#yum install openssl* -y

[root@wentao12 ~]# openssl genrsa -out rsa_private_key.pem 1024

[root@wentao12 ~]# openssl rsa -in rsa_private_key.pem -pubout -out rsa_public_key.pem

[root@wentao12 ~]# openssl pkcs8 -topk8 -inform PEM -in rsa_private_key.pem -outform PEM -nocrypt

<?php
/*** Created by PhpStorm.* User: Administrator* Date: 2018/4/1* Time: 1:50*///注意格式一定要有下面的标识符
$pub_key = "-----BEGIN PUBLIC KEY-----
MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC+p18S45D/xf+EpDpRDwMLp7Im
edUzYhPUAy5orgPnOIwjUo7jDb6Zsn6axv5gDA+ooaxZoT+fXz2gNDhlvCWanLIv
i0o2X6G5l1rCarb8irOQOyAP4Z3M8Pj9maaG3zwU251udcVTcLpV2q65sMKaJBOI
jPpzwPFo+RU040k0kwIDAQAB
-----END PUBLIC KEY-----";
$pri_key = "-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----";$str = "这个是要加密的字符4567串888";//这个例子是演示RSA加密
//非对称加密 分为 公钥和私钥
//通常 公钥加密 私钥解密，私钥加密，公钥解密/** 用到的加密函数
openssl_private_decrypt — Decrypts data with private key
openssl_private_encrypt — Encrypts data with private key
openssl_public_decrypt — Decrypts data with public key
openssl_public_encrypt — Encrypts data with public key**///echo $private_key;
$pi_key =  openssl_pkey_get_private($pri_key);//这个函数可用来判断私钥是否是可用的，可用返回资源id Resource id
$pu_key = openssl_pkey_get_public($pub_key);//这个函数可用来判断公钥是否是可用的
//print_r($pi_key);echo "\n";
//print_r($pu_key);echo "\n";//公钥加密过程
$enStr = '';
openssl_public_encrypt($str,$enStr,$pu_key);
//加密后的字符 有些无法显示 需要 base64_encode ( string $data ) ,解密的时候不需要要 base64_decode ( string $data )
echo base64_encode ($enStr);
echo "<br/>";//私钥解密过程
$deStr = '';
//$enStr = base64_decode ( $enStr);
openssl_private_decrypt($enStr,$deStr,$pi_key);
echo $deStr;
echo "<br/>";//下面是签名验证例子,验证签名 一定是用公钥去验证 对方私钥加密的结果
$binary_signature = "";
// At least with PHP 5.2.2 / OpenSSL 0.9.8b (Fedora 7)
// there seems to be no need to call openssl_get_privatekey or similar.
// Just pass the key as defined above
openssl_sign($str, $binary_signature, $pi_key, OPENSSL_ALGO_SHA1);// Check signature
$ok = openssl_verify($str, $binary_signature, $pu_key, OPENSSL_ALGO_SHA1);echo "check #1: ";
if ($ok == 1) {echo "signature ok (as it should be)\n";
} elseif ($ok == 0) {echo "bad (there's something wrong)\n";
} else {echo "ugly, error checking signature\n";
}//var_dump(openssl_get_cipher_methods() );

$res = openssl_pkey_new();// Get private key
openssl_pkey_export($res, $privkey);// Get public key
$pubkey = openssl_pkey_get_details($res);
$pubkey = $pubkey["key"];
var_dump($privkey);
var_dump($pubkey);