"1111", "VK_VERSION" => "008", "VK_SND_ID" => "HP", "VK_REC_ID" => "uid100052", "VK_STAMP" => "5", "VK_T_NO" => "16542", "VK_AMOUNT" => "966.88", "VK_CURR" => "EUR", "VK_REC_ACC" => "", "VK_REC_NAME" => "", "VK_SND_ACC" => "EE152200221234567897", "VK_SND_NAME" => "Tõõgera Leõpäöldi", "VK_REF" => "", "VK_MSG" => "My cool payment", "VK_T_DATETIME" => "2021-02-18T20:06:12+0000", "VK_ENCODING" => "UTF-8", "VK_LANG" => "EST", "VK_MAC" => "DTKYX3ujENxmheIAgxLw6iJH51K/tVk7tCqfHpYklSjwTSy8m2C2kf3tLGvGzJhJ4PCsIX/NqSZYdGTkiDCfD5ThcNQ/iL+ykFZIfe5oCK4HsPmdAB20nUdu69jmY+XdH7J+2ShOP8WKT4QIUF4Nqt1BHA4GgVdc1/oysUXtIdqtVjS6vEmcdf7/vHK8aUYY5X9t+rjUqMkjC924ikbHF9Z7PoIN5pwgjCsRISsENn0LajSBD08F+CPTxAng8HROf8njmg4SPeMJZmSDfoEdBR4Vg1vm/l+4EQR1HTUy4iwWxit+zS/ylrgDsad++exazGcDO+e8CPdGgxDqBZ8P8Q==", "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! 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) . $fields["VK_SERVICE"] . /* 1111 */ str_pad (mb_strlen($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) . $fields["VK_SND_ID"] . /* HP */ str_pad (mb_strlen($fields["VK_REC_ID"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_REC_ID"] . /* uid100052 */ str_pad (mb_strlen($fields["VK_STAMP"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_STAMP"] . /* 5 */ str_pad (mb_strlen($fields["VK_T_NO"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_T_NO"] . /* 16542 */ str_pad (mb_strlen($fields["VK_AMOUNT"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_AMOUNT"] . /* 966.88 */ str_pad (mb_strlen($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) . $fields["VK_SND_ACC"] . /* EE152200221234567897 */ str_pad (mb_strlen($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) . $fields["VK_REF"] . /* */ str_pad (mb_strlen($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"]; /* 2021-02-18T20:06:12+0000 */ /* $data = "0041111003008002HP009uid100052001500516542006966.88003EUR000000020EE152200221234567897017Tõõgera Leõpäöldi000015My cool payment0242021-02-18T20:06:12+0000"; */ // STEP 4. Verify the data with RSA-SHA1 // ===================================== if (openssl_verify ($data, base64_decode($fields["VK_MAC"]), $public_key) !== 1) { $signatureVerified = false; }else{ $signatureVerified = true; } // STEP 5. Display output of the received payment // ============================================== ?>

Payment results

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Signature: