还需要注意的是加密字符串长度问题，如果加密字符串长度太长需要进行分段加解密，如下代码：
加密：（公匙加密，私密一般用来解密）
function encrypt($originalData){ ???$publicKeyFilePath = ‘/www/ceshi/rsa_public_key.pem‘; ???extension_loaded(‘openssl‘) or die(‘php需要openssl扩展支持‘); ???file_exists($publicKeyFilePath) or die(‘公钥的文件路径不正确‘); ???$publicKey = openssl_pkey_get_public(file_get_contents($publicKeyFilePath)); ???$publicKey or die(‘公钥不可用‘); ???$crypto = ‘‘; ???foreach (str_split($originalData, 117) as $chunk) { ???????$encryptData = ‘‘; ???????if(openssl_public_encrypt($chunk, $encryptData, $publicKey)){ ???????????$crypto .= $encryptData; ???????}else{ ???????????die(‘加密失败‘); ???????} ???} ???return base64_encode($crypto);}解密：
function decrypt($encryptData){ ???$privateKeyFilePath = ‘/www/ceshi/rsa_private_key.pem‘; ???extension_loaded(‘openssl‘) or die(‘php需要openssl扩展支持‘); ???file_exists($privateKeyFilePath) or die(‘密钥的文件路径不正确‘); ???$privateKey = openssl_pkey_get_private(file_get_contents($privateKeyFilePath)); ???$privateKey or die(‘密钥不可用‘); ???$decryptData = ‘‘; ???$crypto = ‘‘; ???foreach (str_split(base64_decode($encryptData), 128) as $chunk) { ???????if(openssl_private_decrypt($chunk, $decryptData, $privateKey)){ ???????????$crypto .= $decryptData; ???????}else{ ???????????die(‘解密失败‘); ???????} ???} ???return $crypto;}调用：
$aa = encrypt(‘aa‘);$bb = decrypt($aa);var_dump($bb);输出的结果为：aa
php7实现基于openssl的加密解密方法
原文地址：http://www.cnblogs.com/herry52/p/7544898.html