frp/vendor/github.com/fatedier/beego/utils/rand.go
2017-11-01 16:21:57 +08:00

45 lines
1.2 KiB
Go

// Copyright 2014 beego Author. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package utils
import (
"crypto/rand"
r "math/rand"
"time"
)
var alphaNum = []byte(`0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz`)
// RandomCreateBytes generate random []byte by specify chars.
func RandomCreateBytes(n int, alphabets ...byte) []byte {
if len(alphabets) == 0 {
alphabets = alphaNum
}
var bytes = make([]byte, n)
var randBy bool
if num, err := rand.Read(bytes); num != n || err != nil {
r.Seed(time.Now().UnixNano())
randBy = true
}
for i, b := range bytes {
if randBy {
bytes[i] = alphabets[r.Intn(len(alphabets))]
} else {
bytes[i] = alphabets[b%byte(len(alphabets))]
}
}
return bytes
}