OpenSSL::PKCS7#add_signer

static VALUE
ossl_pkcs7_add_signer(VALUE self, VALUE signer)
{
    PKCS7 *pkcs7;
    PKCS7_SIGNER_INFO *si, *si_new;

    GetPKCS7(self, pkcs7);
    GetPKCS7si(signer, si);

    si_new = ossl_PKCS7_SIGNER_INFO_dup(si);
    if (!si_new)
        ossl_raise(ePKCS7Error, "PKCS7_SIGNER_INFO_dup");

    if (PKCS7_add_signer(pkcs7, si_new) != 1) {
        PKCS7_SIGNER_INFO_free(si_new);
        ossl_raise(ePKCS7Error, "PKCS7_add_signer");
    }

    return self;
}