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