OSS 上传回调签名 求助

文档说签名会在OSS端发生，可是我瞧了瞧根本就没有.


下面是我获得的
{
    "REDIRECT_STATUS":"200",
    "HTTP_HOST":"www.xxx.com",
    "HTTP_CONNECTION":"close",
    "CONTENT_LENGTH":"159",
    "CONTENT_TYPE":"application/x-www-form-urlencoded",
    "HTTP_USER_AGENT":"e http-client/0.0.1",
    "HTTP_X_OSS_PUB_KEY_URL":"aHR0cHM6Ly9nb3NzcHVibGljLmFsaWNkbi5jxxxxxxxxxxxb20vY2FsbGJhY2tfcHViX2tleV92MS5wZW0=",
    "PATH":"/sbin:/usr/sbin:/bin:/usr/bin",
    "LD_LIBRARY_PATH":"/usr/local/apache/lib",
    "SERVER_SIGNATURE":"",
    "SERVER_SOFTWARE":"Apache",
    "SERVER_NAME":"www.xxx.com",
    "SERVER_ADDR":"182.92.xxx.xxx",
    "SERVER_PORT":"80",
    "REMOTE_ADDR":"101.200.xxx.xxx",
    "DOCUMENT_ROOT":"/home/www.xxx.com",
    "REQUEST_SCHEME":"http",
    "CONTEXT_PREFIX":"",
    "CONTEXT_DOCUMENT_ROOT":"/home/www.xxx.com",
    "SERVER_ADMIN":"xxx@xxx.com",
    "SCRIPT_FILENAME":"/home/www.xxx.com/Admin/Admin.php",
    "REMOTE_PORT":"52098",
    "REDIRECT_URL":"/Admin/Oss/callback",
    "GATEWAY_INTERFACE":"CGI/1.1",
    "SERVER_PROTOCOL":"HTTP/1.0",
    "REQUEST_METHOD":"POST",
    "QUERY_STRING":"",
    "REQUEST_URI":"/Admin/Oss/callback",
    "SCRIPT_NAME":"/Admin/Admin.php",
    "PATH_INFO":"Oss/callback",
    "PATH_TRANSLATED":"/home/www.xxx.com/Oss/callback",
    "PHP_SELF":"/Admin/Admin.php/Oss/callback",
    "REQUEST_TIME":1452577537
}