"1012",
        "VK_VERSION"     => "008",
        "VK_SND_ID"      => "uid100036",
        "VK_STAMP"       => "66364",
        "VK_AMOUNT"      => "138",
        "VK_CURR"        => "EUR",
        "VK_REF"         => "663641",
        "VK_MSG"         => "Order nr. 66364",
        "VK_RETURN"      => "https://vm-backend.dev.elkdata.ee/payment/callback/order/bank",
        "VK_CANCEL"      => "https://vm-backend.dev.elkdata.ee/payment/callback/order/bank",
        "VK_DATETIME"    => "2022-05-10T22:23:33+0300",
        "VK_LANG"        => "EST",
        "VK_ACC"         => "EE171010123456789017",
        "VK_NAME"        => "Veebimajutus",
        "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! SEB 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) . $fields["VK_SND_ID"] .     /* uid100036 */
        str_pad (mb_strlen($fields["VK_STAMP"], "UTF-8"),   3, "0", STR_PAD_LEFT) . $fields["VK_STAMP"] .      /* 66364 */
        str_pad (mb_strlen($fields["VK_AMOUNT"], "UTF-8"),  3, "0", STR_PAD_LEFT) . $fields["VK_AMOUNT"] .     /* 138 */
        str_pad (mb_strlen($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) . $fields["VK_REF"] .        /* 663641 */
        str_pad (mb_strlen($fields["VK_MSG"], "UTF-8"),     3, "0", STR_PAD_LEFT) . $fields["VK_MSG"] .        /* Order nr. 66364 */
        str_pad (mb_strlen($fields["VK_RETURN"], "UTF-8"),  3, "0", STR_PAD_LEFT) . $fields["VK_RETURN"] .     /* https://vm-backend.dev.elkdata.ee/payment/callback/order/bank */
        str_pad (mb_strlen($fields["VK_CANCEL"], "UTF-8"),  3, "0", STR_PAD_LEFT) . $fields["VK_CANCEL"] .     /* https://vm-backend.dev.elkdata.ee/payment/callback/order/bank */
        str_pad (mb_strlen($fields["VK_DATETIME"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_DATETIME"];    /* 2022-05-10T22:23:33+0300 */
/* $data = "0041012003008009uid10003600566364003138003EUR006663641015Order nr. 66364061https://vm-backend.dev.elkdata.ee/payment/callback/order/bank061https://vm-backend.dev.elkdata.ee/payment/callback/order/bank0242022-05-10T22:23:33+0300"; */
// STEP 4. Sign the data with RSA-SHA1 to generate MAC code
// ========================================================
openssl_sign ($data, $signature, $private_key, OPENSSL_ALGO_SHA1);
/* dZfDjHXR4ntkrqtB7EaxjEKUtMUynM2v4q9lj9c3maAr1QjKxxWkxm6QtI1FHo5qh3zjXcNNnbQYCCSqO+RsIOVX5mkiTVd94/3kvQn0uWKQ+CcU0TeyRix+8XbrDxwkySJb2UDpxyniIUDu6Hd1isxHIaIQRGQnX3JG3qLFv640drNb6Se/5An2ab1tUsZsHi2UHlgl6JZhxZR83z1I7dYLnhNiUhuNNjGnWBtW3mxqsIJBycFSkWcu4g0F1ETcDcSaeNL8kAMoH7FoQeJjGBBnMvBrw0RoMEWFyouBlmg4zGhkKqbpAQm7idV7c4QGG0ufcXs8+0A0DMS95K7bjg== */
$fields["VK_MAC"] = base64_encode($signature);
// STEP 5. Generate POST form with payment data that will be sent to the bank
// ==========================================================================
?>
        
        Makse teostamise näidisrakendus "SEB"