關於php rsa加密處理

kolin發表於2022-01-20
PHP加密

最近剛好需要跟一個第三方系統對接幾個介面，對方要求post資料需要rsa加密，於是百度搜了一下php關於rsa加密的處理，然後大家可能就會跟我一樣搜出以下示例：

    /**     
     * @uses 公鑰加密     
     * @param string $data     
     * @return null|string     
     */    
    public function publicEncrypt($data = '') {        
        if (!is_string($data)) {
            return null;        
        }        
        return openssl_public_encrypt($data, $encrypted, $this->_getPublicKey()) ? base64_encode($encrypted) : null;
    }

於是開開心心的複製到自己專案稍微修改修改後測試，簡簡單單傳幾個字串進去：

<?php

$string = '基督教解決基督教解決決';

$ret = publicEncrypt($string);

var_dump($ret);

/**     

 * @uses 公鑰加密     

 * @param string $data     

 * @return null|string     

 */    

function publicEncrypt($data = '') {    

    $publicKey = 'MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAiX1bIq02AFypLOJ4byShfo6+D6pj0rQrdAtZ8Bb2Z4YwdCZS5vlEduBiVCZSKfF70M0nk4gMqhAKcgwqWxgI1/j8OrX401AssfaiXr2JqsAl679s+Xlwe0jppNe1832+3g0YOawDTpAQsUJDu1DpnyGnUz0qeac0/GiAJlXzKUP+/3db8haDuOkgYrT8A6twGAm7YwIuliieDWDcUS/CQzXGRtwtZQqUJDQsWC1lCML1kRUjbZ2EM2EzyttgHN0SsNryhVLHXSFXpDWbeqQwk36axojGF1lbg/oVQy+BnYJx8pKpTgSwIDAQAB';    

    $publicKey = "-----BEGIN PUBLIC KEY-----\n" .

    wordwrap($publicKey, 64, "\n", true) .

    "\n-----END PUBLIC KEY-----";

    if (!is_string($data)) {

        return null;        

    }        

    return openssl_public_encrypt($data, $encrypted, $publicKey) ? base64_encode($encrypted) : null;
}

程式列印：

string(344) "HSqVQbyhmWYrptvgzK+ggqmma88QRFVJerXTrZ+RpYqhZr/Dr9au9wxX+aAYy1wRh0eBk+fIpU4wkEZs6P5yozf5e/rAAEYUOImTJZcOvZqr89znT3yqaV8ME+vR16FLK5sk3BwgpOWI6X+wBwU2cLnHKDdj9RpYWAYhi/mn8XJj4/srKZbSgAjvzWqZI9gfqiJNdz8kf/MPtQ65cSlAhvh4eByY8cLGfgUXV0dxzWAkwTSPl2faSq3GHsNMXnxwoNjIvqz/IuZavqABNVZCwrZC3ZVb+Op7wF9GxrkIdJYzmHpX/wNn1DPLHUvghtO/WmfN4Jb2ZVzTsneB5B3Z6g=="

看似一切正常，實際專案中對一個比較長的json字串進行加密時，發現返回了null，追溯了一下openssl_public_encrypt這個函式此時是返回false的，表示加密失敗。傳入不同長度的字串測試了幾遍後發現字串長度超過100多之後就會出現加密失敗的問題，參考了一下對方發來的java加密示例

    /**
     * 用公鑰加密
     * @param data
     * @param publicKey
     * @return
     * @throws Exception
     */
    public static String rsaEncrypt(String data, PublicKey publicKey) throws Exception {
        Cipher cipher = Cipher.getInstance(RSA_ALGORITHM);
        cipher.init(Cipher.ENCRYPT_MODE, publicKey);
        int inputLen = data.getBytes().length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offset = 0;
        byte[] cache;
        int i = 0;
        // 對資料分段加密
        while (inputLen - offset > 0) {
            if (inputLen - offset > MAX_ENCRYPT_BLOCK) {
                cache = cipher.doFinal(data.getBytes(), offset, MAX_ENCRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(data.getBytes(), offset, inputLen - offset);
            }
            out.write(cache, 0, cache.length);
            i++;
            offset = i * MAX_ENCRYPT_BLOCK;
        }
        byte[] encryptedData = out.toByteArray();
        out.close();
        // 加密後的字串
        return Base64.getEncoder().encodeToString(encryptedData);
    }

發現他們是需要對要加密的字串進行一個分割操作，於是有了以下修改後的版本：

/**
 * 公鑰加密
  * @param string $data
  * @return null|string
 */
 public function publicEncrypt($data = '')
 {
    if (!is_string($data)) {
        return null;
    }
    $dataLength = mb_strlen($data);
    $offet = 0;
    $length = 128;
    $i = 0;
    $string = '';
    while ($dataLength - $offet > 0) {
        if ($dataLength - $offet > $length) {
            $str = mb_substr($data, $offet, $length);
        } else {
            $str = mb_substr($data, $offet, $dataLength - $offet);
        }
        $encrypted = '';
        openssl_public_encrypt($str,$encrypted, $this->rsaPublicKey, OPENSSL_PKCS1_OAEP_PADDING);//這個OPENSSL_PKCS1_OAEP_PADDING是對方要求要用這種padding方式
        $string .= $encrypted;
        $i ++;
        $offet = $i * $length;
    }
    return base64_encode($string);
}

目前測試沒有再發現加密失敗問題~

下面貼一個比較完整的示例：

<?php


namespace Common\Logic;


class Rsa
{

    private $rsaPrivateKey = '';

    private $rsaPublicKey = '';

    private $privateKeyRule = '';

    private $publicKeyRule = '';

    /**
     * Rsa constructor.
     * @param $privateKeyRule 私鑰路徑
     * @param $publicKeyRule 公鑰路徑
     * @param string $rsaPrivateKey 私鑰 一行字串的形式
     * @param string $rsaPublicKey 公鑰 一行字串的形式
     */
    public function __construct($privateKeyRule, $publicKeyRule, $rsaPrivateKey = '', $rsaPublicKey = '')
    {
        $this->rsaPrivateKey = $rsaPrivateKey;
        $this->rsaPublicKey = $rsaPublicKey;
        $this->privateKeyRule = $privateKeyRule;
        $this->publicKeyRule = $publicKeyRule;
        $this->rsaPublicKey = "-----BEGIN PUBLIC KEY-----\n" .
            wordwrap($this->rsaPublicKey, 64, "\n", true) .
            "\n-----END PUBLIC KEY-----";
        if (empty($rsaPrivateKey) && empty($rsaPublicKey)) {
            $this->rsaPrivateKey = $this->getPrivateKey();
            $this->rsaPublicKey = $this->getPublicKey();
        }
    }

    /**
     * 獲取私鑰
     * @return bool|resource
     */
    private function getPrivateKey()
    {
        $absPath = $this->privateKeyRule;
        $content = file_get_contents($absPath);
        return openssl_pkey_get_private($content);
    }

    /**
     * 獲取公鑰
     * @return bool|resource
     */
    private function getPublicKey()
    {
        $absPath = $this->privateKeyRule;
        $content = file_get_contents($absPath);
        return openssl_pkey_get_public($content);
    }

    /**
     * 私鑰加密
     * @param string $data
     * @return null|string
     */
    public function privEncrypt($data = '')
    {
        if (!is_string($data)) {
            return null;
        }
        return openssl_private_encrypt($data,$encrypted, $this->rsaPrivateKey) ? base64_encode($encrypted) : null;
    }

    /**
     * 公鑰加密
     * @param string $data
     * @return null|string
     */
    public function publicEncrypt($data = '')
    {
        if (!is_string($data)) {
            return null;
        }
        $dataLength = mb_strlen($data);
        $offet = 0;
        $length = 128;
        $i = 0;
        $string = '';
        while ($dataLength - $offet > 0) {
            if ($dataLength - $offet > $length) {
                $str = mb_substr($data, $offet, $length);
            } else {
                $str = mb_substr($data, $offet, $dataLength - $offet);
            }
            $encrypted = '';
            openssl_public_encrypt($str,$encrypted, $this->rsaPublicKey, OPENSSL_PKCS1_OAEP_PADDING);
            $string .= $encrypted;
            $i ++;
            $offet = $i * $length;
        }
        return base64_encode($string);
    }

    /**
     * 私鑰解密
     * @param string $encrypted
     * @return null
     */
    public function privDecrypt($encrypted = '')
    {
        if (!is_string($encrypted)) {
            return null;
        }
        return (openssl_private_decrypt(base64_decode($encrypted), $decrypted, $this->rsaPrivateKey)) ? $decrypted : null;
    }

    /**
     * 公鑰解密
     * @param string $encrypted
     * @return null
     */
    public function publicDecrypt($encrypted = '')
    {
        if (!is_string($encrypted)) {
            return null;
        }
        return (openssl_public_decrypt(base64_decode($encrypted), $decrypted, $this->rsaPublicKey)) ? $decrypted : null;
    }
}

呼叫：

<?php
namespace Common\Logic;

class Test
{

    private $publicKey = 'MIIBIjANBgkqhkiG9w0BAQEkdkkddUz0qeac0/GiAJlXzKUP+/3db8haDuOkgYrT8A6twGAm7YwIuliiQYxjdUVdFLdnPUK3TJm38H+79lpqIGv1gseDWDcUS/CQzXGRtwtZQqUJDQsWC1lCML1kRUjbZ2EM2EzyttgHN0SsNryhVLHXSFXpDWbeqQwk36axojGF1lbg/oVQy+BnYJx8pKpTgSwIDAQAB';

    private $privateKey = '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';

    /**
    @param $data array
    **/
    public function rsaData($data)
    {
        $data = json_encode($data);
        $rsa = new Rsa('', '', $this->privateKey, $this->publicKey);
        //加密資料包
        $encryptData = $rsa->publicEncrypt($data);
           return $encryptData;
    }
}
本作品採用《CC 協議》，轉載必須註明作者和本文連結

相關文章