Hello S-1-1-0, Crypt32 is on air! Today I want to explain how ADCS Certification Authority processes extensions from incoming requests and certificate templates. Every X.509 V3 certificate contains certificate extensions to include extra information about certificate owner, issuer, intended usages, limitations/constraints. CA utilize multiple sources to generate extension list to be included in signed certificate,…

Read More

The Name Constraints extension indicates to the relying party what namespaces are acceptable for the various hierarchical name forms such as DN, DNS names, URL, IP address, RFC 822 names, UPN, etc.  The extension is only valid for a CA certificate.  There are two components for this as defined in https://tools.ietf.org/html/rfc5280#section-4.2.1.10 as: Permitted Subtree(s):  This…

Read More

Hello S-1-1-0, @Crypt32 is again on a failboatboard with new blog post. Today I will share information about a little-known portion in configuration of Microsoft ADCS Certification Authority – serial number generation algorithm. This article assumes big-endian encoding Certificate serial number requirements Every X.509 conforming CA generates a unique serial number for each issued certificate,…

Read More

Hello everyone, I’m back again and today I want to share some thoughts on retrieving massive results from ADCS Certification Authority database. Point of interest As a part of my ongoing project I had to collect database statistics (simply, number of revoked, issued, pending, failed, denied requests) and my concern was query performance on relatively…

Read More