RSA加密解密（PHP Demo）

 $private_key = '-----BEGIN RSA PRIVATE KEY-----
 MIICXQIBAAKBgQDpoODVtnSztGyb//p+g/Ob36jb3jzWzS2qovOjpY/rrTjwlVcQ
 pB2m1nZDQNpTFsG8ZBl7uPw3M81lr7NRRn6tY7Om8tbOOsRgY6u0xwbgdRStFFvw
 PzZ1HehiQ6WB8za8cucCyvuqmBRp7HOjO4Aa9t0rIvZ/hoWMeSvjnAVbMwIDAQAB
 AoGBAOEHsaiIDs6NKdP08r1rsXjhLI9i92zawnLKdCybKw4RknfBENSZj2oExnKv
 A9vmXoNsU1NlcaJmRh/85ZaSdS4L+Zx8iz18uwXAjCPpfMd7nG4FD55713Lszhua
 DQIxK06w2mI0ytwEf4cqQmct2/BWchBXZIlz9O0Q70CF2brpAkEA/3NtHrQNxbF0
 KRvrrTw4c9Y76PyeESEmKuF8ZKQu6v1qSb/V3aZsiGPTH+vUf0oAmoJoGx1AtRuk
 DAe9uQ5efQJBAOohcXTh7vgm5ujlyJEi85jGp2BnHxmNAHN6n1q44Hs1wbvICujH
 SEaHhVt6hSf7/NXnGOtJXve0JIt5glvCX28CQCa1jASKDkg10r9j/ruak4diIGP2
 29EGr+zxjFMH2iA71H5mdncHAA1O6zA8IVBEm4DOYA4zyZloHdzA04wWVFUCQQDY
 9+cJVvq6smpYN+E3RrmRwb6IYuf6KKXbXi5gx2UYKQgA+e/KKis7WQlnbdIJ7MYw
 f7mjCVpdmG4pZpA8cpM3AkAFRUXYKlxLusKBRDZSDCyCUzP/Y3ql/qWXOqcA5Brj
 pj+cofEWd/jZqD3drFjDGvccFmTfEAVmXWxCnJAZU2cW
 -----END RSA PRIVATE KEY-----';

 $public_key = '-----BEGIN PUBLIC KEY-----
 MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDpoODVtnSztGyb//p+g/Ob36jb
 3jzWzS2qovOjpY/rrTjwlVcQpB2m1nZDQNpTFsG8ZBl7uPw3M81lr7NRRn6tY7Om
 8tbOOsRgY6u0xwbgdRStFFvwPzZ1HehiQ6WB8za8cucCyvuqmBRp7HOjO4Aa9t0r
 IvZ/hoWMeSvjnAVbMwIDAQAB
 -----END PUBLIC KEY-----';

 //echo $private_key;
 $pi_key =  openssl_pkey_get_private($private_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
 $pu_key = openssl_pkey_get_public($public_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";

 $data = "123";//原始数据
 $encrypted = "";
 $decrypted = "";

 echo "source data:",$data,"\n";

 echo "private key encrypt:\n";

 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 "public key decrypt:\n";

 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";

 echo "---------------------------------------\n";
 echo "public key encrypt:\n";

 openssl_public_encrypt($data,$encrypted,$pu_key);//公钥加密
 $encrypted = base64_encode($encrypted);
 echo $encrypted,"\n";

 echo "private key decrypt:\n";
 openssl_private_decrypt(base64_decode($encrypted),$decrypted,$pi_key);//私钥解密
 echo $decrypted,"\n";

密钥采用openssl工具生成，命令：

1. 生成 rsa 私钥
openssl genrsa -out rsaprivatekey.pem 1024
2. 生成对应的公钥
openssl rsa -in rsaprivatekey.pem -pubout -out rsapublickey.pem
3. 将 RSA 私钥转换成 PKCS8 格式,
openssl pkcs8 -topk8 -inform PEM -in rsaprivatekey.pem -outform PEM -nocrypt -out
rsaprivatepkcs8.pem