Mercurial > gemma

annotate pkg/common/random.go @ 414:c1047fd04a3a

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Moved project specific Go packages to new pkg folder.
author Sascha L. Teichmann <sascha.teichmann@intevation.de>
date Wed, 15 Aug 2018 17:30:50 +0200
parents common/random.go@ac23905e64b1
children a244b18cb916
Ignore whitespace changes - Everywhere: Within whitespace: At end of lines:
rev   line source
408
ac23905e64b1 Improve WFS proxy a lot. It now generates signed re-writings.
Sascha L. Teichmann <sascha.teichmann@intevation.de>
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1 package common
339
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2
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3 import (
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4 "bytes"
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5 "crypto/rand"
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6 "io"
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7 "log"
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8 "math/big"
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9 )
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10
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11 func GenerateRandomKey(length int) []byte {
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12 k := make([]byte, length)
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13 if _, err := io.ReadFull(rand.Reader, k); err != nil {
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14 return nil
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15 }
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16 return k
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17 }
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18
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19 func RandomString(n int) string {
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20
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21 const (
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22 special = "!\"#$%&'()*+,-./:;<=>?@[\\]^_`{|}~"
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23 alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZ" +
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24 "abcdefghijklmnopqrstuvwxyz" +
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25 "0123456789" +
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26 special
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27 )
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28
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29 max := big.NewInt(int64(len(alphabet)))
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30 out := make([]byte, n)
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31
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32 for i := 0; i < 1000; i++ {
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33 for i := range out {
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34 v, err := rand.Int(rand.Reader, max)
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35 if err != nil {
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36 log.Panicf("error: %v\n", err)
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37 }
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38 out[i] = alphabet[v.Int64()]
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39 }
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40 // Ensure at least one special char.
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41 if bytes.IndexAny(out, special) >= 0 {
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42 return string(out)
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43 }
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44 }
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45 log.Println("warn: Your random generator may be broken.")
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46 out[0] = special[0]
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47 return string(out)
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48 }