rng

Documentation

Overview

Package rng provides a feedable CSPRNG.

CSPRNG used is fortuna: github.com/seehuhn/fortuna By default the CSPRNG is fed by two sources: - It starts with a seed from `crypto/rand` and periodically reseeds from there - A really simple tickfeeder which extracts entropy from the internal go scheduler using goroutines and is meant to be used under load.

The RNG can also be easily fed with additional sources.

Index

• Variables
• func Bytes(n int) ([]byte, error)
• func Number(max uint64) (uint64, error)
• func Read(b []byte) (n int, err error)
• type Feeder
  • func NewFeeder() *Feeder
  • func (f *Feeder) CloseFeeder()
  • func (f *Feeder) NeedsEntropy() bool
  • func (f *Feeder) SupplyEntropy(data []byte, entropy int)
  • func (f *Feeder) SupplyEntropyAsInt(n int64, entropy int)
  • func (f *Feeder) SupplyEntropyAsIntIfNeeded(n int64, entropy int)
  • func (f *Feeder) SupplyEntropyIfNeeded(data []byte, entropy int)

Variables

var (
	// Reader provides a global instance to read from the RNG.
	Reader io.Reader
)

Functions

func Bytes

func Bytes(n int) ([]byte, error)

Bytes allocates a new byte slice of given length and fills it with random data.

func Number

func Number(max uint64) (uint64, error)

Number returns a random number from 0 to (incl.) max.

func Read

func Read(b []byte) (n int, err error)

Read reads random bytes into the supplied byte slice.

Types

type Feeder

type Feeder struct {
	// contains filtered or unexported fields
}

The Feeder is used to feed entropy to the RNG.

func NewFeeder

func NewFeeder() *Feeder

NewFeeder returns a new entropy Feeder.

func (*Feeder) CloseFeeder

func (f *Feeder) CloseFeeder()

CloseFeeder stops the feed processing - the responsible goroutine exits. The input channel is closed and the feeder may not be used anymore in any way.

func (*Feeder) NeedsEntropy

func (f *Feeder) NeedsEntropy() bool

NeedsEntropy returns whether the feeder is currently gathering entropy.

func (*Feeder) SupplyEntropy

func (f *Feeder) SupplyEntropy(data []byte, entropy int)

SupplyEntropy supplies entropy to to the Feeder, it will block until the Feeder has read from it.

func (*Feeder) SupplyEntropyAsInt

func (f *Feeder) SupplyEntropyAsInt(n int64, entropy int)

SupplyEntropyAsInt supplies entropy to to the Feeder, it will block until the Feeder has read from it.

func (*Feeder) SupplyEntropyAsIntIfNeeded

func (f *Feeder) SupplyEntropyAsIntIfNeeded(n int64, entropy int)

SupplyEntropyAsIntIfNeeded supplies entropy to to the Feeder, but will not block if no entropy is currently needed.

func (*Feeder) SupplyEntropyIfNeeded

func (f *Feeder) SupplyEntropyIfNeeded(data []byte, entropy int)

SupplyEntropyIfNeeded supplies entropy to to the Feeder, but will not block if no entropy is currently needed.