Yii2 安装 composer 失败 [ 2.0 版本 ]

我的操作系统是linux Deepin2014.3,采用的xampp安装的php，PHP版本高于5.4,调用这个命令的时候出问题了。

composer global require "fxp/composer-asset-plugin:1.0.0"

弹出这样的问题。

Changed current directory to /home/litianci/.composer
./composer.json has been updated
Loading composer repositories with package information
The "https://packagist.org/packages.json" file could not be downloaded: SSL operation failed with code 1. OpenSSL Error messages:
error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed
Failed to enable crypto
failed to open stream: operation failed
https://packagist.org could not be fully loaded, package information was loaded from the local cache and may be out of date
Updating dependencies (including require-dev)
Nothing to install or update
Generating autoload files

看问题是SSL的验证问题，网上搜索了很久没有解决。有没有哪位遇到类似的问题？看这个问题比较像linux的问题，不知道有没有遇到类似问题的人。