Earlier today we sent an email to all certificate authorities in the Mozilla root program to clarify our expectations around certificate issuance. In particular, we made it clear that the issuance of subordinate CA certificates for the purposes of SSL man-in-the-middle interception or traffic management is unacceptable. We made it clear that this practice remains unacceptable even when the intended deployment of such a certificate is restricted to a closed network.

In addition to this clarification, we have made several requests. We have requested that any such certificates be revoked, and their HSMs destroyed. We have requested the serial numbers of those certificates and fingerprints of their signing roots so that we, and other relying parties, can detect and distrust these subCA certificates if encountered. We have requested that any CAs who have issued subCA certificates fulfill these requests no later than April 27, 2012.

Finally, we re-iterated our belief that each root is ultimately accountable for every certificate it signs, directly or through its subordinates. Participation in Mozilla’s root program is at our sole discretion, and we will take whatever steps are necessary to keep our users safe, up to and including the removal of root certificates that mis-issue, as well as any roots that cross-sign them. Nevertheless, we believe that security is best served when browsers and CAs can work together; we hope that frank communication and clear expectations can resolve these issues before any such action is required. We must also be diligent in looking for new ways to improve the security systems of the web. Those systems are built on the trust of web users, and we all have a responsibility to be strong stewards of that trust.

Johnathan Nightingale

Senior Director of Firefox Engineering