Comment by ggm

OpenSSL is a very odd codebase, it's grown by accretion, under many stewards, with several flavours of coding belief, over time from SSLEAY which Eric Young coded over 2 decades ago. It had chip-specific speedups from the days of the Intel 486.

I was part of a body which funded work to include some stuff in the code, and the way you take something like X509 and incorperate a new ASN.1 structure inside the code, to be validated against conformance requirements (so not just signing blindly over the bitstream, but understanding the ASN.1 and validating it has certain properties about what it says, like not overlapping assertions of numeric ranges encoded in it) is to invoke callouts from deep down, to perform tasks and then return state. You basically seem to have to do about a 5 layer deep callout and return. It's a massive wedding cake of dependency on itself, it personifies the xkcd diagram of "...depends on <small thing>" risks.

I'm not surprised people continue to find flaws. I would like to understand if this approach also found flaws in e.g. libsodium or other more modern crytography, or in the OpenBSD maintained libreSSL code (or whatever it is) or Peter Gutmann's code.

OpenSSL is a large target.