OpenSSL::PKCS7.read_smime

static VALUE
ossl_pkcs7_s_read_smime(VALUE klass, VALUE arg)
{
    BIO *in, *out;
    PKCS7 *pkcs7;
    VALUE ret, data;

    ret = NewPKCS7(cPKCS7);
    in = ossl_obj2bio(&arg);
    out = NULL;
    pkcs7 = SMIME_read_PKCS7(in, &out);
    BIO_free(in);
    if(!pkcs7) ossl_raise(ePKCS7Error, NULL);
    data = out ? ossl_membio2str(out) : Qnil;
    SetPKCS7(ret, pkcs7);
    ossl_pkcs7_set_data(ret, data);
    ossl_pkcs7_set_err_string(ret, Qnil);

    return ret;
}