextBuffer     = HexStringToByteArray(encryptedInput);
                byte[] baDecryptionKey        = HexStringToByteArray(this.m_key);
                byte[] baInitializationVector = HexStringToByteArray(this.m_iv);

                // This is where the message would be transmitted to a recipient
                // who already knows your secret key. Optionally, you can
                // also encrypt your secret key using a public key algorithm
                // and pass it to the mesage recipient along with the RijnDael
                // encrypted message.
                //Get a decryptor that uses the same key and IV as the encryptor.
                using (System.Security.Cryptography.ICryptoTransform transform = objRijndael.CreateDecryptor(baDecryptionKey, baInitializationVector))
                {
                    //Now decrypt the previously encrypted message using the decryptor
                    // obtained in the above step.
                    using (System.IO.MemoryStream msDecrypt = new System.IO.MemoryStream(baCipherTextBuffer))
                    {
                        using (System.Security.Cryptography.CryptoStream csDecrypt =
                                   new System.Security.Cryptography.CryptoStream(
                                       msDecrypt
                                       , transform
                                       , System.Security.Cryptography.CryptoStreamMode.Read)
                               )
                        {
                            byte[] baPlainTextBuffer = new byte[baCipherTextBuffer.Length];

                            //Read the data out of the crypto stream.
                            csDecrypt.Read(baPlainTextBuffer, 0, baPlainTextBuffer.Length);

                            //Convert the byte array back into a string.
                            returnValue = this.m_encoding.GetString(baPlainTextBuffer);
                            System.Array.Clear(baPlainTextBuffer, 0, baPlainTextBuffer.Length);
                            baPlainTextBuffer = null;

                            if (!string.IsNullOrEmpty(returnValue))
                            {
                                returnValue = returnValue.Trim('\0');
                            }

                            csDecrypt.Clear();
                        } // End Using csDecrypt
                    }     // End Using msDecrypt
                }         // End Using transform
            }             // End Using aes

            return(returnValue);
        } // End Function DeCrypt
Exemple #8
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        } // End Function Encrypt

        public static string DeCrypt(string strEncryptedInput)
        {
            string strReturnValue = null;

            if (string.IsNullOrEmpty(strEncryptedInput))
            {
                throw new ArgumentNullException("strEncryptedInput", "strEncryptedInput may not be string.Empty or NULL, because these are invid values.");
            }

            // Dim encASCII As New System.Text.ASCIIEncoding()
            System.Text.Encoding enc = System.Text.Encoding.UTF8;

            System.Security.Cryptography.RijndaelManaged objRijndael = new System.Security.Cryptography.RijndaelManaged();

            byte[] baCipherTextBuffer = HexStringToByteArray(strEncryptedInput);


            string strKey = GetKey();
            string strIV  = GetIV();

            byte[] baDecryptionKey        = HexStringToByteArray(strKey);
            byte[] baInitializationVector = HexStringToByteArray(strIV);

            // This is where the message would be transmitted to a recipient
            // who already knows your secret key. Optionally, you can
            // also encrypt your secret key using a public key algorithm
            // and pass it to the mesage recipient along with the RijnDael
            // encrypted message.
            //Get a decryptor that uses the same key and IV as the encryptor.
            System.Security.Cryptography.ICryptoTransform ifaceAESdecryptor = objRijndael.CreateDecryptor(baDecryptionKey, baInitializationVector);

            //Now decrypt the previously encrypted message using the decryptor
            // obtained in the above step.
            System.IO.MemoryStream msDecrypt = new System.IO.MemoryStream(baCipherTextBuffer);
            System.Security.Cryptography.CryptoStream csDecrypt = new System.Security.Cryptography.CryptoStream(msDecrypt, ifaceAESdecryptor, System.Security.Cryptography.CryptoStreamMode.Read);

            //Dim baPlainTextBuffer() As Byte
            //baPlainTextBuffer = New Byte(baCipherTextBuffer.Length) {}
            byte[] baPlainTextBuffer = new byte[baCipherTextBuffer.Length + 1];

            //Read the data out of the crypto stream.
            csDecrypt.Read(baPlainTextBuffer, 0, baPlainTextBuffer.Length);

            //Convert the byte array back into a string.
            strReturnValue = enc.GetString(baPlainTextBuffer);
            if (!string.IsNullOrEmpty(strReturnValue))
            {
                strReturnValue = strReturnValue.Trim('\0');
            }

            return(strReturnValue);
        } // End Function DeCrypt
        private string DecryptString(string value)
        {
            try
            {
                byte[] resultBA = new byte[value.Length / 2], valueBA = new byte[value.Length / 2];
                byte[] iv       = new byte[] { 0x14, 0xD7, 0x5B, 0xA2, 0x47, 0x83, 0x0F, 0xC4 };
                System.Text.ASCIIEncoding ascEncoding = new System.Text.ASCIIEncoding();
                byte[] key = new byte[24] {
                    0x21, 0x24, 0x25, 0x23, 0x34, 0x32, 0x37, 0x34, 0x38, 0x6A, 0x73, 0x54, 0x54, 0x4C, 0x7A, 0X51, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
                };

                MemoryStream memStream = new MemoryStream();
                byte[]       tempBA    = HexStringToBytes(value);
                memStream.Write(tempBA, 0, tempBA.Length);
                memStream.Position = 0;

                System.Security.Cryptography.TripleDES
                    cryptoServiceProvider = System.Security.Cryptography.TripleDESCryptoServiceProvider.Create();

                System.Security.Cryptography.ICryptoTransform
                    decryptor = cryptoServiceProvider.CreateDecryptor(key, iv);

                System.Security.Cryptography.CryptoStream
                    cStream = new System.Security.Cryptography.CryptoStream(
                    memStream,
                    decryptor,
                    System.Security.Cryptography.CryptoStreamMode.Read);

                cStream.Read(resultBA, 0, resultBA.Length);
                cStream.Close();

                // Find the first zero
                int i = 0;
                for (; i < resultBA.GetLength(0); i++)
                {
                    if (resultBA[i] == 0)
                    {
                        break;
                    }
                }
                return(ascEncoding.GetString(resultBA, 0, i));
            }
            catch (Exception exc)
            {
                MessageBox.Show("Decryption failure.  " + exc.ToString());
                return(value);
            }
        }
Exemple #10
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        static internal string DecryptString(string value)
        {
            try
            {
                byte[] resultBA = new byte[value.Length / 2], valueBA = new byte[value.Length / 2];
                byte[] iv       = new byte[] { 0x14, 0xD7, 0x5B, 0xA2, 0x47, 0x83, 0x0F, 0xC4 };
                System.Text.ASCIIEncoding ascEncoding = new System.Text.ASCIIEncoding();
                byte[] key = new byte[24] {
                    0x21, 0x24, 0x25, 0x23, 0x34, 0x32, 0x37, 0x34, 0x38, 0x6A, 0x73, 0x54, 0x54, 0x4C, 0x7A, 0X51, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
                };

                MemoryStream memStream = new MemoryStream();
                byte[]       tempBA    = InternalMethods.HexStringToBytes(value);
                memStream.Write(tempBA, 0, tempBA.Length);
                memStream.Position = 0;

                System.Security.Cryptography.TripleDES
                    cryptoServiceProvider = System.Security.Cryptography.TripleDESCryptoServiceProvider.Create();

                System.Security.Cryptography.ICryptoTransform
                    decryptor = cryptoServiceProvider.CreateDecryptor(key, iv);

                System.Security.Cryptography.CryptoStream
                    cStream = new System.Security.Cryptography.CryptoStream(
                    memStream,
                    decryptor,
                    System.Security.Cryptography.CryptoStreamMode.Read);

                cStream.Read(resultBA, 0, resultBA.Length);
                cStream.Close();

                // Find the first zero
                int i = 0;
                for (; i < resultBA.GetLength(0); i++)
                {
                    if (resultBA[i] == 0)
                    {
                        break;
                    }
                }
                return(ascEncoding.GetString(resultBA, 0, i));
            }
            catch (Exception exc)
            {
                EPSEventLog.WriteEntry("Decryption failure.  Returning original value" + Environment.NewLine + exc.Source, EventLogEntryType.Error);
                return(value);
            }
        }
Exemple #11
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 public void Decode(string inFileName, string outFileName)
 {
     System.Security.Cryptography.ICryptoTransform transform = new System.Security.Cryptography.FromBase64Transform();
     using (System.IO.FileStream inFile = System.IO.File.OpenRead(inFileName),
            outFile = System.IO.File.Create(outFileName))
         using (System.Security.Cryptography.CryptoStream cryptStream = new System.Security.Cryptography.CryptoStream(inFile, transform, System.Security.Cryptography.CryptoStreamMode.Read))
         {
             byte[] buffer = new byte[4096];
             int    bytesRead;
             while ((bytesRead = cryptStream.Read(buffer, 0, buffer.Length)) > 0)
             {
                 outFile.Write(buffer, 0, bytesRead);
             }
             outFile.Flush();
         }
 }
        public static string DeCrypt(string strEncryptedInput)
        {
            string strReturnValue = null;

            if (string.IsNullOrEmpty(strEncryptedInput))
            {
                throw new System.ArgumentNullException("strEncryptedInput", "strEncryptedInput may not be string.Empty or NULL, because these are invid values.");
            }

            // Dim encASCII As New System.Text.ASCIIEncoding()
            System.Text.Encoding enc = System.Text.Encoding.UTF8;

            System.Security.Cryptography.RijndaelManaged objRijndael = new System.Security.Cryptography.RijndaelManaged();

            byte[] baCipherTextBuffer = HexStringToByteArray(strEncryptedInput);

            byte[] baDecryptionKey = HexStringToByteArray(strKey);
            byte[] baInitializationVector = HexStringToByteArray(strIV);

            // This is where the message would be transmitted to a recipient
            // who already knows your secret key. Optionally, you can
            // also encrypt your secret key using a public key algorithm
            // and pass it to the mesage recipient along with the RijnDael
            // encrypted message.
            //Get a decryptor that uses the same key and IV as the encryptor.
            System.Security.Cryptography.ICryptoTransform ifaceAESdecryptor = objRijndael.CreateDecryptor(baDecryptionKey, baInitializationVector);

            //Now decrypt the previously encrypted message using the decryptor
            // obtained in the above step.
            System.IO.MemoryStream msDecrypt = new System.IO.MemoryStream(baCipherTextBuffer);
            System.Security.Cryptography.CryptoStream csDecrypt = new System.Security.Cryptography.CryptoStream(msDecrypt, ifaceAESdecryptor, System.Security.Cryptography.CryptoStreamMode.Read);

            //Dim baPlainTextBuffer() As Byte
            //baPlainTextBuffer = New Byte(baCipherTextBuffer.Length) {}
            byte[] baPlainTextBuffer = new byte[baCipherTextBuffer.Length + 1];

            //Read the data out of the crypto stream.
            csDecrypt.Read(baPlainTextBuffer, 0, baPlainTextBuffer.Length);

            //Convert the byte array back into a string.
            strReturnValue = enc.GetString(baPlainTextBuffer);
            if (!string.IsNullOrEmpty(strReturnValue))
                strReturnValue = strReturnValue.Trim('\0');

            return strReturnValue;
        }
Exemple #13
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            /// <summary>
            /// Decrypt a stream based on fixed internal keys
            /// </summary>
            /// <param name="EncryptedStream"></param>
            /// <returns></returns>
            private MemoryStream DecryptStream(Stream EncryptedStream)
            {
                try
                {
                    System.Security.Cryptography.RijndaelManaged Enc = new System.Security.Cryptography.RijndaelManaged();
                    Enc.KeySize = 256;
                    // KEY is 32 byte array
                    Enc.Key = LineMapKeys.ENCKEY;
                    // IV is 16 byte array
                    Enc.IV = LineMapKeys.ENCIV;

                    var cryptoStream = new System.Security.Cryptography.CryptoStream(EncryptedStream, Enc.CreateDecryptor(), System.Security.Cryptography.CryptoStreamMode.Read);

                    byte[] buf = null;
                    buf = new byte[1024];
                    MemoryStream DecryptedStream = new MemoryStream();
                    while (EncryptedStream.Length > 0)
                    {
                        var l = cryptoStream.Read(buf, 0, 1024);
                        if (l == 0)
                        {
                            break;                             // TODO: might not be correct. Was : Exit Do
                        }
                        if (l < 1024)
                        {
                            Array.Resize(ref buf, l);
                        }
                        DecryptedStream.Write(buf, 0, buf.GetUpperBound(0) + 1);
                        if (l < 1024)
                        {
                            break;                             // TODO: might not be correct. Was : Exit Do
                        }
                    }
                    DecryptedStream.Position = 0;
                    return(DecryptedStream);
                }
                catch (Exception ex)
                {
                    System.Diagnostics.Debug.WriteLine(string.Format("ERROR: {0}", ex.ToString()));
                    // any problems, nothing much to do, so return an empty stream
                    return(new MemoryStream());
                }
            }
        /// <summary>
        /// Descriptografa um array de bytes em outro array de bytes.
        /// </summary>
        /// <returns>Array de bytes descriptografado.</returns>
        /// <param name="p_ciphertextbytes">Array de bytes criptografado.</param>
        public byte[] DecryptToBytes(byte[] p_ciphertextbytes)
        {
            byte[] v_plaintextbytes;
            byte[] v_decryptedbytes;
            int    v_decryptedbytecount;
            int    v_saltlength;

            System.IO.MemoryStream v_memory;
            System.Security.Cryptography.CryptoStream v_crypto;

            try
            {
                this.Initialize();

                v_memory = new System.IO.MemoryStream(p_ciphertextbytes);

                v_decryptedbytes = new byte[p_ciphertextbytes.Length];

                lock (this)
                {
                    v_crypto             = new System.Security.Cryptography.CryptoStream(v_memory, this.v_decryptor, System.Security.Cryptography.CryptoStreamMode.Read);
                    v_decryptedbytecount = v_crypto.Read(v_decryptedbytes, 0, v_decryptedbytes.Length);

                    v_memory.Close();
                    v_crypto.Close();
                }

                v_saltlength = (v_decryptedbytes[0] & 0x03) |
                               (v_decryptedbytes[1] & 0x0c) |
                               (v_decryptedbytes[2] & 0x30) |
                               (v_decryptedbytes[3] & 0xc0);

                v_plaintextbytes = new byte[v_decryptedbytecount - v_saltlength];

                System.Array.Copy(v_decryptedbytes, v_saltlength, v_plaintextbytes, 0, v_decryptedbytecount - v_saltlength);

                return(v_plaintextbytes);
            }
            catch (System.Security.Cryptography.CryptographicException e)
            {
                throw new SpartacusMin.Utils.Exception(e);
            }
        }
Exemple #15
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        public string DecryptString(string value, string keyString)
        {
            try
            {
                byte[] resultBA = new byte[value.Length / 2], valueBA = new byte[value.Length / 2];
                byte[] iv       = new byte[] { 0x14, 0xD7, 0x5B, 0xA2, 0x47, 0x83, 0x0F, 0xC4 };
                System.Text.ASCIIEncoding ascEncoding = new System.Text.ASCIIEncoding();
                byte[] key = new byte[24];
                ascEncoding.GetBytes(keyString, 0, keyString.Length < 24?keyString.Length:24, key, 0);

                MemoryStream memStream = new MemoryStream();
                byte[]       tempBA    = InternalMethods.HexStringToBytes(value);
                memStream.Write(tempBA, 0, tempBA.Length);
                memStream.Position = 0;

                System.Security.Cryptography.TripleDES
                    cryptoServiceProvider = System.Security.Cryptography.TripleDESCryptoServiceProvider.Create();

                System.Security.Cryptography.ICryptoTransform
                    decryptor = cryptoServiceProvider.CreateDecryptor(key, iv);

                System.Security.Cryptography.CryptoStream
                    cStream = new System.Security.Cryptography.CryptoStream(
                    memStream,
                    decryptor,
                    System.Security.Cryptography.CryptoStreamMode.Read);

                cStream.Read(resultBA, 0, resultBA.Length);
                cStream.Close();

                return(ascEncoding.GetString(resultBA));
            }
            catch (Exception exc)
            {
                LogEvent("Decryption failure.  Returning original value" +
                         Environment.NewLine + exc.Source, "DecryptString()", exc.ToString(), 3);
                return(value);
            }
        }
        private byte[] AESDecrypt(byte[] data, int index, int count, byte[] key)
        {
            byte[] decryptedBytes = null;

            //  Create uninitialized Rijndael encryption object.
            System.Security.Cryptography.RijndaelManaged symmetricKey = new  System.Security.Cryptography.RijndaelManaged();

            // It is required that the encryption mode is Electronic Codebook (ECB)
            // see MS-OFFCRYPTO v1.0 2.3.4.7 pp 39.
            symmetricKey.Mode    = System.Security.Cryptography.CipherMode.ECB;
            symmetricKey.Padding = System.Security.Cryptography.PaddingMode.None;
            symmetricKey.KeySize = keySize;
            // symmetricKey.IV = null; // new byte[16];
            // symmetricKey.Key = key;

            //  Generate decryptor from the existing key bytes and initialization
            //  vector. Key size will be defined based on the number of the key
            //  bytes.
            System.Security.Cryptography.ICryptoTransform decryptor;
            decryptor = symmetricKey.CreateDecryptor(key, null);

            //  Define memory stream which will be used to hold encrypted data.
            using (System.IO.MemoryStream memoryStream = new System.IO.MemoryStream(data, index, count))
            {
                //  Define memory stream which will be used to hold encrypted data.
                using (System.Security.Cryptography.CryptoStream cryptoStream
                           = new System.Security.Cryptography.CryptoStream(memoryStream, decryptor, System.Security.Cryptography.CryptoStreamMode.Read))
                {
                    //  Since at this point we don't know what the size of decrypted data
                    //  will be, allocate the buffer long enough to hold ciphertext;
                    //  plaintext is never longer than ciphertext.
                    decryptedBytes = new byte[data.Length];
                    int decryptedByteCount = cryptoStream.Read(decryptedBytes, 0, decryptedBytes.Length);

                    return(decryptedBytes);
                }
            }
        }
Exemple #17
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        public static string strDecifraString(string strTextoASerDecifrado)
        {
            string strRetorno = "";

            try
            {
                byte[] byTextoASerDeCifrado, byTextoDeCifrado;
                byte[] byKey = new byte[] { 255, 241, 3, 17, 206, 69, 56, 167, 94, 220, 219, 76, 112, 179, 12, 97, 178, 233, 14, 172, 238, 20, 54, 232, 212, 54, 50, 151, 138, 32, 26, 122 };
                byte[] byIV  = new byte[] { 207, 100, 146, 104, 139, 60, 94, 109, 109, 195, 236, 213, 235, 234, 233, 114 };
                System.Text.UnicodeEncoding conversorTexto = new System.Text.UnicodeEncoding();
                System.Security.Cryptography.RijndaelManaged clsSecCrypRijndael = new System.Security.Cryptography.RijndaelManaged();
                clsSecCrypRijndael.Padding = System.Security.Cryptography.PaddingMode.Zeros;

                //Get an encryptor.
                System.Security.Cryptography.ICryptoTransform decifrador = clsSecCrypRijndael.CreateDecryptor(byKey, byIV);

                byTextoASerDeCifrado = System.Convert.FromBase64String(strTextoASerDecifrado);

                // Cria os Streams
                System.IO.MemoryStream memoryStream = new System.IO.MemoryStream(byTextoASerDeCifrado);
                System.Security.Cryptography.CryptoStream cryptoStream = new System.Security.Cryptography.CryptoStream(memoryStream, decifrador, System.Security.Cryptography.CryptoStreamMode.Read);

                byTextoDeCifrado = new byte[byTextoASerDeCifrado.Length];

                // Read all data to the crypto stream and flush it.
                cryptoStream.Read(byTextoDeCifrado, 0, byTextoDeCifrado.Length);

                strRetorno = conversorTexto.GetString(byTextoDeCifrado).Replace("\0", "");
            }
            catch (Exception err)
            {
                m_errException = err;
                return(strRetorno);
            }
            return(strRetorno);
        }
Exemple #18
0
 public override int Read(byte[] buffer, int offset, int count)
 {
     return(_cryptoStream.Read(buffer, offset, count));
 }
Exemple #19
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            public static string Decrypt(string CipherText, string Password,
                string Salt, string HashAlgorithm,
                int PasswordIterations = 2, string InitialVector = "OFRna73m*aze01xY",
                int KeySize = 256)
            {
                if (string.IsNullOrEmpty(CipherText))
                    return "";
                byte[] InitialVectorBytes = Encoding.ASCII.GetBytes(InitialVector);
                byte[] SaltValueBytes = Encoding.ASCII.GetBytes(Salt);
                byte[] CipherTextBytes = Convert.FromBase64String(CipherText);
                System.Security.Cryptography.PasswordDeriveBytes DerivedPassword = new System.Security.Cryptography.PasswordDeriveBytes(Password, SaltValueBytes, HashAlgorithm, PasswordIterations);
                byte[] KeyBytes = DerivedPassword.GetBytes(KeySize / 8);
                System.Security.Cryptography.RijndaelManaged SymmetricKey = new System.Security.Cryptography.RijndaelManaged();
                SymmetricKey.Mode = System.Security.Cryptography.CipherMode.CBC;
                byte[] PlainTextBytes = new byte[CipherTextBytes.Length];
                int ByteCount = 0;
                using (System.Security.Cryptography.ICryptoTransform Decryptor = SymmetricKey.CreateDecryptor(KeyBytes, InitialVectorBytes))
                {
                    using (MemoryStream MemStream = new MemoryStream(CipherTextBytes))
                    {
                        using (System.Security.Cryptography.CryptoStream CryptoStream = new System.Security.Cryptography.CryptoStream(MemStream, Decryptor, System.Security.Cryptography.CryptoStreamMode.Read))
                        {

                            ByteCount = CryptoStream.Read(PlainTextBytes, 0, PlainTextBytes.Length);
                            MemStream.Close();
                            CryptoStream.Close();
                        }
                    }
                }
                SymmetricKey.Clear();
                return Encoding.UTF8.GetString(PlainTextBytes, 0, ByteCount);
            }
Exemple #20
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        public static T ReceiveEncrypted <T>(SharedNetwork.SharedNetworkInfo info)
        {
            Packet packet = ProtoBuf.Serializer.DeserializeWithLengthPrefix <Packet>(info.Stream, ProtoBuf.PrefixStyle.Fixed32);

            if (packet == null)
            {
                throw new Exception("Received packet was null!");
            }

            Printer.PrintDiagnostics("Received {0} byte packet.", packet.Data.Length);

            byte[] decryptedData = packet.Data;
            if (info.DecryptorFunction != null)
            {
                decryptedData = new byte[packet.PayloadSize];
                if (packet.PayloadSize > 0)
                {
                    using (System.IO.MemoryStream memoryStream = new System.IO.MemoryStream(packet.Data))
                        using (System.Security.Cryptography.CryptoStream cs = new System.Security.Cryptography.CryptoStream(memoryStream, info.Decryptor, System.Security.Cryptography.CryptoStreamMode.Read))
                        {
                            cs.Read(decryptedData, 0, decryptedData.Length);
                        }
                }
            }

            if (packet.DecompressedSize.HasValue)
            {
                switch (packet.Compression)
                {
                case PacketCompressionCodec.None:
                    break;

                case PacketCompressionCodec.LZ4:
                    decryptedData = LZ4.LZ4Codec.Decode(decryptedData, 0, decryptedData.Length, packet.DecompressedSize.Value);
                    break;

                case PacketCompressionCodec.LZH:
                {
                    Versionr.Utilities.LZHL.ResetDecompressor(info.LZHLDecompressor);
                    byte[] result = new byte[packet.DecompressedSize.Value];
                    Versionr.Utilities.LZHL.Decompress(info.LZHLDecompressor, decryptedData, (uint)decryptedData.Length, result, (uint)result.Length);
                    decryptedData = result;
                    break;
                }
                }
                Printer.PrintDiagnostics(" - {0} bytes decompressed ({1})", packet.DecompressedSize.Value, packet.Compression);
            }

            if (packet.Checksum != ChecksumCodec.None)
            {
                uint checksum = 0;
                if (packet.Checksum == ChecksumCodec.XXHash)
                {
                    checksum = ComputeChecksumXXHash(decryptedData);
                }
                if (packet.Checksum == ChecksumCodec.Adler32)
                {
                    checksum = ComputeChecksumAdler32(decryptedData);
                }
                if (packet.Checksum == ChecksumCodec.FastFNV)
                {
                    checksum = ComputeChecksumFNVWeak(decryptedData);
                }
                if (packet.Checksum == ChecksumCodec.MurMur3)
                {
                    var hasher = new Versionr.Utilities.Murmur3();
                    var hash   = hasher.ComputeHash(decryptedData);
                    checksum = BitConverter.ToUInt32(hash, 0) ^ BitConverter.ToUInt32(hash, 4) ^ BitConverter.ToUInt32(hash, 8) ^ BitConverter.ToUInt32(hash, 12);
                }
                if (checksum != packet.Hash)
                {
                    throw new Exception("Data did not survive the trip!");
                }
            }

            using (System.IO.MemoryStream memoryStream = new System.IO.MemoryStream(decryptedData))
            {
                return(ProtoBuf.Serializer.Deserialize <T>(memoryStream));
            }
        }
Exemple #21
0
        static void Main(string[] args)
        {
            Intuit.Spc.Map.Features.EntitlementClient.Api.Entitlements.IEntitlementManager e = new Intuit.Spc.Map.Features.EntitlementClient.Api.Entitlements.EntitlementManager();
            e.EntitlementManifestFileName = "C:\\Program Files\\Intuit\\QuickBooks 2010\\Components\\PConfig\\manifest.ecml";

            /*
             * if (e.CheckOfferingCode("068741"))
             * {
             *  Console.WriteLine("OK");
             * }
             *
             * Api.Synchronization.ISynchronizationManager ism = e.GetSynchronizationManager("103347861573284", "405697");
             * object output;
             * if (ism.ApplyVerbalSyncEntitlementsResponse("TOTAL_FLOATING_KEYS", "71477210", out output))
             * {
             *  Console.WriteLine("Good - {0}", output.ToString());
             * }
             *
             * Common.Data.Manifest me = new Common.Data.Manifest();
             * try
             * {
             *  Common.Data.PropertyTypeDescriptor ptd = me.GetPropertyTypeDescriptorByName("TOTAL_FLOATING_KEYS");
             *  Console.WriteLine(ptd.Name);
             * }
             * catch (Exception k)
             * {
             *
             *  Console.WriteLine(k.ToString());
             * }
             */

            /*
             * Api.Entitlements.Custom.IOfferingEntitlement1 iof = (Api.Entitlements.Custom.IOfferingEntitlement1)e.GetOfferingEntitlement("103347861573284", "405697");
             *
             * Console.WriteLine(iof.BindableResourceId);
             *
             * Common.PhoneTransaction.PhoneTransactionManager pm = new Common.PhoneTransaction.PhoneTransactionManager();
             * if (pm.IsEnablementCodeValid("103347861573284", "405697", "", "493864"))
             * {
             *  Console.WriteLine("OKOKOK");
             * }
             */
            /*
             * string c0 = "136471550573136405697";
             * //int k0 = pm.ComputeIndex(c0);
             * //Console.WriteLine("1:{0}", k0);
             *
             * System.Security.Cryptography.HashAlgorithm ha = System.Security.Cryptography.HashAlgorithm.Create("SHA1");
             * System.Text.UTF8Encoding u8e = new System.Text.UTF8Encoding();
             * byte[] c1 = u8e.GetBytes(c0);
             *
             * int tick = System.Environment.TickCount;
             *
             * byte[] c2 = ha.ComputeHash(c1);
             *
             * //Console.WriteLine(BitConverter.ToString(c2));
             *
             * for (int i = 0; i < 0x270f; i++)
             * {
             *  c2 = ha.ComputeHash(c2);
             * }
             *
             * Console.WriteLine("s: {0}", System.Environment.TickCount - tick);
             * Console.WriteLine(BitConverter.ToString(c2));
             *
             * BigInteger bi = new BigInteger(c2);
             * BigInteger bc = new BigInteger((Int64)0x186a0);
             * BigInteger bv = bi % bc;
             *
             * Console.WriteLine("2:{0}", bv.IntValue());
             * int k0 = bv.IntValue();
             *
             * //k0 = pm.ComputeIndex(c0);
             * //Console.WriteLine("1:{0}", k0);
             */
            /*
             * Assembly ab = Assembly.GetAssembly(typeof(BigInteger));
             * Console.WriteLine(ab.FullName);
             *
             *
             * try
             * {
             *  System.Resources.ResourceManager rm = new System.Resources.ResourceManager("Intuit.Spc.Map.Features.EntitlementClient.Common.hash", ab);
             *  byte[] go = (byte[])(rm.GetObject("Hash Table"));
             *
             *  BinaryWriter bw = new BinaryWriter(File.Open("e:\\htv10.dat", FileMode.Create));
             *  bw.Write(go);
             *  bw.Close();
             *
             *  byte[] sum = new byte[20];
             *
             *  Array.Copy(go, k0 * 20, sum, 0, 20);
             *
             *  BigInteger v1 = new BigInteger(sum);
             *  string v2 = k0.ToString().PadLeft(5, '0');
             *  System.Text.UTF8Encoding v3 = new System.Text.UTF8Encoding();
             *  System.Security.Cryptography.HashAlgorithm v4 = System.Security.Cryptography.HashAlgorithm.Create("SHA1");
             *  int v5 = 0;
             *  bool done = false;
             *  m _m = new m(4);
             *  string cc;
             *
             *  int start = Int32.Parse(Console.ReadLine());
             *  int end = Int32.Parse(Console.ReadLine());
             *  Console.WriteLine("start:{0} end{1}", start, end);
             *
             *  for (int k = start; k < end; k++)
             *  {
             *      cc = k.ToString().PadLeft(6, '0');
             *      if(k % 10 == 0) Console.WriteLine(">{0}", cc);
             *      //if (!_m.a_s(cc)) continue;
             *
             *      for (v5 = 0; v5 < 0x2710; v5++)
             *      {
             *          //if(v5 % 1000 == 0) Console.WriteLine("-{0}", v5);
             *
             *          string tt = cc + v5.ToString().PadLeft(4, '0') + v2;
             *          BigInteger bt = new BigInteger(v4.ComputeHash(v3.GetBytes(tt)));
             *
             *          if (v1 == bt)
             *          {
             *              done = true;
             *              Console.WriteLine("Done -- {0}-{1}", k, v5);
             *              break;
             *          }
             *      }
             *
             *      if (done) break;
             *  }
             *
             * }
             * catch (Exception k)
             * {
             *
             *  Console.WriteLine(k.ToString());
             * }
             */

            try
            {
                Type type = typeof(Common.Security.CryptoManager);

                BindingFlags privateBindings = BindingFlags.NonPublic | BindingFlags.Instance | BindingFlags.Public | BindingFlags.Static;

                MethodInfo miGetDescription = type.GetMethod("g", privateBindings);

                object retObj = miGetDescription.Invoke(null, new object[] { });

                System.Security.Cryptography.ICryptoTransform v2 = (System.Security.Cryptography.ICryptoTransform)retObj;

                FileInfo f = Common.Utilities.DirectoryUtilities.GetManifestFileLocation();

                System.IO.FileStream v1 = new System.IO.FileStream(f.FullName,
                                                                   (System.IO.FileMode) 3,
                                                                   (System.IO.FileAccess) 1,
                                                                   (System.IO.FileShare) 3
                                                                   );

                byte[] v0 = null;

                System.Security.Cryptography.ICryptoTransform v7 = v2;

                System.Security.Cryptography.CryptoStream v3 = new System.Security.Cryptography.CryptoStream(v1, v2, (System.Security.Cryptography.CryptoStreamMode) 0);

                if (v1.Length <= 0x7fffffff)
                {
                    Console.WriteLine("{0}------", v1.Length);

                    v0 = new Byte[v1.Length];

                    int len = v3.Read(v0, 0, v0.Length);

                    Console.WriteLine("size read: {0}", len);

                    string pp = System.Text.Encoding.UTF8.GetString(v0);

                    //Console.WriteLine(pp);

                    StreamWriter wp = new StreamWriter("c:\\pk.xml");
                    wp.Write(pp);
                    wp.Close();
                }
            }
            catch (Exception k)
            {
                Console.WriteLine(k.ToString());
            }

            Console.WriteLine("end");
            Console.Read();
        }
Exemple #22
0
        } // End Function Encrypt

        public static string Decrypt(string encryptedInput)
        {
            string returnValue = null;

            if (string.IsNullOrEmpty(encryptedInput))
            {
                return(encryptedInput);
            }

            // System.Text.Encoding enc = System.Text.Encoding.ASCII;
            System.Text.Encoding enc = System.Text.Encoding.UTF8;

            byte[] cipherTextBuffer     = HexStringToByteArray(encryptedInput);
            byte[] decryptionKey        = HexStringToByteArray(s_key);
            byte[] initializationVector = HexStringToByteArray(s_IV);

            using (System.Security.Cryptography.Aes aes = System.Security.Cryptography.Aes.Create())
            {
                // This is where the message would be transmitted to a recipient
                // who already knows your secret key. Optionally, you can
                // also encrypt your secret key using a public key algorithm
                // and pass it to the mesage recipient along with the RijnDael
                // encrypted message.
                //Get a decryptor that uses the same key and IV as the encryptor.
                using (System.Security.Cryptography.ICryptoTransform aesDecryptor = aes.CreateDecryptor(decryptionKey, initializationVector))
                {
                    //Now decrypt the previously encrypted message using the decryptor
                    // obtained in the above step.
                    using (System.IO.MemoryStream msDecrypt = new System.IO.MemoryStream(cipherTextBuffer))
                    {
                        using (System.Security.Cryptography.CryptoStream csDecrypt = new System.Security.Cryptography.CryptoStream(msDecrypt, aesDecryptor, System.Security.Cryptography.CryptoStreamMode.Read))
                        {
                            //Dim baPlainTextBuffer() As Byte
                            //baPlainTextBuffer = New Byte(baCipherTextBuffer.Length) {}
                            byte[] baPlainTextBuffer = new byte[cipherTextBuffer.Length + 1];

                            //Read the data out of the crypto stream.
                            csDecrypt.Read(baPlainTextBuffer, 0, baPlainTextBuffer.Length);

                            //Convert the byte array back into a string.
                            returnValue = enc.GetString(baPlainTextBuffer);
                            if (!string.IsNullOrEmpty(returnValue))
                            {
                                returnValue = returnValue.Trim('\0');
                            }
                        } // End Using csDecrypt
                    }     // End Using msDecrypt
                }         // End Using aesDecryptor
            }             // End Using aes

            System.Array.Clear(cipherTextBuffer, 0, cipherTextBuffer.Length);
            cipherTextBuffer = null;

            System.Array.Clear(decryptionKey, 0, decryptionKey.Length);
            decryptionKey = null;

            System.Array.Clear(initializationVector, 0, initializationVector.Length);
            initializationVector = null;

            return(returnValue);
        } // End Function DeCrypt
        /// <summary>
        /// Descriptografa um array de bytes em outro array de bytes.
        /// </summary>
        /// <returns>Array de bytes descriptografado.</returns>
        /// <param name="p_ciphertextbytes">Array de bytes criptografado.</param>
        public byte[] DecryptToBytes(byte[] p_ciphertextbytes)
        {
            byte[] v_plaintextbytes;
            byte[] v_decryptedbytes;
            int v_decryptedbytecount;
            int v_saltlength;
            System.IO.MemoryStream v_memory;
            System.Security.Cryptography.CryptoStream v_crypto;

            try
            {
                this.Initialize();

                v_memory = new System.IO.MemoryStream(p_ciphertextbytes);

                v_decryptedbytes = new byte[p_ciphertextbytes.Length];

                lock (this)
                {
                    v_crypto = new System.Security.Cryptography.CryptoStream(v_memory, this.v_decryptor, System.Security.Cryptography.CryptoStreamMode.Read);
                    v_decryptedbytecount = v_crypto.Read(v_decryptedbytes, 0, v_decryptedbytes.Length);

                    v_memory.Close();
                    v_crypto.Close();
                }

                v_saltlength = (v_decryptedbytes[0] & 0x03) |
                               (v_decryptedbytes[1] & 0x0c) |
                               (v_decryptedbytes[2] & 0x30) |
                               (v_decryptedbytes[3] & 0xc0);

                v_plaintextbytes = new byte[v_decryptedbytecount - v_saltlength];

                System.Array.Copy(v_decryptedbytes, v_saltlength, v_plaintextbytes, 0, v_decryptedbytecount - v_saltlength);

                return v_plaintextbytes;
            }
            catch (System.Security.Cryptography.CryptographicException e)
            {
                throw new Spartacus.Utils.Exception(e);
            }
        }
Exemple #24
0
        /// <SUMMARY>
        /// Decrypts specified ciphertext using Rijndael symmetric key algorithm.
        /// </SUMMARY>
        /// <PARAM name="cipherText">
        /// Base64-formatted ciphertext value.
        /// </PARAM>
        /// <PARAM name="passPhrase">
        /// Passphrase from which a pseudo-random password will be derived. The
        /// derived password will be used to generate the encryption key.
        /// Passphrase can be any string. In this example we assume that this
        /// passphrase is an ASCII string.
        /// </PARAM>
        /// <PARAM name="saltValue">
        /// Salt value used along with passphrase to generate password. Salt can
        /// be any string. In this example we assume that salt is an ASCII string.
        /// </PARAM>
        /// <PARAM name="hashAlgorithm">
        /// Hash algorithm used to generate password. Allowed values are: "MD5" and
        /// "SHA1". SHA1 hashes are a bit slower, but more secure than MD5 hashes.
        /// </PARAM>
        /// <PARAM name="passwordIterations">
        /// Number of iterations used to generate password. One or two iterations
        /// should be enough.
        /// </PARAM>
        /// <PARAM name="initVector">
        /// Initialization vector (or IV). This value is required to encrypt the
        /// first block of plaintext data. For RijndaelManaged class IV must be
        /// exactly 16 ASCII characters long.
        /// </PARAM>
        /// <PARAM name="keySize">
        /// Size of encryption key in bits. Allowed values are: 128, 192, and 256.
        /// Longer keys are more secure than shorter keys.
        /// </PARAM>
        /// <RETURNS>
        /// Decrypted string value.
        /// </RETURNS>
        /// <REMARKS>
        /// Most of the logic in this function is similar to the Encrypt
        /// logic. In order for decryption to work, all parameters of this function
        /// - except cipherText value - must match the corresponding parameters of
        /// the Encrypt function which was called to generate the
        /// ciphertext.
        /// </REMARKS>
        public string Decrypt(string cipherText)
        {
            // Convert strings defining encryption key characteristics to byte
            // arrays. Let us assume that strings only contain ASCII codes.
            // If strings include Unicode characters, use Unicode, UTF7, or UTF8
            // encoding.
            byte[] initVectorBytes = Encoding.ASCII.GetBytes(initVector);
            byte[] saltValueBytes  = Encoding.ASCII.GetBytes(saltValue);

            // Convert our ciphertext to a byte array.
            byte[] cipherTextBytes = Convert.FromBase64String(cipherText);

            // First, we must create a password, from which the key will be
            // derived. This password will be generated from the specified
            // passphrase and salt value. The password will be created using
            // the specified hash algorithm. Password creation can be done in
            // several iterations.
            System.Security.Cryptography.PasswordDeriveBytes password = new System.Security.Cryptography.PasswordDeriveBytes(
                passPhrase,
                saltValueBytes,
                hashAlgorithm,
                passwordIterations);

            // Use the password to generate pseudo-random bytes for the encryption
            // key. Specify the size of the key in bytes (instead of bits).
            byte[] keyBytes = password.GetBytes(keySize / 8);

            // Create uninitialized Rijndael encryption object.
            System.Security.Cryptography.RijndaelManaged symmetricKey = new System.Security.Cryptography.RijndaelManaged();

            // It is reasonable to set encryption mode to Cipher Block Chaining
            // (CBC). Use default options for other symmetric key parameters.
            symmetricKey.Mode = System.Security.Cryptography.CipherMode.CBC;

            // Generate decryptor from the existing key bytes and initialization
            // vector. Key size will be defined based on the number of the key
            // bytes.
            System.Security.Cryptography.ICryptoTransform decryptor = symmetricKey.CreateDecryptor(
                keyBytes,
                initVectorBytes);

            // Define memory stream which will be used to hold encrypted data.
            System.IO.MemoryStream memoryStream = new System.IO.MemoryStream(cipherTextBytes);

            // Define cryptographic stream (always use Read mode for encryption).
            System.Security.Cryptography.CryptoStream cryptoStream = new System.Security.Cryptography.CryptoStream(memoryStream,
                                                                                                                   decryptor,
                                                                                                                   System.Security.Cryptography.CryptoStreamMode.Read);

            // Since at this point we don't know what the size of decrypted data
            // will be, allocate the buffer long enough to hold ciphertext;
            // plaintext is never longer than ciphertext.
            byte[] plainTextBytes = new byte[cipherTextBytes.Length];

            // Start decrypting.
            int decryptedByteCount = cryptoStream.Read(plainTextBytes,
                                                       0,
                                                       plainTextBytes.Length);

            // Close both streams.
            memoryStream.Close();
            cryptoStream.Close();

            // Convert decrypted data to a string.
            // Let us assume that the original plaintext string was UTF8-encoded.
            string plainText = Encoding.UTF8.GetString(plainTextBytes,
                                                       0,
                                                       decryptedByteCount);

            // Return decrypted string.
            return(plainText);
        }
        private byte[] AESDecrypt(byte[] data, int index, int count, byte[] key)
        {
            byte[] decryptedBytes = null;

            //  Create uninitialized Rijndael encryption object.
             System.Security.Cryptography.RijndaelManaged symmetricKey = new  System.Security.Cryptography.RijndaelManaged();

            // It is required that the encryption mode is Electronic Codebook (ECB)
            // see MS-OFFCRYPTO v1.0 2.3.4.7 pp 39.
            symmetricKey.Mode = System.Security.Cryptography.CipherMode.ECB;
            symmetricKey.Padding = System.Security.Cryptography.PaddingMode.None;
            symmetricKey.KeySize = keySize;
            // symmetricKey.IV = null; // new byte[16];
            // symmetricKey.Key = key;

            //  Generate decryptor from the existing key bytes and initialization
            //  vector. Key size will be defined based on the number of the key
            //  bytes.
            System.Security.Cryptography.ICryptoTransform decryptor;
            decryptor = symmetricKey.CreateDecryptor(key, null);

            //  Define memory stream which will be used to hold encrypted data.
            using (System.IO.MemoryStream memoryStream = new System.IO.MemoryStream(data, index, count))
            {
                //  Define memory stream which will be used to hold encrypted data.
                using (System.Security.Cryptography.CryptoStream cryptoStream
                        = new System.Security.Cryptography.CryptoStream(memoryStream, decryptor, System.Security.Cryptography.CryptoStreamMode.Read))
                {
                    //  Since at this point we don't know what the size of decrypted data
                    //  will be, allocate the buffer long enough to hold ciphertext;
                    //  plaintext is never longer than ciphertext.
                    decryptedBytes = new byte[data.Length];
                    int decryptedByteCount = cryptoStream.Read(decryptedBytes, 0, decryptedBytes.Length);

                    return decryptedBytes;
                }
            }
        }
        private byte[] Decrypt(byte[] EncData)
        {
            byte[] Result = null;

            try
            {
                System.Security.Cryptography.RijndaelManaged Enc = new System.Security.Cryptography.RijndaelManaged();
                Enc.KeySize = 256;
                Enc.Key = this.Encryption_Key();
                Enc.IV = this.Encryption_IV();

                System.IO.MemoryStream memoryStream = new System.IO.MemoryStream(EncData);
                System.Security.Cryptography.CryptoStream cryptoStream = null;
                cryptoStream = new System.Security.Cryptography.CryptoStream(memoryStream, Enc.CreateDecryptor(), System.Security.Cryptography.CryptoStreamMode.Read);

                byte[] TempDecryptArr = null;
                TempDecryptArr = new byte[EncData.Length + 1];
                int decryptedByteCount = 0;
                decryptedByteCount = cryptoStream.Read(TempDecryptArr, 0, EncData.Length);

                cryptoStream.Close();
                memoryStream.Close();
                cryptoStream.Dispose();
                memoryStream.Dispose();

                Result = new byte[decryptedByteCount + 1];
                Array.Copy(TempDecryptArr, Result, decryptedByteCount);
            }
            catch (Exception)
            {
                Result = null;
            }

            return Result;
        }