Don’t Use Low-Level Crypto Libraries

Hopefully, we’re now in agreement that we shouldn’t roll our own crypto. It might seem that all we need to do is grab a low-level encryption library and start using it’s AES encryption and decryption functions. After all, that’s not “rolling our own crypto.”

Low-level libraries are easy to misconfigure

As we’ll see in this lesson that low-level encryption libraries present a lot of configuration choices that are easy to misuse.

For example, many low-level cryptography libraries provide support for outdated algorithms like MD5 and 3DES. And oftentimes comparisons of libraries such as Wikipedia’s show supported algorithms in a way makes it seem as though libraries with support for more algorithms are fuller featured.

Low-level libraries don’t provide guidance; instead, they force the developer to know which algorithms are safe to use. Even if the developer knows to choose a strong encryption algorithm like AES, low-level cryptography libraries still provide dangerous configuration choices. These choices include things like block mode and key size. Getting these choices wrong can result in a system that’s insecure. In contrast, a high-level encryption library is opinionated and makes these configuration choices for the developer. This makes a high-level encryption library ...