Not enough entropy in random pool for secure operations

报错信息：

random: Only 19/20 bytes of strong random data available from /dev/random
random: Not enough entropy pool available for secure operations
WPA: Not enough entropy in random pool for secure operations - update keys later when the first station connects
Code language: HTTP (http)

RNG池不够用，而导致无法进行握手。

以下是临时解决方法。

apt install rng-tools

安装完成以后的样子：

root@aml:~# systemctl status rng-tools
* rng-tools.service
   Loaded: loaded (/etc/init.d/rng-tools; generated)
   Active: active (running) since Sat 2019-04-20 09:34:29 UTC; 18s ago
     Docs: man:systemd-sysv-generator(8)
    Tasks: 1 (limit: 1120)
   CGroup: /system.slice/rng-tools.service
           `-6951 /usr/sbin/rngd -r /dev/hwrng

Apr 20 09:34:29 aml systemd[1]: Starting rng-tools.service...
Apr 20 09:34:29 aml rng-tools[6949]: Starting Hardware RNG entropy gatherer daemon: rngd.
Apr 20 09:34:29 aml systemd[1]: Started rng-tools.service.
Code language: PHP (php)

至此，结束。