PHP RSA密文过长加密解密,PHP RSA证书大小自动适配,PHP RSA分段加密
项目中需要加密超长json内容才发现rsa加密长度有限制，于是换一种思路：我们将原本需要加密的内容拆分为多个字符串，一段一段的加密，解密端也是一段一段的解密即可完成。
(1).确认每次加密多少长度
首先我们要知道rsa加密长度是多少，1024位的rsa能加密的长度也是1024位。那么我们一次加密多长的字符串比较好？ 是不是1024/8呢？不是的！因为如果你每次能保证每次要加密的是1024位那就没事这样算是对，但是如果你要加密的字符串不足1024位，不足的部分会用你设置的padding方式去填充这部分内容。那么我们分段加密的长度的公式就是：证书位数/8-padding长度，例如1024的证书配合OPENSSL_PKCS1_PADDING 长度的公式：1024/8-11即可
(2).确认每次解密多少长度
解密不需要考虑填充，所以每次解密大小 = 证书位数/8
(3).我们封装了一个简单的类你可以直接使用，同事(刘平)编写，我整理完善了下。
string. * privateKey => string. * * @var mixed */ protected $config; /** * 初始化. * * @param array $config */ public function __construct($config) { $this->config = $config; } /** * 获取密钥分段加密长度. * * @param Closure $keyClosure * * @return int * * @throws Exception */ protected function getEncryptBlockLen($keyClosure) { $key_info = openssl_pkey_get_details($keyClosure); if (!$key_info) { throw new Exception('获取密钥信息失败' . openssl_error_string()); } // bits数除以8 减去padding长度，OPENSSL_PKCS1_PADDING 长度是11 // php openssl 默认填充方式是 OPENSSL_PKCS1_PADDING return $key_info['bits'] / 8 - 11; } /** * 获取密钥分段解密长度. * * @param Closure $keyClosure * * @return int * * @throws Exception */ protected function getDecryptBlockLen($keyClosure) { $key_info = openssl_pkey_get_details($keyClosure); if (!$key_info) { throw new Exception('获取密钥信息失败' . openssl_error_string()); } // bits数除以8得到字符长度 return $key_info['bits'] / 8; } /** * 数据加密. * * @param string $text 需要加密的文本 * @param int $type 加密方式:1.公钥加密 2.私钥加密 * * @return string * * @throws Exception */ public function encrypt($text, $type) { //获取密钥资源 $keyClosure = 1 == $type ? openssl_pkey_get_public($this->config['publicKey']) : openssl_pkey_get_private($this->config['privateKey']); if (!$keyClosure) { throw new Exception('获取密钥失败,请检查密钥是否合法'); } //RSA进行加密 $encrypt = ''; $plainData = str_split($text, $this->getEncryptBlockLen($keyClosure)); foreach ($plainData as $key => $encrypt_item) { $isEncrypted = (1 == $type) ? openssl_public_encrypt($encrypt_item, $encrypted, $keyClosure) : openssl_private_encrypt($encrypt_item, $encrypted, $keyClosure); if (!$isEncrypted) { throw new Exception('加密数据失败,请检查密钥是否合法,' . openssl_error_string()); } $encrypt .= $encrypted; } $encrypt = base64_encode($encrypt); //返回 return $encrypt; } /** * 数据解密. * * @param string $text 需要加密的文本 * @param int $type 加密方式:1.公钥加密 2.私钥加密 * * @return string * * @throws Exception * @throws */ public function decrypt($text, $type) { //获取密钥资源 $keyClosure = 1 == $type ? openssl_pkey_get_public($this->config['publicKey']) : openssl_pkey_get_private($this->config['privateKey']); if (!$keyClosure) { throw new Exception('获取密钥失败,请检查密钥是否合法'); } //RSA进行解密 $data = base64_decode($text); $data = str_split($data, $this->getDecryptBlockLen($keyClosure)); $decrypt = ''; foreach ($data as $key => $chunk) { $isDecrypted = (1 == $type) ? openssl_public_decrypt($chunk, $encrypted, $keyClosure) : openssl_private_decrypt($chunk, $encrypted, $keyClosure); if (!$isDecrypted) { throw new Exception('解密数据失败,请检查密钥是否合法,' . openssl_error_string()); } $decrypt .= $encrypted; } //返回 return $decrypt; } } //01.配置公钥私钥 $config = [ 'publicKey' => '-----BEGIN PUBLIC KEY----- MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDAsst/VK6RA+4tFTJtHUTEUY4E uN/NdXBUc3Lbb9/P+SqvpTI7NCyvl/bSCSXGOeURzIKGffSTe7oKbAITO5GAKbxS dz8bj8/rb7r9QUwzdvjY6/9x0M3M295GCwrH5ROXv/dGGh4FKcnl31pHuTJmuz4D HugXS8FNnxlnHwZNLwIDAQAB -----END PUBLIC KEY-----', 'privateKey' => '-----BEGIN PRIVATE KEY----- MIICdgIBADANBgkqhkiG9w0BAQEFAASCAmAwggJcAgEAAoGBAMCyy39UrpED7i0V Mm0dRMRRjgS43811cFRzcttv38/5Kq+lMjs0LK+X9tIJJcY55RHMgoZ99JN7ugps AhM7kYApvFJ3PxuPz+tvuv1BTDN2+Njr/3HQzczb3kYLCsflE5e/90YaHgUpyeXf Wke5Mma7PgMe6BdLwU2fGWcfBk0vAgMBAAECgYANOPePwC7OUpe4TjkMlbKPSg1V s53fykwv71AVUKLp8W4FaW998oGSdvn/xZLq/DQEuaTHN8Ndj2LfrjOiQDcmlrQS 5vaazxhTaBW4JuFEXltXnstf+mZhyu3bpm5Ta/yLQiZ8ROUPXMFEvANyg7WgOKCv fY1olbhGpIMexRkMgQJBAOfrjA9fFUT31h7qFwZhJXKkAydPqZZFyxDhkSPNEkpA dRqUn4AoTW3LdCHpy7ka+/zFLvPrPkwrd8AVZKZyX8ECQQDUtLuH1tC9xY2xTMI3 4JDpw1TSPEpgT2kng1zSLfL0Qj4aKCm9PFlqx8REksf9H4+7ZztOSb9846JAJXdx eOjvAkAF1A6WCE6xiATyi/F+MIzPX73QjBj39NMQnoqWOr4d7ZbDzz5e6yRfAQDv JUAAa+QvSwlOCfhr05/TzPXVlQRBAkEAs2CHFZNPDfrf9zloQH8dNkYH7hPyFS5i 23Oof4dIcDy86oocSP3v2mEFX175ULmhGMWB+g+vcL73QWlXRVZV+QJAXDPOLW2C S9ot0TwcHuWFY4hZkc5E8dHV3v5Hip6b12dkeVqyzNZ1onftUV5VlqG5LnzyMcS9 TXlJaV2+SL97nQ== -----END PRIVATE KEY-----', ]; //02.初始化 $openssl = new Openssl($config); //03.私钥加密->公钥解密,加密5000长度的字符串A $waitChar = str_repeat('A', 5000); $privateEnData = $openssl->encrypt($waitChar, 2); //私钥加密 $publicDeData = $openssl->decrypt($privateEnData, 1); //公钥解密 //04.公钥加密->私钥解密,加密10000长度的字符串B $waitChar = str_repeat('B', 10000); $publicEnData = $openssl->encrypt($waitChar, 1); //公钥加密 $privateDeData = $openssl->decrypt($publicEnData, 2); //私钥解密
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