Adding AuthType Basic HTTP Authentication for WordPress wp-admin , phpMyAdmin, etc

Posted on 3rd October 2016 by azio

Hey folks, so this comes up really often with Rackspace customers, how to add AuthType Basic HTTP authentication. This is akin to an additional user/pass dialog box which appears when navigating to the url. It is really easy to create a new password:

htpasswd -c /etc/httpd/.htpasswd-private username

Please note .htpasswd-private can be anything, however it’s better to make it a hidden file by prefixing with a . dot, also important to ensure that the password file isn’t in a web documentroot, the file should have user and group root root, but that should be done automatically when you create the file with root user.

This is what I added to phpmyadmin configuration file in /etc/httpd/conf.d/phpMyAdmin.conf

 
<Location "/phpMyAdmin/">
AuthType Basic
AuthName "Private Server"
AuthUserFile /etc/httpd/.htpasswd-private
Require valid-user
</Location>

You could do the same for WordPress;

<Location "/wp-admin/">
AuthType Basic
AuthName "Private Server"
AuthUserFile /etc/httpd/.htpasswd-private
Require valid-user
</Location>

Please note that I am using Location, but you can apply the same thing within a directive instead.

Securing your WordPress with chmod 644 and chmod 755 the easy (but pro) way

Posted on 16th September 2016 by azio

Let’s say we have a document root like:

It’s interesting to note the instructions for this will vary from environment to environment, it depends on which user is looking after apache2, etc.

/var/www/mysite.com/htdocs

Make all files read/write and owned by www-data apache2 user only

root@meine:/var/www/mysite.com/htdocs# find . -type f -exec chown apache2:apache2 {} \; 
root@meine:/var/www/mysite.com/htdocs# find . -type f -exec chmod 644 {} \;

Make all folders accessible Read + Execute, but no write permissions

root@meine:/var/www/mysite.com/htdocs# find . -type d -exec chmod 755 {} \;
root@meine:/var/www/mysite.com/htdocs# find . -type d -exec chown apache2:apache2 {} \;

PLEASE NOTE THIS BREAKS YOUR WORDPRESS ABILITY TO AUTO-UPDATE ITSELF. BUT IT IS MORE SECURE 😀

Note debian users, may need to use www-data:www-data instead.

Using Sar to tell a story

Posted on 12th August 2016 by azio

So, a customer is experiencing slowness/sluggishness in their app. You know there is not issue with the hypervisor from instinct, but instinct isn’t enough. Using tools like xentop, sar, bwm-ng are critical parts of live and historical troubleshooting.

Sar can tell you a story, if you can ask the storyteller the write questions, or even better, pick up the book and read it properly. You’ll understand what the plot, scenario, situation and exactly how to proceed with troubleshooting by paying attention to these data and knowing which things to check under certain circumstances.

This article doesn’t go in depth to that, but it gives you a good reference of a variety of tests, the most important being, cpu usage, io usage, network usage, and load averages.

CPU Usage of all processors

# Grab details live
sar -u 1 3

# Use historical binary sar file
# sa10 means '10th day' of current month.
sar -u -f /var/log/sa/sa10

CPU Usage of a particular Processor

sar -P ALL 1 1

‘-P 1’ means check only the 2nd Core. (Core numbers start from 0).

sar -P 1 1 5

The above command displays real time CPU usage for core number 1, every 1 second for 5 times.

Observing Changes in Memory over time

sar -r 1 3

The above command provides memory stats every 1 second for a total of 3 times.

Observing Swap usage over time

sar -S 1 5

The above command reports swap statistics every 1 seconds, a total 3 times.

Overall I/O activity

sar -b 1 3

The above command checks every 1 seconds, 3 times.

Individual Block Device I/O Activities

This is a useful check for LUN , block devices and other specific mounts

sar -d 1 1 
sar -p d

DEV – indicates block device, i.e. sda, sda1, sdb1 etc.

Total Number processors created a second / Context switches

sar -w 1 3

Run Queue and Load Average

sar -q 1 3

This reports the run queue size and load average of last 1 minute, 5 minutes, and 15 minutes. “1 3” reports for every 1 seconds a total of 3 times.

Report Network Statistics

sar -n KEYWORD

KEYWORDS Available;

DEV – Displays network devices vital statistics for eth0, eth1, etc.,
EDEV – Display network device failure statistics
NFS – Displays NFS client activities
NFSD – Displays NFS server activities
SOCK – Displays sockets in use for IPv4
IP – Displays IPv4 network traffic
EIP – Displays IPv4 network errors
ICMP – Displays ICMPv4 network traffic
EICMP – Displays ICMPv4 network errors
TCP – Displays TCPv4 network traffic
ETCP – Displays TCPv4 network errors
UDP – Displays UDPv4 network traffic
SOCK6, IP6, EIP6, ICMP6, UDP6 are for IPv6
ALL – This displays all of the above information. The output will be very long.

sar -n DEV 1 1

Specify Start Time

sar -q -f /var/log/sa/sa11 -s 11:00:00

sar -q -f /var/log/sa/sa11 -s 11:00:00 | head -n 10

Posted on 14th July 2016 by azio

Analyse the process ID’s and check their legitimacy

 for pid in $(ps aux | grep -v '\[' | grep -v grep | awk '{print $2}' | grep -v PID); do SERVICE=$(ps aux | grep -v grep | grep " $pid " | awk '{print $11}' | egrep -v 'nimbus|delloma' | tr -d '-' | tr -d ':'); [ "X$SERVICE" != "X" ] && ls -lh /proc/$pid | grep ' exe ' | tr -d '-' | grep -v $SERVICE >/dev/null 2>&1 && echo "$pid should be $SERVICE but it is actually $(ls -lh /proc/$pid | grep ' exe ' | awk '{print $11}')"; done

Check the netstat detail

netstat -np | awk '{print $7}' | awk -F/ '{count[$2]++}END{for(j in count) print count[j],j}' | sort -nr

Full process list and commands

ps auxfwww

Whitelisting IP’s in modsecurity 1 and modsecurity 2

Posted on 1st July 2016 by azio

Hey folks, so I have noticed that in the new modsecurity CRS version 2, that ‘chained’ rules are supported. This means that whitelisting IP’s has been altered slightly.

Previously whitelisting in modsecurity v2 ip whitelisting was simpler like:
SecRule REMOTE_ADDR “^11.22.33.44” phase:1,nolog,allow,ctl:ruleEngine=off

Now in modsecurity v2 the whitelist configuration must look something like
SecRule REMOTE_ADDR "^11\.22\.33\.44$" phase:1,log,allow,ctl:ruleEngine=Off,id:999945

Now it’s kind of weird, but I hear that chains are much more secure so in that regard maybe v2 has something awesome to offer. Just was head scratching on this one for a good 20 minutes!

You might be wondering why you are receiving an error like ‘configtest failed’ when restarting apache2 using modsecurity. This is probably the fix for v2 you need.

Windows Password reset for Rackspace Cloud Servers

Posted on 6th May 2016 by azio

In the previous articles Using API and BASH to validate changing conditions and Reset windows administrator password using rescue mode without nova-agent I explained both the steps how to reset the password of a windows VM instance by modifying the SAM file by using a Linux ‘rescue’ image in the cloud, and, I also explained how to automate checks for BASH automation thru the API. The checks specifically waited until the server entered rescue, and then lifted the ipv4 address, connecting only when the rescue server had finished building.

That way the automation is handling the delay it takes, as well as setting and lifting the access credentials and ip address to use each time. Here is the complete script. Please note that backticks are deprecated but I’m a bit ‘oldskool’. This is a rough alpha, but it works really nicely. After testing it consistently allows ourselves, or our customers to reset a Windows Cloud Server password, in the case that a customer loses access to it, and cannot use other Rackspace services to do the reset. This effectively turns a useless server, back into a usable one again and saves a lot of time.

#!/bin/bash
# Adam Bull, Rackspace UK
# This script automates the resetting of windows passwords
# Arguments $1 == username
# Arguments $2 == apikey
# Arguments $3 == ddi
# Arguments $4 == instanceid

echo "Rackspace windows cloud server Password Reset"
echo "written by Adam Bull, Rackspace UK"
sleep 2
PASSWORD=39fdfgk4d3fdovszc932456j2oZ

# Provide an instance uuid to rescue and reset windows password

USERNAME=mycloudusernamehere
APIKEY=myapikeyhere
# DDI is the 'customer ID', if you don't know this login to the control panel and check the number in the URL
DDI=10010101
# The instance uuid you want to rescue
INSTANCE=ca371a8b-748e-46da-9e6d-8c594691f71c

# INITIATE RESCUE PROCESS

nova  --os-username $USERNAME --os-auth-system=rackspace  --os-tenant-name $DDI --os-auth-url https://lon.identity.api.rackspacecloud.com/v2.0/ --os-password $APIKEY --insecure rescue --password "$PASSWORD" --image 7fade26a-0cca-415f-a988-49c021768fca $INSTANCE

# LOOP UNTIL STATE DETECTED AS RESCUED

STATE=0
until [[ $STATE == rescued ]]; do
echo "start rescue check"
STATE=`nova --os-username $USERNAME --os-auth-system=rackspace  --os-tenant-name $DDI --os-auth-url https://lon.identity.api.rackspacecloud.com/v2.0/ --os-password $APIKEY --insecure show $INSTANCE | grep rescued | awk '{print $4}'`

echo "STATE =" $STATE
echo "sleeping.."
sleep 5
done

# EXTRACT PUBLIC ipv4 FROM INSTANCE

IP=`nova --os-username $USERNAME --os-auth-system=rackspace  --os-tenant-name $DDI --os-auth-url https://lon.identity.api.rackspacecloud.com/v2.0/ --os-password $APIKEY --insecure show $INSTANCE | grep public | awk '{print $5}' | grep -oE '((1?[0-9][0-9]?|2[0-4][0-9]|25[0-5])\.){3}(1?[0-9][0-9]?|2[0-4][0-9]|25[0-5])'`
echo "IP = $IP"

# UPDATE AND INSTALL RESCUE TOOLS AND RESET WINDOWS PASS
# Set environment locally
yum install sshpass -y

# Execute environment remotely
echo "Performing Rescue..."
sshpass -p "$PASSWORD" ssh -o StrictHostKeyChecking=no root@"$IP" 'yum update -y; yum install ntfs-3g -y; mount /dev/xvdb1 /mnt; curl li.nux.ro/download/nux/dextop/el7/x86_64/nux-dextop-release-0-5.el7.nux.noarch.rpm -o /root/nux.rpm; rpm -Uvh /root/nux.rpm; yum install chntpw -y; cd /mnt/Windows/System32/config; echo -e "1\ny\n" | chntpw -u "Administrator" SAM'

echo "Unrescuing in 100 seconds..."
sleep 100
nova  --os-username $USERNAME --os-auth-system=rackspace  --os-tenant-name $DDI --os-auth-url https://lon.identity.api.rackspacecloud.com/v2.0/ --os-password $APIKEY --insecure unrescue $INSTANCE

Thanks again to my friend Cory who gave me the instructions, I simply automated the process to make it easier and learned something in the process 😉

Disabling SELinux

Posted on 5th May 2016 by azio

Today we had a customer that needed to perform a first generation server to next generation migration however they cannot have SELinux enabled during this process.

I explain to the customer how to disable this, it’s pretty simple.

vi /etc/sysconfig/selinux

SELINUX=enforcing

Needs to be changed to

SELINUX=disabled

Job done. A simple one but nonetheless important stuff. If you wanted to automate this it would look something like this;

sed -i 's/SELINUX=enforcing/SELINUX=disabled/g'/etc/selinux/config

This sed oneliner simply swaps SELINUX=enforcing to SELINUX=disabled, pretty simple stuffs. It will work on CentOS6 and 7 anyway, and should but I can’t guarantee work on CentOS 5.

HOWTO: Rackspace Automation, Using BASH with API (to validate conditions to perform conditional tasks)

Posted on 29th April 2016 by azio

In the previous article, I showed how to wipe clean the windows password from a broken Virtual Machine that you were locked out of by rescuing with a Linux image. In this article I explain steps of how you would automate this with a bash script, that looked at the STATE of the server, and accepts commandline arguments.

It’s quite a simple script;

#!/bin/bash
# Adam Bull
# April 28 2016
# This script automates the resetting of windows passwords
# Arguments $1 == instanceuuid
# Arguments $2 == username
# Arguments $3 == apikey

PASSWORD=mypassword

# Provide an instance uuid to rescue and reset windows password

USERNAME=$1
APIKEY=$2
DDI=$3
INSTANCE=$4


nova  --os-username $USERNAME --os-auth-system=rackspace  --os-tenant-name $DDI --os-auth-url https://lon.identity.api.rackspacecloud.com/v2.0/ --os-password $APIKEY --insecure rescue --password mypassword --image 7fade26a-0cca-415f-a988-49c021768fca $INSTANCE

The above script takes the arguments I give the executable script on the commandline, in this case the first argument passed is $1, the Rackspace mycloud username. The second argument the apikey. etc. This basically puts the server into rescue. But.. what if we wanted to run some automation AFTER it rescued? We don’t want to try and let the automation ssh to the box and run the automation early, so we could use a supernova show to find whether the VM state has changed to ‘rescue’. Whilst its initiating the state will be rescuing. So we have the option of using when !rescueing logic, or, when == equal to rescue. Lets use when equal to rescue in our validation loop.

This loop will continue until the task state changes to the desired value. Here is how we achieve it

#!/bin/bash
# Initialize Variable
STATE=0
# Validate $STATE variable, looping UNTIL $STATE == rescued
until [[ $STATE == rescued ]]; do
echo "start rescue check"
# 'show' the servers data, and grep for rescued and extract only the correct value if it is found
STATE=`nova --os-username $USERNAME --os-auth-system=rackspace  --os-tenant-name $DDI --os-auth-url https://lon.identity.api.rackspacecloud.com/v2.0/ --os-password $APIKEY --insecure show $INSTANCE | grep rescued | awk '{print $4}'`

# For debugging
echo "STATE =" $STATE
echo "sleeping.."

# For API Limit control
sleep 5
# Exit the loop once until condition satisfied
done

# Post Rescue
echo "If you read this, it means that the program detected a rescued state"

It’s quite a simple script to use. We just provide the arguments $1, $2, $3 and $4.

 
./rescue.sh mycloudusername mycloudapikey 10010101 e744af0f-6643-44f4-a63f-d99db1588c94

Where 10010101 is the tenant id and e744af0f-6643-44f4-a63f-d99db1588c94 is the UUID of your server.

It’s really quite simple to do! But this is not enough we want to go a step further. Let’s move the rescue.sh to /bin

# WARNING /bin is not a playground this is for demonstration purposes of how to 'install' bin system applications
cp rescue.sh /bin/rescue.sh

Now you can call the command ‘rescue’.

rescue mycloudusername mycloudapikey mycustomerid mycloudserveruuidgoeshere

nice, and quite simple too. Obviously ‘post rescue’ in the script I can upload a script via ssh to the server, and then execute it remotely to perform the password reset.

Reset Windows Administrator Password on Rackspace Cloud Server using Rescue Mode (without nova-agent)

Posted on 29th April 2016 by azio

So, you have lost your Windows Administrator password for your Rackspace cloud server? I’d like to thank my friend Cory for providing the link details for how to do this.

No problem. Simply put the Windows VM into rescue mode using a Linux image (yup!)

Put Windows VM into Rescue mode using Linux image

# Initiate rescue using the CentOS 7 image for the server uuid 0b67faf7-bc56-4844-ad0b-16e39f289ef6
$ nova me rescue --password mypasswordforrescuemodehere --image 7fade26a-0cca-415f-a988-49c021768fca 0b67faf7-bc56-4844-ad0b-16e39f289ef6

If you’ve broken your Rackspace server and you don’t know how to perform the above step, send a ticket to Rackspace support and they should be able to put your server in rescue so you can reset the password of your windows machine!

SSH to rescue server

ssh root@myserveriphere

Check which disk is Windows NTFS

# fdisk -l

Disk /dev/xvdc: 2147 MB, 2147483648 bytes, 4194304 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x0003e9b3

    Device Boot      Start         End      Blocks   Id  System
/dev/xvdc1            2048     4194303     2096128   83  Linux

Disk /dev/xvdb: 85.9 GB, 85899345920 bytes, 167772160 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0xfcb073fc

    Device Boot      Start         End      Blocks   Id  System
/dev/xvdb1   *        2048   167770111    83884032    7  HPFS/NTFS/exFAT

Disk /dev/xvda: 85.9 GB, 85899345920 bytes, 167772160 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x00070dc0

Here we can see that the disk we want is /dev/xvdb1 since this is the HPFS/NTFS/exFAT partition format used by windows. The rescue mode builds a new server and disk, attaching your old disk as the ‘b’ disk, xvdb. Lets mount the disk and install the application we need to wipe the password for the box.

Mount the disk

yum update -y
yum install ntfs-3g -y
mount /dev/xvdb1 /mnt

Download and install the chntpw tool

 
curl li.nux.ro/download/nux/dextop/el7/x86_64/nux-dextop-release-0-5.el7.nux.noarch.rpm -o /root/nux.rpm
rpm -Uvh /root/nux.rpm
yum install chntpw -y

Run tool against Windows Administrator SAM file

Once run press 1 to ‘clear password’.

root@RESCUE-test config]# chntpw -u "Administrator" SAM
chntpw version 0.99.6 110511 , (c) Petter N Hagen
Hive  name (from header): <\SystemRoot\System32\Config\SAM>
ROOT KEY at offset: 0x001020 * Subkey indexing type is: 666c 
File size 262144 [40000] bytes, containing 6 pages (+ 1 headerpage)
Used for data: 255/20712 blocks/bytes, unused: 13/3672 blocks/bytes.


* SAM policy limits:
Failed logins before lockout is: 0
Minimum password length        : 0
Password history count         : 0
| RID -|---------- Username ------------| Admin? |- Lock? --|
| 01f4 | Administrator                  | ADMIN  |          |
| 01f5 | Guest                          |        | dis/lock |

---------------------> SYSKEY CHECK <-----------------------
SYSTEM   SecureBoot            : -1 -> Not Set (not installed, good!)
SAM      Account\F             : 0 -> off
SECURITY PolSecretEncryptionKey: -1 -> Not Set (OK if this is NT4)
Syskey not installed!

RID     : 0500 [01f4]
Username: Administrator
fullname:
comment : Built-in account for administering the computer/domain
homedir :

User is member of 1 groups:
00000220 = Administrators (which has 1 members)

Account bits: 0x0010 =
[ ] Disabled        | [ ] Homedir req.    | [ ] Passwd not req. |
[ ] Temp. duplicate | [X] Normal account  | [ ] NMS account     |
[ ] Domain trust ac | [ ] Wks trust act.  | [ ] Srv trust act   |
[ ] Pwd don't expir | [ ] Auto lockout    | [ ] (unknown 0x08)  |
[ ] (unknown 0x10)  | [ ] (unknown 0x20)  | [ ] (unknown 0x40)  |

Failed login count: 0, while max tries is: 0
Total  login count: 15

- - - - User Edit Menu:
 1 - Clear (blank) user password
 2 - Edit (set new) user password (careful with this on XP or Vista)
 3 - Promote user (make user an administrator)
(4 - Unlock and enable user account) [seems unlocked already]
 q - Quit editing user, back to user select
Select: [q] > 1
Password cleared!

Hives that have changed:
 #  Name
 0  
Write hive files? (y/n) [n] : y
 0   - OK

It’s been done, yay!

Unrescue the cloud server, either from control panel or using nova

abull-mb:~ adam$ supernova me unrescue 0b67faf7-bc56-4844-ad0b-16e39f289ef6

Yay! We now automatically bypass the ordinary login screen so we can get into the server to reconfigure it properly again.

You might have some questions about… setting up nova.

Setting up Nova

# Nova configuration

#export OS_AUTH_URL=https://lon.identity.api.rackspacecloud.com/v2.0/
#export OS_AUTH_SYSTEM=rackspace_uk
#export OS_REGION_NAME=LON
#export OS_USERNAME=mycloudusernamehere
# Tenant Name is customer number shown in url of mycloud control panel
##export OS_TENANT_NAME=10101010
#export NOVA_RAX_AUTH=1
#export OS_PASSWORD=mycloudapikeyhere
# Project ID is customer number shown in url of mycloud control panel
#export OS_PROJECT_ID=100101010
#export OS_NO_CACHE=1

These ‘environment variables’ should be put in a file like your .bash_profile. Then you will want to source it before using nova

source .bash_profile
or
. .bash_profile

This just sets the variables on the commandline so they can be used by nova. It is possible to provide all of the credentials on the nova commandline as described in previous articles on this blog concerning nova.

Using nova without .bash_profile or environment variables

Initiate Rescue Mode

nova --os-username mycloudusernamegoeshere --os-auth-system=rackspace  --os-tenant-name tenantidgoeshere --os-auth-url https://lon.identity.api.rackspacecloud.com/v2.0/ --os-password apigoeshere rescue --password mypasswordforrescuemodehere --image 7fade26a-0cca-415f-a988-49c021768fca 0b67faf7-bc56-4844-ad0b-16e39f289ef6

Un-rescue

nova --os-username mycloudusernamegoeshere --os-auth-system=rackspace  --os-tenant-name tenantidgoeshere --os-auth-url https://lon.identity.api.rackspacecloud.com/v2.0/ --os-password apigoeshere unrescue

Installing nova

for more details about how to install python based nova, used in this article, please see;
https://support.rackspace.com/how-to/installing-python-novaclient-on-linux-and-mac-os/

Protecting yourself from Brute Force Attacks on SSH

Posted on 26th April 2016 by azio

To protect yourself against this type of attack succeeding, namely to guess your password and compromise your server, you can choose an extremely long password utilizing many symbols %$!&^ and numbers 190921, both UPPERCASE and lowercase letters.

Alternatively, and the most effective way to protect yourself against these attacks is to change the port with which your SSH service runs on. However some caution should be taken when changing SSH ports of the server, as if done improperly this can cause you to lock yourself out with the firewall. The process is simple though;

locate sshd_config in /etc/ssh/sshd_config

vi /etc/ssh/sshd_config

Change port to something else like 777

Change from:

#Port 22

Change to:

Port 777

Open up Firewall rule (very important)

sudo iptables -I INPUT 1 -p tcp  --dport 777 -j ACCEPT

Save Firewall Rule

/etc/init.d/iptables save

The entire process is described at:
https://support.rackspace.com/how-to/introduction-to-iptables/

Other alternatives ways to resolve this other than using secure passwords, or a less obvious port than SSH’s default port 22, is to install something like fail2ban. Which will ban any IP address preventing it from logging in if it gets the password wrong a certain number of times in a row. However, pleas be careful with this too as you can lock yourself out if you are not careful, as with all security software.