76 lines
2.5 KiB
Go
76 lines
2.5 KiB
Go
// This file has code copied from the "randstr" Go module, which can be found at
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// https://github.com/thanhpk/randsr. The original code is licensed under the MIT
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// license, which a copy can be found at https://github.com/thanhpk/randstr/blob/master/LICENSE
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// and is provided below:
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//
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// # The MIT License
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//
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// Copyright (c) 2010-2018 Google, Inc. http://angularjs.org
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//
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// Permission is hereby granted, free of charge, to any person obtaining a copy
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// of this software and associated documentation files (the "Software"), to deal
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// in the Software without restriction, including without limitation the rights
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// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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// copies of the Software, and to permit persons to whom the Software is
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// furnished to do so, subject to the following conditions:
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//
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// The above copyright notice and this permission notice shall be included in
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// all copies or substantial portions of the Software.
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//
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// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
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// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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// THE SOFTWARE.
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// Package randstr provides basic functions for generating random bytes, string
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package randstr
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import (
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"bytes"
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"crypto/rand"
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"encoding/binary"
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)
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// HexChars holds a string containing all characters used in a hexadecimal value.
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const HexChars = "0123456789abcdef"
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// NewHex generates a new Hexadecimal string with length of n
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//
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// Example: 67aab2d956bd7cc621af22cfb169cba8
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func NewHex(n int) (string, error) { return New(n, HexChars) }
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// New generates a random string using only letters provided in the letters parameter.
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//
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// If the letters parameter is omitted, this function will use HexChars instead.
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func New(n int, chars ...string) (string, error) {
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runes := []rune(HexChars)
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if len(chars) > 0 {
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runes = []rune(chars[0])
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}
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var b bytes.Buffer
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b.Grow(n)
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l := uint32(len(runes))
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for range n {
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by, err := Bytes(4)
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if err != nil {
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return "", err
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}
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b.WriteRune(runes[binary.BigEndian.Uint32(by)%l])
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}
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return b.String(), nil
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}
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// Bytes generates n random bytes
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func Bytes(n int) ([]byte, error) {
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b := make([]byte, n)
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_, err := rand.Read(b)
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if err != nil {
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return []byte{}, err
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}
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return b, nil
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}
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