Install Certum Trusted Network CA 2 on Ubuntu 24.04

README.md

Install Certum Trusted Network CA 2 on Ubuntu 24.04

This guide explains how to manually install and trust the Certum Trusted Network CA 2 root certificate on Ubuntu 24.04 systems.

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🧭 Why this is needed

Some systems (e.g. GitLab, Mattermost, Magento integrations, etc.) may fail SSL validation due to outdated or missing Certum root certificates.

You might see errors such as:

Connection failed. Check your integration settings. SSL_connect returned=1 errno=0 state=error: certificate verify failed (unable to get local issuer certificate)

Some versions of the certificate file distributed by Certum contain unwanted leading spaces or invisible bytes (such as BOM).
These may cause OpenSSL or update-ca-certificates to fail with:

Could not read certificate [...] Unable to load certificate

The commands below fetch the certificate, remove any whitespace at the beginning of the file, and register it in the system trust store.

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🧩 Commands

wget -q "https://www.certum.pl/pl/upload_module/wysiwyg/certyfikaty/Certum-Trusted-Network-CA%20-2.pem" -O - \
  | sed 's/^[[:space:]]*//' \
  | sudo tee /usr/local/share/ca-certificates/certum_trusted_network_ca_2.crt > /dev/null

sudo update-ca-certificates

✅ Result

Updating certificates in /etc/ssl/certs...
1 added, 0 removed; done.

🔍 Verify

openssl x509 -in /usr/local/share/ca-certificates/certum_trusted_network_ca_2.crt -noout -issuer -subject -dates -fingerprint