View source for SecurityEngineering/Removing Compatibility Workarounds in mozilla::pkix

In the process of implementing mozilla::pkix, a number of compatibility issues were encountered involving certificates that did not conform to the Baseline Requirements. To maintain interoperability, some workarounds were added to allow these malformed or improper certificates to validate successfully. However, to improve the state of the web PKI, these workarounds will be removed. As of Firefox 49, if a certificate has a notBefore time after 0:00 23 August 2016 and is affected by any of these workarounds (see below), it will not validate successfully. This document will track the implementation work necessary to remove those workarounds.

=== Completed ===
* use of subject CN for naming information (Firefox 48)
** Workaround introduced in [https://bugzilla.mozilla.org/show_bug.cgi?id=1063281 bug 1063281]
** Workaround removed in [https://bugzilla.mozilla.org/show_bug.cgi?id=1245280 bug 1245280]
* id-Netscape-stepUp in Extended Key Usage extension instead of id-kp-serverAuth (Firefox 49)
** Workaround introduced in [https://bugzilla.mozilla.org/show_bug.cgi?id=1006041 bug 1006041]
** Workaround removed in [https://bugzilla.mozilla.org/show_bug.cgi?id=982932 bug 982932]
=== Ready to be Removed ===
* DER: pathLenConstraint included when cA:False
** Workaround introduced in [https://bugzilla.mozilla.org/show_bug.cgi?id=985021 bug 985021]
** Workaround to be removed in [https://bugzilla.mozilla.org/show_bug.cgi?id=985025 bug 985025]
** Code affected: CheckIssuerIndependentProperties -> CheckBasicConstraints (pkixcheck.cpp)
** Expected difficulty: easy
* nameConstraints/subjectAlternativeName encoding mismatches
** Workaround introduced in [https://bugzilla.mozilla.org/show_bug.cgi?id=1150114 bug 1150114]
** Workaround to be removed in [https://bugzilla.mozilla.org/show_bug.cgi?id=1256073 bug 1256073]
** Code affected: pkixnames.cpp
** Expected difficulty: moderate
* keyUsage lacking keyEncipherment for certs with RSA keys
** Workaround introduced in n/a
** Workaround to be removed in [https://bugzilla.mozilla.org/show_bug.cgi?id=970760 bug 970760]
** See also [https://bugzilla.mozilla.org/show_bug.cgi?id=1133562 bug 1133562]
** Code affected: CertVerifier.cpp
** Expected difficulty: moderate
=== Potentially Ready to be Removed ===
* empty SEQUENCE in OCSP responses
** Workaround introduced in [https://bugzilla.mozilla.org/show_bug.cgi?id=991898 bug 991898]
** Workaround to be removed in [https://bugzilla.mozilla.org/show_bug.cgi?id=997994 bug 997994]
** Code affected: pkixocsp.cpp, pkixder.h
** Expected difficulty: moderate
=== Not Ready to be Removed ===
* DER: default value of OPTIONAL BOOLEAN explicitly encoded
** Workaround introduced in [https://bugzilla.mozilla.org/show_bug.cgi?id=989516 bug 989516] for Basic Constraints (cA field)
** Workaround introduced in [https://bugzilla.mozilla.org/show_bug.cgi?id=1060929 bug 1060929] for Extension (critical field)
** Workaround to be removed in [https://bugzilla.mozilla.org/show_bug.cgi?id=989518 bug 989518]
** Code affected: pkixcheck.cpp, pkixder.h, pkixcert.cpp, pkixocsp.cpp
** Expected difficulty: difficult
* Non-PrintableString/UTF8String in DNs
** Workaround introduced in [https://bugzilla.mozilla.org/show_bug.cgi?id=1089104 bug 1089104]
** Workaround to be removed in [https://bugzilla.mozilla.org/show_bug.cgi?id=1256071 bug 1256071]
** Code affected: pkixnames.cpp
** Expected difficulty: moderate