feat: crypto nonce randomness

[krpeacock]

Description

Currently default nonce generation is using Math.random, a pseudorandom source of randomness. We can take advantage of better tools when they are available

Fixes SDK-1194

How Has This Been Tested?

Updated and new unit tests

Checklist:

• My changes follow the guidelines in CONTRIBUTING.md.
• The title of this PR complies with Conventional Commits.
• I have edited the CHANGELOG accordingly.
• I have made corresponding changes to the documentation.

[krpeacock]

I was aiming initially to reproduce the behavior of Math.random, but I agree that yielding a random integer is preferable. I'll simplify, using your recommendations

[ericswanson-dfinity]

Could you write some rationale here for why we are not requiring some well-established crypto library and always using it here?

import { randomBytes } from 'crypto';

export const randomNumber = (): number => {
  return randomBytes(4).readUInt32BE(0);
};

[krpeacock]

There are two goals we are satisfying we are taking this approach.

1. In the interest of keeping package size small, we try to avoid introducing new dependencies, particularly in the @dfinity/agent package.

2. The native Node.js and Browser crypto libraries are well-established in their own ecosystem. While this approach does require us to inspect the global context to determine which tool is available, it does mean that we can tap into more powerful randomness APIs than are available in any pure JavaScript implementation

See documentation below:

• Node crypto https://nodejs.org/api/crypto.html
• Browser https://developer.mozilla.org/en-US/docs/Web/API/Web_Crypto_API

[ericswanson-dfinity]

Thanks!

[krpeacock]

neither API is universally available (webcrypto is available in some but not all versions of Node we support), so using whichever we can detect is a compromise

[github-actions]

size-limit report 📦

Path	Size
@dfinity/agent	89.2 KB (+0.09% 🔺)
@dfinity/candid	15.48 KB (0%)
@dfinity/principal	6.77 KB (0%)
@dfinity/auth-client	94.89 KB (0%)
@dfinity/assets	91.7 KB (0%)
@dfinity/identity	91.96 KB (0%)
@dfinity/identity-secp256k1	230.53 KB (+0.05% 🔺)