Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

client-server application encrypt/decrypt

Posted on 2014-12-26
8
Medium Priority
?
225 Views
Last Modified: 2015-01-03
Hi,

I have client server application, I am trying to encrypt all data communication between client and server. Please suggest me how can i do it? Should I use System.Security.Cryptography class or there is any easy way too.

Please guide,

Thanks
0
Comment
Question by:Bertrand Russell
  • 4
  • 3
8 Comments
 
LVL 36

Expert Comment

by:ste5an
ID: 40518403
Well, it depends on your concrete type of communications and the concrete requirements.

Do you need protocol or message encryption? The first could be done by tunneling, e.g. SSL/SSH. So this can be done by the OS.
Message encryption means that you application needs to handled by you application.

So without further information, it's hard to guess.
0
 

Author Comment

by:Bertrand Russell
ID: 40518433
thanks for message. I need message level encryption
Please guide

Thanks
0
 
LVL 36

Expert Comment

by:ste5an
ID: 40518454
What kind of communications? Web Services (WCF) has already a built-in mechanism for that:

E.g.

<bindings>
	<wsHttpBinding>
		<binding name="netTcpEndpointBinding">
			<security mode="message"></security>
		</binding>
	</wsHttpBinding>
</bindings>

Open in new window


See also:

* Message Security in WCF
* Chapter 7: Message and Transport Security
0
VIDEO: THE CONCERTO CLOUD FOR HEALTHCARE

Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

 

Author Comment

by:Bertrand Russell
ID: 40518485
It is windows service, so client is c# interface/application and server is a windows service. Please guide how to make message level encryption! thx
0
 
LVL 36

Expert Comment

by:ste5an
ID: 40518535
In this general case you need to encrypt/decrypt each message. Here you use the System.Security.Cryptography namspace of the .Net framework.

See Encrypting and Decrypting Data.
0
 

Author Comment

by:Bertrand Russell
ID: 40518565
I have tried this code, it is encrypting and decrypting data well on local machine but when I send data to remote machine, the decryption fails. What is wrong in this code that make it not working on remote machine while working on local is fine!

  public static byte[] Key = new byte[]{0x43, 0x72, 0x6e, 0x6d, 0x54, 0x4d, 0x65,
                                      0x94, 0x16, 0x32, 0x44, 0x84, 0x7e, 0x18,
                                      0x64, 0x76, 0x6e, 0x63, 0x64, 0x7a, 0x5f,
                                      0x84, 0x7f, 0x9a};

        public static string Encrypt(string toEncrypt, bool useHashing)
        {
            byte[] keyArray;
            byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);


            if (useHashing)
            {
                MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
                //keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
                keyArray = hashmd5.ComputeHash(Key);

                hashmd5.Clear();
            }
            else
                keyArray = Key;

            TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
            tdes.Key = keyArray;
            tdes.Mode = CipherMode.ECB;
            tdes.Padding = PaddingMode.PKCS7;

            ICryptoTransform cTransform = tdes.CreateEncryptor();
            byte[] resultArray =
              cTransform.TransformFinalBlock(toEncryptArray, 0,
              toEncryptArray.Length);
            //Release resources held by TripleDes Encryptor
            tdes.Clear();
            //Return the encrypted data into unreadable string format
            return Convert.ToBase64String(resultArray, 0, resultArray.Length);
        }

        public static string Decrypt(string cipherString, bool useHashing)
        {
            byte[] keyArray;
            //get the byte code of the string

            byte[] toEncryptArray = Convert.FromBase64String(cipherString);



            if (useHashing)
            {
                //if hashing was used get the hash code with regards to your key
                MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
                //keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
                keyArray = hashmd5.ComputeHash(Key);
                //release any resource held by the MD5CryptoServiceProvider

                hashmd5.Clear();
            }
            else
            {
                keyArray = Key;
            }

            TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
            //set the secret key for the tripleDES algorithm
            tdes.Key = keyArray;

            tdes.Mode = CipherMode.ECB;
            //padding mode(if any extra byte added)
            tdes.Padding = PaddingMode.PKCS7;

            ICryptoTransform cTransform = tdes.CreateDecryptor();
            byte[] resultArray = cTransform.TransformFinalBlock(
                                 toEncryptArray, 0, toEncryptArray.Length);
            //Release resources held by TripleDes Encryptor                
            tdes.Clear();
            //return the Clear decrypted TEXT
            return UTF8Encoding.UTF8.GetString(resultArray);
        }

        public static Byte[] Encrypt(Byte[] toEncrypt, bool useHashing)
        {
            byte[] keyArray;
            // byte[] toEncryptArray = UTF8Encoding.UTF8.GetBytes(toEncrypt);
            byte[] toEncryptArray = toEncrypt;

            if (useHashing)
            {
                MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
                //keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
                keyArray = hashmd5.ComputeHash(Key);

                hashmd5.Clear();
            }
            else
                keyArray = Key;

            TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
            //set the secret key for the tripleDES algorithm
            tdes.Key = keyArray;
            //mode of operation. there are other 4 modes.
            //We choose ECB(Electronic code Book)
            tdes.Mode = CipherMode.ECB;
            //padding mode(if any extra byte added)

            tdes.Padding = PaddingMode.PKCS7;

            ICryptoTransform cTransform = tdes.CreateEncryptor();
            //transform the specified region of bytes array to resultArray
            byte[] resultArray =
              cTransform.TransformFinalBlock(toEncryptArray, 0,
              toEncryptArray.Length);
            //Release resources held by TripleDes Encryptor
            tdes.Clear();
            //Return the encrypted data into unreadable string format
            // return Convert.ToBase64String(resultArray, 0, resultArray.Length);
            return resultArray;
        }

        public static Byte[] Decrypt(Byte[] cipherString, bool useHashing)
        {
            byte[] keyArray;
            //get the byte code of the string

            // byte[] toEncryptArray = Convert.FromBase64String(cipherString);
            byte[] toEncryptArray = cipherString;



            if (useHashing)
            {
                //if hashing was used get the hash code with regards to your key
                MD5CryptoServiceProvider hashmd5 = new MD5CryptoServiceProvider();
                //keyArray = hashmd5.ComputeHash(UTF8Encoding.UTF8.GetBytes(key));
                keyArray = hashmd5.ComputeHash(Key);
                //release any resource held by the MD5CryptoServiceProvider

                hashmd5.Clear();
            }
            else
            {
                //if hashing was not implemented get the byte code of the key
                //keyArray = UTF8Encoding.UTF8.GetBytes(key);
                keyArray = Key;
            }

            TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
            //set the secret key for the tripleDES algorithm
            tdes.Key = keyArray;
            //mode of operation. there are other 4 modes. 
            //We choose ECB(Electronic code Book)

            tdes.Mode = CipherMode.ECB;
            //padding mode(if any extra byte added)
            tdes.Padding = PaddingMode.PKCS7;

            ICryptoTransform cTransform = tdes.CreateDecryptor();
            byte[] resultArray = cTransform.TransformFinalBlock(
                                 toEncryptArray, 0, toEncryptArray.Length);
            //Release resources held by TripleDes Encryptor                
            tdes.Clear();
            //return the Clear decrypted TEXT
            // return UTF8Encoding.UTF8.GetString(resultArray);
            return resultArray;
        }

Open in new window

0
 
LVL 1

Accepted Solution

by:
mkk3939 earned 2000 total points
ID: 40529576
key on both sides should be same, otherwise it can make problem. Otherwise, code is fine, I checked it at my end.
0
 

Author Closing Comment

by:Bertrand Russell
ID: 40529577
Yes, thanks
0

Featured Post

Free Tool: IP Lookup

Get more info about an IP address or domain name, such as organization, abuse contacts and geolocation.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article is for Object-Oriented Programming (OOP) beginners. An Interface contains declarations of events, indexers, methods and/or properties. Any class which implements the Interface should provide the concrete implementation for each Inter…
Hello there! As a developer I have modified and refactored the unit tests which was written by fellow developers in the past. On the course, I have gone through various misconceptions and technical challenges when it comes to implementation. I would…
Please read the paragraph below before following the instructions in the video — there are important caveats in the paragraph that I did not mention in the video. If your PaperPort 12 or PaperPort 14 is failing to start, or crashing, or hanging, …
In a question here at Experts Exchange (https://www.experts-exchange.com/questions/29062564/Adobe-acrobat-reader-DC.html), a member asked how to create a signature in Adobe Acrobat Reader DC (the free Reader product, not the paid, full Acrobat produ…

926 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question