Decrypt Files using System.Security.Cryptography in SSIS package

We are getting the encrypted file (Rijndael Algorithm). We need to decrypt these files is load it into the database.

Read: Encrypt Files using System.Security.Cryptography inSSIS package

https://bageshkumarbagi-msbi.blogspot.com/2019/10/encrypt-files-using-systemsecuritycrypt.html

We have an encrypted file that is not a human-readable file.

Here I will decrypt this file using System.Security.Cryptography (Rijndael Algorithm).

I am taking script task. We need to write the below code (in this demo I am decrypting the file which is encrypted by above example post https://bageshkumarbagi-msbi.blogspot.com/2019/10/encrypt-files-using-systemsecuritycrypt.html )

We need to include below namespaces

• using System.Security.Cryptography;
• using System.IO;

Below is the C# code

// Open filestream for encrypted source file             FileStream fsIn = new FileStream(@"J:\SSIS1\Source\sales_10062019__ENCRYPTED.csv", FileMode.Open, FileAccess.Read);             // Open filestream for decrypted file             FileStream fsOut = new FileStream(@"J:\SSIS1\Source\sales_10062019_DECRYPTED.csv", FileMode.OpenOrCreate, FileAccess.Write);             string encryptionKey = "Bagesh"; //Encryption key             // Create Key and IV from the password with salt technique             PasswordDeriveBytes pdb = new PasswordDeriveBytes(encryptionKey, new byte[] { 0x49, 0x76, 0x61, 0x6e, 0x20, 0x4d, 0x65, 0x64, 0x76, 0x65, 0x64, 0x65, 0x76 });             // Create a symmetric algorithm with Rijndael             Rijndael alg = Rijndael.Create();             // Set Key and IV             alg.Key = pdb.GetBytes(32);             alg.IV = pdb.GetBytes(16);             CryptoStream cs = new CryptoStream(fsOut, alg.CreateDecryptor(), CryptoStreamMode.Write);             int bufferLen = 4096;             byte[] buffer = new byte[bufferLen];             int bytesRead;             do             {   // read a chunk of data from the input file                 bytesRead = fsIn.Read(buffer, 0, bufferLen);                 // Decrypt it                 cs.Write(buffer, 0, bytesRead);             } while (bytesRead != 0);             cs.Close();             fsIn.Close();

Compile and save and close this window.

Note: for the encryption and decryption, we need to use the same encryption Key

 Now I am running this package.

  

Executed successfully.

  

Now we can read this file.