GPG

GnuPG, GNU Privacy Guard, is a complete and free implementation of the OpenPGP standard as defined by RFC4880 (also known as PGP). GnuPG allows you to encrypt and sign your data and communications.

- gnupg.org

Cheat Sheet

• Generating a new GPG key

• How to use GPG to encrypt stuff

Keys Management

Generate A New Key

# You will be prompted with a few questions. Follow the instructions to generate the key.
gpg --full-generate-key

List Keys

# List the private keys
gpg --list-secret-keys [--keyid-format=long]

# List the public keys
gpg --list-keys [--keyid-format=long]

Export Keys

# Export the private key
gpg --output /path/to/output/private.asc --armor --export-secret-key KEY_ID

# Export the public key
gpg --output /path/to/output/public.asc --armor --export KEY_ID

Import Key

gpg --import /path/to/key

Delete Keys

# Delete private keys
gpg --delete-secret-key KEY_ID [...KEY_IDS]

# Delete public keys
# - If the public key is associated with the private key, the private key has to be deleted first.
gpg --delete-key KEY_ID [...KEY_IDS]

Encryption/Decryption

# Encrypt the file
# - You must first import the public key of the recipient.
gpg --output /path/to/encrypted.txt.gpg --encrypt --recipient [email protected] /path/to/plain.txt

# Decrypt the file
# - You will need the corresponding private key.
gpg --output /path/to/plain.txt --decrypt /path/to/encrypted.txt.gpg

Signature

# Sign the message
shasum -a 256 /path/to/file.txt | awk '{print $1}' > /path/to/file.txt.sha256sum
gpg --output /path/to/file.txt.sha256sum.sig --sign /path/to/file.txt.sha256sum

# Verify the signature
gpg --verify /path/to/file.txt.sha256sum.sig