"1012",
        "VK_VERSION"     => "008",
        "VK_SND_ID"      => "uid100052",
        "VK_STAMP"       => "137",
        "VK_AMOUNT"      => "15.00",
        "VK_CURR"        => "EUR",
        "VK_REF"         => "1371",
        "VK_MSG"         => "Vaheajatellimus 2107290006 05.08.2021 22:42",
        "VK_RETURN"      => "https://opera.egg.thorgate.eu/en/orders/banks/thorbanks_response/",
        "VK_CANCEL"      => "https://opera.egg.thorgate.eu/en/orders/banks/thorbanks_response/",
        "VK_DATETIME"    => "2021-07-29T20:28:09+0000",
        "VK_LANG"        => "EST",
        "VK_ENCODING"    => "UTF-8"
);
// STEP 3. Generate data to be signed
// ==================================
// Data to be signed is in the form of XXXYYYYY where XXX is 3 char
// zero padded length of the value and YYY the value itself
// NB! Swedbank expects symbol count, not byte count with UTF-8,
// so use `mb_strlen` instead of `strlen` to detect the length of a string
$data = str_pad (mb_strlen($fields["VK_SERVICE"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_SERVICE"] .    /* 1012 */
        str_pad (mb_strlen($fields["VK_VERSION"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_VERSION"] .    /* 008 */
        str_pad (mb_strlen($fields["VK_SND_ID"], "UTF-8"),  3, "0", STR_PAD_LEFT) . $fields["VK_SND_ID"] .     /* uid100052 */
        str_pad (mb_strlen($fields["VK_STAMP"], "UTF-8"),   3, "0", STR_PAD_LEFT) . $fields["VK_STAMP"] .      /* 137 */
        str_pad (mb_strlen($fields["VK_AMOUNT"], "UTF-8"),  3, "0", STR_PAD_LEFT) . $fields["VK_AMOUNT"] .     /* 15.00 */
        str_pad (mb_strlen($fields["VK_CURR"], "UTF-8"),    3, "0", STR_PAD_LEFT) . $fields["VK_CURR"] .       /* EUR */
        str_pad (mb_strlen($fields["VK_REF"], "UTF-8"),     3, "0", STR_PAD_LEFT) . $fields["VK_REF"] .        /* 1371 */
        str_pad (mb_strlen($fields["VK_MSG"], "UTF-8"),     3, "0", STR_PAD_LEFT) . $fields["VK_MSG"] .        /* Vaheajatellimus 2107290006 05.08.2021 22:42 */
        str_pad (mb_strlen($fields["VK_RETURN"], "UTF-8"),  3, "0", STR_PAD_LEFT) . $fields["VK_RETURN"] .     /* https://opera.egg.thorgate.eu/en/orders/banks/thorbanks_response/ */
        str_pad (mb_strlen($fields["VK_CANCEL"], "UTF-8"),  3, "0", STR_PAD_LEFT) . $fields["VK_CANCEL"] .     /* https://opera.egg.thorgate.eu/en/orders/banks/thorbanks_response/ */
        str_pad (mb_strlen($fields["VK_DATETIME"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_DATETIME"];    /* 2021-07-29T20:28:09+0000 */
/* $data = "0041012003008009uid10005200313700515.00003EUR0041371043Vaheajatellimus 2107290006 05.08.2021 22:42065https://opera.egg.thorgate.eu/en/orders/banks/thorbanks_response/065https://opera.egg.thorgate.eu/en/orders/banks/thorbanks_response/0242021-07-29T20:28:09+0000"; */
// STEP 4. Sign the data with RSA-SHA1 to generate MAC code
// ========================================================
openssl_sign ($data, $signature, $private_key, OPENSSL_ALGO_SHA1);
/* pIwew7HJyMgHQOxFuGKBwBf8u5SqQOdH2n5TLVfTHGkVndXUNTXCy9cH82Qmb3NByuimwB/lYQVhlbq1sAYKphXA/IhO88M4Pi+CxHjIwysLN760Wfu/BLhJNvvRJ5mZjpd9XnzKV+ro6w4qJpTA5xYIcXhW+lhjxi4/t6mcK4GtgR3yYAaWMAtUcv/Ok7Cw/gNuhgiBAcMOxjK4GeA7PFYZYpDl4os29XMafUMDQ6k+KqQKIHYOoGOEcgucDajNSyzY5D3qa1GEG3GwFq15voAburszt0hikqWoj0QPEtX3KzXDrz19RDbRu73LC6t9qItoGxXWLMns2MZ/8p34NA== */
$fields["VK_MAC"] = base64_encode($signature);
// STEP 5. Generate POST form with payment data that will be sent to the bank
// ==========================================================================
?>
        
        Makse teostamise näidisrakendus "Swedbank"