"1111", "VK_VERSION" => "008", "VK_SND_ID" => "EYP", "VK_REC_ID" => "uid100036", "VK_STAMP" => "6", "VK_T_NO" => "15840", "VK_AMOUNT" => "3079.12", "VK_CURR" => "EUR", "VK_REC_ACC" => "", "VK_REC_NAME" => "", "VK_SND_ACC" => "EE171010123456789017", "VK_SND_NAME" => "Tõõgera Leõpäöldi", "VK_REF" => "", "VK_MSG" => "My cool payment", "VK_T_DATETIME" => "2021-02-18T20:03:55+0000", "VK_ENCODING" => "UTF-8", "VK_LANG" => "EST", "VK_MAC" => "HOeZEYGmCCdFNNzzE8aEJDMjQxX2q07qbXuvN6WdA5fBeKoYSQKeA0Qj1A1ZU0agPBjZJsRNJLBj586Ox1a6914MPU5BMAKPkKTSZbA7nBTuWt0ibsLfNvBNOIPzWMwIiThR7y7bnzP+9JG00z+DpOeX+41FSjn7RQRzHpShxVLCxSTphURNbKysSF9mXZXA07DDiIOD1kbRTSLl/9X5C7Qo+fZSBRZzTDNtBTeV6PI0nf7ziJ1X54CqUOaZQM0FBZNe0NaEOmL4jPUdC2Z3qj538fH7rT+rZJ/U04bZYr15IZ/9XFsFNzq75jSzsTJWla+OGIYkEo7yC2w+hTGNrA==", "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) . $fields["VK_STAMP"] . /* 6 */ str_pad (mb_strlen($fields["VK_T_NO"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_T_NO"] . /* 15840 */ str_pad (mb_strlen($fields["VK_AMOUNT"], "UTF-8"), 3, "0", STR_PAD_LEFT) . $fields["VK_AMOUNT"] . /* 3079.12 */ str_pad (mb_strlen($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) . $fields["VK_REF"] . /* */ str_pad (mb_strlen($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"]; /* 2021-02-18T20:03:55+0000 */ /* $data = "0041111003008003EYP009uid1000360016005158400073079.12003EUR000000020EE171010123456789017017Tõõgera Leõpäöldi000015My cool payment0242021-02-18T20:03:55+0000"; */ // STEP 4. Verify the data with RSA-SHA1 // ===================================== if (openssl_verify ($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: