You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
321 lines
5.9 KiB
321 lines
5.9 KiB
package common
|
|
|
|
import (
|
|
crand "crypto/rand"
|
|
mrand "math/rand"
|
|
"sync"
|
|
"time"
|
|
)
|
|
|
|
const (
|
|
strChars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz" // 62 characters
|
|
)
|
|
|
|
// pseudo random number generator.
|
|
// seeded with OS randomness (crand)
|
|
|
|
type Rand struct {
|
|
sync.Mutex
|
|
rand *mrand.Rand
|
|
}
|
|
|
|
var grand *Rand
|
|
|
|
func init() {
|
|
grand = NewRand()
|
|
grand.init()
|
|
}
|
|
|
|
func NewRand() *Rand {
|
|
rand := &Rand{}
|
|
rand.init()
|
|
return rand
|
|
}
|
|
|
|
func (r *Rand) init() {
|
|
bz := cRandBytes(8)
|
|
var seed uint64
|
|
for i := 0; i < 8; i++ {
|
|
seed |= uint64(bz[i])
|
|
seed <<= 8
|
|
}
|
|
r.reset(int64(seed))
|
|
}
|
|
|
|
func (r *Rand) reset(seed int64) {
|
|
r.rand = mrand.New(mrand.NewSource(seed))
|
|
}
|
|
|
|
//----------------------------------------
|
|
// Global functions
|
|
|
|
func Seed(seed int64) {
|
|
grand.Seed(seed)
|
|
}
|
|
|
|
func RandStr(length int) string {
|
|
return grand.Str(length)
|
|
}
|
|
|
|
func RandUint16() uint16 {
|
|
return grand.Uint16()
|
|
}
|
|
|
|
func RandUint32() uint32 {
|
|
return grand.Uint32()
|
|
}
|
|
|
|
func RandUint64() uint64 {
|
|
return grand.Uint64()
|
|
}
|
|
|
|
func RandUint() uint {
|
|
return grand.Uint()
|
|
}
|
|
|
|
func RandInt16() int16 {
|
|
return grand.Int16()
|
|
}
|
|
|
|
func RandInt32() int32 {
|
|
return grand.Int32()
|
|
}
|
|
|
|
func RandInt64() int64 {
|
|
return grand.Int64()
|
|
}
|
|
|
|
func RandInt() int {
|
|
return grand.Int()
|
|
}
|
|
|
|
func RandInt31() int32 {
|
|
return grand.Int31()
|
|
}
|
|
|
|
func RandInt63() int64 {
|
|
return grand.Int63()
|
|
}
|
|
|
|
func RandUint16Exp() uint16 {
|
|
return grand.Uint16Exp()
|
|
}
|
|
|
|
func RandUint32Exp() uint32 {
|
|
return grand.Uint32Exp()
|
|
}
|
|
|
|
func RandUint64Exp() uint64 {
|
|
return grand.Uint64Exp()
|
|
}
|
|
|
|
func RandFloat32() float32 {
|
|
return grand.Float32()
|
|
}
|
|
|
|
func RandTime() time.Time {
|
|
return grand.Time()
|
|
}
|
|
|
|
func RandBytes(n int) []byte {
|
|
return grand.Bytes(n)
|
|
}
|
|
|
|
func RandIntn(n int) int {
|
|
return grand.Intn(n)
|
|
}
|
|
|
|
func RandPerm(n int) []int {
|
|
return grand.Perm(n)
|
|
}
|
|
|
|
//----------------------------------------
|
|
// Rand methods
|
|
|
|
func (r *Rand) Seed(seed int64) {
|
|
r.Lock()
|
|
r.reset(seed)
|
|
r.Unlock()
|
|
}
|
|
|
|
// Constructs an alphanumeric string of given length.
|
|
// It is not safe for cryptographic usage.
|
|
func (r *Rand) Str(length int) string {
|
|
chars := []byte{}
|
|
MAIN_LOOP:
|
|
for {
|
|
val := r.Int63()
|
|
for i := 0; i < 10; i++ {
|
|
v := int(val & 0x3f) // rightmost 6 bits
|
|
if v >= 62 { // only 62 characters in strChars
|
|
val >>= 6
|
|
continue
|
|
} else {
|
|
chars = append(chars, strChars[v])
|
|
if len(chars) == length {
|
|
break MAIN_LOOP
|
|
}
|
|
val >>= 6
|
|
}
|
|
}
|
|
}
|
|
|
|
return string(chars)
|
|
}
|
|
|
|
// It is not safe for cryptographic usage.
|
|
func (r *Rand) Uint16() uint16 {
|
|
return uint16(r.rand.Uint32() & (1<<16 - 1))
|
|
}
|
|
|
|
// It is not safe for cryptographic usage.
|
|
func (r *Rand) Uint32() uint32 {
|
|
r.Lock()
|
|
u32 := r.rand.Uint32()
|
|
r.Unlock()
|
|
return u32
|
|
}
|
|
|
|
// It is not safe for cryptographic usage.
|
|
func (r *Rand) Uint64() uint64 {
|
|
return uint64(r.rand.Uint32())<<32 + uint64(r.rand.Uint32())
|
|
}
|
|
|
|
// It is not safe for cryptographic usage.
|
|
func (r *Rand) Uint() uint {
|
|
r.Lock()
|
|
i := r.rand.Int()
|
|
r.Unlock()
|
|
return uint(i)
|
|
}
|
|
|
|
// It is not safe for cryptographic usage.
|
|
func (r *Rand) Int16() int16 {
|
|
return int16(r.rand.Uint32() & (1<<16 - 1))
|
|
}
|
|
|
|
// It is not safe for cryptographic usage.
|
|
func (r *Rand) Int32() int32 {
|
|
return int32(r.rand.Uint32())
|
|
}
|
|
|
|
// It is not safe for cryptographic usage.
|
|
func (r *Rand) Int64() int64 {
|
|
return int64(r.rand.Uint64())
|
|
}
|
|
|
|
// It is not safe for cryptographic usage.
|
|
func (r *Rand) Int() int {
|
|
r.Lock()
|
|
i := r.rand.Int()
|
|
r.Unlock()
|
|
return i
|
|
}
|
|
|
|
// It is not safe for cryptographic usage.
|
|
func (r *Rand) Int31() int32 {
|
|
r.Lock()
|
|
i31 := r.rand.Int31()
|
|
r.Unlock()
|
|
return i31
|
|
}
|
|
|
|
// It is not safe for cryptographic usage.
|
|
func (r *Rand) Int63() int64 {
|
|
r.Lock()
|
|
i63 := r.rand.Int63()
|
|
r.Unlock()
|
|
return i63
|
|
}
|
|
|
|
// Distributed pseudo-exponentially to test for various cases
|
|
// It is not safe for cryptographic usage.
|
|
func (r *Rand) Uint16Exp() uint16 {
|
|
bits := r.rand.Uint32() % 16
|
|
if bits == 0 {
|
|
return 0
|
|
}
|
|
n := uint16(1 << (bits - 1))
|
|
n += uint16(r.rand.Int31()) & ((1 << (bits - 1)) - 1)
|
|
return n
|
|
}
|
|
|
|
// Distributed pseudo-exponentially to test for various cases
|
|
// It is not safe for cryptographic usage.
|
|
func (r *Rand) Uint32Exp() uint32 {
|
|
bits := r.rand.Uint32() % 32
|
|
if bits == 0 {
|
|
return 0
|
|
}
|
|
n := uint32(1 << (bits - 1))
|
|
n += uint32(r.rand.Int31()) & ((1 << (bits - 1)) - 1)
|
|
return n
|
|
}
|
|
|
|
// Distributed pseudo-exponentially to test for various cases
|
|
// It is not safe for cryptographic usage.
|
|
func (r *Rand) Uint64Exp() uint64 {
|
|
bits := r.rand.Uint32() % 64
|
|
if bits == 0 {
|
|
return 0
|
|
}
|
|
n := uint64(1 << (bits - 1))
|
|
n += uint64(r.rand.Int63()) & ((1 << (bits - 1)) - 1)
|
|
return n
|
|
}
|
|
|
|
// It is not safe for cryptographic usage.
|
|
func (r *Rand) Float32() float32 {
|
|
r.Lock()
|
|
f32 := r.rand.Float32()
|
|
r.Unlock()
|
|
return f32
|
|
}
|
|
|
|
// It is not safe for cryptographic usage.
|
|
func (r *Rand) Time() time.Time {
|
|
return time.Unix(int64(r.Uint64Exp()), 0)
|
|
}
|
|
|
|
// RandBytes returns n random bytes from the OS's source of entropy ie. via crypto/rand.
|
|
// It is not safe for cryptographic usage.
|
|
func (r *Rand) Bytes(n int) []byte {
|
|
// cRandBytes isn't guaranteed to be fast so instead
|
|
// use random bytes generated from the internal PRNG
|
|
bs := make([]byte, n)
|
|
for i := 0; i < len(bs); i++ {
|
|
bs[i] = byte(r.rand.Int() & 0xFF)
|
|
}
|
|
return bs
|
|
}
|
|
|
|
// RandIntn returns, as an int, a non-negative pseudo-random number in [0, n).
|
|
// It panics if n <= 0.
|
|
// It is not safe for cryptographic usage.
|
|
func (r *Rand) Intn(n int) int {
|
|
r.Lock()
|
|
i := r.rand.Intn(n)
|
|
r.Unlock()
|
|
return i
|
|
}
|
|
|
|
// RandPerm returns a pseudo-random permutation of n integers in [0, n).
|
|
// It is not safe for cryptographic usage.
|
|
func (r *Rand) Perm(n int) []int {
|
|
r.Lock()
|
|
perm := r.rand.Perm(n)
|
|
r.Unlock()
|
|
return perm
|
|
}
|
|
|
|
// NOTE: This relies on the os's random number generator.
|
|
// For real security, we should salt that with some seed.
|
|
// See github.com/tendermint/go-crypto for a more secure reader.
|
|
func cRandBytes(numBytes int) []byte {
|
|
b := make([]byte, numBytes)
|
|
_, err := crand.Read(b)
|
|
if err != nil {
|
|
PanicCrisis(err)
|
|
}
|
|
return b
|
|
}
|