Detailed explanation of the steps to implement public key encryption using PHP+openssl extension

// 生成私钥
# openssl genrsa -out rsa_private_key.pem 1024
// 生成公钥
# openssl rsa -in rsa_private_key.pem -pubout -out rsa_public_key.pem

<?php
// openssl 扩展检测
var_dump(extension_loaded(&#39;openssl&#39;));
$prikey = openssl_pkey_get_private(file_get_contents(&#39;rsa_private_key.pem&#39;)); //私钥
$pubkey = openssl_pkey_get_public(file_get_contents(&#39;rsa_public_key.pem&#39;)); //公钥
// 明文数据
$data = &#39;test-string!&#39;;
/**
 * 可能会出的问题：Don&#39;t know how to get public key from this private key
 * 原因：PHP 的 openssl 扩展和 Apache 的不一致导致, 当然在命令行下运行程序则不会出现此问题
 */
// 公钥加密
$encrypt_data = &#39;&#39;;
openssl_public_encrypt($data, $encrypt_data, $pubkey);
$encrypt_data = base64_encode($encrypt_data);
echo $encrypt_data;
echo &#39;<br/>&#39;;
// ------------------------------------------------------------
// 私钥解密
$encrypt_data = base64_decode($encrypt_data);
openssl_private_decrypt($encrypt_data, $decrypt_data, $prikey);
var_dump($decrypt_data);