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Security

Connecting to a server via SSH with Putty

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This post aims to show how you can connect to a remote VM server using Telnet/SSH Secure shell with a free program called Putty on Windows. This not an advanced guide, I hope you find it useful.

You will learn how to connect (via Windows) to a remote computer (Linux) over the Telnet protocol using SSH (Secure Shell). Once you login you can remotely edit web pages, learn to code, install programs or do just about anything.

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Common Terms (Glossary)

  • Putty: Putty is a free program that allows you to connect to a server via Telnet. Putty can be downloaded from here.
  • Port: A port is a number given to a virtual lane on the internet (a port is similar to a frequency in radio waves but all ports share the same transport layer frequency on the internet). Older unencrypted webpages work on Port (lane 80), older mail worked on Port 25, encrypted web pages work on Port 443. Telnet (that SSH Secure Shell uses) used Port 22. Read about port numbers here.
  • SSH: SSH is a standard that allows you to securely connect to a server over the telnet protocol. Read more here.
  • Shell: Shell or Unix Shell is the name given to the interactive command line interface to Linux. Read more about the shell here.
  • Telnet: Telnet is a standard on the TCP/IP protocol that allows two-way communication between computers (all communicatin issent as characters and not graphics). Read more on telnet here and read about the TCP protocols here and here.
  • VM: VM stands for Virtual Machine and is a name given to a server you can buy (but it is owned by someone else). Read more here.

Read about other common glossary terms used on the Inetre here:
https://en.wikipedia.org/wiki/Glossary_of_Internet-related_terms

Background

If you want a webpage on the internet (or just a server to learn how to program) it’s easier to rent a VM for a few dollars a month and manage it yourself (with Telnet/SSH Secure Shell) than it is to buy a $5,000 server, place it in a data centre and pay for electricity and drive in every few days and update it. Remote management of VM servers via SSH/Secure Shell is the way for small to medium solutions.

  • A simple web hosting site may cost < $5 a month but is very limited.
  • A self-managed VM costs about $5 a month
  • A website service like Wix, Squarespace, Shopify or WordPress will cost about $30~99 a month.
  • A self-owned server will cost hundreds to thousands upfront.

There are pros and cons to all solutions above (e.g cost, security, scalability, performance, risk) but these are outside this post’s topic. I have deployed VMs on provides like AWS, Digital Ocean, Vultr and UpCloud for years. If you need to buy a VM you can use this link and get $25 free credit.

I used to use the OSX Operating System on Apple computers. I was used to using the VSSH software program to connect to servers deployed on UpCloud (using this method). With the demise of my old Apple Mac book (due to heat) I have moved back to using Windows (I am never using Apple hardware again until they solve the heat issues).

Also, I prefer to use Linux servers in the cloud (over say Windows) because I believe they are cheaper, faster and more secure.

Enough talking lets configure a connection.

Public and Private Keys?

Whenever you want to connect to a remote server via Telnet/SSH Secure Shell you will need a public and private key to encrypt communications between you and the remote server.

The public key is configured on your server (on Linux you add the public key to this file ~/.ssh/authorized_keys).

The private key is used by programs (usually on your local computer) to connect to the remote server.


How to create a Public and Private Key on Linux

I usually run this command on Ubuntu or Debian Linux to generate a public and private SSH key.

The key below was generated for this post and is not used online. Keys are like physical keys, people who have them and know where to use them can use them.

Output:

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The two files were created

  • “server” is the private key
  • “server.pub“is the public key

Public/Private Key Contents

Public Key Contents (“server.pub”)

Private Key Contents (“server”), always keep the private key safe and never publish it.

The Public and Private keys is used to encrypt all Telnet/SSH connections and traffic to your server. Keep these key’s private.

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fyi: Putty can create SSH Keys too

If you do not have a Linux computer or Linux server to generate keys the Putty generator can create keys too.

Puttygen generating a key based on the randomness of mouse movements.

I did not know Putty can create keys.

Do save the public and private key(s) that were generated in Puttygen (tip: PPK files are what we are after along with the public key later in this post).

Public keys are added to your server when you deploy them. On Linux, you can add new Pulic keys after deployment by adding them to this file “~/.ssh/authorized_keys” to allow people to log in.

Puttygen does format the keys differently than how Ubuntu generates them. Read more here. I’ll keep generating keys in Linux over Puttygen.

Output of the public and PPK files from Puttygen

Putty SSH Client on Windows

Putty is a free windows program that you can use to connect to serves via SSH. Download and install the Putty program.

Open Putty

Putty Icon

Default Putty User Interface.

Screenshot of the Putty Program

To create a connection add an exiting IP address (server name) and SSH port (22) to Putty.

Screenshot of an IP and port entered into putty

In Putty (note the tree view to the left of the image), You can set the auto login name to use to log into the remote server under the Connection the Data in the tree view item

Screenshot showing the SSH usename being added to putty under Connection then Data menu,

You can also set the username under the Connection then Rlogin section of Putty.

Set the usernmae undser rlogin area of putty

OK, lets add the private SSH Key to Putty.

Putty Screehshot showing no support for standard SSH keys (only PPK files)

It looks like Putty only supports PPK private key files not ones generated by Linux. I used to be able to use the private key in the VSSH program on OSX and add the private key to connect to the server over SSH. Putty does not allow you to use Linux generated Private keys directly.

Convert your (Linux generated) private key to (Putty) PPK format with Puttygen

Putty comes with a Key Generator/Converter, you can open your existing RSA private key and convert it (or generate a new one).

TIP: If you generate a key in Puttygen don;t forget to ad’d it to your authorized host file in your remote server.

Open Puttygen

Puttygen icon

Click Conversions than Import Key and choose the private key you generated in Linux

Screenshot showing import RSA key to convert

The private key will be opened

Screenshot of imported RSA key

You can then save the private key as a PPK file.

Save the private key as a PPK file

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“server.ppk” Key contents

Now the PPK key can be added to Putty for any server connection that uses the public key. Use the right key for the right server though.

Add the private key to a Putty server by clicking Connection, SSH, AUTH section and browing to the PPK file.

Screenshot showing the PPK key file added to Putty

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Now we need to save the connection, click back on the Session note at the top of the treeview, type a server name and click Save

Save Putty connection.

Connecting to your sever via Telnet/SSH wiht Putty.

Once you have added a server name, port, usernames and private key to Putty you can double click the server list item to connect to your server.

You will see a message about accepting the public key from the server. Click Yes. This fingerprint will be the same fingerprint that was shown when you generated the keys (if not maybe someone is hacking in the middle of your local computer and server)

Putty messgae box asking to to remember the public key

Hopefully, you will now have full access to your server with the account you logged in with.

Screenshot of an Ubuntu screen after login

Happy Coding.

Alternatives to self-managed VM’s

I will always run self-managed server (and configure it myself) as its the most economical way to build a fast and secure server in my humble opinion.

I have blogged about alternatives but these solutions always sacrifice something and costs are usually higher and performance can be slower.

I am also lucky enough I can do this as a hobby and its not my day job. when you self manage a VM you will have endless tasks or securing your server and tweaking but its fun.

More Reading

Read some useful Linux commands here and read my past guides here. If you want to buy a domain name click here.

If you are bored and want to learn more about SSH Secure shell read this.

Related Blog Posts

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Version: Draft 1.0 Initial Draft

How to install PHP 7.2.latest on Ubuntu 16.04

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How to install PHP 7.2.latest on Ubuntu 16.04/ Ubuntu 18.04/Debian etc/

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I have a number of guides on moving away from CPanel, Setting up VM’s on UpCloud, AWS, Vultr or Digital Ocean along with installing and managing WordPress from the command line. PHP is my programming language of choice.

PHP has a support page that declares the support date ranges and support types: http://php.net/supported-versions.php

 

PHP 7.0 going EOL

A version of PHP is either actively supported, security fix supported or end of life. Read this post to check WordPress for PHP compatibility.

 

From time to time vulnerabilities come up that require PHP updates to be applied.

Source Link here

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I have guides on setting up PHP 7 here on Digital Ocean, here on AWS and here on Vultr. I have tried upgrading to PHP 7.1 in the past with no luck (I forgot to change something and rolled back to 7.0).

FYI: I have a guide on setting up PHP child workers so the output from some commands below may be different than yours. Here are the steps I performed to install PHP 7.2 alongside 7.0 then switch. to 7.2.

Backup your system

Do perform a Snapshot or Backup before proceeding. Nothing beats a quick restore if things fail.

Note: Use this information at your own risk.

Updating php 7.2.12 to 7.2.12

Update your Ubuntu systems

Updating from an older php (e.g 5.x, 7.1, 7.1 to say 7.2.12)

Backup PHP

Install Helper

This software provides an abstraction of the used apt repositories. It allows you to easily manage your distribution and independent software vendor software sources. More Info

Add the main PHP repo (more information)

Update the package lists

“In a nutshell, apt-get update doesn’t actually install new versions of the software. Instead, it updates the package lists for upgrades for packages that need upgrading, as well as new packages that have just come to the repositories.” from here

List Installed Packages (optional)

Install PHP 7.2

Install common PHP modules

Install PHP FPM

Update all packages (may be needed to update from php 7.2.4 to 7.2.5)

Edit your NGINX sites-available config

Edit your NGINX sites-enabled config

I edited these lines

Edit your PHP config (and make desired changes)

Edit your PHP pool config file (as required). See this guide here.

e.g.

> cgi.fix_pathinfo=0
> max_input_vars = 1000
> memory_limit = 1024M
> max_file_uploads = 8M
> post_max_size = 8M

Make sure you set: listen = /run/php/php7.2-fpm.sock

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Set PHP 7.2 as the default PHP

Check your PHP version

Reload PHP

Reload NGINX

Check the status of your PHP (and child workers)

Check your website.

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Troubleshooting

Guides that helped me.

https://thishosting.rocks/install-php-on-ubuntu/

https://websiteforstudents.com/wordpress-supports-php-7-2-heres-how-to-install-with-nginx-and-mariadb-support/

Check your log files

Debug FPM Service

Remove PHP 7.0

PHP 7.0 Removed 🙂

Remove other unused packages

At the time of writing (November the 18th 2018) PHP 7.2.12 is the latest version of PHP and PHP 7.3 will be out at the end of the year.

Good luck and I hope this guide helps someone

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Revision History

v1.4 Updated the post to mention PHP 7.0 EOL

v1.3 Updated to add PHP 7.2.12 information

v1.2 PHP 7.2.9 and PHP 7.2 updates

v1.1 Remove PHP 7.0 steps

v1.0 Initial post

Using the Yubico YubiKey NEO hardware-based two-factor authentication device to improve authentication and logins to OSX and software

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This post aims to show you how you can use a Yubico YubiKey NEO hardware-based two-factor authentication device to improve authentication and logins to OSX and other software and services.

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Background

Although I am a developer I do like security related topics and I try and do as much as I can to secure my systems and applications. Reading the Multi-Factor Authentication Wikipedia page has all the details on Multi-Factor authentication.

I have been a big fan of 1Password to generate strong and unique passwords for separate accounts for a while now. Read my guide on upgrading from a standalone 1Password licence to a 1Password subscription. I love generating unique and complex passwords with 1Password.

Screenshot of the 1Password.com software generating a complex password with 63 chars

But what happens if someone gets access to my 1password vault? Yubico has a catalogue of support services that I can use Yubikeys with to have, 1password is one supported service 🙂

I want to add Yubico protections with these services.

  • macOS Logins (DONE)
  • macOS Screensavers (DONE)
  • 1Password (DONE)
  • Dropbox (DONE)
  • Twitter (DONE)
  • Google (DONE)
  • Google GSuite (DONE, WAITING TO VERIFY)
  • Google GMail (DONE)
  • Google Analytics and AdSense (DONE)
  • Github (DONE)
  • Thunderbird Email (DONE)
  • Debian servers in the cloud (SSH) (DONE)
  • Ubuntu servers in the cloud (SSH) (DONE)
  • Securing WordPress (DONE)

Etc

Final Warning

Do not attempt to activate Two Factor Authentication on a system unless you…

  • A) Have backups of your data
  • B) Have backup methods of getting into your account(s)

Murphy’s Law: “Anything that can go wrong will go wrong”

You never know when a Two Factor Authentication Key may die or an Authenticator app or a Mac/PC may stop working so always have a backup method just in case.

 

General

General Yubico YubiKey Setup guides https://www.yubico.com/setup/

 

Buying a Yubico YubiKey

International visitors can buy a YubiKey from the official store here. Australian readers can buy a key locally here. I grabbed 2x YubiKey YubiKey Neo 4 (with NFC) for $50 USD (about $75 AUD) each.

This blog post will aim to show how you can set up a primary key and backup key for use on macOS and other apps to add hardware-based two-factor authentication to logins.

 

Authenticator Apps

You can use Google Authenticator, Yubico Authenticator or freeOTP from https://freeotp.github.io

 

Plugging the YubiKey into macOS Mojave

First I read this guide: https://www.yubico.com/works-with-yubikey/catalog/macos/

1) I plugged in my Yubico Neo key into my USB slot.
2) I closed the Keyboard setup window that appeared (I guess the YubiKey is a kind of a keyboard to allow inserting of challenge-response character streams into apps and websites).

Picture of macOS Mojave wrongly detecting the eYubiKey as a keyboard device type.

3) I followed the basic troubleshooting page and confirmed that the key was being detected (yes it was.)

macOS device list showing the Yubico YubiKey was detected

4) I followed this guide to test U2F functionality and this guide to test OTP functionality. Web pages and Google Chome can talk to the plugged-in YubiKey(s).

I was prompted to register a UTF deice (and create an account)

Register a Device

I was prompted to (insert) and touch my Yubico key.

picture of the browser asking me to insert my YubiKey

Google Chome asked for some permissions first.

FYI: Chrome 67 is recommended to securely allow the reading of UbiKey’s from web pages. Only allow sites you trust access to your USB devices and use a modern browser.

Picture of Google Chrome browser asking for permissions to read the inserted YubiKey

Success, Chrome could now see my YubiKey and my device was now verified.

Picture showing YubiKey registration success in a browser

Technical data is available to let you know what is going on in the background. I am not going to break down how this works but Yubico has in-depth whitepapers and documentation if you are interested.

Nice

 

Configuring OSX

I logged into my Mac with the account that I was going to secure.

I performed a complete time machine backup before proceeding. If you lock yourself out you will need to restore OSX from a Time Machine backup.

I Read the “Using Yubico Pluggable Authentication Module (PAM) with Challenge-Response” login guide: https://www.yubico.com/wp-content/uploads/2016/07/yubico_YubiKeyMacLoginGuide_en.pdf

I downloaded the Download the YubiKey Manager

I downloaded the yubikey-manager from here so I could configure the keys to use “HMAC-SHA1 Challenge-Response”.

Oops, I downloaded the wrong tool, good to know this one exists though.

Screenshot of the Yubikey Manager Software showing firmware update and OTP configuration settings

I will update what this tool does in future (update firmware?)

I Downloaded the Yubikey Personalization Tool

I went back to the Yubico download page and downloaded the Personalization tool.

Picture of the Yubico Personalisation tool showing it's available software options

Many options are available here.

It’s time to configure a primary and backup (duplicate YubiKey) for use with macOS etc.

 

Enable Challenge Response

I opened the YubiKey Personalization Tool, Inserted my primary key, clicked the Settings tab, and in the Logging Settings group, selected Log configuration output and Yubico format.

I then clicked on the Challenge Response Tab, clicked the HMAC-SHA1 button, selected Configuration Slot 2, ticked “Program Multiple YubiKeys“, changed the “Parameter Generation Scheme = Same for all Keys“, Selected “Fixed 64 byte input” under “HMAC-SHA1 Parameters” and generated a new key (wrote it down).

Under “Configuration Protection” then I selected Enable Protection” I then visited here and generated a 6 digit string to convert to hex array (with spaces (e.g: “70 61 73 73 77 64”)).

Warning: If you set an access code and later forget it, you cannot make any programming changes to this YubiKey. You would need to buy another YubiKey.

I clicked on Write Configuration

If you chose Configuration Slot 1 you will receive a warning about not saving over Configuration Slot 1 due to Yubico VIP/Symantec, I personally do not trust Symantec or the https://vip.symantec.com/ service due to Symantec issuing non-compliant certificates for use on websites. Yubico allows you to swap configuration slots if want to keep the configuration data.

YubiCo Prompt asking for permissions to overwrite slot 1

On the output of the first write, I was prompted to save a file. I saved this to “secretkey.csv” onto the Desktop.

Screenshot of save configuration to CSV

When the write to my primary key was successful, I ejected it then inserted my backup key and wrote the same configuration data to it too (on Configuration Slot 2).

Screenshot of a list view showing the successful Write of information to two keys

Testing the HMAX-SHA1 Challenge

I open the YubiKey Personalization Tool, then click the Tools tab and click Challenge Response. Choose Configuration Slot 2, I selected HMAC-SHA1. I typed a sample input challenge (e.g “hello world”) and clicked Perform.

I noticed the Yubico key touch panel was flashing. I pressed the button, then a response appeared below the input textbox. I copied this response text then insert your second key and perform the same test so I could compare the responses (they should be the same). They were.

If the responses don’t match rewrite the configuration to your primary and secondary keys and ensure the same key and secret was used for both keys.

FYI: I rewrote configuration a few times until I got it right.

Installing the Pluggable Authentication Module (PAM) on macOS

I re-read the Mac login guide here as I don’t want to lock myself out of my Mac.

I opened the Yubico Software Download page here and clicked Computer Login Tools and downloaded the PAM for Mac.

Screenshot of the YubiCo PAM Module download page

I installed the PAM package and verified the package installation with this command.

Output:

Screenshot of the PAM Module Installed (ls on a folder)

Text Output:

> drwxr-xr-x 3 root wheel 96 9 Oct 10:29 .

> drwxrwxr-x 74 simon admin 2368 9 Oct 10:29 ..

> -rwxr-xr-x 1 root wheel 143172 20 Apr 21:13 pam_yubico.so

 

Backup macOS

Again I ensured my Mac was backed up with Time Machine.

Screenshot of backing up my Mac with Time Machine

I logged in to my Mac with the account I wanted to be protected with the Yubico YubiKeys.

I ran the following command in terminal

I double checked that my Yubico key(s) were set up for challenge response (above).

I inserted my Uubico key and ran this command

Feel free to read the “ykpamcfg” manual here. The yubico-pam source code is located here.

Output:

Screenshot of the output of ykpamcfg -2

The contents of “/Users/simon/.yubico/challenge-#######” looked like (I replaced 232 random chars with #’s below). The filename ended with my keys serial number.

v2:########################################################################################################################################################################################################################################:10000:2

Next, I was supposed to copy the challenge output from ykpamcfg to /var/root/.yubico/challenge-[YUBIKEY SERIAL NUMBER] with this command..

But I had this error.

Weird as the source file existed?? macOS issues?

I Opened /Users/[USERNAME]/.yubico/challenge-[YUBIKEY SERIAL NUMBER] in the nano editor (sudo elevated process) and saved the file to /var/root/.yubico/challenge-[YUBIKEY SERIAL NUMBER].

I reopened my terminal and verified the contents of /var/root/.yubico/challenge-[YUBIKEY SERIAL NUMBER]. The file is now there.

Permissions on the file is “-rw——-“. Good.

I inserted my second backuP key and re-ran “ykpamcfg -2” and copied the file to “/Users/simon/.yubico”

I verified the file contents

Output

ls -al output of /var/root/.yubico/

Text Output:

> drwxr-xr-x 4 root wheel 128 9 Oct 09:50 .
> drwxr-x— 12 root wheel 384 9 Oct 09:39 ..
> -rw-r–r– 1 root wheel 244 9 Oct 09:50 challenge-#######
> -rw-r–r– 1 root wheel 244 9 Oct 09:42 challenge-#######

Snip from: https://www.yubico.com/wp-content/uploads/2016/07/yubico_YubiKeyMacLoginGuide_en.pdf

“Program at least two YubiKeys when implementing a requirement for authentication with a YubiKey on your Mac. If you configure only one YubiKey and something happens to the YubiKey, you must restore the Mac from a Time Machine backup that you created before editing the authorization file before you can log back in to your account. ”

Reading the guide regarding multiple accounts (setting up a Key for each login). I have 5 logins on my Mac but when this works I will disable the other accounts from logging in.

 

Enable the use of the Yubico key when the screensaver is deactivated on macOS

I opened a terminal and edited “/etc/pam.d/screensaver ” (I use the easier nano editor)

I added this line

auth[7 spaces]required[7 spaces]/usr/local/lib/security/pam_yubico.so mode=challenge-response

editing /etc/pam.d/screensaver added auth required /usr/local/lib/security/pam_yubico.so mode=challenge-response

I saved the file ( [CTRL+O], [CTRL+X] ) and exited nano.

I tested my screensaver and no extra protection was provided (the screensaver just exited).

I rebooted, still no change?

I reinstalled the PAM module.

Silly me, I needed to enable the password on the screensaver to then activate the /etc/pam.d/screensaver entries.

I enabled the screensaver passwordsEnable screensaver password in macOS

I am now prompted to enter my password and inset and tap my Yubico Key on screensaver exit (on both keys). Awesome.

Next, I need to enable this at macOS login.

 

Enable the use of the Yubico key at macOS Login

I edited /etc/pam.d/authorization file with nano in the terminal

I added the same line as was added to the file /etc/pam.d/screensaver

auth[7 spaces]required[7 spaces]/usr/local/lib/security/pam_yubico.so mode=challenge-response

/etc/pam.d/authorization

I saved the file ( [CTRL+O], [CTRL+X] ) and exited nano.

Now let’s log out and test this.

It’s working.

Excellent

 

Add Two Factor Authentication to 1Password

Here is a guide on using the Yubico YubiKey with 1Password. This directed me to https://support.1password.com/yubikey/

I downloaded the Yubico Authenticator app on macOS and installed it.

Authenticator app

After I inserted my primary Key I received a “No Credentials Found”message.

No Credentials Found

I logged into https://my.1password.com/signin and clicked My Profile.

I clicked More Actions then Turn On Two-Factor Authentication

Enable 1Password Two Factor Auth

I added the generated QR code details to the Android Authenticator and macOS Yubico Authenticator app. At first, I could not scan the QR code in macOS (was Mojave blocking this?), I manually entered the details (after confirming them from the Android app QR code scan).

Details:

  • Issuer: 1Password
  • Account Name: my.1password.com
  • Secret Key: ###################
  • Time: 30
  • Algorithm: SHA-1
  • Period: 30
  • Digits: 6

Add 2nd Factor Details

Now, 1Password web and the desktop app are asking for the 2-factor code (generated in the Yubico Authenticator app after I insert my YubioKey).

Nice

2 Factor Auth enabled on 1password

I logged off and I was not prompted for my Two Factor code?

Snip from: https://support.1password.com/two-factor-authentication/

“Your 1Password account is now protected by two-factor authentication. From now on, you’ll need to enter a six-digit authentication code from your authenticator app when you sign in to 1Password on a new device.”

I logged in to 1Password from Google Chrome on Android and indeed I was prompted for a two-factor auth code form the Yubico Authenticator app (with a KubiKey inserted).

2nd Factor prompted on new devices

 

Add Two Factor Authentication to Dropbox
I read https://www.yubico.com/works-with-yubikey/catalog/dropbox-personal/. Dropbox also has setup instructions here.

I logged into Dropbox and went to Settings then Security then clicked Add next to Security Keys

Dropbox 2 factor auth

I started the Wizard, entered my Dropbox password, then inserted my YubiKey.

Add YubiKey to Dropbox

Name the Key

Name the YubiKey

I added my Primary and Backup Key(s)

Added Two Keys

I logged out and back in and no Security Key prompt?

I am using Chrome and had cleared past browsers from the Dropbox list of web browsers at https://www.dropbox.com/account/security

I discovered that I need to set the primary authentication method to Use Mobile App (My Bad, it would be nice if Dropbox set this as default after I added the keys).

Set Primary Method of Two Factor Auth

I added the Dropbox QR code to the Yuboico Authenticator app

Add Dropbox Two Factor Auth to Authenticator

I was asked to enter a 6 digit code from my Yubico Authenticator app to verify the working link. I inserted my YubiKey into my machine to show the code.

Now Dropbox is configured 🙂

Dropbox is configured

Success

I now have to insert my primary key when logging into Dropbox

Dropbox now demands a YubiKey is inserted
I need to find a way to copy my Authenticator credentials to my Backup Key from my Primary key

Authenticator Credential not on both keys

 

Add Two Factor Authentication to Twitter

I read https://www.yubico.com/works-with-yubikey/catalog/twitter/ (Setup Instructions)

1) Login to Twitter

2) Open your Settings and Look For Security

Twitter Security

3) Click Start

Start Wizard

4) Enter Your Password

5) Accept and enter any SMS codes if you set up SMS Two Factor codes via SMS

6) Click “Review your login verification methods”

Review Login Methods

7) Click “Setup Key”

Setup Key

8) Insert Your YubiKey and follow the prompts to activate it.

Insert Key

9) Now the key will be requoted to log in to Twitter

Activated Key

 

Testing Two Factor Login to Twitter

I logged out of and back into Twitter but the SMS Two Factor Authentication method was still active?

SMS Two Factor Still Activated

I tried to disable the SMS method in Twitter but two factor was disabled altogether and the registered key was deleted. I re-added my key 🙁

I solved this by choosing “Choose a different verification method” when logging in then choosing “Use your security key“, Twitter then accessed my YubiKey and further login attempts used the key instead of SMS 🙂 I could use an Authenticator code but they YubiKey touch method is quicker.

Alternate Two Factor Options

Done

It would be nice if Twitter allowed multiple keys to be used to log in?

 

Add Two Factor Authentication to Google, Google cloud, Gsuite etc

I read https://www.yubico.com/works-with-yubikey/catalog/google-accounts (Instructions https://myaccount.google.com/).

Adding two Factor authentication details to Google was not easily accessible at Google so I Googled (lol) this https://support.yubico.com/support/solutions/articles/15000006418-using-your-yubikey-with-google

I loaded: https://myaccount.google.com/signinoptions/two-step-verification/enroll-welcome

I clicked Get Start

Add Two Factor to Google Get Started

I clicked Choose Another Option (not SMS Two factor)

Add Other Two Factor

Clicked Security Key

Add Security Key

As prompted I inserted my key and allowed access to it.

Insert Key

I named the Key

Name the key

I repeated the steps and added my 2nd key.

Add 2nd Key

Done

I logged out my https://myaccount.google.com and logged back in and I was prompted to insert my YubiKey

Insert YubiKey

Nice

I did try and login to my google GSuite account at https://admin.google.com but it did not prompt me to insert a key. I will do this next.

 

Add Two Factor Authentication to GSuite

I logged into the GSuite admin interface at https://admin.google.com/ I generated some backup codes in case I need them in the future.

I checked my main admin user account and I could see the 2 google security keys synced through from Google.

Check Securiy Keys

I then searched GSuite for “Two Factor” and loaded the “Enforcement” Page

I enabled “Turn On Enforcement Now”

I enabled “Only Security Keys”

I logged out and back into https://gsuite.google.com/ TWICE and no security key prompt.

Silly me: I forgot to click save at the bottom of the screen and it appears there is a 24-hour delay?

Don't forget to press save

Add Two Factor Authentication to GMail

This is already done (above), GSuite email takes up to 24 hours to become active, GMail is instant.

Gmail two factor auth working.

Add Two Factor Authentication to Google Analytics

I can’t see an option to turn Two Factor Auth on in Google Analytics 🙂

I did send feedback to the Google Analytics team.

Adsense Feedback

 

Add Two Factor Authentication to Google Adsense

I can’t see an option to turn Two Factor Auth on in Google Adsense either 🙂

I did send feedback to the Google AdSense team.

No AdSense 2FA

Add Two Factor Authentication to Github

I logged into Github, opened my Settings and clicked Security then Enable two-factor authentication

GitHub

Click Setup using an app save the recovery codes.

Open the Yubico Authenticator app (ensure you can see the QR Code in GitHub)

In the Yubico Authenticator, App click File then Scan QR Code

The GitHub details should be added to the Authenticator

Authenticator App

Two Factor via authenticator tokens is enabled and now I can see a Keys options,

Add Keys

I clicked Add next to security keys then Register New Device, I gave the key a name then clicked Add.

Add 2 Keys

I added both keys then I Logged out and back in and two factor was enabled by YubiKey 🙂

Two Factor Enabled

Add Two Factor Authentication to Debian servers in the cloud (SSH)

Read Setup two-factor authenticator protection at login on Ubuntu or Debian

 

Add Two Factor Authentication to Ubuntu servers in the cloud (SSH)

Read Setup two-factor authenticator protection at login on Ubuntu or Debian

 

YubiKey Support

There are loads of Yubico support articles here: https://support.1password.com/yubikey/

 

Yubico Developer Info

A GitHub repository of source code is located here: https://github.com/Yubico

Other developer related pages here

 

Securing WordPress

Read this guide on Securing WordPress with 2FA (YubiKey insertion or Authenticator app).

I found a good WordPress plugin to handle 2FA logn methods.

Set all desired 2FA login methods

I am prompted to insert my YubiKey after logging into WordPress.

Nice

 

Java Code to use the Yubico YubiKey in software (challenge mode)

todo: I will add this section soon.

Yubico has Java repository that contains a Java library with an accompanying demo server, as well as a JAAS module, to validate YubiKey OTP’s (One-Time Passwords).

https://developers.yubico.com/yubico-java-client/

 

PHP Code to use the Yubico YubiKey in software (challenge mode)

todo: I will add this section soon.

Yubico has PHP library ad source code but it has not been updated in 3 years. I cannot get this working on PHP 7.2.

https://github.com/Yubico/php-yubico

 

Using Yubico YubiKeys as 2fA with one-time Passwords.

The YubiKeys can be used to store and generate one time passwords.

Read more about 2fa here

Here is a good plugin to tell you what sites use 2fa as you browse: https://2fanotifier.org

I have used my YubuKeys to store dozens of 2fa One time password son sites

e.g Namecheap

Namecheap enable 2fa

I enabled 2fa OTP (over phone/SMS 2fa) at Namecheap

2fa enabled at namecheap

Recovery info and backup

Always setup, and obtain backup access codes (or set alternate two-factor login methods) to software and know how you can disable YubiKey 2FA logins if needed.

Read more on YubiKey data backup policy here.

 

Copy Yubico Authenticator credentials to my Backup Key from my Primary Key

My Primary and Secondary YubiKeys have different Authenticator credentials (I need to sync them)

Authenticator Credential not on both keys

Set a YubKey Password (Yubico Authenticator App)

You can set a YubiKey Password so limit access to Two Factor Linked Accounts in the Yubico Authenticator. Nice.

      1. Open the Yubico Authenticator App
      2. Insert your YubiKey
      3. Open the File then Set Password Menu
      4. Click Set Password

Now when you insert the YubiKey you will be prompted for a password Before Two Factor tokens are displayed.

Set Yubico Password

Find a YubiKey Device Quiz

Use this quiz to find the right YubiKey for you: https://www.yubico.com/quiz/

 

Final Warning

Do not attempt to activate Two Factor Authentication on a system unless you…

  • A) Have backups of your data
  • B) Have backup methods of getting into your account(s)

Murphy’s Law: “Anything that can go wrong will go wrong”

You never know when a Two Factor Authentication Key may die or an Authenticator app or a Mac/PC may stop working so always have a backup method just in case.

 

Issue(s)

Thunderbird email on Google Chrome (accessing GSuite) is not accepting the key.

It is prompting…

Thunderbird prompting for the key

But it is not recognising the key (no matter how many times I insert or press the key)?

Key not detecting in Thunderbird

It appears Thunderbird 52 may not support keys yet, May have to wait until release 60.

I installed Thunderbird 63 (BETA) from https://www.thunderbird.net/en-US/channel/

Installed Thunderbird 63 BETA

After I installed Thunderbird it asked for my Security Key, accepted it and asked for further permissions.

Thunderbord a63 beta asking for permissions

I can now read my email in Thunderbird with my YubiKey

 

Links

YubiCo Device Comparison Chart: https://www.yubico.com/products/yubikey-hardware/compare-yubikeys/

Email Subscription form YubiCo: https://pages.yubico.com/email_subscription.html

 

Conclusion

Thunderbird issues (solved by installing a BETA).

Not all apps have the same method (some have Authenticator App only) and some have YubiKey Insert/Touch, some allow one key or multiple keys.

The only issue is my Huawei Mate 9 phone is a little flakey at reading NFC (fixed: I just have to tap for 5 seconds)

I have attached the YubiKeys to a dog chain’s and they live around my neck.

dog_clains

Version History

v1.1 Added authenticator/Namecheap 2fa info.
v1.0.1 YubiKey Backup Policy and comparison chart
v1.0.0 WordPress
v0.8.1 authenticator apps
v0.8.0 Draft: Debian/Ubuntu and many other changes
v0.7.0.1 Draft: Issue – Thunderbird Issue Solved
v0.7.0 Draft: Issue – Thunderbird Issue
v0.6.9 Draft: Protected GitHub
v0.6.9 Draft: Unable to Protect Google AdSense and Analytics
v0.6.8 Draft: Protected Google Gmail (https://gmail.com)
v0.6.7 Draft: Protected Google GSuite (https://gsuite.google.com/ and https://admin.google.com/)
v0.6.6 Draft: Protected Google (https://myaccount.google.com/)
v0.6.5 Draft: Protected Twitter
v0.6 Draft: Set a YubKey Password (Yubico Authenticator App)
v0.5 Draft: Sync Authenticator credentials?
v0.4 Draft: Protected Dropbox
v0.3 Draft: Protected 1Password
v0.2 Draft: Protected macOS Login
v0.1 Draft: Protected macOS Screensaver

No matter what server-provider you are using I strongly recommend you have a hot spare ready on a different provider

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No matter what server-provider you are using I strongly recommend you have a hot spare ready on a different provider

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Aside

If you have not read my previous posts I have now moved my blog to the awesome UpCloud host (signup using this link to get $25 free UpCloud VM credit). I compared Digital Ocean, Vultr and UpCloud Disk IO here and UpCloud came out on top by a long way (read the blog post here). Here is my blog post on moving from Vultr to UpCloud.

Buy a domain name here

Domain names for just 88 cents!

Now on with the post.

Murphy’s Law

I recently had an issue where I set up a website for a friend. I invested 6 hours into setting up..

I setup…

  • Debian OS
  • NGINX Web Server
  • MySQL Database
  • PHP 7.2
  • PHP-FPM Child Workers
  • HTTPS Certificate
  • Security (Firewall/Headers/SSH, WordPress, Plugins etc).
  • Installed WordPress and Plugins
  • Setup DNSSEC
  • Etc

I had tested GTMetrix scores = less than 1 second.  Security headers were tested and I was happy with the site.

The server and backups were automatically deleted after 7 days while I was away from my keyboard because I assumed the account was valid and had credits.

Lesson Learned

  • Always have a backup (of the server, setup/ www, MySQL etc).
  • Script setups (Ansible, Puppet or Scripts) to sate time redeploying if need be.
  • Backups are not always available.
  • Do have setup documented (Check)
  • Do have a disaster plan

I have guides on setting up a server on UpCloud, AWS, Vultr, Digital Ocean but setting up can be rather repetitive so how can you prevent resetting up servers?

Why Plan for the Worst

  • Companies disappear.
  • Some hosts go down.
  • Some hosts have weird trial modes and internal process that could take your site down.
  • Human error?
  • Murphy’s Law

How I will prevent this in future

  1. I am building a Java desktop app for Windows/OSX/Linux app that will deploy and set up on UpCloud/Vultr/Digital Ocean providers and allow for 1 click deploy and backup and restore.
  2. I am going to re-establish replication between servers with RSync etc.
  3. I am going to start to automate installs and environments.
  4. I am going to set up a hot (ready to go) Green/Blue mirrored environments (www and DB server) on different providers in case of emergency. Then I can set the active live servers with DNS (blog posts soon).
  5. Consider a server farm (same provider or different providers)

 

I hope this guide helps someone.

Please consider using my referral code and get $25 UpCloud VM credit if you need to create a server online.

https://www.upcloud.com/register/?promo=D84793

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Set up Feature-Policy, Referrer-Policy and Content Security Policy headers in Nginx

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This is a quick post that shows how I set up the “Feature-Policy”, “Referrer-Policy” and “Content Security Policy” headers in Nginx to tighter security and privacy.

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Aside

If you have not read my previous posts I have now moved my blog to the awesome UpCloud host (signup using this link to get $25 free UpCloud VM credit). I compared Digital Ocean, Vultr and UpCloud Disk IO here and UpCloud came out on top by a long way (read the blog post here). Here is my blog post on moving from Vultr to UpCloud.

Buy a domain name here

Domain names for just 88 cents!

Now on with the post.

Add a Feature Policy Header

Upon visiting https://securityheaders.com/ I found references to a Feature-Policy header (WC3 internet standard) that allows you to define what browse features you webpage can use along with other headers.

Google mentions the Feature-Policy header here.

Browser features that we can enable or block with feature-policy headers.

  • geolocation
  • midi
  • notifications
  • push
  • sync-xhr
  • microphone
  • camera
  • magnetometer
  • gyroscope
  • speaker
  • vibrate
  • fullscreen
  • payment

Feature Policy Values

  • * = The feature is allowed in documents in top-level browsing contexts by default, and when allowed, is allowed by default to documents in nested browsing contexts.
  • self = The feature is allowed in documents in top-level browsing contexts by default, and when allowed, is allowed by default to same-origin domain documents in nested browsing contexts, but is disallowed by default in cross-origin documents in nested browsing contexts.
  • none = The feature is disallowed in documents in top-level browsing contexts by default and is also disallowed by default to documents in nested browsing contexts.

My Final Feature Policy Header

I added this header to Nginx

This essentially disables all browser features when visitors access my site

I reloaded Nginx config and restart Nginx

Feature-Policy Results

I verified my feature-policy header with https://securityheaders.com/

Feature Policy score from https://securityheaders.com/?q=fearby.com&followRedirects=on

Nice, Feature -Policy is now enabled.

Now I need to enable the following headers

Add a Referrer Policy Header

I added this header configuration in Nginx to prevent referrers being leaked over insecure protocols.

Referrer-Policy Results

Again, I verified my referrer policy header with https://securityheaders.com/

Referrer Policy resu;ts from https://securityheaders.com/?q=fearby.com&followRedirects=on

Done, now I just need to setup Content Security Policy.

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Add a Content Security Policy header

I read my old guide on Beyond SSL with Content Security Policy, Public Key Pinning etc before setting up a Content Security policy again (I had disabled it a while ago). Setting a fully working CSP is very complex and if you don’t want to review CSP errors and modify the CSP over time this may not be for you.

Read more about Content Security Policy here: https://content-security-policy.com/

I added my old CSP to Nginx

I then imported the CSP into https://report-uri.com/home/generate and enabled more recent CSP values.

I restarted Nginx

I loaded the Google Developer Console to see any CSP errors when loading my site.

CPS Errors

I enabled reporting of CSP errors to https://fearby.report-uri.com/r/d/csp/enforce

Fyi: Content Security Policy OWASP Cheat Sheet.

You can validate CSP with https://cspvalidator.org

Now I won’t have to check my Chrome Developer Console and visitors to my site will report errors. I can see my site’s visitors CSP errors at https://report-uri.com/

report-cri.com Report

Content Security Policy Results

I reviewed the reported errors and made some more CSP changes. I will continue to lock down my CSP and make more changes before making this CSP policy live.

I verified my header with https://securityheaders.com/

Security Headers report from https://securityheaders.com/?q=https%3A%2F%2Ffearby.com&followRedirects=on

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Testing Policies

TIP: Use the header name of “Content-Security-Policy-Report-Only” instead of “Content-Security-Policy” to report errors before making CSP changes live.

I did not want to go live too soon, I had issues with some WordPress plugins not working in the WordPress admins screens.

Reviewing Errors

Do check your reported errors and update your CSP often, I had a post with a load of Twitter related errors.

Do check report-uri errors.

I hope this guide helps someone.

Please consider using my referral code and get $25 UpCloud VM credit if you need to create a server online.

https://www.upcloud.com/register/?promo=D84793

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Revision History

V1.3 https://cspvalidator.org

v1.2 OWASP Cheat Sheet.

v1.1 added info on WordPress errors.

v1.0 Initial Post

Setting strong SSL cryptographic protocols and ciphers on Ubuntu and NGINX

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This guide will aim to inform you of strong cryptographic protocols and ciphers to use on a web server on Ubuntu 16.04 and NGINX.

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Secure encryption protocols are used to secure communications between a server and client. Older SSL protocols like Netscape’s Secure Sockets Layer (SSL) are flagged as DO NOT USE use by the Internet Engineering Task Force (IETF). Newer protocols like Transport Layer Security (TLS) are the newer recommended SSL protocols to use.

Wikipedia Article on Cryptographic Protocol’s

A security protocol (cryptographic protocol or encryption protocol) is an abstract or concrete protocol that performs a security-related function and applies cryptographic methods, often as sequences of cryptographic primitives. A protocol describes how the algorithms should be used. A sufficiently detailed protocol includes details about data structures and representations, at which point it can be used to implement multiple, interoperable versions of a program.

Wikipedia on Ciphers

In cryptography, a cipher (or cypher) is an algorithm for performing encryption or decryption—a series of well-defined steps that can be followed as a procedure. An alternative, less common term is encipherment. To encipher or encode is to convert information into cipher or code. In common parlance, “cipher” is synonymous with “code,” as they are both a set of steps that encrypt a message; however, the concepts are distinct in cryptography, especially classical cryptography.

Wikipedia article on Elliptic-curve cryptography

Wikipedia article on Diffie–Hellman key exchange

Bad SSL Assumptions I have heard for not using HTTPS

  • I am not a bank so I don’t need HTTPS
  • SSL overhead is was too high on servers.
  • My site only has static content, I don’t need HTTPS
  • I don’t need SSL to secure my site I just need to be less of a target than others
  • I don’t hold confidential information (Wrong)

Don’t be Lazy and secure a site poorly

A local business that wanted me to buy their goods is not convincing me.

Bad SSL

(tested with SSL labs and asafaweb)

Why SSL

If you are unsure of why you need SSL visit https://doesmysiteneedhttps.com/, Avoiding the Not Secure Warning in Chrome, Why HTTPS matters and securing your site with HTTPS.

Google has an HTTPS usage graph for all communications to its services (hint it’s growing): https://transparencyreport.google.com/https/overview?hl=en

SSL Usage

SSL Future

SSL is here to stay, Non-SSL sites will soon be labelled insecure, Non-SSL sites will have Search Engine Optimization (SEO) adversely affected.

http insecure

Also, secure pages will be treated as normal (not flagged as secure)

History of Protocol’s – Launch Dates

  • SSL 1.0 (never launched)
  • SSL 2.0 1995
  • SSL 3.0 1996
  • TLS 1.0 1999
  • TLS 1.1 2006
  • TLS 1.2 2008
  • TLS 1.3 2018

Sites like https://caniuse.com can show you if our browser an use new protocols like TLS (e.g TLS 1.0, TLS 1.1, TLS 1.2, TLS 1.3)

  • TLS 1.0 is supported by All Browsers
  • TLS 1.1 is supported on IE11+, Edge, Firefox 24+, Chrome 22+, Safari 7+, Opera 12.1+, iOS Safari 5.1+, Chrome 62 on Android 5+ etc
  • TLS 1.2 is supported on IE11+, Edge, Firefox 27, Chrome 30+, Safari 7+, Opera 17+, iOS Safari 5.1, Chrome 62 on Android 5+ etc
  • TLS 1.3 is not Supported by IE, Edge, Safari, iOS Safari, Android but is supported by Firefox 52, Chrome 56, Opera 43.

TLS 1.3

I have a guide here on setting up TLS 1.3 on Ubuntu 16.05 and Chrome, I use the draft build of OpenSSL but Open SSL 1.1.1 will support TLS 1.3. I am still figuring our TLS 1.3 on Ubuntu 18.04.

At the time of writing, you need to opt into TLS 1.3 draft specification in Chrome.

Enable TLS in Chrome

Cipher or Cypher

Read this page to see the history of the word Cipher or Cypher?

Buying an SSL certificate

Opening your wallet may not buy you the best certificate either, this was an SSL Labs review of a $150 SSL certificate Ii purchased a few years ago from a CPanel web host.

Bad CPanel SSL Certificate

I don’t buy commercial certificates anymore, I prefer free SSL certificates from Lets Encrypt

SSL Strength

I prefer to set up my own (free) SSL certificate with Lest Encrypt and tets those certificated with https://dev.ssllabs.com/ssltest/

You can configure your web server to only use certain protocols.

And define preferred ciphers

SSL Test 2018

Don’t forget to renew your SSL certificates ahead of time.

Also run a modern browser like Google Chrome Canary as some old browsers thnk expired SSL certificates are Secure

Ciphers

OpenSSL has implemented support for five TLS v1.3 cipher suites:

  • TLS13-AES-256-GCM-SHA384
  • TLS13-CHACHA20-POLY1305-SHA256
  • TLS13-AES-128-GCM-SHA256
  • TLS13-AES-128-CCM-8-SHA256
  • TLS13-AES-128-CCM-SHA256

Test OpenSSL Cipher Suites

A handy guide about using ciphers

SSL/TLS: How to choose your cipher suite

Testing a remote host’s ciphers and protocols with cipherscan

Clone this repository: https://github.com/mozilla/cipherscan

Scan a site

Result

Cipher scan can also recommend settings to change to help you harden a server (based on https://wiki.mozilla.org/Security/Server_Side_TLS)

Analyze Command

Results

More info on hardening here.

TLS 1.3 Information

More Reading

SSLLabs Grading of certificates

Read about SSL Labs grading here

snip from here

  • A+ – exceptional configuration
  • A – strong commercial security
  • B – adequate security with modern clients, with older and potentially obsolete crypto used with older clients; potentially smaller configuration problems
  • C – obsolete configuration, uses obsolete crypto with modern clients; potentially bigger configuration problems
  • D – configuration with security issues that are typically difficult or unlikely to be exploited, but can and should be addressed
  • E – unused
  • F – exploitable and/or patchable problems, misconfigured server, insecure protocols, etc.

We wish to make clear that, while A+ is clearly the desired grade, both A and B grades are acceptable and result in adequate commercial security. The B grade, in particular, may be applied to configurations designed to support very wide audiences, many of whom use very old programs to connect. The C grade is generally used for configurations that don’t follow best practices. Grades D and F are used for servers with serious configuration and security issues.

REady to go SSL configuration: https://cipherli.st/

Download ready to go Diffie–Hellman primes. https://2ton.com.au/dhtool/

We have dedicated 48 CPU cores to the task of continuously generating 2048, 3072, 4096 and 8192 bit DH parameters, and the public service we present here allows access to the most-recent 128 of each.

Diffie–Hellman key exchange (DH) is a method of securely exchanging cryptographic keys over a public channel and was one of the first public-key protocols as originally conceptualized by Ralph Merkle and named after Whitfield Diffie and Martin Hellman. DH is one of the earliest practical examples of public key exchange implemented within the field of cryptography.

Traditionally, secure encrypted communication between two parties required that they first exchange keys by some secure physical channel, such as paper key lists transported by a trusted courier. The Diffie–Hellman key exchange method allows two parties that have no prior knowledge of each other to jointly establish a shared secret key over an insecure channel. This key can then be used to encrypt subsequent communications using a symmetric key cipher.

Diffie–Hellman is used to secure a variety of Internet services. However, research published in October 2015 suggests that the parameters in use for many DH Internet applications at that time are not strong enough to prevent compromise by very well-funded attackers, such as the security services of large governments.

More to come, I hope this guide helps someone.

fyi:

Windows Protocol/Cipher installer: https://www.nartac.com/

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V1.2 expired and use a modern browser

v1.1 bad SSL

v1.0 Initial post

Securing Google G Suite email by setting up SPF, DKIM and DMARC with Cloudflare

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This post will show you how you can setup Sender Policy Framework (SPF), DomainKeys Identified Mail (DKIM) Signatures and Domain-based Message Authentication, Reporting, and Conformance (DMARC) on your GMail (G Suite) email to limit spam and increase security.

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I have a number of guides on moving away form CPanel, Setting up VM’s on AWS, Vultr or Digital Ocean along with installing and managing WordPress from the command line. I use Google G Suite to send and receive emails that are linked to my domain (even via the command line) using multiple domains (with aliases).

For the best performing VM host (UpCloud) read my guide on the awesome UpCloud VM hosts (get $25 free credit by signing up here).

Buy a domain name from Namecheap here.

Domain names for just 88 cents!

Buy how can you extend your email security and limit spam?

Enter..

Sender Policy Framework (SPF) for Authorizing Use of Domains in Email

Background: SPF summary from the RFC document from the Internet Engineering Task Force (IETF).

“Email on the Internet can be forged in a number of ways. In particular, existing protocols place no restriction on what a sending host can use as the “MAIL FROM” of a message or the domain given on the SMTP HELO/EHLO commands. This document describes version 1 of the Sender Policy Framework (SPF) protocol, whereby ADministrative Management Domains (ADMDs) can explicitly authorize the hosts that are allowed to use their domain names, and a receiving host can check such authorization.”

Google has a guide in setting up SPF records for your G Suite account.

Scan your site for SPF, DKIM and DMARC configuration(s).

Gmail has a test site where you can check your site SPF, DKIM and DMARC etc: https://toolbox.googleapps.com/apps/checkmx/

Secure GSuite

How to set up an SPF Record

I followed this guide to set up an SPF record on my G Suite account. I use Cloudflare for my DNS provider so I’ll make my DNS changes there.

Add SPF Record

Update: Google instructions were wrong, use a TXT record and not a SPF record.

Read more on SPF at Wikipedia here.

DNS will take a while to replicate so do wait a few hours before checking again with the checkmx tool.

Now let’s set up DomainKeys Identified Mail (DKIM) Signatures

Read more on DKIM at Wikipedia here.

Background: The DKIM RFC form the Internet Engineering Task Force (IETF) states…

“DomainKeys Identified Mail (DKIM) permits a person, role, or organization that owns the signing domain to claim some responsibility for a message by associating the domain with the message. This can be an author’s organization, an operational relay, or one of their agents. DKIM separates the question of the identity of the Signer of the message from the purported author of the message. Assertion of responsibility is validated through a cryptographic signature and by querying the Signer’s domain directly to retrieve the appropriate public key. Message transit from author to recipient is through relays that typically make no substantive change to the message content and thus preserve the DKIM signature.”

Google has a DKIM FAQ: https://support.google.com/a/answer/174124

Login to your G Suite account and load this FAQ.

The FAQ page states..

“You can help prevent spoofing by adding a digital signature to outgoing message headers using the DKIM standard. This involves using a private domain key to encrypt your domain’s outgoing mail headers, and adding a public version of the key to the domain’s DNS records. Recipient servers can then retrieve the public key to decrypt incoming headers and verify that the message really comes from your domain and hasn’t been changed along the way.”

Click Generate the Domain Key

Generate Domain Key

Follow the steps and generate a key

Generate Key

Generate a new record

Generate key

Add the DKIM key to your DNS record

Add DNS record

DNS will take a while to replicate so do wait a few hours before checking again with the checkmx tool.

Domain-based Message Authentication, Reporting, and Conformance (DMARC)

Read more on DMARC at Wikipedia here. Read the official page here https://dmarc.org/.

Background: The DMARC RFC form the Internet Engineering Task Force (IETF) states…

DMARC Flow

DMARC Flow

“Domain-based Message Authentication, Reporting, and Conformance (DMARC) is a scalable mechanism by which a mail-originating organization can express domain-level policies and preferences for message validation, disposition, and reporting, that a mail-receiving organization can use to improve mail handling.

Originators of Internet Mail need to be able to associate reliable and authenticated domain identifiers with messages, communicate policies about messages that use those identifiers, and report about mail using those identifiers. These abilities have several benefits: Receivers can provide feedback to Domain Owners about the use of their domains; this feedback can provide valuable insight about the management of internal operations and the presence of external domain name abuse.

DMARC does not produce or encourage elevated delivery privilege of authenticated email. DMARC is a mechanism for policy distribution that enables increasingly strict handling of messages that fail authentication checks, ranging from no action, through altered delivery, up to message rejection.”

Google G Suite has a guide to setting up a DMARC record here

Snip from the Google guide here..

“Spammers can sometimes forge the “From” address on email messages so the spam appears to come from a user in your domain. To help prevent this sort of abuse, Google is participating in DMARC.org, which gives domain owners more control over what Gmail does with spam email messages from their domain.

G Suite follows the DMARC.org standard and allows you to decide how Gmail treats unauthenticated emails coming from your domain. Domain owners can publish a policy telling Gmail and other participating email providers how to handle unauthenticated messages sent from their domain. By defining a policy, you can help combat phishing to protect users and your reputation.“

Login to your G Suite account and load this FAQ

Click Add A DMARC Record

Add DMARC

You will then need to set up a DKIM Domain Key (if you have not done so yet)

When you are done you need to choose your DMARC rules, I would suggest you go to https://mxtoolbox.com/DMARCRecordGenerator.aspx to generate a record

I generated these rules

Dmarc Rules

Warning: Setting a DMARC policy that is too strict may block mail from being delivered. Tighten rules over time.

Login to your DNS provider and add your TXT record.

DMARC Record

You should now have an SPF, DKIM and DMARC record in DNS.

DNS

Update: The SPD record above should be a TXT (Google led me astray)

DNS will take a while to replicate so do wait a few hours before checking again with the checkmx tool.

Now go to bed and wait for DNS to replicate.

Troubleshooting SPF

My TXT record would not validate with https://toolbox.googleapps.com/apps/checkmx/check

Google Toolbox

The MX Toolbox SPF checker reports that SPF records are deprecated and to use TXT records instead.

SPF TXT Record

Fix (remove the SPF record and add a TXT record with the same contents). Don’t forget to delete the old SPF record.

TXT Record

Results

SPF Setup

Reports

SPF/DKIM reports will let me know when unauthorized people send email from my domain.

Also, DMARC will alert me to unauthorized activity

 

I hope this guide helps someone.

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Revision History

v1.4 Reports

v1.3 DMARC Flow image

V1.2 Updated wording

V1.1 Fixed typos (they were free)

v1.0 Initial post