Trusted certificate authority Certigna leaks its private key
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Re: Trusted certificate authority Certigna leaks its private key
#2I'm not terribly familiar with private key formats, but it appears to be encrypted (the `Proc-Type` and `DEK-Info` lines). Is the `localKeyID` the password used to encrypt?
Re: Trusted certificate authority Certigna leaks its private key
#3I'm not terribly familiar with private key formats, but it appears to be encrypted (the `Proc-Type` and `DEK-Info` lines). Is the `localKeyID` the password used to encrypt?
I'm not sure either.
If it is encrypted, it would at least buy some time to replace all the certificates signed by this private key. Depending on the strength of the encryption key, obviously.
Re: Trusted certificate authority Certigna leaks its private key
#4Of course, "just revoke" doesn't actually work: serving a outdated certificate revocation list, or preventing a connection to the OCSP ("is this cert revoked?") server causes browsers to trust "revoked" certificates. Worse, lots of software doesn't even bother to do this check. This is why the browsers hardcoded a list of compromised certificates last time.
This is even worse, though, because a lot of "real" certificates depend on this CA. Also, there are no logs to make a blacklist of "bad" certificates, so you can't just revoke a handful...
Re: Trusted certificate authority Certigna leaks its private key
#5I'm not terribly familiar with private key formats, but it appears to be encrypted (the `Proc-Type` and `DEK-Info` lines). Is the `localKeyID` the password used to encrypt?
(1) Yes, the key is encrypted.
(2) This is not necessarily the private key used to sign other certificates.
(3) If they're lucky, this is a private key only used for their web server. OR, this key is an intermediate key. In which case they can invalidate it, create a new one, and reissue certificates for all the affected customers.
Re: Trusted certificate authority Certigna leaks its private key
#6Of course, "just revoke" doesn't actually work: serving a outdated certificate revocation list, or preventing a connection to the OCSP ("is this cert revoked?") server causes browsers to trust "revoked" certificates. Worse, lots of software doesn't even bother to do this check. This is why the browsers hardcoded a list of compromised certificates last time. This is even worse, though, because a lot of "real" certific…
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Re: Trusted certificate authority Certigna leaks its private key
#7I'm not terribly familiar with private key formats, but it appears to be encrypted (the `Proc-Type` and `DEK-Info` lines). Is the `localKeyID` the password used to encrypt?
(1) Yes, the key is encrypted. (2) This is not necessarily the private key used to sign other certificates. (3) If they're lucky, this is a private key only used for their web server. OR, this key is an intermediate key. In which case they can invalidate it, create a new one, and reissue certificates for all the affected customers.
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Re: Trusted certificate authority Certigna leaks its private key
#8I don't think this leak has included their own certificate authority key to allow you to generate your own key signed by the CA (which thinq claims), just the private key for the website, but it's certainly embarrassing for them.
They seem to have modified all the files in the directory overnight, and removed the offending www.certigna.fr files from http://www.certigna.fr/crl/ (unless the website has an archived directory that the thinq.co.uk writer was looking at)
Re: Trusted certificate authority Certigna leaks its private key
#9I'm not terribly familiar with private key formats, but it appears to be encrypted (the `Proc-Type` and `DEK-Info` lines). Is the `localKeyID` the password used to encrypt?
I'm not sure either. If it is encrypted, it would at least buy some time to replace all the certificates signed by this private key. Depending on the strength of the encryption key, obviously.
Just by looking at the PEM's number of lines you can tell it's a 1024 bit key.
Re: Trusted certificate authority Certigna leaks its private key
#10I don't think this leak has included their own certificate authority key to allow you to generate your own key signed by the CA (which thinq claims), just the private key for the website, but it's certainly embarrassing for them. They seem to have modified all the files in the directory overnight, and removed the offending www.certigna.fr files from http://www.certigna.fr/crl/ (unless the website has an archived dire…
Well, unfortunately there are also other .pem files in the list.