terraform/vendor/github.com/sean-/seed/README.md

45 lines
1.5 KiB
Markdown
Raw Normal View History

# `seed` - Quickly Seed Go's Random Number Generator
Boiler-plate to securely [seed](https://en.wikipedia.org/wiki/Random_seed) Go's
random number generator (if possible). This library isn't anything fancy, it's
just a canonical way of seeding Go's random number generator. Cribbed from
[`Nomad`](https://github.com/hashicorp/nomad/commit/f89a993ec6b91636a3384dd568898245fbc273a1)
before it was moved into
[`Consul`](https://github.com/hashicorp/consul/commit/d695bcaae6e31ee307c11fdf55bb0bf46ea9fcf4)
and made into a helper function, and now further modularized to be a super
lightweight and reusable library.
Time is better than
[Go's default seed of `1`](https://golang.org/pkg/math/rand/#Seed), but friends
don't let friends use time as a seed to a random number generator. Use
`seed.MustInit()` instead.
`seed.Init()` is an idempotent and reentrant call that will return an error if
it can't seed the value the first time it is called. `Init()` is reentrant.
`seed.MustInit()` is idempotent and reentrant call that will `panic()` if it
can't seed the value the first time it is called. `MustInit()` is reentrant.
## Usage
```
package mypackage
import (
"github.com/sean-/seed"
)
// MustInit will panic() if it is unable to set a high-entropy random seed:
func init() {
seed.MustInit()
}
// Or if you want to not panic() and can actually handle this error:
func init() {
if secure, err := !seed.Init(); !secure {
// Handle the error
//panic(fmt.Sprintf("Unable to securely seed Go's RNG: %v", err))
}
}
```