my bad.i meant disable/remove the certificate from the browser and not 'revoke' as such. Also curious, what is the browser's audit mechanism of the CA? what safeguards do the audit provide end users like us from malicious CA's and how is the audit carried out? Is a non disclosure agreement signed between the browser and the CA? Doesn't the following attack model also work. Say we have rouge intermediate CA X(trusted by the bowser) itself issuing a certificate to BankofA.com. Note: BankofA.com never requested this certificate from CA X. BankofA has its legitimate certificate issued by (say for example Verisign). Now, say that is possible to carry out a MITM attack at the end user (bank's client) ISP. When the end user opens BankofA.com on the browser, with the MITM in place - the fake certificate issued by CA X will be presented to the end user. The end user's browser trusts CA X and no red flags are raised. If any monetary transactions are carried out, all the money can be funneled out. Thank you, Sarad AV
From: Peter Gutmann <pgut001@cs.auckland.ac.nz> Subject: Re: Fwd: [ PRIVACY Forum ] Surveillance via bogus SSL certificates To: alexbrennen@gmail.com, jtrjtrjtr2001@yahoo.com Cc: cypherpunks@al-qaeda.net Date: Saturday, April 10, 2010, 5:14 AM Sarad AV <jtrjtrjtr2001@yahoo.com> writes:
i also wonder what the browser policy for major browsers are when a root CA company is acquired by another company. Is trust automatically transfered to the new company?
Yes. When your CA goes bankrupt its only significant asset is often the root CA cert(s) it owns, which get onsold to the highest bidder by the receivers. This has occurred numerous times in the past, and some roots have been onsold multiple times, since it's both a means of monetising the CA's remaining assets and (usually) the cheapest way for a new CA to get their own cert.
Will the browser keep or revoke these certificates?
Keep.
(I'm not sure whether the browser vendor will even know if it's been on-sold, or how the vendor is supposed to know unless the new owner volunteers the information. Also you can't really "revoke" a root, and the browser vendors certainly can't do it, the best they can do is disable/remove it in the next release).
Peter.