v/vlib/crypto/README.md

## Description:

`crypto` is a module that exposes cryptographic algorithms to V programs.

Each submodule implements things differently, so be sure to consider the documentation
of the specific algorithm you need, but in general, the method is to create a `cipher`
struct using one of the module functions, and then to call the `encrypt` or `decrypt`
method on that struct to actually encrypt or decrypt your data.

This module is a work-in-progress. For example, the AES implementation currently requires you
to create a destination buffer of the correct size to receive the decrypted data, and the AesCipher
`encrypt` and `decrypt` functions only operate on the first block of the `src`.

The implementations here are loosely based on [Go's crypto package](https://pkg.go.dev/crypto).

## Examples:

```v
import crypto.aes
import crypto.rand

fn main() {
	// remember to save this key somewhere if you ever want to decrypt your data
	key := rand.bytes(32) ?
	println('KEY: $key')

	// this data is one block (16 bytes) big
	mut data := 'THIS IS THE DATA'.bytes()

	println('generating cipher')
	cipher := aes.new_cipher(key)

	println('performing encryption')
	mut encrypted := []u8{len: aes.block_size}
	cipher.encrypt(mut encrypted, data)
	println(encrypted)

	println('performing decryption')
	mut decrypted := []u8{len: aes.block_size}
	cipher.decrypt(mut decrypted, encrypted)
	println(decrypted)

	assert decrypted == data
}
```