生成签名证书

<?php$dn = array(  "countryName" => 'CN', //所在国家名称  "stateOrProvinceName" => 'Beijing', //所在省份名称  "localityName" => 'Beijing', //所在城市名称  "organizationName" => 'ma.alex',   //注册人姓名  "organizationalUnitName" => 'MaAlex', //组织名称  "commonName" => 'mySelf', //公共名称 "emailAddress" => 'ma.alex@qq.com' //邮箱
);
$privkeypass = '123456'; //私钥密码
$numberofdays = 365;     //有效时长
$cerpath = "./rsa_private_key.cer"; //生成证书路径
$pfxpath = "./rsa_public_key.pfx"; //密钥文件路径 //生成证书
$privkey = openssl_pkey_new(array('private_key_bits' => 512));
$csr = openssl_csr_new($dn, $privkey);
$sscert = openssl_csr_sign($csr, null, $privkey, $numberofdays);
openssl_x509_export($sscert, $csrkey); //导出证书$csrkey
openssl_pkcs12_export($sscert, $privatekey, $privkey, $privkeypass); //导出密钥$privatekey
//生成证书文件
$fp = fopen($cerpath, "w");
fwrite($fp, $csrkey);
fclose($fp);
//生成密钥文件
$fp = fopen($pfxpath, "w");
fwrite($fp, $privatekey);
fclose($fp);

类似支付宝的使用

<?php
$privkeypass = '123456'; //私钥密码
$pfxpath = "./rsa_public_key.pfx"; //密钥文件路径
$priv_key = file_get_contents($pfxpath); //获取密钥文件内容
$data = "test123"; //加密数据测试test  //私钥加密
openssl_pkcs12_read($priv_key, $certs, $privkeypass); //读取公钥、私钥
$prikeyid = $certs['pkey']; //私钥
openssl_sign($data, $signMsg, $prikeyid,OPENSSL_ALGO_SHA1); //注册生成加密信息
$signMsg = base64_encode($signMsg); //base64转码加密信息
echo "加密内容：";
print_r($signMsg);echo "\n";
//公钥解密
/*************************签名验证 只验证签名错误**********************************/
$unsignMsg=base64_decode($signMsg);//base64解码加密信息
// print_r($unsignMsg);
openssl_pkcs12_read($priv_key, $certs, $privkeypass); //读取公钥、私钥
$pubkeyid = $certs['cert']; //公钥
$res = openssl_verify($data, $unsignMsg, $pubkeyid); //验证
// echo $res; //输出验证结果，1：验证成功，0：验证失败 /*************************私钥加密，公钥解密，传输数据使用**********************************/
$pi_key = openssl_pkey_get_private($prikeyid);//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
$pu_key = openssl_pkey_get_public($pubkeyid);//这个函数可用来判断公钥是否是可用的
// echo $pi_key;echo "<hr>";
// echo $pu_key;echo "<hr>";echo "加密内容：";
openssl_private_encrypt($data,$encrypted,$pi_key);//私钥加密
$encrypted = base64_encode($encrypted);//加密后的内容通常含有特殊字符，需要编码转换下，在网络间通过url传输时要注意base64编码是否是url安全的
echo $encrypted,"\n";  echo "解密开始:";
openssl_public_decrypt(base64_decode($encrypted),$decrypted,$pu_key);//私钥加密的内容通过公钥可用解密出来
echo $decrypted,"\n";