Encrypt on CLR decrypt in SQL?

Question

Hi folks,
I'm trying to encrypt a small token of data on my client c# application and have it decrypted by SQL on the server side, the problem is i cannot find articles on the subject. I don;t really want to get involved with certificates but base the system on a simple symmetric key that is shared by both parties.
I'm attempting to use the TRIPLE_DES algorithm on both sides and thus far have used the decryptbypassphrase on the server side with the data encrypted on the client side by .Net with no initialization vector setup.
If anyone can recommend any articles or have example (client and server side) code for this situation it would be greatly appreciated.
Many thanks in advance
Simon

Answer 1

I tried doing the exact same thing and so far didn't find a way of doing it. Even though both .net and sql server uses Triple DES algorithm I can not decrypt the string generated in .net from SQL Server.
I .net i use simple provider with a key and a vector. I assume the key corresponds to a passphrase in SQL Server, but unfortunetely I do not know what vector corresponds to.
.NET CODE
public static string Encrypt(string strPlainText)
string strKey16 = "123456789012345";
TripleDESCryptoServiceProvider crp = new TripleDESCryptoServiceProvider();
UnicodeEncoding uEncode = new UnicodeEncoding();
ASCIIEncoding aEncode = new ASCIIEncoding();
// Store plaintext as a byte array
byte[] bytPlainText = uEncode.GetBytes(strPlainText);
// Create a memory stream for holding encrypted text
MemoryStream stmCipherText = new MemoryStream();
// Private key
crp.Key = aEncode.GetBytes(strKey16.Substring(0, 16));
// Initialization vector is the encryption seed
crp.IV = aEncode.GetBytes(strKey16.Substring(8, 8));
// Create a crypto-writer to encrypt a bytearray into a stream
CryptoStream csEncrypted = new CryptoStream(stmCipherText, crp.CreateEncryptor(), CryptoStreamMode.Write);
csEncrypted.Write(bytPlainText, 0, bytPlainText.Length);
csEncrypted.FlushFinalBlock();
// Return result as a Base64 encoded string
return Convert.ToBase64String(stmCipherText.ToArray());
SQL 2005 CODE
DECLARE @cipherText varbinary(1000)
set @cipherText = CAST(N'4hRbT6QDk30DfyHbGyRqfA==' as varbinary(1000))
SELECT CAST(DecryptByPassphrase('WOhPorN5VIKZl$Eqcz4CR104O', @cipherText) AS nvarchar)
The SQL statement returns null.