SOHO : Small Office Home Office
Freeware - Opensource software tips, tricks, tweaks & fixes for managing, securing, improving the performance of SOHO Desktop, Laptop, Networks

Login to dd-wrt by ssh (+diffie-hellman-group1-sha1)

  • Enable ssh from Services page

In your windows or linux machine, under the user home folder

  • Create a folder ".ssh" (dot ssh)
  • Create a file named "config" inside the .ssh folder
  • Contents of config file

    Host  192.168.1.1 ddwrt.lan
        KexAlgorithms +diffie-hellman-group1-sha1
        user root
        port 2222

  • Set the file permission to 600
             chmod 600 ~/.ssh/config (linux)
  • Steps to set the file permission on windows

Right click config file > properties > security> Advanced>Disable inheritance

Right click config file > properties > security> Advanced>remove all from permission entries except your username

Right click config file > properties > security> Advanced> select your username > edit > full control 

Apply and close window

  
  •     Run command  : 
ssh -o KexAlgorithms=+diffie-hellman-group1-sha1 root@ddwrt.lan

 

where root is the user name of router admin, ddwrt.lan is the hostname router, can be replaced with the ip address
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How to clear DNS cache on dd-wrt?

My router is flashed with dd-wrt which uses the dnsmaq daemon.

About dnsmasq? 

dnsmasq is a lightweight DNS, TFTP and DHCP server. It is intended to provide coupled DNS and DHCP service to a LAN. Dnsmasq accepts DNS queries and either answers them from a small, local, cache or forwards them to a real, recursive, DNS server. 

To flush out dns cache the dnsmasq daemon has to be restarted.

Login to the router terminal and run commands

# stopservice dnsmasq

# startservice dnsmasq

 

image

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python3 [virtualenvwrapper] : set up virtualenv in ubuntu LTS

Setting up virtual environment in ubuntu lts.


  • Installing virtualenv: Install into user folder instead of system wide

sudo apt-get install python3-pip

python3 -m pip install --user virtualenvwrapper

  • Config virtualenvwrapper

nano ~/home/username/.bashrc

  • Add below lines to .bashrc

#setup virtualenv

export WORKON_HOME=$HOME/.virtualenvs

export ROJECT_HOME=$HOME/Devel

export VIRTUALENVWRAPPER_PYTHON = /usr/bin/python3

export VIRTUALENVWRAPPER_SCRIPT=/home/username/.local/bin/virtualenvwrapper.sh

source /home/username/.local/bin/virtualenvwrapper.sh

  • Enable config 

source ~/.bashrc

  • For below error or screenshot :  export VIRTUALENVWRAPPER_PYTHON=/usr/bin/virtualenvwrapper.sh

/usr/bin/python: No module named virtualenvwrapper

virtualenvwrapper.sh: There was a problem running the initialization hooks.

If python could not import the module virtualenvwrapper.hook_loader,

check that virtualenvwrapper has been installed for 

VIRTUALENVWRAPPER_PYTHON=/usr/bin/python and that python is set properly.



  • Quick-Start

Run: workon

A list of environments, empty, is printed.

Run: mkvirtualenv temp

A new environment, temp is created and activated.

Run: workon

This time, the temp environment is included.

Ref: https://virtualenvwrapper.readthedocs.io/en/latest/install.html#basic-installation

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Mysql (adminer) : error "Access denied for user 'root'@'localhost'(using password :yes)

  •  Server

 ubuntu 18.04LTS

  • Mysql 

mysql-server v5.7


  • Error: 
image

  • edit mysql config file

sudo nano /etc/mysql/my.cnf

  • Add to my.cnf

[mysqld]

skip-grant-tables

  • restart mysql

sudo systemctl restart mysql

  • login to mysql and run command

$ mysql -u root 

UPDATE mysql.user SET authentication_string=PASSWORD('YOURNEWPASSWORD'), plugin='mysql_native_password' WHERE User='root';

exit;

  • disable the added lines from my.cnf

#[mysqld]

#skip-grant-tables

  • Restart mysql 

sudo systemctl restart mysql

  • Run mysql_secure_installation and set 'y' for all options

sudo mysql_secure_installation

  • check login to mysql 

mysql -u root -p  

Now login to mysql as user root with new password must be possible.




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Apache2 : Setup https with self signed certificate and redirect http to https

Note : Internet Browser will issue warning  on self signed certificates.

Self signed secure socket layer (TLS/SSL) certificate, to enable https on apache2 server. Even though the server is on lan, security is a concern when there is a large group of nodes. A zero cost self signed certificate is generated and all http request is rerouted to https

  • Create a folder to hold certificate

sudo mkdir /etc/apache2/ssl

 

  • Create cretificate and key valid for three years (days 1095 is 3 years)

sudo openssl req -x509 -nodes -days 1095 -newkey rsa:2048 -out /etc/apache2/ssl/server.crt -keyout /etc/apache2/ssl/server.key

 

  • Openssl information of certificate

Country Name (2 letter code) [AU]: IN
State or Province Name (full name) [Some-State]: KA
Locality Name (eg, city) []: Bangalore
Organization Name (eg, company) [My Company]: my company
Organizational Unit Name (eg, section) []: IT
The common name is your domain name or the server IP address.
Common Name (e.g. server FQDN or YOUR name) []:
192.168.2.3 or secure.myserver.lan 
Email Address []:dummy@example.com
                     
                    • Enable ssl

                    sudo a2enmod ssl

                     

                    • Edit config file (my personal preference I add both http and https conf in one file)

                    <VirtualHost  *:80>

                    ServerName myserver.lan

                    ServerAlias www.myserver.lan

                    ServerAdmin servername@localhost

                    ErrorLog ${APACHE_LOG_DIR}/myserver-lan-error.log

                    CustomLog ${APACHE_LOG_DIR}/myserver-lan-access.log combined

                                        # below line will redirect all http request to https 

                    Redirect permanent / https://myserver.lan

                    </VirtualHost>

                    <VirtualHost  *:443>

                    ServerName myserver.lan

                    ServerAdmin servername@localhost

                    DocumentRoot /var/www/secure

                    <Directory /var/www/secure/>

                    require host localhost

                    require ip 127.0.0.1

                    require ip 192.168

                    </Directory>

                    ErrorLog ${APACHE_LOG_DIR}/myserver_lan-error.log

                    CustomLog ${APACHE_LOG_DIR}/myserver_lan.log combined

                    SSLEngine on

                    SSLCertificateFile  /etc/apache2/ssl/myservre-lan.crt

                    SSLCertificateKeyFile  /etc/apache2/ssl/myserver-lan.key

                    <FilesMatch "\.(cgi|shtml|phtml|php)$">

                    SSLOptions +StdEnvVars

                    </FilesMatch>

                    <Directory /usr/lib/cgi-bin>

                    SSLOptions +StdEnvVars

                    </Directory>

                    </VirtualHost> 


                    • Restart apache

                    sudo systemctl restart apache2

                     

                    • Enable firewall

                    sudo ufw allow 'Apache full'

                     

                    For named virtual host create ssl certificates as per the domain name and follow the above steps.


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                    Apache2 : Setup named virtual hosts

                    A server is setup on local lan which acts as a development server, backup server, a secure domain to manage database servers and host other important data on local lan. The setup is same for a valid FQDN which can be accessed from WAN.

                    Server : Ubuntu 18.04 LTS
                    Application server :  LAMP stack
                    Main site path : /var/www/html
                    domain name : myserver.lan
                    Virtual host path :  /var/www/vhosts                 
                    domain name1 : your domain name. 
                    Example : dev.myserve.lan
                    domain name2 : your domain name. 
                    Example : secure.myserver.lan
                    • Create config files for vhosts 
                    run command :             
                    cd /etc/apache2/sites-available
                    sudo cp  000-default.conf  dev-myserver-lan.conf
                    sudo cp 000-default.conf  secure-myserver-lan.conf

                    • Edit config files:
                    sudo nano /etc/apache2/sites-available/secure-myserver-lan.conf
                    # Note: you can add ip as <VirtualHost 192.168.1.1:80> to respond to a specific ip.
                    <VirtualHost *:80>
                        ServerName secure.myserver.lan
                        #ServerAlias www.myserver.lan 
                        ServerAdmin secure_myserver_lan@localhost
                        DocumentRoot /var/www/secure
                    # This site can be accessed from local lan  and ip range (192.168.*.*) only
                        <Directory /var/www/secure/>
                            require host localhost
                            require ip 127.0.0.1
                            require ip 192.168
                        </Directory> 
                    # very important set logs for each site (personal preference)
                        ErrorLog ${APACHE_LOG_DIR}/secire_myserver_lan-error.log
                     
                        CustomLog ${APACHE_LOG_DIR}/secure_myserver_lan-access.log combined

                    <VirtualHost>

                    • Enable virtual host
                    # sudo a2ensite your-domain-conf
                    sudo a2ensite secure-myserver-lan.conf
                    sudo systemctl restart apache2

                    • Disable virtualhost
                    # sudo a2ensite your-domain-conf
                    sudo a2dissite secure-myserver-lan.conf
                    sudo systemctl restart apache2

                    • Routing : If the domains are on local lan, you can forward the requests from your router or add to local host file
                    sudo nano /etc/hosts
                    [...]
                    192.168.1.251    secure.myserver.lan
                    192.168.1.251    dev.myserver.lan
                    [...]

                    • To access the site from a browser use the http or https tag without fail or you may be redirected to websearch
                    Browser address bar

                    Wrong : dev.myserver.lan

                    Right : http://dev.myserver.lan

                    Right : https://dev.myserver.lan 

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                    reset wordpress user password

                    On updating my wordpress user password I forgot...

                    Refering : https://codex.wordpress.org/Resetting_Your_Password

                    I opted for the ftp option but instead of downloading and uploading I logged in through ssh and edited the file. Super easy

                    1. Login to your site via FTP / SSH  and download or edit your active theme's functions.php file.
                    2. Edit the file and add this code to it, right at the beginning, after the first <?php:
                    wp_set_password( 'password', 1 );
                    
                    Put in your own new password for the main admin user. The "1" is the user ID number in the wp_users table.
                    3. Upload the modified file back to your site.
                    4. After you then are able to login, make sure to go back and remove that code. It will reset your password on every page load until you do.
                    Next step is hardening wordpress
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                    Reset dd-wrt web gui password

                    I changed the dd-wrt router password and could no longer access the device. Lucky, I was able to login to the router with ssh and default username and my old password. This means that the web gui password was corrupted. With the below steps I was able to gain access to the routers web gui.



                    • Login to the router via ssh.
                    • Type in nvram set http_passwd=
                    • Then type in nvram commit
                    • open browser, connect to the router and change the password "immediately"
                    • Power off the router for atleast a minute and power on again.
                    • login to the router and take backup of your settings.

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                    list ppa and uninstall with ppa-purge

                    Remove installed ppa from ubuntu system.

                    • Install  ppa-purge 
                    sudo apt-get install ppa-purge
                    • Run command in terminal to list all configured repositories and ppa in readable format
                    apt-cache policy | grep http | awk '{print $2 $3}' | sort -u

                    • Uninstall the ppa with syntax : sudo ppa-purge ppa:<repository-name>/<subdirectory> example in my case
                    sudo ppa-purge ppa:ubuntu-audio-dev/alsa-daily



                    • Delete the unwanted source list from the location /etc/apt/sources.list.d. example in my case
                    sudo rm /etc/apt/sources.list.d/ubuntu-audio-dev-ppa-trusty.list ubuntu-audio-dev-ppa-trusty.list.save 

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                    Regain access to lost dd-wrt webmin

                    I was playing with the webmin of dd-wrt and lost access to it.
                    1. https://router-ip throws up connection error
                    2. http://router-ip throws up invalid url

                    Fortunately I had the ssh port enabled.

                    To recover the web access, log in to the router and run the below commands.
                    nvram set remote_management=1
                    nvram set http_wanport=8080
                    nvram set httpsd_enable=1
                    nvram set https_enable=1
                    nvram set remote_mgt_https=1
                    nvram commit
                    reboot

                    I got access and lessons learned
                    Very important to take backup from the webaccess in the administration section and under backup
                    • Direct url: http://192.168.1.1/config.asp
                    • In the above case my router ip is 192.168.1.1 
                    Have an secure alternative access to the router ssh or telnet.
                    If you have an dd-wrt router working well PLEASE do take a backup of the settings.
                    • IF there is a backup then life is easy.
                    • Perform hard reset and recover from the backup file.
                    Now I have a backup file and peace of mind.
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