PHP 使用非對稱式加密演算法（RSA）

解釋

非對稱式加密演算法需要兩個密鑰：公開密鑰（publickey）和私人密鑰（privatekey）。公開密鑰與私人密鑰是一對，如果用公開金鑰組資料進行加密，只有用對應的私人密鑰才能解密；如果用私人金鑰組資料進行加密，那麼只有用對應的公開密鑰才能解密。因為加密和解密使用的是兩個不同的密鑰，所以這種演算法叫作非對稱式加密演算法。

使用情境

PHP 為用戶端(Android，Ios)編寫API，對資料進行解密。

建立私密金鑰、公開金鑰

openssl genrsa -out rsa_private_key.pem 1024//產生原始 RSA私密金鑰檔案openssl pkcs8 -topk8 -inform PEM -in rsa_private_key.pem -outform PEM -nocrypt -out private_key.pem//將原始 RSA私密金鑰轉換為 pkcs8格式openssl rsa -in rsa_private_key.pem -pubout -out rsa_public_key.pem//產生RSA公開金鑰//我們將私密金鑰rsa_private_key.pem用在伺服器端，公開金鑰發放給android跟ios等前端。

服務端類庫

class Rsa {        private static $PRIVATE_KEY = '-----BEGIN RSA PRIVATE KEY-----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-----END RSA PRIVATE KEY-----';        private static $PUBLIC_KEY = '-----BEGIN PUBLIC KEY-----MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCoZZ8iUBprOIc0kGckr5ax6/Fd9IKKMc/XHayKEAvqpS0oz0b1ojEkpkdZBk0OWNhp73YNV+YLKBwwxOwb3u3hl8nBLoG/RilEbBMdCf55cUzNsfn/XF5CiLr/aci/OHuTe6ULvXs280T5M+nUh3iKdiT6z9XrFbH69C+xFoNInwIDAQAB-----END PUBLIC KEY-----';       /**          * 擷取私密金鑰          * @return bool|resource          */        private static function getPrivateKey()     {                $privKey = self::$PRIVATE_KEY;                return openssl_pkey_get_private($privKey);        }        /**          * 擷取公開金鑰          * @return bool|resource          */        private static function getPublicKey()    {                $publicKey = self::$PUBLIC_KEY;                return openssl_pkey_get_public($publicKey);        }        /**          * 私密金鑰加密          * @param string $data          * @return null|string          */        public static function privEncrypt($data = '')        {                if (!is_string($data)) {                        return null;               }                return openssl_private_encrypt($data,$encrypted,self::getPrivateKey()) ? base64_encode($encrypted) : null;        }        /**          * 公開金鑰加密          * @param string $data          * @return null|string          */        public static function publicEncrypt($data = '')       {                if (!is_string($data)) {                        return null;                }                return openssl_public_encrypt($data,$encrypted,self::getPublicKey()) ? base64_encode($encrypted) : null;        }        /**          * 私密金鑰解密          * @param string $encrypted          * @return null          */        public static function privDecrypt($encrypted = '')        {                if (!is_string($encrypted)) {                        return null;                }                return (openssl_private_decrypt(base64_decode($encrypted), $decrypted, self::getPrivateKey())) ? $decrypted : null;        }        /**          * 公開金鑰解密          * @param string $encrypted          * @return null          */        public static function publicDecrypt($encrypted = '')        {                if (!is_string($encrypted)) {                        return null;                }            return (openssl_public_decrypt(base64_decode($encrypted), $decrypted, self::getPublicKey())) ? $decrypted : null;        }}

服務端使用

require_once "Rsa.php";$rsa = new Rsa();$data['name'] = 'Tom';$data['age']  = '20';$privEncrypt = $rsa->privEncrypt(json_encode($data));echo '私密金鑰加密後:'.$privEncrypt.'
';$publicDecrypt = $rsa->publicDecrypt($privEncrypt);echo '公開金鑰解密後:'.$publicDecrypt.'
';$publicEncrypt = $rsa->publicEncrypt(json_encode($data));echo '公開金鑰加密後:'.$publicEncrypt.'
';$privDecrypt = $rsa->privDecrypt($publicEncrypt);echo '私密金鑰解密後:'.$privDecrypt.'
';

Thanks ~

什麼是好的API設計？

