"1111", "VK_VERSION" => "008", "VK_SND_ID" => "EYP", "VK_REC_ID" => "uid100036", "VK_STAMP" => "2", "VK_T_NO" => "15859", "VK_AMOUNT" => "1392.42", "VK_CURR" => "EUR", "VK_REC_ACC" => "", "VK_REC_NAME" => "", "VK_SND_ACC" => "EE171010123456789017", "VK_SND_NAME" => "Tõõgera Leõpäöldi", "VK_REF" => "26", "VK_MSG" => "My cool payment", "VK_T_DATETIME" => "2021-02-18T20:22:25+0000", "VK_ENCODING" => "UTF-8", "VK_LANG" => "EST", "VK_MAC" => "maINtqkD+VfDbKUVTumFOX3tf0/Gux2GwkVKk5vpt6B4gyUq+dKd3poWwtBHiiBlhBKDVk732mANcGIJUbzXaAwW/frp2I9c6HVrzrCMXsplckuQON5Bqcc6xrfIaYwQ3sQ9vmYDuLnMrJwgFWPEQrKxmqFzSp8Fz3y9rXH5qDt4mGf/2wnJSLTFoMAhYWILq0IQRcFAOeaQe2YPF5yhuKnws/B4TBaAC4P4qAfohQpCZX3gTCA5wtd+tBPB6jscb+H2PP13uSglHT6L+BPCgrNTayl9/Tx2gTdWmauKIKYjE6FUZHeo+t0KNCOYps4YokyU8zU9ebEtjTMoeCdweQ==", "VK_AUTO" => "N" ); // STEP 3. Generate data to be verified // ==================================== // Data to be verified 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) . $fields["VK_SERVICE"] . /* 1111 */ str_pad (mb_strlen($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) . $fields["VK_SND_ID"] . /* EYP */ str_pad (mb_strlen($fields["VK_REC_ID"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_REC_ID"] . /* uid100036 */ str_pad (mb_strlen($fields["VK_STAMP"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_STAMP"] . /* 2 */ str_pad (mb_strlen($fields["VK_T_NO"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_T_NO"] . /* 15859 */ str_pad (mb_strlen($fields["VK_AMOUNT"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_AMOUNT"] . /* 1392.42 */ str_pad (mb_strlen($fields["VK_CURR"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_CURR"] . /* EUR */ str_pad (mb_strlen($fields["VK_REC_ACC"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_REC_ACC"] . /* */ str_pad (mb_strlen($fields["VK_REC_NAME"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_REC_NAME"] . /* */ str_pad (mb_strlen($fields["VK_SND_ACC"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_SND_ACC"] . /* EE171010123456789017 */ str_pad (mb_strlen($fields["VK_SND_NAME"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_SND_NAME"] . /* Tõõgera Leõpäöldi */ str_pad (mb_strlen($fields["VK_REF"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_REF"] . /* 26 */ str_pad (mb_strlen($fields["VK_MSG"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_MSG"] . /* My cool payment */ str_pad (mb_strlen($fields["VK_T_DATETIME"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_T_DATETIME"]; /* 2021-02-18T20:22:25+0000 */ /* $data = "0041111003008003EYP009uid1000360012005158590071392.42003EUR000000020EE171010123456789017017Tõõgera Leõpäöldi00226015My cool payment0242021-02-18T20:22:25+0000"; */ // STEP 4. Verify the data with RSA-SHA1 // ===================================== if (openssl_verify ($data, base64_decode($fields["VK_MAC"]), $public_key) !== 1) { $signatureVerified = false; }else{ $signatureVerified = true; } // STEP 5. Display output of the received payment // ============================================== ?>

Payment results

Payment:

Signature: