Upgrading to OpenSSL 3

Starting from version 17.5, GitLab uses OpenSSL 3. This version of OpenSSL is a major release with notable deprecations and changes to the default behavior of OpenSSL (for more details see the OpenSSL 3 migration guide).

Some of the older versions of TLS and cipher suites for external integrations may not be compatible with these changes. Therefore, it is crucial that you assess the compatibility of your external integrations before upgrading to a GitLab version that uses OpenSSL 3.

With the upgrade to OpenSSL 3:

  • TLS 1.2 or higher is required for all incoming and outgoing TLS connections.
  • TLS certificates must have at least 112 bits of security. RSA, DSA, and DH keys shorter than 2048 bits, and ECC keys shorter than 224 bits are prohibited.

Identifying external integrations

External integrations can be configured either with gitlab.rb or through the GitLab web interface under the project, group, or admin Settings.

Here is a preliminary list of integrations that you can use:

All components that are shipped with the Linux package are compatible with OpenSSL 3. Therefore, you only need to verify the services that are not part of the GitLab package and are “external”.

Assessing compatibility with OpenSSL 3

You can use different tools to verify compatibility of the external integration endpoints. Regardless of the tool that your’re using, you need to check the supported TLS version and cipher suites.

openssl command-line tool

You can use openssl s_client command-line tool to connect to TLS-enabled server. It has a wide range of options that you can use to enforce specific TLS version or ciphers:

  1. Make sure that you are using the OpenSSL 3 command-line tool by checking the version: 

    openssl version

  2. Use the following example script that checks if a server supports the ciphers and TLS versions: 

    # Host and port of the server
SERVER='HOST:PORT'

# Check supported ciphers for TLS1.2 and TLS1.3
# See `openssl s_client` manual for other available options.
for tls_version in tls1_2 tls1_3; do
  echo "Supported ciphers for ${tls_version}:"
  for cipher in $(openssl ciphers -${tls_version} | sed -e 's/:/ /g'); do
    # NOTE: The cipher will be combined with any TLSv1.3 cipher suites that
    # have been configured.
    if openssl s_client -${tls_version} -cipher "${cipher}" -connect ${SERVER} </dev/null >/dev/null 2>&1; then
      echo "\t${cipher}"
    fi
  done
done

Nmap ssl-enum-ciphers script

Nmap’s ssl-enum-ciphers script identifies supported TLS versions and ciphers and provides a detailed output.

  1. Install nmap.

  2. Check that the version you’re using is compatible with OpenSSL 3: 

    nmap --version

    The output should show version details including the OpenSSL version that Namp is “compiled with”.

  3. Run nmap against the site you’re testing: 

    nmap -sV --script ssl-enum-ciphers -p PORT HOST

    You should see an output similar to the following: 

    PORT    STATE SERVICE  VERSION
443/tcp open  ssl/http Cloudflare http proxy
| ssl-enum-ciphers:
|   TLSv1.2:
|     ciphers:
|       TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (ecdh_x25519) - A
|       TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 (ecdh_x25519) - A
|       TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256-draft (ecdh_x25519) - A
|       TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA (ecdh_x25519) - A
|       TLS_RSA_WITH_AES_128_GCM_SHA256 (rsa 2048) - A
|       TLS_RSA_WITH_AES_128_CBC_SHA (rsa 2048) - A
|       TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
|       TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA (ecdh_x25519) - A
|       TLS_RSA_WITH_AES_256_GCM_SHA384 (rsa 2048) - A
|       TLS_RSA_WITH_AES_256_CBC_SHA (rsa 2048) - A
|       TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 (ecdh_x25519) - A
|       TLS_RSA_WITH_AES_128_CBC_SHA256 (rsa 2048) - A
|       TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384 (ecdh_x25519) - A
|       TLS_RSA_WITH_AES_256_CBC_SHA256 (rsa 2048) - A
|     compressors:
|       NULL
|     cipher preference: server
|   TLSv1.3:
|     ciphers:
|       TLS_AKE_WITH_AES_128_GCM_SHA256 (ecdh_x25519) - A
|       TLS_AKE_WITH_AES_256_GCM_SHA384 (ecdh_x25519) - A
|       TLS_AKE_WITH_CHACHA20_POLY1305_SHA256 (ecdh_x25519) - A
|     cipher preference: client
|_  least strength: A
|_http-server-header: cloudflare