Cryptographic details related to omnibus-gitlab packages All tiers Self-managed

GitLab uses a packagecloud instance to share the different OS packages it offers, and uses various cryptographic methods to ensure the integrity of these packages. This page serves to provide details regarding these methods.

Package repository metadata signing keys

The apt and yum repositories on the GitLab packagecloud instance uses a GPG key to sign their metadata. This key is automatically installed by the repo setup script specified in the installation instructions.

Current key

Key Attribute Value
Name GitLab B.V.
EMail packages@gitlab.com
Comment package repository signing key
Fingerprint F640 3F65 44A3 8863 DAA0 B6E0 3F01 618A 5131 2F3F
Expiry 2024-03-01

This key is active from 2020-04-06. Existing users who already have configured the GitLab apt/yum package repositories will have to fetch and add this key to their trusted keyring again to continue installing packages from those repositories without apt/yum complaining about mismatches, which is described below.

This key’s expiration was extended from 2022-03-02 to 2024-03-01. If you encounter a complaint of expiration on 2022-03-02, perform the steps in Update keys after expiry extension to incorporate the updated public key content.

Update keys after expiry extension

For Debian based distributions:

PackageCloud generally made use of apt-key, which will be deprecated in the future. Manually installed or configured repositories from some distributions, such as TurnKey Linux, are already using the signed-by support within Debian package source lists.

  1. Determine if you’re using apt-key or signed-by functionality:

     grep 'deb \[signed-by=' /etc/apt/sources.list.d/gitlab_gitlab-?e.list
    
    • If this grep returns any lines, you’re using signed-by functionality. This takes precedence over any apt-key usage.
    • If this grep returns no lines, you’re using apt-key functionality.
  2. For signed-by, the following script (run as root) updates the public keys for GitLab repositories:

     awk '/deb \[signed-by=/{
           pubkey = $2;
           sub(/\[signed-by=/, "", pubkey);
           sub(/\]$/, "", pubkey);
           print pubkey
         }' /etc/apt/sources.list.d/gitlab_gitlab-?e.list | \
       while read line; do
         curl -s "https://packages.gitlab.com/gpg.key" | gpg --dearmor > $line
       done
    
  3. For apt-key, the following script (run as root) updates the public keys for GitLab repositories:

     apt-key del 3F01618A51312F3F
     curl -s "https://packages.gitlab.com/gpg.key" | apt-key add -
     apt-key list 3F01618A51312F3F
    

For RPM based distributions:

There are mild differences between Yum and Dnf, but the underlying configuration is identical.

  1. Remove any existing key from the repository keyrings:

     for pubring in /var/cache/dnf/gitlab_gitlab-?e-*/pubring
     do
       gpg --homedir $pubring --delete-key F6403F6544A38863DAA0B6E03F01618A51312F3F
     done
    
  2. Update the repository data/cache, which asks you to confirm keys:

     dnf check-update
    

Fetching new keys before 2020-04-06

# Download the new key
curl "https://gitlab-org.gitlab.io/omnibus-gitlab/gitlab_new_gpg.key" -o /tmp/omnibus_gitlab_gpg.key

# Import the key
## Debian/Ubuntu/Raspbian
sudo apt-key add /tmp/omnibus_gitlab_gpg.key

# CentOS/OpenSUSE/SLES
sudo rpm --import /tmp/omnibus_gitlab_gpg.key

Fetching new keys after 2020-04-06

To fetch the latest repository signing key, users can run the curl command used to add GitLab repository, as mentioned in the install page, again. It will fetch the new key and add it to the user’s keyring.

Or, users can manually fetch and add the new key using the following commands

# Download the new key
curl "https://packages.gitlab.com/gpg.key" -o /tmp/omnibus_gitlab_gpg.key

# Import the key
## Debian/Ubuntu/Raspbian
sudo apt-key add /tmp/omnibus_gitlab_gpg.key

# CentOS/OpenSUSE/SLES
sudo rpm --import /tmp/omnibus_gitlab_gpg.key

Previous keys

Sl. No. Key ID Expiry Date
1 1A4C 919D B987 D435 9396 38B9 1421 9A96 E15E 78F4 2020-04-15

Package Signatures

This document will provide methods for verifying the signatures of GitLab produced packages, both manually and automatically where supported.

RPM based distributions

The RPM format contains a full implementation of GPG signing functionality, and thus is fully integrated with the package management systems based upon that format. There are two methods of verification.

Verify GitLab public key is present

To verify a package on an RPM based distribution, we’ll need to ensure that the GitLab, Inc. public key is present in the rpm tool’s keychain.

rpm -q gpg-pubkey-f27eab47-60d4a67e --qf '%{name}-%{version}-%{release} --> %{summary}'

This will produce either the information on the public key, or gpg-pubkey-f27eab47-60d4a67e is not installed. If the key is not present, perform the following steps:

rpm --import https://packages.gitlab.com/gitlab/gitlab-ce/gpgkey/gitlab-gitlab-ce-3D645A26AB9FBD22.pub.gpg

Verify if signature check is active

The simplest method of checking if package signature checking is active on an existing install is to compare the content of the repository file in use.

  • Check if the repository file exist: file /etc/yum.repos.d/gitlab_gitlab-ce.repo
  • Check that signature checking is active: grep gpgcheck /etc/yum.repos.d/gitlab_gitlab-ce.repo should output

    repo_gpgcheck=1
    gpgcheck=1
    

    or

    repo_gpgcheck=1
    pkg_gpgcheck=1
    

If the file does not exist, you don’t have the repository installed. If the file exists, but the output shows gpgpcheck=0, then you will need to edit that value to enable it, as below.

Enable Automatic Verification

The rpm tool and related package managers (yum,zypper) directly support the automatic verification of packages without intervention. If you used the automated repository configuration script after signed packages became available, then you will have no additional steps required. If you installed prior to the release of signed packages, you can either make the necessary changes, or re-run the automatic repository configuration script as found on the Installation page.

Yum (RedHat, CentOS)
  1. Enable GPG checking of the packages

    sudo sed -i'' 's/^gpgcheck=0/gpgcheck=1/' /etc/yum.repos.d/gitlab_gitlab-ce.repo
    
  2. Add the package signing public key to the gpgkey list: Edit /etc/yum.repos.d/gitlab_gitlab-ce.repo, changing gpgkey to read:

    gpgkey=https://packages.gitlab.com/gitlab/gitlab-ce/gpgkey
            https://packages.gitlab.com/gitlab/gitlab-ce/gpgkey/gitlab-gitlab-ce-3D645A26AB9FBD22.pub.gpg
    
  3. Tell yum to refresh the cache for the repository

    sudo yum -q makecache -y --disablerepo='*' --enablerepo='gitlab_gitlab-ce'
    
Zypper (SuSE/SLES)
  1. Enable GPG checking of the packages

    sudo sed -i'' 's/pkg_gpgcheck=0/pkg_gpgcheck=1/' /etc/zypp/repos.d/gitlab_gitlab-ce.repo
    
  2. Add the package signing public key to the gpgkey list: Edit /etc/zypp/repos.d/gitlab_gitlab-ce.repo, changing gpgkey to read:

    gpgkey=https://packages.gitlab.com/gitlab/gitlab-ce/gpgkey
            https://packages.gitlab.com/gitlab/gitlab-ce/gpgkey/gitlab-gitlab-ce-3D645A26AB9FBD22.pub.gpg
    
  3. Tell zypper to refresh the repository and import the keys

    sudo zypper --gpg-auto-import-keys refresh gitlab_gitlab-ce
    

Manual Verification

Once the public key is confirmed present, an RPM package can be manually verified with rpm --checksig gitlab-xxx.rpm.

DEB based distributions

The DEB format does not officially contain a default and included method for signing packages. At GitLab, we have chosen to implement the standard for debsig which is well documented, while not enabled by default on most distributions.

Manual Verification

Manual verification of DEB packages signed with debsigs can be performed in two ways: using debsig-verify after configuring the necessary debsigs policy and keyring, or manually checking the contained _gpgorigin file with GnuPG.

Manually verify with GnuPG

The debsig-verify package has a slew of dependencies that a user may not wish to install. To verify the debsigs based signature without installing debsig-verify and dependencies, a user can complete the following manual steps:

  1. Download and import the package signing public key

    curl -JLO "https://packages.gitlab.com/gitlab/gitlab-ce/gpgkey/gitlab-gitlab-ce-3D645A26AB9FBD22.pub.gpg"
    gpg --import gitlab-gitlab-ce-3D645A26AB9FBD22.pub.gpg
    
  2. Extract the signature file (_gpgorigin)

    ar x gitlab-ce-xxx.deb _gpgorigin
    
  3. Verify the signature matches the content

    ar p gitlab-xxx.deb debian-binary control.tar.gz data.tar.gz | gpg --verify _gpgorigin -
    

The output of the final command should appear as such:

$ ar p gitlab-xxx.deb debian-binary control.tar.gz data.tar.gz | gpg --verify _gpgorigin -

gpg: Signature made Tue Aug 01 22:21:11 2017 UTC
gpg:                using RSA key DBEF89774DDB9EB37D9FC3A03CFCF9BAF27EAB47
gpg:                issuer "support@gitlab.com"
gpg: Good signature from "GitLab, Inc. <support@gitlab.com>" [unknown]
Primary key fingerprint: DBEF 8977 4DDB 9EB3 7D9F  C3A0 3CFC F9BA F27E AB47
Configuring debsigs

Configuring a policy and keyring for debsigs can be complicated, so GitLab provides gitlab-debsigs.sh as a scripted method of configuration.

To use this script, you will need to download the public key and the script.

curl -JLO "https://packages.gitlab.com/gitlab/gitlab-ce/gpgkey/gitlab-gitlab-ce-3D645A26AB9FBD22.pub.gpg"
curl -JLO "https://gitlab.com/gitlab-org/omnibus-gitlab/raw/master/scripts/gitlab-debsigs.sh"
chmod +x gitlab-debsigs.sh
sudo ./gitlab-debsigs.sh gitlab-gitlab-ce-3D645A26AB9FBD22.pub.gpg
Verify with debsig-verify

To make use of debsig-verify, perform the steps in Configuring debsigs and install the debsig-verify package.

debsig-verify gitlab-xxx.deb