##伺服器是centos7
##首先確定伺服器是否安裝openssl協議(未安裝的請執行命令yum install -y openssl-devel):  [root@iz2vcf47jzvf8dxrapolf7z test]# openssl version  OpenSSL 1.0.2k-fips  26 Jan 2017  [root@iz2vcf47jzvf8dxrapolf7z test]#    #生成私鑰文件rsa_private_key.pem文件  [root@iz2vcf47jzvf8dxrapolf7z test]# openssl genrsa -out rsa_private_key.pem 1024  Generating RSA private key, 1024 bit long modulus  ..................................................++++++  ........................................................................++++++  e is 65537 (0x10001)
##私鑰轉成pkcs8模式(文末附各模式說明)
[root@iz2vcf47jzvf8dxrapolf7z test]# openssl pkcs8 -topk8 -inform PEM -in rsa_private_key.pem -outform PEM -nocrypt -out private_key.pem
##列印私鑰文件  [root@iz2vcf47jzvf8dxrapolf7z test]# cat rsa_private_key.pem  -----BEGIN RSA PRIVATE KEY-----  MIICXQIBAAKBgQCh13gUKZWQlx7cuYQvY1A6JuJjArMax8yHcTrtcL+kpa5Cg6mD  609QNiTacuJxmh7Q/w+1Lw/cuWN0Q7s3s4WzJET6YCi3fH4zqVmpqWIcKWC/hE3p  VV3lJsBvMpoz2bFn1eRwVtmSp4dVAqe542YvbZ13VGheEvkKi5uqWyhY1wIDAQAB  AoGAIYSjjOFz5Wc28BXH55yU8AY/mqvjdidtF5v+zVAtkKbzqTjlcbnZSk58YXWr  qkV2HmjE0wx1J4yJqXmhm46loLkIpWdQfzRyFFnK3xmo9Lc6jXbIrKmFYyN7FTqT  5cADvrTJ2jO9BlDG0ddTp7pl6dRi00jkrTRU3mgxZZ1kOWkCQQDRZZl9LKs+lz0v  kOEKGuhjfHpFYpjce/mg0XfOZuFIqYXdm/nO1nx/KAr+xtUhiqkRzdxADOA0Nrxg  alCtT1NbAkEAxdxotvcFYKOFES1aOAg35mv7Inlnjelbj1Jx0wtGRVUV/0nvMVKf  TLInECD2mUaE00OWjuXanAI2FQQWbML1NQJBAL/AGDRGaXJhsIgUVd+ZEGG6JYXQ  akbNyKR57Qo3r+mIQ6vSH4pHY65VjuwMTDPw9C33o8+LeuyVix+He+WZFK0CQQDA  Gb+9LFYXPou6Yqr+TdRgLiSUkwScfp27qBMFESQ3umVyB8lovMwXPby5ZxelNxdM  uolZ0gaOg4MYonBXRm2lAkAEOjH32XMSTB+HI+lQrLCFiumyRjHpgbRgTcyUQolY  fjR63M0E/rzVIneKPqLP+ySOYLFcO3bjuMa75CQic8PF  -----END RSA PRIVATE KEY-----

 ##根據私鑰得到相應的公鑰
 [root@iz2vcf47jzvf8dxrapolf7z test]# openssl rsa -in rsa_private_key.pem -pubout -out rsa_public_key.pem
 writing RSA key
 [root@iz2vcf47jzvf8dxrapolf7z test]# cat rsa_public_key.pem
 —–BEGIN PUBLIC KEY—–
 MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCh13gUKZWQlx7cuYQvY1A6JuJj
 ArMax8yHcTrtcL+kpa5Cg6mD609QNiTacuJxmh7Q/w+1Lw/cuWN0Q7s3s4WzJET6
 YCi3fH4zqVmpqWIcKWC/hE3pVV3lJsBvMpoz2bFn1eRwVtmSp4dVAqe542YvbZ13
 VGheEvkKi5uqWyhY1wIDAQAB
 —–END PUBLIC KEY—–

<?
/**
 * 私鑰加密/公鑰解密
 *
 * @param $str string 待加解密字元串
 * @param $isEncrypt boolean
 * return string|null
 */
 function opensslPrivateEncrypt($str, $isEncrypt = true)
 {

　　if($isEncrypt){
　　　　$privateKey = file_get_contents(‘./rsa_private_key.pem’);
　　　　$privateKey = openssl_pkey_get_private($privateKey);

　　　　return openssl_private_encrypt($str, $encryptedStr, $privateKey)
　　　　　　? base64_encode($encryptedStr) : null;
　　}else{
　　　　$publicKey = file_get_contents(‘./rsa_public_key.pem’);
　　　　$publicKey = openssl_pkey_get_public($publicKey);

　　　　return (openssl_public_decrypt(base64_decode($str), $decryptedStr, $publicKey))
　　　　? $decryptedStr : null;
　　}
}

/**
 * 公鑰加密/私鑰解密
 *
 * @param $str string 待加解密字元串
 * @param $isEncrypt boolean
 * return string|null
 */
function opensslPublicEncrypt($str , $isEncrypt = true)
{

　　if($isEncrypt){
　　　　$publicKey = file_get_contents(‘./rsa_public_key.pem’);
　　　　$publicKey = openssl_pkey_get_public($publicKey);

　　　　return openssl_public_encrypt($str, $encryptedStr, $publicKey)
　　　　　　? base64_encode($encryptedStr) : null;
　　}else{
　　　　$privateKey = file_get_contents(‘./rsa_private_key.pem’);
　　　　$privateKey = openssl_pkey_get_private($privateKey);

　　　　return (openssl_private_decrypt(base64_decode($str), $decryptedStr, $privateKey))
　　　　　　? $decryptedStr : null;
　　}
}

$config = array();
$config[‘title’] = ‘PHP is the best program language.’;
$config[‘comment’] = ‘PHPERS are great people.’;

$privateEncrypt = opensslPrivateEncrypt(json_encode($config));
echo(“##privateEncrypt is:” . PHP_EOL);
echo($privateEncrypt . PHP_EOL);
$privateDecrypt = opensslPrivateEncrypt($privateEncrypt, false);
echo(“##privateDecrypt is:” . PHP_EOL);
echo($privateDecrypt . PHP_EOL);

$publicEncrypt = opensslPublicEncrypt(json_encode($config));
echo(“##publicEncrypt is:” . PHP_EOL);
echo($publicEncrypt . PHP_EOL);
$publicDecrypt = opensslPublicEncrypt($publicEncrypt, false);
echo(“##publicDecrypt is:” . PHP_EOL);
echo($publicDecrypt . PHP_EOL);

##執行腳本
[root@iz2vcf47jzvf8dxrapolf7z test]# php openssl.php
##privateEncrypt is:
mLrLIAwbwlE69Yj5/lnNw1t8qSjhnFa+96s/kSMYweAn/HEsV7jfVAJ6mn/FY2DRRWkKeOnguUYsRcFTBcS1ieG7UtqbUAASXA5dwVgtTrFoDcDhHMl7p90+dIO8n+vMoBx1kkUegpvtH03y3MgUVSj/BLkLE8jrFXyjGufIcv0=
##privateDecrypt is:
{“title”:”PHP is the best program language.”,”comment”:”PHPERS are great people.”}
##publicEncrypt is:
NW2k5m2pKrZmEMSHXiK7mfyC+yDjH1+b6TrEMPv+ywBfsUlo2P8eWwcXOQxvsV4UG87a1S4Xa2QySntdEwhpYoim97457ODVVCb6jx+cqqdWJ1wlLS+gx7FJxw7Z0kMPmCm5iMcQwWPK+UzF+dpc/gJFa9uGAAmYczUumOauAx0=
##publicDecrypt is:
{“title”:”PHP is the best program language.”,”comment”:”PHPERS are great people.”}