On 15/09/2020 22:48, Sage Gerard wrote: > I have a Racket program that uses libcrypto through FFI bindings to > compute digests. It's wrong because it returns different answers than > `openssl dgst`,regardless of hash algorithm. > > The code is here: > https://github.com/zyrolasting/xiden/blob/libcrypto/openssl.rkt#L76 > It is based on the example in: > https://wiki.openssl.org/index.php/EVP_Message_Digests. > > I'm not expecting anyone to run this program or review Racket code in > detail. The links are just there for context. I just want to know if > there are common C-level mistakes libcrypto users make that would make > their digests disagree with the CLI. As far as I can tell, I replicated > the example on wiki.openssl.org well enough to deterministically compute > a digest with any byte string. > > Let me know if there is any other context I can provide. Common "rookie" errors that spring to mind are: 1) Use strlen on binary data and end up passing the wrong length of data to the functions. 2) Include carriage return/line feed in the input data in one context but not in another. Matt
