Month: October 2016

  • Today’s news on security

    Article: https://techcrunch.com/2016/10/21/many-sites-including-twitter-and-spotify-suffering-outage/

  • Today I’ve learned…

    My colleagues from the linux.org.ru board have found out one small flaw, so everyone including me stared to dance around PGP/GPG. So far I have found that among my systems: Linux works as it should: two mouse clicks and you are ready. Covers 100% of my work mail, 75% of my personal mail. Mac OS Sierra is not ready: GPG Suite has […]

  • Interesing “feature” of the Mediawiki

    Just have a bit digged in the Mediawiki, that is quite popular Wiki engine 🙂 Found out that the  articles are located in the “prefix_text” table, with all the changes, obviously. So changes are being stored as a new copy of the article: if you have 100kb article and you need to save a change in 1 symbol, there would be 100kb growth (plus additional data) of the table. No wonder that […]

  • E-mail notification on every login

    It’s useful sometimes to get notifications on every ssh login that is happen on the server (though, could be used to monitor logins made by other means). First method is based on the /etc/profile, but it should not be used because user can override it with setting own variables if home directory is writable for him. Most convenient is to use PAM, putting in the /etc/pam.d/sshd execution of the script that […]

  • Backuping mysql

    Recently I have to backup mysql database on quite heavily loaded server and I wanted to make backup daily on one hand and I wanted them not to affect production on the other. DB size is more than 150 Gb, about 50k users daily. First approach was ty try to simply run musqldump and see what would happen. Site was down right after the backup has begun. Then […]

  • DNSBL checkers list

    Since I am now running my own smtp-server, I have to deal with different black list servers myself and check my IP from time to time if it’s there or not.To cover pretty much everything valuable: https://www.whatismyip.com/blacklist-check/http://whatismyipaddress.com/blacklist-checkhttp://mxtoolbox.com/SuperTool.aspx?action=blacklist%3a85.17.249.170&run=toolpage My IP was in 2 lists, DAN ME, APEWS and Barracuda. DAN ME is a list maintained by some loser, who lists there all TOR-related IP addresses […]

  • Leaseweb IPv6 PTR

    Just for the record: Leaseweb does not support PTR record setting for the IPv6 address from the web panel, but you can ask the support team to set it with ticket. Google rejects my mail that comes from the IPv6 network with “PTR not found” message.

  • SUDO !-rules

    Checked one insecure approach to use sudo not to allow commands, but to prohibit commands for user with the NOT-operator “!”. Why it’s a bad idea we can see in the sudoers man page: ” Limitations of the ‘!’ operator It is generally not effective to “subtract” commands from ALL using the ‘!’ operator. A user can trivially circumvent this by copying the  desired command to a different name and then executing that. For example: bill […]

  • Переезды сервисов из страны в страну

    Смена страны проживания в разных сервисах: Google: просто нельзя переехать из РФ в Чехию. Поддержка говорит, что можно воспользоваться услугами партнера и перенести, но в реальности ни один партнер на захотел со мной возиться. Сценарий “удалить все и зарегистрировать новый” меня не устраивает, проще переехать на собственный сервер (что я и сделал). Steam: просто прописать […]

  • Из наблюдений за интернетом

    Примерно полтора года, пока была жива подписка на Google я почти не пользовался этим сервером. Он существовал как-то сам по себе своей жизнью, спамеры нагадили в комментариях ссылками на дорвеи, иногда пропадал файл rome-club.pdf, на который в сети очень много ссылок (лол, никогда бы не подумал, что им кто-то будет интересоваться). При этом Yandex считал […]