V-268124

Discussion

Without path validation, an informed trust decision by the relying party cannot be made when presented with any certificate not already explicitly trusted. A trust anchor is an authoritative entity represented via a public key and associated data. It is used in the context of public key infrastructures, X.509 digital certificates, and DNSSEC. When there is a chain of trust, usually the top entity to be trusted becomes the trust anchor; it can be, for example, a Certification Authority (CA). A certification path starts with the subject certificate and proceeds through a number of intermediate certificates up to a trusted root certificate, typically issued by a trusted CA. This requirement verifies that a certification path to an accepted trust anchor is used for certificate validation and that the path includes status information. Path validation is necessary for a relying party to make an informed trust decision when presented with any certificate not already explicitly trusted. Status information for certification paths includes certificate revocation lists or online certificate status protocol responses. Validation of the certificate status information is out of scope for this requirement. Satisfies: SRG-OS-000066-GPOS-00034, SRG-OS-000403-GPOS-00182, SRG-OS-000775-GPOS-00230

Check Content

Verify NixOS only allows the use of DOD PKI-established certificate authorities by running the following:

$ openssl x509 -text -in /etc/sssd/pki/sssd_auth_ca_db.pem
Certificate:
Data:
Version: 3 (0x2)
Serial Number: 1 (0x1)
Signature Algorithm: sha256WithRSAEncryption
Issuer: C = US, O = U.S. Government, OU = DOD, OU = PKI, CN = DOD Root CA 3
Validity
Not Before: Mar 20 18:46:41 2012 GMT
Not After : Dec 30 18:46:41 2029 GMT
Subject: C = US, O = U.S. Government, OU = DOD, OU = PKI, CN = DOD Root CA 3
Subject Public Key Info:
Public Key Algorithm: rsaEncryption

If the root CA file is not a DOD-issued certificate with a valid date and installed in the /etc/sssd/pki/sssd_auth_ca_db.pem location, this is a finding.