How to run the sudo command without a password

The sudo command is an excellent part of the Linux command-line. It allows users to execute root commands without needing to log into root, protecting their security. The problem is, to use the sudo command, you’ll need to enter your password.

Having to enter your password to execute the sudo command is undoubtedly an excellent security feature, but it can be incredibly tedious and annoying. If you’re OK with the trade-off in security features, you can make it so that password isn’t required to use sudo.

Method 1 – running sudo commands without password temporarily

The easiest way to run sudo commands without a password is to do it temporarily — meaning no editing to the system files to change settings. To do this, the sudo -s command is used.

The sudo -s command grants the user a Sudo shell. Essentially, you log into the terminal with your user and password and are given a root shell. You’ll then be able to enter any command as if you were doing them with the sudo command.

To use the sudo -s command, start by opening up a terminal. Then, enter the command below. 

sudo -s

You’ll then see your terminal prompt logged in to the Sudo shell as root. From here, enter any command you’d like to run with the sudo command without having to enter a password. 

It is possible to access the Sudo shell at any time, in any user. To exit the Sudo shell, enter the exit command. 

exit

Method 2 – adding passwordless sudo to Linux via sudoers file

If you want to execute Sudo commands without having to enter the Sudo shell each time, you can enable passwordless sudo. Passwordless sudo is a configuration file change that, when enabled, will make every sudo command run without a password.

However, before we begin, please understand that passwordless sudo is a considerable security risk. If you have a weak password set for your user account and then you enable passwordless sudo, a malicious attacker may be able to infiltrate your system. Be sure that your user account’s password is secure by changing the password.

To change your user account’s password, start by opening up a terminal window. When the terminal window is open, execute the passwd command. 

passwd

After executing the passwd command, you’ll be asked to change the password to your Linux user account. Be sure to enter something secure and memorable. When your password is changed, follow the step-by-step instructions below to enable passwordless sudo via the sudoers file.

Step 1: Execute the visudo command to open up the sudoers file for editing. You should always use the visudo command to edit this file rather than /etc/sudoers, for security purposes.

sudo EDITOR=nano visudo

Please note that if the visudo command does not work with the sudo command, you can also access it by using su to log into root.

su -

EDITOR=nano visudo

Step 2: Once inside of the Nano editor,  locate the line of code root ALL=(ALL) ALL and press the Enter key on the keyboard to write a new line directly under it.

After pressing the Enter key, write out a new line of code. Be sure to change “user” in the code line below to your user account, or the code will not work.

user ALL=(ALL) NOPASSWD

Step 3: Press the Ctrl + O button to save the edits to the configuration file. After saving the edits, exit the editor by pressing the Ctrl + X button. 

With the configuration file changed, you’ll be able to execute any sudo command without the need to enter a password!

Allow specific commands to be exected without sudo password

If you don’t want to have the sudo command work without a password for every single terminal command, you can restrict it so that only specific things can run without a password. Here’s how to set it up.

First, open up the sudoers file with the visudo command below.

sudo EDITOR=nano visudo

Inside of the Nano text editor, look through and find the root ALL=(ALL) ALL line of code. Then, press the Enter key to create a new line directly below it. After creating a new line, add in the following code, but be sure to change “user” to your username.

user ALL=(ALL) NOPASSWD:

After writing out the code above, add the commands you would like to run without a password. For example, to make the cp command work in sudo without a password, you’d do:

user ALL=(ALL) NOPASSWD:/usr/bin/cp

To add multiple commands, separate them with a “,”. When done editing the sudoers file, press the Ctrl + O button combination on the keyboard to save the edits. Then, press Ctrl + X to close Nano.

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How to verify ISO checksums on Linux

If you’ve used Linux for any amount of time, you might notice that many Linux operating system developers ask that you “verify the checksums” after downloading. What is a checksum? It’s a data block that is algorithmically generated. It is used to check for tampering or errors in a file.

In the Linux community, developers use checksums to prevent tampering with operating system downloads. For example, if a hacker got into the Ubuntu.com website and tampered with the ISO files, you’d be able to detect that your download has been tampered with by verifying the checksum.

In this guide, we’ll go over how you can very a checksum on Linux using graphical tools and the terminal as well. In this tutorial, we will be using the latest Linux Mint ISO as an example.

Method 1 – verifying a checksum with the GUI

The best way to verify a checksum on Linux with the GUI is by using the GTKhash utility. It’s an easy to use program that doesn’t require a whole lot of advanced knowledge to use. However, it needs to be installed first, as GTKhash is not pre-installed on many Linux operating systems.

To start the installation of GTKhash on Linux, open up a terminal window. To do this, press Ctrl + Alt + T or Ctrl + Shift + T on the keyboard. Then, when the terminal window is open, follow along with the command-line installation instructions outlined below that corresponds with your distribution.

Ubuntu

On Ubuntu Linux, you can easily get the GTKHash application installed by using the Apt command below.

sudo apt install gtkhash

Debian

If you’re a Debian Linux user, you’ll be able to install GTKHash on your computer with the following apt-get command.

sudo apt-get install gtkhash

Arch Linux

On Arch Linux, the GTKHash program is not in the repos. However, there is a third-party Arch Linux software repository that has the app pre-compiled and ready to go. To install it, enter the two commands below.

wget https://lonewolf.pedrohlc.com/chaotic-aur/x86_64/gtkhash-1.4-2-x86_64.pkg.tar.zst
sudo pacman -U gtkhash-1.4-2-x86_64.pkg.tar.zst

If you’re not a huge fan of third-party repositories, you can also get the GTKHash app working for Arch Linux by installing it through the AUR using your favorite AUR helper.

Fedora

On Fedora Linux, you’ll be able to install the GTKHash application using the dnf command below.

sudo dnf install gtkhash

OpenSUSE

On OpenSUSE Linux, the GTKHash app is available, but only through a third-party software repository. To install the app, click on this link. Then, select the “1 Click Install” button next to the release of OpenSUSE Linux you use.

Once the GTKHash application is set up on your computer, launch the app by searching for it in the app menu. Then, follow the step-by-step instructions below to learn how to verify checksums using GTKhash.

Step 1: Find the “File” section of GTKHash. It should say “(None)” by default. Click it, and select the ISO file you want to verify. In this guide, we’ll be using Linux Mint 20 Cinnamon as an example.

Step 2: Go to the website from which you downloaded the ISO and locate the checksum hash. It should be a long string of numbers. If you cannot find it, check out the official documentation for your Linux OS.

Step 3: Copy the checksum code to your clipboard. Then, paste it in the “Check” box.

Step 4: Find the “Hash” button at the bottom of the page and click it. GTKHash will compute for a minute and verify the code you posted with the ISO file. If the hash matches, you shouldn’t see any difference from the “Check” box and the output boxes.

Method 2 – Verifying checksum with Terminal

Verifying the checksum with the terminal is simple on Linux, but not nearly as convenient. On most modern Linux distributions, SHA265 hashes are used. However, some use MD5 sums. We will cover both in this section.

To verify a SHA265 checksum, do the following. Again, just like in the GUI section, we will be using the Linux Mint 20 Cinnamon ISO as an example.

Open up a terminal window on the Linux desktop. Then, move the terminal session to where the ISO file is. In this example, it is in “Downloads”.

cd ~/Downloads

Run the sha256sum command on the downloaded ISO file. If the output matches the checksum on the website, it is clean and untampered with. If it does not, it is corrupted and you should not use it.

sha256sum iso-file.iso

To check an MD5 checksum, make use of the md5sum command.

md5sum iso-file.iso

Just like the SHA256 sum, if the output does not match the checksum code on the website, you have a corrupted ISO file, and you shouldn’t use it. If they match, everything is safe to use!

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How to reset the PIN on Windows 10

Windows 10 allows users to lock their desktop with a password. A password can be set for both local accounts and for Microsoft Live accounts. Passwords aren’t the only way to lock a desktop though. Users have the option to set a PIN, use Windows Hello if they have a supported device, or set a picture password.

If you want to change your PIN or you’ve forgotten it, it can be reset easily enough.

Reset PIN Windows 10

You can reset the PIN on Windows 10 from the login screen and from the desktop. If you’ve forgotten the PIN, and are unable to get to your desktop, you can still reset it.

1. Reset forgotten PIN from lock screen

  1. On the login screen, click ‘I forgot my PIN’.
  2. In the window that opens, enter the password to your Microsoft Account.
  3. Set a new PIN for the device.

2. Reset forgotten PIN from desktop

  1. On your login screen, click ‘Sign in options’ to reveal other sign-in options that have been set up.
  2. Select the password option.
  3. Enter the password to your Microsoft Account to unlock your desktop.
  4. Open the Settings app.
  5. Go to Accounts.
  6. Select the Sign-in Options tab.
  7. Select Windows Hello PIN.
  8. Click Remove.
  9. Confirm that you want to remove the PIN.
  10. Enter the password to your Microsoft live account.
  11. Once the PIN has been removed, select Windows Hello PIN again.
  12. Click Add.
  13. In the window that opens, click Next.
  14. Enter the password to your Microsoft account.
  15. Enter your new PIN, and click OK.

3. Change PIN from desktop

If you remember your current PIN and simply want to change it, you can do so from the desktop.

  1. Open the Settings app.
  2. Go to Accounts.
  3. Select the Sign-in options tab.
  4. Click Windows Hello PIN.
  5. Click ‘Change’
  6. Enter the current PIN in the first field.
  7. Enter your new PIN in the other two fields. 
  8. Click OK and the PIN will be changed.

Conclusion

A PIN is considered more secure because it will only serve to unlock the desktop, if it is ever stolen. If you were to rely on your Microsoft Account password to sign in, and it was stolen, you stand to lose access to your entire account. Your Windows 10 key is likely linked to your Microsoft Account as are Microsoft 365 subscriptions and other purchases from the Microsoft Store. The PIN adds a decent layer of security and you don’t have to limit it to four numbers. A Windows 10 PIN can be longe and it can be alphanumeric.

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How to fix the ‘Untrusted Developer’ error on iOS

Apps on iOS generally only come from the App Store. These apps have been vetted by Apple and are safe. They are also signed by the developers who made them, and they meet all security requirements that Apple has set. That said, apps can come from outside the App Store. Getting them isn’t easy but it isn’t impossible. Sometimes when you try to run these apps, you get an error that it’s from an ‘Untrusted Developer’. All you can do is dismiss this error. It doesn’t tell you how you can run the app if you trust it. Here’s how you can fix the ‘Untrusted Developer’ error on iOS.

This applies to iOS 8 and later.

Fix ‘Untrusted Developer’ error

Open the Settings app and go to General>Device Management.

The app that you tried to run will be listed here. Tap it, and tap the trust option. Confirm that you trust the app and then return to your home screen. Tap the app and this time it will open.

A word of caution

While it isn’t easy to side-load apps on iOS, it has become relatively easier in the past few years. Users with a Mac can do it and often developers who have made an app that is highly unlikely to be approved in the App Store choose to distribute them as such. The code is put on Github with instructions on how to compile it. Given it’s open-source, you can probably tell if the app is doing something it shouldn’t but you’d have to be able to understand code which not everyone can.

What all this means is that there is a chance you end up with a malicious app on your device. If you are installing apps from outside the App Store, practice extreme caution on where you get them from. Apple tends to take security very seriously and if it chooses to exclude an app from its store, it likely has a good reason.

This error can also appear for apps that you’re beta testing or even ones you’ve developed and compiled yourself. You can run these apps the same way but if you’re looking to make the error go away for an app that you’ve developed, make sure you have signed it and that its security certificates are all correct, and up to date. In some cases, you might have to install a profile on your device to run some of these apps. Regardless, be careful with what you install and run.

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How to check if an app is signed on macOS

App signing is a way to verify that an app is trustworthy. macOS checks an app for a valid signature and if it doesn’t have one, it will block the app from running and/or installing. There is a way to get around the stop if you want to run an unsigned app but you do so at your own risk. If you’ve installed an app, or you’re about to run one, there’s no simple way to check if it’s signed or not. You can run it and macOS will tell you it couldn’t verify something but, to be sure, you can use a free app called What’s your sign to check if an app is signed.

Check app signature

This works for apps that have not been installed, and for apps that are in the user’s Application folder. It seems that if you go to the system’s Application folder, the app won’t work. This is simple enough to work around.

First, download and install What’s your sign. The app works via the context menu and it will restart Finder once when you install it.

Navigate to an app that you’d like to verify the signature of. Right-click it and look for the ‘Signing Info’ option. Click it.

A new window will open with information on whether or not the app is signed. You can also view hash values and see who the signing authority is.

As for apps that are in the system Application folder, what you can do is, you can copy them to any other folder that’s inside your own user folder. This will do just fine since you’re only looking to verify the signature. Right-click the copied file and select the signing info option.

This works for apps that are installed, and that aren’t. If all you have is the app file that still needs to be moved to the Applications folder, you can run the signature check on it.

Signing is not something that users can control. It is up to developers to sign their apps, many do, some don’t. For those that do not sign apps, there is usually just one or two extra steps involved to get them running. That said, if you’re working in an environment where unsigned apps simply cannot be used and the app you’re looking to use is indeed unsigned, there isn’t much you can do. You can try asking the developer to have their app verified or you can look for an alternative to it.

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