C#: System.Security.Cryptography
SQL Server: Sql Server Encryption
C# Example from here:
private static void EncryptData(String inName, String outName, byte[] tdesKey, byte[] tdesIV)
{
//Create the file streams to handle the input and output files.
FileStream fin = new FileStream(inName, FileMode.Open, FileAccess.Read);
FileStream fout = new FileStream(outName, FileMode.OpenOrCreate, FileAccess.Write);
fout.SetLength(0);
//Create variables to help with read and write.
byte[] bin = new byte[100]; //This is intermediate storage for the encryption.
long rdlen = 0; //This is the total number of bytes written.
long totlen = fin.Length; //This is the total length of the input file.
int len; //This is the number of bytes to be written at a time.
TripleDESCryptoServiceProvider tdes = new TripleDESCryptoServiceProvider();
CryptoStream encStream = new CryptoStream(fout, tdes.CreateEncryptor(tdesKey, tdesIV), CryptoStreamMode.Write);
Console.WriteLine("Encrypting...");
//Read from the input file, then encrypt and write to the output file.
while(rdlen < totlen)
{
len = fin.Read(bin, 0, 100);
encStream.Write(bin, 0, len);
rdlen = rdlen + len;
Console.WriteLine("{0} bytes processed", rdlen);
}
encStream.Close();
}
SQL Server Example from here:
USE AdventureWorks2008R2;
GO
--If there is no master key, create one now.
IF NOT EXISTS
(SELECT * FROM sys.symmetric_keys WHERE symmetric_key_id = 101)
CREATE MASTER KEY ENCRYPTION BY
PASSWORD = '23987hxJKL969#ghf0%94467GRkjg5k3fd117r$$#1946kcj$n44nhdlj'
GO
CREATE CERTIFICATE HumanResources037
WITH SUBJECT = 'Employee Social Security Numbers';
GO
CREATE SYMMETRIC KEY SSN_Key_01
WITH ALGORITHM = AES_256
ENCRYPTION BY CERTIFICATE HumanResources037;
GO
USE [AdventureWorks2008R2];
GO
-- Create a column in which to store the encrypted data.
ALTER TABLE HumanResources.Employee
ADD EncryptedNationalIDNumber varbinary(128);
GO
-- Open the symmetric key with which to encrypt the data.
OPEN SYMMETRIC KEY SSN_Key_01
DECRYPTION BY CERTIFICATE HumanResources037;
-- Encrypt the value in column NationalIDNumber with symmetric
-- key SSN_Key_01. Save the result in column EncryptedNationalIDNumber.
UPDATE HumanResources.Employee
SET EncryptedNationalIDNumber = EncryptByKey(Key_GUID('SSN_Key_01'), NationalIDNumber);
GO
-- Verify the encryption.
-- First, open the symmetric key with which to decrypt the data.
OPEN SYMMETRIC KEY SSN_Key_01
DECRYPTION BY CERTIFICATE HumanResources037;
GO
-- Now list the original ID, the encrypted ID, and the
-- decrypted ciphertext. If the decryption worked, the original
-- and the decrypted ID will match.
SELECT NationalIDNumber, EncryptedNationalIDNumber
AS 'Encrypted ID Number',
CONVERT(nvarchar, DecryptByKey(EncryptedNationalIDNumber))
AS 'Decrypted ID Number'
FROM HumanResources.Employee;
GO