Implement gost 28147-89 algorithm for encrypting and decripting in java using bouncycastle

Question

I am trying to implement gost 28147-89 algorithm for encrypting and decrypting string.

In the bouncycastle documentation I didn't understand how to implement gost 28147. How can I make a simple class which encrypts and decrypts a string using the gost 28147-89 algorithm?

Answer 1

Quoting from GOST28147Test.java (basically an example class from the bouncy castle people for exactly that encryption scheme):

key = new SecretKeySpec(keyBytes, "GOST28147");

in = Cipher.getInstance("GOST28147/ECB/NoPadding", "BC");
out = Cipher.getInstance("GOST28147/ECB/NoPadding", "BC");
out.init(Cipher.ENCRYPT_MODE, key);
in.init(Cipher.DECRYPT_MODE, key);

//
// encryption pass
//
bOut = new ByteArrayOutputStream();

cOut = new CipherOutputStream(bOut, out);

for (int i = 0; i != input.length / 2; i++)
{
    cOut.write(input[i]);
}

And so on ...