Github

SSH Key

• Generate key

ssh-keygen -t rsa -b 4096 -C "[e-mail]"

• Add private key to ssh-client

eval "$(ssh-agent -s)"
ssh-add ~/.ssh/id_rsa

• Install xclip

sudo apt-get install xclip

• Copy generated file to clipboard (CTRL + C)

xclip -sel clip < ~/.ssh/id_rsa.pub

# Example of generated key
# ssh-rsa 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 [e-mail]

• Open Github and Add the ssh key

Github Shortcuts

Shift + /

Github: Signing commits using GPG (Ubuntu/Mac)

• Do you have a Github account?

  • If not, create one.

• Install the required tools

• Latest Git Client

Install GPG Tools

# Ubuntu
sudo apt-get install gpa seahorse
# Mac
brew install gpg

Generate a new GPG key

gpg --gen-key

Answer the questions asked

Note: When asked to enter your email address, ensure that you enter the verified email address for your GitHub account.

List generated key

gpg --list-secret-keys --keyid-format LONG

# Output
# 
# /home/username/.gnupg/secring.gpg
# -------------------------------
# sec   4096R/<COPY_LONG_KEY> 2016-08-11 [expires: 2018-08-11]
# uid                          User Name <[e-mail]>
# ssb   4096R/62E5B29EEA7145E 2016-08-11

• Note down your key COPY_LONG_KEY from above

• Export this (public) key to a text file

gpg --armor --export <PASTE_LONG_KEY_HERE> > gpg-key.txt

• The above command will create a new txt file gpg-key.txt

• Add this key to GitHub

• Login to Github and goto profile settings
• Click New GPG Key and paste the content of gpg-key.txt file then save

• Tell git client to auto sign your future commits

• Run this command

gpg --list-keys

# Output
# 
# /home/username/.gnupg/pubring.gpg
# -------------------------------
# pub   4096R/<COPY_SHORT_KEY> 2016-08-11 [expires: 2018-08-11]
# uid                  Your Name <[e-mail]>
# sub   4096R/EB61969F 2016-08-11 [expires: 2017-08-11]

• Copy the short key from above and use this in the command below

git config --global user.signingKey <PASTE_SHORT_KEY_HERE>
git config --global commit.gpgsign true

• You are done, next time when you commit changes; GPG will ask you the passphrase.

Make GPG remember your passphrase (tricky)

To make it remember your password, you can use gpg-agent

Edit your ~/.gnupg/gpg-agent.conf file and paste these lines

default-cache-ttl 28800
max-cache-ttl 28800

28800 seconds means 8 hours

If gpg-agent is not running you can start it with this command

gpg-agent --daemon

Change your key passphrase

gpg --edit-key <PASTE_YOUR_KEY_ID_HERE>

At the gpg prompt type:

passwd

Type in the current passphrase when prompted Type in the new passphrase twice when prompted Type:

save

Reference Links

• https://help.github.com/categories/gpg/
• http://nishanttotla.com/blog/signing-git-commits-gpg/
• https://git-scm.com/book/en/v2/Git-Tools-Signing-Your-Work
• https://news.ycombinator.com/item?id=7792026
• https://overflow.no/blog/2016/08/11/signed-commits-with-gpg-git-and-github-on-linux/
• http://stackoverflow.com/questions/10161198/is-there-a-way-to-autosign-commits-in-git-with-a-gpg-key
• http://irtfweb.ifa.hawaii.edu/~lockhart/gpg/gpg-cs.html
• https://help.ubuntu.com/community/GnuPrivacyGuardHowto
• https://medium.com/@timmywil/sign-your-commits-on-github-with-gpg-566f07762a43#.aovevj80y
• https://blog.erincall.com/p/signing-your-git-commits-with-gpg