serval-dna/nacl/nacl-20110221/tests/box8.c

#include <stdio.h>
#include "crypto_box.h"
#include "randombytes.h"

unsigned char alicesk[crypto_box_SECRETKEYBYTES];
unsigned char alicepk[crypto_box_PUBLICKEYBYTES];
unsigned char bobsk[crypto_box_SECRETKEYBYTES];
unsigned char bobpk[crypto_box_PUBLICKEYBYTES];
unsigned char n[crypto_box_NONCEBYTES];
unsigned char m[10000];
unsigned char c[10000];
unsigned char m2[10000];

main()
{
  int mlen;
  int i;
  int caught;

  for (mlen = 0;mlen < 1000 && mlen + crypto_box_ZEROBYTES < sizeof m;++mlen) {
    crypto_box_keypair(alicepk,alicesk);
    crypto_box_keypair(bobpk,bobsk);
    randombytes(n,crypto_box_NONCEBYTES);
    randombytes(m + crypto_box_ZEROBYTES,mlen);
    crypto_box(c,m,mlen + crypto_box_ZEROBYTES,n,bobpk,alicesk);
    caught = 0;
    while (caught < 10) {
      c[random() % (mlen + crypto_box_ZEROBYTES)] = random();
      if (crypto_box_open(m2,c,mlen + crypto_box_ZEROBYTES,n,alicepk,bobsk) == 0) {
        for (i = 0;i < mlen + crypto_box_ZEROBYTES;++i)
          if (m2[i] != m[i]) {
	    printf("forgery\n");
	    return 100;
	  }
      } else {
        ++caught;
      }
    }
  }
  return 0;
}