> OpenSSL decided to use a “512 bit long modulus”, the default. We’re told: “don’t roll your own crypto; instead trust standard tools like OpenSSL”. The modulus

> OpenSSL decided to use a “512 bit long modulus”, the default. We’re told: “don’t roll your own crypto; instead trust standard tools like OpenSSL”. The modulus length is a good example of why: a wrong value results in a trivially breakable key, and you the user shouldn’t need to know what the right value is. So OpenSSL chooses a sensible modulus length for you. Checking the OpenBSD man page for the LibreSSL genrsa, it does seem to generate 2048-bit RSA keys by default[1]. Perhaps Apple just stuck with an older default (for backwards compat) or perhaps this wasn't changed yet in the old version of LibreSSL that Apple uses? [1] https://man.openbsd.org/openssl#GENRSA https://man.openbsd.org/openssl#GENRSA