Encrypting Data table object

Question

Hello All,

Can any one please help in finding the best method to encrypt and decry-pt a data table object in c# windows forms.  It would be really great, if i can get the code snippet also.

- I wish, i could use the symmetric method of encryption for this.

Regards

Rithesh Krishnan

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RK

Answer 1

You can use DataTable.ReadXml method to convert datable into xml and then you can encrypt it and save it in file

public static void EncryptFile(DataTable dataTable, string destinationFilePath)
{
	XmlTextWriter writer = new XmlTextWriter(destinationFilePath, Encoding.UTF8);
	UnicodeEncoding a = new UnicodeEncoding();
	byte[] key = a.GetBytes(mKey);
	RijndaelManaged rm = new RijndaelManaged();
	CryptoStream strm = new CryptoStream(writer.BaseStream, rm.CreateEncryptor(key, key), CryptoStreamMode.Write);

	dataTable.WriteXml(strm);
	strm.Close();
}


public static DataSet DecryptFile(string sourceFilePath)
{
	DataSet dt = new DataSet();
	FileStream fs = new FileStream(sourceFilePath, FileMode.Open);
	StreamReader sr = new StreamReader(fs);
	UnicodeEncoding encoding = new UnicodeEncoding();
	byte[] key = encoding.GetBytes(mKey);
	RijndaelManaged rm = new RijndaelManaged();
	CryptoStream strm = new CryptoStream(fs, rm.CreateDecryptor(key, key), CryptoStreamMode.Read);

	dt.ReadXml(strm);
	sr.Close();
	fs.Close();
	return dt;
}

You can use following code to Encrypt datable

DataTable dt = new DataTable("TEST");

dt.Columns.Add("FileName");
dt.Rows.Add("GAURAV");
dt.Rows.Add("KHANNA");
EncryptFile(dt, "C:\\ABC.txt");

And following code to decrypt it

DataSet ds= DecryptFile("C:\\ABC.txt")

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Gaurav Khanna | Microsoft VB.NET MVP

Answer 2

Hi Gaurav,

Could you please help about the parameter 'mkey' used in the snippet.

byte[] key = encoding.GetBytes(mKey);

- Just also would like to add, i wish to add a secret key encryption for this. How do i implement in the above code.

Regards

Rithesh

---

RK

Answer 3

You can have a secret text in mKey variable in above code. It should be same in encryption and decryption code

For example,

mKey = "12345678";

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Gaurav Khanna | Microsoft VB.NET MVP

Answer 4

Hi Rithesh,
How is it going with Gaurav’s suggestions?
If you want to decrypt it with Asymmetric Keys, you might read How to: Encrypt XML Elements with Asymmetric Keys.
If you want to decrypt it with Symmetric Keys, you might read How to: Encrypt XML Elements with Symmetric Keys.
If you have anything unclear, please feel free to let us know.
Best Regards,

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Bob Wu [MSFT]
MSDN Community Support | Feedback to us

Answer 5

Hello Gaurav, Bob,

First of all, my apologies for late reply. I couldn't access my net due to some technical issues.

Gaurav, i implemented the snippet which you have kindly given. Thanks a ton for that.

Bob, The links which you had given provided me a greater insight to the possibilities in cryptography.  Thanks again.

Just a doubt, since i am working with the data table objects, just curious whether we can generate MD5 hash code of a data grid view row (having columns of multiple data type).

Regards

Rithesh

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RK