The following code example shows how to set the key schedule for DES encryption or decryption rounds. This step must be performed before encryption or decryption can begin.

#include "msp430xxxx.h"
#include "TI_DES.h"

int main( void )
{  des_ctx       dc1; // Key schedule structure
   des_ctx       dc2; // Key schedule structure

  unsigned char key[8] = {0x01,0x23,0x45,0x67,0x89,0xab,0xcd, 0xfe};

Des_Key(&dc1, key, EN0 );  // Sets up key schedule for Encryption only
Des_Key(&dc1, key, DE1 );  // Sets up key schedule for Decryption only
Des_Key(&dc2, key, ENDE ); // Sets up key schedule for Encryption and Decryption

return 0;
}