OpenSSL::PKCS7.write_smime

static VALUE
ossl_pkcs7_s_write_smime(int argc, VALUE *argv, VALUE klass)
{
    VALUE pkcs7, data, flags;
    BIO *out, *in;
    PKCS7 *p7;
    VALUE str;
    int flg;

    rb_scan_args(argc, argv, "12", &pkcs7, &data, &flags);
    flg = NIL_P(flags) ? 0 : NUM2INT(flags);
    if(NIL_P(data)) data = ossl_pkcs7_get_data(pkcs7);
    GetPKCS7(pkcs7, p7);
    if(!NIL_P(data) && PKCS7_is_detached(p7))
        flg |= PKCS7_DETACHED;
    in = NIL_P(data) ? NULL : ossl_obj2bio(&data);
    if(!(out = BIO_new(BIO_s_mem()))){
        BIO_free(in);
        ossl_raise(ePKCS7Error, NULL);
    }
    if(!SMIME_write_PKCS7(out, p7, in, flg)){
        BIO_free(out);
        BIO_free(in);
        ossl_raise(ePKCS7Error, NULL);
    }
    BIO_free(in);
    str = ossl_membio2str(out);

    return str;
}