Key generation

[jevonearth]

This is a placeholder issue related to key generation.

As part of the CII Best Practices which this project is enrolled in, it provides the following requirements around key generation. I have set this to "N/A" in our projects checklist, but this should be updated after this issue has been implemented.

The security mechanisms within the software produced by the project MUST generate all cryptographic keys and nonces using a cryptographically secure random number generator, and MUST NOT do so using generators that are cryptographically insecure. [crypto_random]
A cryptographically secure random number generator may be a hardware random number generator, or it may be a cryptographically secure pseudo-random number generator (CSPRNG) using an algorithm such as Hash_DRBG, HMAC_DRBG, CTR_DRBG, Yarrow, or Fortuna. Examples of calls to secure random number generators include Java's java.security.SecureRandom and JavaScript's window.crypto.getRandomValues. Examples of calls to insecure random number generators include Java's java.util.Random and JavaScript's Math.random.