原來來自:第一夫人:https://www.cnblogs.com/firstlady/p/11327204.html

現在很多專案中會使用到rsa加解密和驗證相關的技術，分別整理程式碼如下，方便記憶和使用。

【簽名和驗證】

 1 //獲得簽名
 2 function getSign($data) {
 3     $pem =  'my_rsa_private_key.pem';
 4     $privateKey = openssl_get_privatekey(file_get_contents($pem));
 5     openssl_sign($data, $sign, $privateKey);
 6     openssl_free_key($privateKey);
 7     return base64_encode($sign);
 8 }
 9 //驗證簽名
10 function checkSign($data, $sign) {
11     $pem =  'my_rsa_public_key.pem';
12     $publicKey = openssl_get_publickey(file_get_contents($pem));
13     $result = openssl_verify($data, $sign, $publicKey);
14     openssl_free_key($publicKey);
15     return $result;
16 }
17 $signData = 'php-rsa';
18 $getSign = getSign($data);
19 $checkSign = checkSign($data, base64_decode($sign));
 
20 echo '簽名資料：'.$signData;
21 echo '獲得簽名：'.$getSign;
22 echo '驗證簽名：'.$checkSign;

執行結果如下：
簽名資料：php-rsa
簽名結果：LOVAjWTgHeUvJIK0scVOQO2VlId+1qEuUc70cb7Z/dyMONpheldefkKJXZDF9HelTz/UnwEd00Tre698VGN1IX/sV7WTQJFCY+ypArfNx9mCzaEhMt0U60yGkIPh8wXqNG10YhgzPIw3Lvd/36FnRlTBXOZeJMbxFxhdJmSdeOQ=
驗證簽名：1

【資料加解密】

 1 //加密資料
 2 function sslEncrypt($source, $type, $key) {
 3     $maxlength = 117;
 4     $output = '';
 5     while ($source) {
 6         $input = substr($source, 0, $maxlength);
 7         $source = substr($source, $maxlength);
 8         if ($type == 'private') {
 9             $ok = openssl_private_encrypt($input, $encrypted, $key);
10         } else {
11             $ok = openssl_public_encrypt($input, $encrypted, $key);
12         }
13         $output .= $encrypted;
14     }
15     return $output;
16 }
17 //解密資料
18 function sslDecrypt($source, $type, $key) {
19     $maxlength = 128;
20     $output = '';
21     while ($source) {
22         $input = substr($source, 0, $maxlength);
23         $source = substr($source, $maxlength);
24         if ($type == 'private') {
25             $ok = openssl_private_decrypt($input, $out, $key);
26         } else {
27             $ok = openssl_public_decrypt($input, $out, $key);
28         }
29         $output .= $out;
30     }
31     return $output;
32 }
33 $data = 'php-rsa';
34 $privatekey = openssl_get_privatekey(file_get_contents('my_rsa_private_key.pem'));
35 $publickey = openssl_get_publickey(file_get_contents('my_rsa_public_key.pem'));
36 $sign = base64_encode(sslEncrypt($data, 'private', $privatekey));
37 $jiemi = sslDecrypt(base64_decode($sign), 'public', $publickey);
 
38 echo '加密資料：'.$data;
39 echo '加密結果：'.$sign;
40 echo '解密資料：'.$jiemi;

執行結果如下：
加密資料：php-rsa
加密結果：aMCpl34vXbofR7a3OPPLElQg6jwG+xbdIsdfYGeVPtIhVp0INMu/0p9M8h+JiBBmGL/WVY9ynbrvNH6QtLXDoW23rm6EWPPKn53EIqt/9jM/fDX8EyaAvhIuaSJ2Q7dxz4hNF+Ykm0XZ5ytsCB71zYVPYfaHyo3Xk+VkZ/JvznE=
解密資料：php-rsa