#include "../lib/lib2.h"
#include "../lib/lib.h"
/**
  * produces an identical bit error in the following block
  * this means: we can control the whole content of the following
  * block, when the counterpart decrpyts it
  * If there is a 0 in the second block and we want a 1, then flip
  * the bit in the prior block at the same position
  * If there is a 0 and we want a null, than do nothing
  * For one respectivally.
  *
  * Since ; and = are escaped we need charecters so that with one flip
  * we can get ; and =.
  * for ; use : in the plaintext. in the ciphtertext we need to flip the
  * last bit of : and the resulting plaintext get ;
  * for = we use <. we also need to flip the last bit
  *
  * so out plaintext we give the orcale function is :admin<true:
  *
  *
  *
  */
int main(int argc, char **argv)
{
	// initialize key
	generate_random_bytes(key, 16);
	memset(iv, 0, 16);
	//generate_random_bytes(iv, 16);
	char *encrypted;
	// one block of our input
	int length = challenge16_encrypt(":admin<true:1234", &encrypted);

	printf("first the unchanged string:\n");
	challenge16_decrypt(encrypted, length);
	/**
	  * change ciphertext here
	  * we now that our text start a the third block, because the 
	  * challenge16_encrypt function prepends a string
	  * we need to flip three bits, the 8th bit, 56th bit and the
	  * 96th bit
	  */
	encrypted[32-16] ^= 0x01;
	encrypted[38-16] ^= 0x01;
	encrypted[43-16] ^= 0x01;

	printf("now the changed string:\n");
	challenge16_decrypt(encrypted, length);
}