The OpenSSL library and CLI is a complete set of tools to work with SSL (and TLS) objects. It is an open source project and is widely used by companies all around. As one would expect, Rust has bindings for using as a library in Rust projects. In this discussion, we will take a closer look at the certificates we saw in the last section.
These are commonly defined by a standard called X.509 (defined in RFC 5280) and have the following fields:
- Version number: Almost always set to 2, corresponding to version 3 (since the first version is 0). According to the standard, this field can be omitted and should be assumed to be version 1 (value set to 0).
- Serial number: A 20 octet identifier that is unique for the CA which signed ...