if (callback != NULL) callback(0,counter,cb_arg);
DSA *DSA_generate_parameters(int bits, unsigned char *seed_in, int seed_len,	     int *counter_ret, unsigned long *h_ret, void (*callback)(),	     void *cb_arg)	{	int ok=0;	unsigned char seed[SHA_DIGEST_LENGTH];	unsigned char md[SHA_DIGEST_LENGTH];	unsigned char buf[SHA_DIGEST_LENGTH],buf2[SHA_DIGEST_LENGTH];	BIGNUM *r0,*W,*X,*c,*test;	BIGNUM *g=NULL,*q=NULL,*p=NULL;	BN_MONT_CTX *mont=NULL;	int k,n=0,i,b,m=0;	int counter=0;	BN_CTX *ctx=NULL,*ctx2=NULL;	unsigned int h=2;	DSA *ret=NULL;	if (bits < 512) bits=512;	bits=(bits+63)/64*64;	if (seed_len < 20) seed_in = NULL;	if ((seed_in != NULL) && (seed_len == 20))		memcpy(seed,seed_in,seed_len);	if ((ctx=BN_CTX_new()) == NULL) goto err;	if ((ctx2=BN_CTX_new()) == NULL) goto err;	if ((ret=DSA_new()) == NULL) goto err;	if ((mont=BN_MONT_CTX_new()) == NULL) goto err;	r0= &(ctx2->bn[0]);	g= &(ctx2->bn[1]);	W= &(ctx2->bn[2]);	q= &(ctx2->bn[3]);	X= &(ctx2->bn[4]);	c= &(ctx2->bn[5]);	p= &(ctx2->bn[6]);	test= &(ctx2->bn[7]);	BN_lshift(test,BN_value_one(),bits-1);	for (;;)		{		for (;;)			{			/* step 1 */			if (callback != NULL) callback(0,m++,cb_arg);			if (!seed_len)				RAND_pseudo_bytes(seed,SHA_DIGEST_LENGTH);			else				seed_len=0;			memcpy(buf,seed,SHA_DIGEST_LENGTH);			memcpy(buf2,seed,SHA_DIGEST_LENGTH);			for (i=SHA_DIGEST_LENGTH-1; i >= 0; i--)				{				buf[i]++;				if (buf[i] != 0) break;				}			/* step 2 */			HASH(seed,SHA_DIGEST_LENGTH,md);			HASH(buf,SHA_DIGEST_LENGTH,buf2);			for (i=0; i<SHA_DIGEST_LENGTH; i++)				md[i]^=buf2[i];			/* step 3 */			md[0]|=0x80;			md[SHA_DIGEST_LENGTH-1]|=0x01;			if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,q)) goto err;			/* step 4 */			if (BN_is_prime(q,BN_prime_checks,callback,NULL,cb_arg) > 0) break;			/* do a callback call */			/* step 5 */			}		if (callback != NULL) callback(2,0,cb_arg);		if (callback != NULL) callback(3,0,cb_arg);		/* step 6 */		counter=0;		n=(bits-1)/160;		b=(bits-1)-n*160;		for (;;)			{			/* step 7 */			BN_zero(W);			for (k=0; k<=n; k++)				{				for (i=SHA_DIGEST_LENGTH-1; i >= 0; i--)					{					buf[i]++;					if (buf[i] != 0) break;					}				HASH(buf,SHA_DIGEST_LENGTH,md);				/* step 8 */				if (!BN_bin2bn(md,SHA_DIGEST_LENGTH,r0))					goto err;				BN_lshift(r0,r0,160*k);				BN_add(W,W,r0);				}			/* more of step 8 */			BN_mask_bits(W,bits-1);			BN_copy(X,W); /* this should be ok */			BN_add(X,X,test); /* this should be ok */			/* step 9 */			BN_lshift1(r0,q);			BN_mod(c,X,r0,ctx);			BN_sub(r0,c,BN_value_one());			BN_sub(p,X,r0);			/* step 10 */			if (BN_cmp(p,test) >= 0)				{				/* step 11 */				if (BN_is_prime(p,BN_prime_checks,callback,NULL,cb_arg) > 0)					goto end;				}			/* step 13 */			counter++;			/* step 14 */			if (counter >= 4096) break;			if (callback != NULL) callback(0,counter,cb_arg);			}		}end:	if (callback != NULL) callback(2,1,cb_arg);	/* We now need to generate g */	/* Set r0=(p-1)/q */	BN_sub(test,p,BN_value_one());	BN_div(r0,NULL,test,q,ctx);	BN_set_word(test,h);	BN_MONT_CTX_set(mont,p,ctx);	for (;;)		{		/* g=test^r0%p */		BN_mod_exp_mont(g,test,r0,p,ctx,mont);		if (!BN_is_one(g)) break;		BN_add(test,test,BN_value_one());		h++;		}	if (callback != NULL) callback(3,1,cb_arg);	ok=1;err:	if (!ok)		{		if (ret != NULL) DSA_free(ret);		}	else		{		ret->p=BN_dup(p);		ret->q=BN_dup(q);		ret->g=BN_dup(g);		if ((m > 1) && (seed_in != NULL)) memcpy(seed_in,seed,20);		if (counter_ret != NULL) *counter_ret=counter;		if (h_ret != NULL) *h_ret=h;		}	if (ctx != NULL) BN_CTX_free(ctx);	if (ctx != NULL) BN_CTX_free(ctx2);	if (mont != NULL) BN_MONT_CTX_free(mont);	return(ok?ret:NULL);	}