Category Archives: Security

PHPHOST BLOG

Web Hosting Related Articles You May Need

[one-liner]: Securing your Subversion Password using GPG Agent

Background

If you’ve ever dealt with subversion on Unix, one of the annoyances is that it essentially stores it’s password in clear text under your $HOME/.subversion/auth/svn.simple directory in text files. Not a huge deal to a single developer or user but if you work in a large company or even a small one this is a […]

Continue reading

Posted in one-liner, Security, subversion, Syndicated, tips & tricks | Comments Off on [one-liner]: Securing your Subversion Password using GPG Agent

How does a process deal with user credentials?

Background

A question came up on the Stack Exchange site Unix & Linux in which I wrote up a pretty good answer, that describes some of the mechanics of how a process deals with its user credentials, so I’m adding my writeup to the blog.

It really comes down to what makes up a process in Unix. […]

Continue reading

Posted in credentials, linux, permissions, process, Security, Syndicated, tutorials | Comments Off on How does a process deal with user credentials?

How is my password stored in Linux?

Background

People that use Linux on a daily basis probably are completely oblivious to the actual mechanisms being used to store their passwords safely and securely on a given Linux system. Oh they might guess that their password is stored in the /etc/passwd file (they’d be wrong by the way) but most probably never even gave […]

Continue reading

Posted in encryption, linux, passwords, Security, SHA-512, shadow, Syndicated, sysadmin, tutorials | Comments Off on How is my password stored in Linux?

Java Zero Day Vulnerability Exploits JMX and MethodHandles

I recently identified software security issues (#2), especially related to Java, as one of the most significant software development themes of 2012. Not even a month into 2013, a news story receiving a lot of press is the U.S. Department of Homeland Se… Continue reading

Posted in Java SE 7, Security, Syndicated | Comments Off on Java Zero Day Vulnerability Exploits JMX and MethodHandles

[one-liner]: Command Line Calculator – bc – Example

Background

I was recently listening to the podcast Security Now! episode #316. In this episode Steve Gibson discussed his Off the Grid paper based password system, where he mentioned the number 9.337 × 10426. This number represents the total number of 26×26 Latin Squares.

Excerpt from grc.com’s Off The Grid details page…

This number, expressed in scientific notation, […] Continue reading

Posted in bc, linux, one-liner, Security, Syndicated, tips & tricks | Comments Off on [one-liner]: Command Line Calculator – bc – Example

Prevent Ubuntu from asking a password after resuming from Hibernate or Suspend

When you close the lid of your laptop and Ubuntu is running, the computer goes into Suspend mode. Same goes for chosing Hibernate from the shutdown menu, when the laptop goes into deep sleep and consumes less power. When resuming from these two states, Ubuntu will ask you for your password. If you’d like to […] Continue reading

Posted in GNOME, Security, Syndicated, System | Comments Off on Prevent Ubuntu from asking a password after resuming from Hibernate or Suspend

[one-liner]: Working with ssh-keygen & SSH Key Pair Files

Background

Here are some typical examples for creating ssh RSA key files. SSH keys are generated & modified using the command ssh-keygen.

Example #1 – defaults

For starters here’s what happens when you run ssh-keygen with just it’s defaults:

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
% ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key (/home/jaml/.ssh/id_rsa):
Enter passphrase (empty for no […] Continue reading

Posted in linux, one-liner, Security, shell, ssh, Syndicated, tips & tricks | Comments Off on [one-liner]: Working with ssh-keygen & SSH Key Pair Files

[one-liner]: Working around the SSH error message: Too many authentication failures for root

Background

Yesterday I ran into an issue while trying to ssh to one of my computers. I started getting this error, Too many authentication failures for root. At first I thought it has something to do with PAM or some sort of login detection protection related to /var/log/btmp (a log file maintaining bad login attempts). Turns […] Continue reading

Posted in linux, one-liner, Security, shell, ssh, Syndicated, sysadmin, tip, tips & tricks | Comments Off on [one-liner]: Working around the SSH error message: Too many authentication failures for root

Leave no traces in your .bash_history file

If you wish to not leave traces of your CLI activity in the .bash_history file, you can exclude the logging of certain commands by appending a space character before them. For example, press the space bar before you type cat /etc/passwd:
<space>c… Continue reading

Posted in cli, Security, Syndicated, System | Comments Off on Leave no traces in your .bash_history file

Monitor your changed files in real-time in Linux

Everybody knows top or htop. Ever wished there was something similar but to monitor your files instead of CPU usage and processes? Well, there is.Run this: watch -d -n 2 ‘df; ls -FlAt;’ and you’ll get to spy on which files are getting written on your system. Every time a file gets modified it will […] Continue reading

Posted in cli, Security, Syndicated, System | Comments Off on Monitor your changed files in real-time in Linux