#include <openssl/bn.h>#include <openssl/rand.h>static int Rand(n){    unsigned char x[2];    RAND_pseudo_bytes(x,2);    return (x[0] + 2*x[1]);}static void bug(char *m, BIGNUM *a, BIGNUM *b){    printf("%s!\na=",m);    BN_print_fp(stdout, a);    printf("\nb=");    BN_print_fp(stdout, b);    printf("\n");    fflush(stdout);}main(){    BIGNUM *a=BN_new(), *b=BN_new(), *c=BN_new(), *d=BN_new(),	*C=BN_new(), *D=BN_new();    BN_RECP_CTX *recp=BN_RECP_CTX_new();    BN_CTX *ctx=BN_CTX_new();    for(;;) {	BN_pseudo_rand(a,Rand(),0,0);	BN_pseudo_rand(b,Rand(),0,0);	if (BN_is_zero(b)) continue;	BN_RECP_CTX_set(recp,b,ctx);	if (BN_div(C,D,a,b,ctx) != 1)	    bug("BN_div failed",a,b);	if (BN_div_recp(c,d,a,recp,ctx) != 1)	    bug("BN_div_recp failed",a,b);	else if (BN_cmp(c,C) != 0 || BN_cmp(c,C) != 0)	    bug("mismatch",a,b);    }}