/* makes a bignum test harness with NUM tests per operation
 *
 * the output is made in the following format [one parameter per line]

operation
operand1
operand2
[... operandN]
result1
result2
[... resultN]

So for example "a * b mod n" would be 

mulmod
a
b
n
a*b mod n

e.g. if a=3, b=4 n=11 then 

mulmod
3
4
11
1

 */

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include "mpi.c"

FILE *rng;

void rand_num(mp_int *a)
{
   int n, size;
   unsigned char buf[512];

top:
   size = 1 + ((fgetc(rng)*fgetc(rng)) % 32);
   buf[0] = (fgetc(rng)&1)?1:0;
   fread(buf+1, 1, size, rng);
   for (n = 0; n < size; n++) {
       if (buf[n+1]) break;
   }
   if (n == size) goto top;
   mp_read_raw(a, buf, 1+size);
}

void rand_num2(mp_int *a)
{
   int n, size;
   unsigned char buf[512];

top:
   size = 1 + ((fgetc(rng)*fgetc(rng)) % 32);
   buf[0] = (fgetc(rng)&1)?1:0;
   fread(buf+1, 1, size, rng);
   for (n = 0; n < size; n++) {
       if (buf[n+1]) break;
   }
   if (n == size) goto top;
   mp_read_raw(a, buf, 1+size);
}

int main(void)
{
   int n;
   mp_int a, b, c, d, e;
   char buf[4096];

   mp_init(&a);
   mp_init(&b);
   mp_init(&c);
   mp_init(&d);
   mp_init(&e);

   rng = fopen("/dev/urandom", "rb");

   for (;;) {
       n = fgetc(rng) % 11;

   if (n == 0) {
       /* add tests */
       rand_num(&a);
       rand_num(&b);
       mp_add(&a, &b, &c);
       printf("add\n");
       mp_todecimal(&a, buf);
       printf("%s\n", buf);
       mp_todecimal(&b, buf);
       printf("%s\n", buf);
       mp_todecimal(&c, buf);
       printf("%s\n", buf);
   } else if (n == 1) {
      /* sub tests */
       rand_num(&a);
       rand_num(&b);
       mp_sub(&a, &b, &c);
       printf("sub\n");
       mp_todecimal(&a, buf);
       printf("%s\n", buf);
       mp_todecimal(&b, buf);
       printf("%s\n", buf);
       mp_todecimal(&c, buf);
       printf("%s\n", buf);
   } else if (n == 2) {
       /* mul tests */
       rand_num(&a);
       rand_num(&b);
       mp_mul(&a, &b, &c);
       printf("mul\n");
       mp_todecimal(&a, buf);
       printf("%s\n", buf);
       mp_todecimal(&b, buf);
       printf("%s\n", buf);
       mp_todecimal(&c, buf);
       printf("%s\n", buf);
   } else if (n == 3) {
      /* div tests */
       rand_num(&a);
       rand_num(&b);
       mp_div(&a, &b, &c, &d);
       printf("div\n");
       mp_todecimal(&a, buf);
       printf("%s\n", buf);
       mp_todecimal(&b, buf);
       printf("%s\n", buf);
       mp_todecimal(&c, buf);
       printf("%s\n", buf);
       mp_todecimal(&d, buf);
       printf("%s\n", buf);
   } else if (n == 4) {
      /* sqr tests */
       rand_num(&a);
       mp_sqr(&a, &b);
       printf("sqr\n");
       mp_todecimal(&a, buf);
       printf("%s\n", buf);
       mp_todecimal(&b, buf);
       printf("%s\n", buf);
   } else if (n == 5) {
      /* mul_2d test */
      rand_num(&a);
      mp_copy(&a, &b);
      n = fgetc(rng) & 63;
      mp_mul_2d(&b, n, &b);
      mp_todecimal(&a, buf);
      printf("mul2d\n");
      printf("%s\n", buf);
      printf("%d\n", n);
      mp_todecimal(&b, buf);
      printf("%s\n", buf);
   } else if (n == 6) {
      /* div_2d test */
      rand_num(&a);
      mp_copy(&a, &b);
      n = fgetc(rng) & 63;
      mp_div_2d(&b, n, &b, NULL);
      mp_todecimal(&a, buf);
      printf("div2d\n");
      printf("%s\n", buf);
      printf("%d\n", n);
      mp_todecimal(&b, buf);
      printf("%s\n", buf);
   } else if (n == 7) {
      /* gcd test */
      rand_num(&a);
      rand_num(&b);
      a.sign = MP_ZPOS;
      b.sign = MP_ZPOS;
      mp_gcd(&a, &b, &c);
      printf("gcd\n");
      mp_todecimal(&a, buf);
      printf("%s\n", buf);      
      mp_todecimal(&b, buf);
      printf("%s\n", buf);      
      mp_todecimal(&c, buf);
      printf("%s\n", buf);      
   } else if (n == 8) {
      /* lcm test */
      rand_num(&a);
      rand_num(&b);
      a.sign = MP_ZPOS;
      b.sign = MP_ZPOS;
      mp_lcm(&a, &b, &c);
      printf("lcm\n");
      mp_todecimal(&a, buf);
      printf("%s\n", buf);      
      mp_todecimal(&b, buf);
      printf("%s\n", buf);      
      mp_todecimal(&c, buf);
      printf("%s\n", buf);      
   } else if (n == 9) {
      /* exptmod test */
      rand_num2(&a);
      rand_num2(&b);
      rand_num2(&c);
      a.sign = b.sign = c.sign = 0;
      mp_exptmod(&a, &b, &c, &d);
      printf("expt\n");
      mp_todecimal(&a, buf);
      printf("%s\n", buf);      
      mp_todecimal(&b, buf);
      printf("%s\n", buf);      
      mp_todecimal(&c, buf);
      printf("%s\n", buf);      
      mp_todecimal(&d, buf);
      printf("%s\n", buf);      
   } else if (n == 10) {
      /* invmod test */
      rand_num2(&a);
      rand_num2(&b);
      b.sign = MP_ZPOS;
      a.sign = MP_ZPOS;
      mp_gcd(&a, &b, &c);
      if (mp_cmp_d(&c, 1) != 0) continue;
      if (mp_cmp_d(&b, 1) == 0) continue;
      mp_invmod(&a, &b, &c);
      printf("invmod\n");
      mp_todecimal(&a, buf);
      printf("%s\n", buf);      
      mp_todecimal(&b, buf);
      printf("%s\n", buf);      
      mp_todecimal(&c, buf);
      printf("%s\n", buf);      
   } 
   }
   fclose(rng);
   return 0;
}