Is the KDF pbkdf2 included in the openssl suite? I'm trying to encrypt a file using DES in CBC mode but when I try to specify the key derivation function it tells me my command is wrong. It only fails when I try specify the KDF and works when I don't. This is the command i'm trying to use - openssl enc -des-cbc -pbkdf2 -in test.txt -out test.bin -pass pass:test

This command is taken directly from my reference so why does it not pick up the KDF? Is it because i'm using the wrong version of openssl (LibreSSL 2.6.4) or do I have to manually add pbkdf2? If so how do I?
LibreSSL enc docs: https://man.openbsd.org/openssl.1#ENC

OpenSSL enc docs for version 1.1.1 : https://www.openssl.org/docs/man1.1.1/man1/enc.html

Both support pbkdf2. I am kinda surprised LibreSSL still supports DES, I would not support it. Can you paste the exact error you're getting?

Edit:

The changelog of libressl says pbkdf2 support was added in version 2.9.1 (latest current version).

Comparing the openssl 1.1.1 man page above with the openssl 1.1.0 enc man page, I see pbkdf2 support was added in version 1.1.1 (latest current stable version).

You're trying to use a very new feature.