I have to decrypt a string encrypted in C# as a part of our project. This decryption is done using AES algorithm and packing mode as PKCS7. For generating the initialization vector they have used the following:
Rfc2898DeriveBytes keyGenerator = new Rfc2898DeriveBytes("somestring", salt);
The salt is the default bytes.
This IV is used in encrypting the string using AES.
I have read through some documents and found that AES can be implemented in Java. But not sure on how to pass the IV and packing mode.
Also, I have seen that there are modes CBC, ECB for mentioning the Cipher block mode. I am not sure what mode is used in C# counterpart.
Below is the code in C#
/// Method to encrypt the plain text based on the key and Iv
/// </summary>
/// <param name="plainText"></param>
/// <param name="key"></param>
/// <returns>encrypted Text</returns>
private string Encrypt(string plainText, byte[] key)
{
if (plainText == null || plainText.Length <= 0)
throw new ArgumentNullException("plainText");
if (key == null || key.Length <= 0)
throw new ArgumentNullException("Key");
// Declare the stream used to encrypt to an in memory
// array of bytes.
MemoryStream msEncrypt = null;
// Declare the RijndaelManaged object
// used to encrypt the data.
AesCryptoServiceProvider aesAlg = null;
// using (new Tracer("Encryption","",""))
// {
try
{
// Create a RijndaelManaged object
// with the specified key and IV.
aesAlg = new AesCryptoServiceProvider();
aesAlg.Key = key;
aesAlg.IV = GetInitializationVector();
aesAlg.Padding = PaddingMode.PKCS7;
// Create an encryptor to perform the stream transform.
ICryptoTransform encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV);
// Create the streams used for encryption.
msEncrypt = new MemoryStream();
using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
{
using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
{
//Write all data to the stream.
swEncrypt.Write(plainText);
}
}
}
catch (Exception ex)
{
throw ex;
}
finally
{
// Clear the RijndaelManaged object.
if (aesAlg != null)
aesAlg.Clear();
}
// Return the encrypted bytes from the memory stream.
// Console.WriteLine();
return Convert.ToBase64String(msEncrypt.ToArray());
// }
}
private byte[] GetInitializationVector()
{
byte[] iv;
//create the initial salt
byte[] salt = Encoding.Default.GetBytes("abcdefghijkl");
//create the key generator
Rfc2898DeriveBytes keyGenerator = new Rfc2898DeriveBytes("ricksaw", salt);
iv = keyGenerator.GetBytes(16);
return iv;
}
Can any one help me to create the equivalent in Java?