Bugtraq mailing list archives
Re: Windows doesn't verify digital signature of CRL files
From: "Neil Gierman" <ngierman () roadrunn com>
Date: Tue, 10 Aug 2004 11:07:47 -0500 (CDT)
Correct me if I am wrong but I understood that certificate validation was processed by the information in the certificate to be validated (CDP or AIA extension). If the CDP location contains a valid CRL URL and that CA's CRL is not already in cache, then the CRL is retreived from that CDP URL in the certificate. If a person was able to inject a modified CRL into that CDP URL, or redirect the client machine to an alternate server for LDAP/HTTP CRL download, and CAPI is not validating signatures on CRL's then a person could use a revoked certificate for access to systems among other things. While this may not be a bug I think it would be a wise security practice to validate a signature if it is there. Neil
* Faro Poplar wrote:Has anyone noticed that Windows doesn't verify the digital signature of CRL files (*.crl).Yes, I noticed that about 2 years ago. IMO this is no security issue. CRLs are retrieved from the certificate store via CertGetCRLFromStore. Sane use of CertGetCRLFromStore makes sure only properly signed CRLs are used (http://msdn.microsoft.com/library/default.asp?url=/library/en-us/ seccrypto/security/certverifycrlrevocation.asp). Thomas Walpuski
Current thread:
- Windows doesn't verify digital signature of CRL files Faro Poplar (Aug 09)
- Re: Windows doesn't verify digital signature of CRL files Thomas Walpuski (Aug 10)
- Re: Windows doesn't verify digital signature of CRL files Neil Gierman (Aug 10)
- Re: Windows doesn't verify digital signature of CRL files Jack Lloyd (Aug 10)
- Re: Windows doesn't verify digital signature of CRL files Thomas Walpuski (Aug 11)
- Re: Windows doesn't verify digital signature of CRL files Thomas Walpuski (Aug 10)
- Re: Windows doesn't verify digital signature of CRL files Neil Gierman (Aug 10)
- Re: Windows doesn't verify digital signature of CRL files Valdis . Kletnieks (Aug 10)
- Re: Windows doesn't verify digital signature of CRL files Thomas Walpuski (Aug 10)
- <Possible follow-ups>
- Windows doesn't verify digital signature of CRL files Michael Howard (Aug 11)