Git Security and Signing Commits: Ensuring Trust and Integrity

Git Security and Signing Commits: Ensuring Trust and Integrity

Signing commits and tags with GPG (GNU Privacy Guard) keys ensures the authenticity and integrity of your code. This prevents tampering and verifies that the commit was made by a trusted author. In this advanced blog, we’ll explore how to generate and use GPG keys, sign commits, verify signatures, and enforce signing policies.

Table of Contents

• Why Sign Commits?
• Generating a GPG Key
• Configuring Git for Signing
• Signing Commits and Tags
• Verifying Signatures
• Enforcing Signing Policies
• Exercise: Signing Commits

Why Sign Commits?

Signed commits:

• Prove authorship.
• Prevent unauthorized modifications.
• Build trust in collaborative projects.

Generating a GPG Key

Generate a GPG key:

  gpg --full-generate-key
          

Export the public key:

  gpg --armor --export <key-id>
          

Configuring Git for Signing

Set your GPG signing key:

  git config --global user.signingkey <key-id>
  git config --global commit.gpgsign true
          

Signing Commits and Tags

Sign a commit:

  git commit -S -m "Signed commit"
          

Sign a tag:

  git tag -s v1.0.0 -m "Signed tag"
          

Verifying Signatures

Verify a signed commit:

  git log --show-signature
          

Verify a signed tag:

  git tag -v v1.0.0
          

Enforcing Signing Policies

On GitHub or GitLab, require signed commits for protected branches:

  # Enable branch protection rules to enforce signed commits
          

Exercise: Signing Commits

Practice signing commits:

• Generate a GPG key and export the public key.
• Configure Git to use the GPG key for signing.
• Sign a commit and verify its signature.
• Sign a tag and verify its signature.
• Set up a repository to require signed commits.

Coming Up Next

In the next part of this series, we’ll explore integrating Git with CI/CD pipelines to automate testing, building, and deployment workflows.