BN_CTX *ctx;
static int cswift_rsa_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa)	{	BN_CTX *ctx;	int to_return = 0;	if((ctx = BN_CTX_new()) == NULL)		goto err;	if(!rsa->p || !rsa->q || !rsa->dmp1 || !rsa->dmq1 || !rsa->iqmp)		{		CSWIFTerr(CSWIFT_F_CSWIFT_RSA_MOD_EXP,CSWIFT_R_MISSING_KEY_COMPONENTS);		goto err;		}	to_return = cswift_mod_exp_crt(r0, I, rsa->p, rsa->q, rsa->dmp1,		rsa->dmq1, rsa->iqmp, ctx);err:	if(ctx)		BN_CTX_free(ctx);	return to_return;	}