ICAO Master List viewer

What a CSCA Master List is

A CSCA Master List is defined in ICAO Doc 9303 Part 12. It is a CMS SignedData structure with the content type id-icao-cscaMasterList (2.23.136.1.1.2) that carries a set of Country Signing CA certificates. The publishing state has checked these certificates and signs the list with a Master List Signer certificate issued by its own CSCA. Inspection systems use the certificates as trust anchors to validate Document Signer certificates and, through them, the security object (SOD) of an eMRTD chip.

What the checks mean

Content hash compares the hash of the certificate list with the messageDigest attribute inside the signature. Signature verifies the signer’s signature over the signed attributes with the Master List Signer certificate. Signer certificate checks that this certificate was issued by a CSCA contained in the loaded lists.

The browser’s Web Crypto API supports RSA, RSA-PSS and the NIST curves P-256, P-384 and P-521, but not the Brainpool curves that many CSCAs use. When a check is not possible in the browser, the viewer says so instead of guessing. You can verify such a list with OpenSSL; the -noverify option skips the certificate chain but still checks the signature:

openssl cms -verify -inform DER -in masterlist.ml -noverify -out content.der

Link certificates and explicit curve parameters

When a CSCA changes its key, it issues a link certificate: a certificate with the CSCA’s own name that carries the new public key and is signed with the old one. The viewer marks a certificate as a link certificate when it is self-issued but its authority key identifier differs from its subject key identifier.

Many CSCA certificates encode elliptic curve parameters explicitly instead of naming the curve. The viewer recognises the standard NIST and Brainpool curves from the field prime and shows the curve name with the note “explicit parameters”.

Where to get Master Lists

The ICAO PKD offers Master Lists in LDIF format to its participants and through its download service, and several states publish their own lists. Germany’s Federal Office for Information Security (BSI), for example, publishes the German CSCA Master List as a ZIP archive under its own terms of use. This site is not affiliated with ICAO, the BSI or any issuing authority and does not host or redistribute any Master List.

Questions

Is my file uploaded?

No. The file is parsed in your browser with JavaScript and the Web Crypto API. Master Lists contain public certificates only, with no personal data.

Why does the list contain expired certificates?

A passport stays valid for years after the Document Signer that signed it stopped being used, so states keep older CSCA certificates in their lists while documents issued under them can still be in circulation. Expired certificates are hidden by default; tick “Show expired” to see them.

Which file formats are supported?

Master Lists as DER or PEM (.ml), ZIP archives containing them, ICAO PKD LDIF files with Master List or certificate entries, and individual certificates in DER or PEM.