AWSのElasticSearchのkibanaにnginxでBasic認証をかける ref: http://qiita.com/marufeuille/items/cb0c98fd0134cc1ae174

file0.conf

server {
    server_name XXXXXX.ap-northeast-1.compute.amazonaws.com;
    location / {
        proxy_pass http://XXXXXXX.ap-northeast-1.es.amazonaws.com/;
        auth_basic "Restricted";
        auth_basic_user_file /etc/nginx/.htpasswd;
    }
}

file1.txt

{"message":"Authorization header requires 'Credential' parameter. Authorization header requires 'Signature' parameter. Authorization header requires 'SignedHeaders' parameter. Authorization header requires existence of either a 'X-Amz-Date' or a 'Date' header. Authorization=Basic XXXXXXXX"}

file2.conf

server {
    server_name XXXXXX.ap-northeast-1.compute.amazonaws.com;
    location / {
        proxy_pass http://XXXXXXX.ap-northeast-1.es.amazonaws.com/;
        auth_basic "Restricted";
        auth_basic_user_file /etc/nginx/.htpasswd;
        proxy_set_header Authorization  "";
    }
}

file3.conf

server {
    server_name XXXXXX.ap-northeast-1.compute.amazonaws.com;
    location / {
        proxy_pass http://XXXXXXX.ap-northeast-1.es.amazonaws.com/_plugin/kibana/;
        auth_basic "Restricted";
        auth_basic_user_file /etc/nginx/.htpasswd;
        proxy_set_header Authorization  "";
    }
}