"1111", "VK_VERSION" => "008", "VK_SND_ID" => "EYP", "VK_REC_ID" => "uid100036", "VK_STAMP" => "2", "VK_T_NO" => "15792", "VK_AMOUNT" => "4230.77", "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" => "2021-02-18T18:29:07+0000", "VK_ENCODING" => "UTF-8", "VK_LANG" => "EST", "VK_MAC" => "alNGiQEEBrTkYYKpMlVh1wXDVWnKgkngnwSN5y4d8DyNho5Jdd2LEbf8t801b0vupB0TaLOPUSEDQ/ecDZY5QzfqkDx5Y22LJrzfbSTio2TuCZFxNJVFIUnsPfgnHhGOI4Mu4OgcRUpGDdZDwZB26Ss9e/yu/Do4XprZhH9CWfBXefRTrDMcw0sObOZeWVe3j+CSLNKwvxjNv/ce8YD1V+JNDZUn1P+MTTVuvg+T1MQ9DNfwPPrlizKBSUi8D3+f5fQLXX9NFgAQlDyasu11+6dYswLGe5jV5+moN2NBIsQfy+CBqNGvpP3zym/BWToU+5Ggsbm/OZjUhlImh4LHfg==", "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) . $fields["VK_T_NO"] . /* 15792 */ str_pad (mb_strlen($fields["VK_AMOUNT"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_AMOUNT"] . /* 4230.77 */ str_pad (mb_strlen($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"]; /* 2021-02-18T18:29:07+0000 */ /* $data = "0041111003008003EYP009uid1000360012005157920074230.77003EUR000000020EE171010123456789017017Tõõgera Leõpäöldi00226015My cool payment0242021-02-18T18:29:07+0000"; */ // STEP 4. Verify the data with RSA-SHA1 // ===================================== if (openssl_verify ($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: