serval-dna/nacl/nacl-20110221/tests/box6.cpp

#include <string>
using std::string;
#include <stdlib.h>
#include <stdio.h>
#include "crypto_box.h"
#include "randombytes.h"

main()
{
  int mlen;
  for (mlen = 0;mlen < 1000;++mlen) {
    string alicesk;
    string alicepk = crypto_box_keypair(&alicesk);
    string bobsk;
    string bobpk = crypto_box_keypair(&bobsk);
    unsigned char nbytes[crypto_box_NONCEBYTES];
    randombytes(nbytes,crypto_box_NONCEBYTES);
    string n((char *) nbytes,crypto_box_NONCEBYTES);
    unsigned char mbytes[mlen];
    randombytes(mbytes,mlen);
    string m((char *) mbytes,mlen);
    string c = crypto_box(m,n,bobpk,alicesk);
    int caught = 0;
    while (caught < 10) {
      c.replace(random() % c.size(),1,1,random());
      try {
        string m2 = crypto_box_open(c,n,alicepk,bobsk);
        if (m != m2) {
	  printf("forgery\n");
	  return 100;
        }
      } catch(const char *s) {
	if (string(s) == string("ciphertext fails verification"))
	  ++caught;
	else {
	  printf("%s\n",s);
	  return 111;
        }
      }
    }
  }
  return 0;
}