1package mox

2

3import (

4 cryptorand "crypto/rand"

5 "encoding/binary"

6 mathrand2 "math/rand/v2"

7 "sync"

8)

9

10type rand struct {

11 rand *mathrand2.Rand

12 sync.Mutex

13}

14

15// NewPseudoRand returns a new PRNG seeded with random bytes from crypto/rand. Its

16// functions can be called concurrently.

17func NewPseudoRand() *rand {

18 var seed [32]byte

19 cryptorand.Read(seed[:])

20 return &rand{rand: mathrand2.New(mathrand2.NewChaCha8(seed))}

21}

22

23func (r *rand) Float64() float64 {

24 r.Lock()

25 defer r.Unlock()

26 return r.rand.Float64()

27}

28

29func (r *rand) IntN(n int) int {

30 r.Lock()

31 defer r.Unlock()

32 return r.rand.IntN(n)

33}

34

35// CryptoRandInt returns a cryptographically random number.

36func CryptoRandInt() int64 {

37 var buf [8]byte

38 cryptorand.Read(buf[:])

39 return int64(binary.LittleEndian.Uint64(buf[:]))

40}

41