IRubyObject cert = args[1];
PrivateKey key = ((PKey)pkey).getPrivateKey();
X509AuxCertificate x509 = ((X509Cert)cert).getAuxCert();
int flg = dflags.isNil() ? 0 : RubyNumeric.fix2int(dflags);
BIO out = BIO.mem();
try {
p7.decrypt(key, x509, out, flg);
} catch (PKCS7Exception pkcs7e) {
throw newPKCS7Exception(getRuntime(), pkcs7e);
}