GNU/Linux

How to Create a Custom Local DNS Entry on a Ubiquity Dream Machine Pro

 in GNU/Linux  tagged DNS / DNS Entry / dnsmasq / Dream Machine Pro / HostKeyAlgorithms / Local DNS Entry / PubkeyAcceptedKeyTypes / ssh / ssh-rsa / Ubiquity by

DNS (Domain Name System) is an essential part of the internet infrastructure that translates domain names into IP addresses. However, you can also use DNS for internal networks to assign custom hostnames to specific IP addresses. In this post, we will discuss how to create a custom local DNS entry on a Ubiquity Dream Machine Pro.

The first step is to assign a static IP address to the machine you want to create a custom DNS entry for. To do this, log in to the Dream Machine Pro’s web interface and navigate to https://10.1.1.254/network/default/clients. Find the machine you want to assign a static IP address to and click the “Static” button. Enter the IP address you want to assign and click “Save”.

Next, you need to assign a specific hostname to the machine. However, you might run into an error message that says “An error occurred while changing your settings”. This error occurs when you use a specific domain name like “bytefreaks.lcl”. To work around this issue, you can use a different TLD like “.net” instead.

If you still want to use the “.lcl” TLD, you will need to SSH into the Dream Machine Pro to modify the configuration files. Use the following SSH command to log in as root:

ssh -p 22 -o HostKeyAlgorithms=+ssh-rsa -o PubkeyAcceptedKeyTypes=+ssh-rsa [email protected];

If the default SSH command produces an error, you can use the above custom SSH command to log in successfully.

Once you have logged in via SSH, you will need to modify the following files:

  • /run/dnsmasq.conf.d/dns.conf
  • /mnt/data/udapi-config/ubios-udapi-server/ubios-udapi-server.state

The /run/dnsmasq.conf.d/dns.conf and /mnt/data/udapi-config/ubios-udapi-server/ubios-udapi-server.state files contain information about the local DNS entries. Use the “vi” editor to modify the /run/dnsmasq.conf.d/dns.conf file and replace the “.net” TLD with the “.lcl” TLD.

After you have made the necessary changes, exit the editor and kill the dnsmasq process using the following command:

pkill dnsmasq;

This command will stop the dnsmasq process, which is responsible for the DNS resolution. Then, execute dnsmasq again to ensure that it is running properly.

Now, you should be able to view your machine using the custom “.lcl” TLD from a browser. By creating a custom local DNS entry, you can simplify your local network administration and access your devices more easily.

Splitting a zip file (or any file) into smaller parts

 in Bash / GNU/Linux  tagged bash / cat / GNU/Linux / split / unzip / zip by

In this post, we will explain the following commands:

  1. zip Original.zip Original/
  2. split -b 5M -d Original.zip Parts.zip.
  3. cat Parts.zip* > Final.zip
  4. unzip Final.zip -d Final

These commands are commonly used in Linux/Unix systems and can be very helpful when working with large files or transferring files over a network.

Command 1: zip Original.zip Original/

The zip command is used to compress files and create a compressed archive. In this command, we are compressing the directory named Original and creating an archive named Original.zip. The -r option is used to recursively include all files and directories inside the Original directory in the archive.

Command 2: split -b 5M -d Original.zip Parts.zip.

The split command is used to split a large file into smaller files. In this command, we are splitting the file Original.zip into smaller files with a size of 5 MB each. The -b option specifies the size of each split file, and the -d option is used to create numeric suffixes for the split files. The Parts.zip is the prefix for the split files.

Command 3: cat Parts.zip* > Final.zip

The cat command is used to concatenate files and print the output to the standard output. In this command, we are concatenating all the split files (which have the prefix Parts.zip) into a single file named Final.zip. The * is a wildcard character that matches any file with the specified prefix.

Command 4: unzip Final.zip -d Final

The unzip command is used to extract files from a compressed archive. In this command, we extract the files from the archive Final.zip and store them in a directory named Final. The -d option is used to specify the destination directory for the extracted files.

In conclusion, these commands can be beneficial when working with large files or transferring files over a network. By using the zip and split commands, we can compress and split large files into smaller ones, making them easier to transfer. Then, using the cat command, we can concatenate the split files into a single file. Finally, we can use the unzip command to extract the files from the compressed archive.

Create a PKCS#12 file that contains both the certificate and the private key

 in Firewall / GNU/Linux  tagged certificate / openssl / PEM / PKCS#12 by

In today’s world, security is a significant concern for everyone. Securing sensitive information such as passwords, certificates, and private keys is important. OpenSSL is a widely used tool for encrypting, decrypting, and managing digital certificates and keys. In this blog, we will explain the following command:

openssl pkcs12 -export -out certificate.p12 -in certificate.pem -inkey key.pem -passin pass:bytefreaks -passout pass:bytefreaks;

This command creates a PKCS#12 file containing the certificate and the private key. PKCS#12 (Public-Key Cryptography Standards #12) is a file format that stores cryptographic objects such as private keys, certificates, and intermediate certificates.

Let’s break down this command and explain what each option does:

openssl pkcs12

This is the OpenSSL command for PKCS#12.

-export

This option tells OpenSSL to export the certificate and private key.

-out certificate.p12

This option specifies the output file name and format. In this case, the output file will be named certificate.p12.

-in certificate.pem

This option specifies the input file name and format. In this case, the input file is the certificate file named certificate.pem.

-inkey key.pem

This option specifies the private key file name and format. In this case, the private key file is named key.pem.

-passin pass:bytefreaks

This option specifies the password to decrypt the private key. In this case, the password is “bytefreaks”.

-passout pass:bytefreaks

This option specifies the password to encrypt the PKCS#12 file. In this case, the password is “bytefreaks”

;

This symbol indicates the end of the command.

When you run this command, OpenSSL will prompt you to enter the password for the private key. Once you enter the correct password, OpenSSL will create a PKCS#12 file named certificate.p12 that contains both the certificate and the private key encrypted with the password “bytefreaks”.

In conclusion, the openssl pkcs12 -export -out certificate.p12 -in certificate.pem -inkey key.pem -passin pass:bytefreaks -passout pass:bytefreaks; command is used to create a PKCS#12 file that contains both the certificate and the private key. This file is encrypted with the password “bytefreaks” to ensure security.

Remove Disabled Snaps.

 in Bash / GNU/Linux  tagged bash / clean up / free space / GNU/Linux / snap / ubuntu by 
LANG=C snap list --all | awk '/disabled/{print $1" --revision "$3}' | xargs -rn3 sudo snap remove;

Let us break down the command for you:

  1. LANG=C sets the language to English (C locale), which can be helpful to ensure consistent behavior across different systems with different default languages. We used this to make sure that the word disabled will appear for disabled snaps and not some other translation.
  2. snap list --all lists all installed snaps (i.e., packages) along with their details. The output of this command is piped to the following command.
  3. awk '/disabled/{print $1" --revision "$3}' searches for lines in the output that contain the word “disabled” and prints the first field (i.e., the name of the snap) followed by the string “–revision” and the third field (i.e., the revision number). This output is piped to the next command.
  4. xargs -rn3 sudo snap remove takes groups of three arguments from the input and runs the command snap remove with those arguments. In this case, the first argument is the name of the disabled snap; the second argument is the string “–revision”, and the third argument is the revision number. This will remove all disabled snaps and their associated revisions.

So, in summary, the command searches for all disabled snaps on the system, extracts their name and revision number and then removes them using the snap remove command. This is a very useful command to free up some space without losing data or functionality.