50 lines
1.2 KiB
Go
50 lines
1.2 KiB
Go
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package utils
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import (
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"fmt"
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"hash/crc32"
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rand2 "math/rand"
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"time"
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"github.com/google/uuid"
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)
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func GenUUID() string {
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uuidHash := crc32.ChecksumIEEE([]byte(uuid.New().String()))
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return fmt.Sprint(uuidHash)
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}
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func RandomNum() string {
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//n, _ := rand.Int(rand.Reader, big.NewInt(100000000))
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//return n.String()
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return fmt.Sprintf("%08v", rand2.New(rand2.NewSource(time.Now().UnixNano())).Int31n(100000000))
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}
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const letterBytes = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
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const (
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letterIdxBits = 6 // 6 bits to represent a letter index
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letterIdxMask = 1<<letterIdxBits - 1 // All 1-bits, as many as letterIdxBits
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letterIdxMax = 63 / letterIdxBits // # of letter indices fitting in 63 bits
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)
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func GenerateDeviceSecret(n int) string {
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b := make([]byte, n)
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// A rand.Int63() generates 63 random bits, enough for letterIdxMax letters!
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for i, cache, remain := n-1, rand2.Int63(), letterIdxMax; i >= 0; {
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if remain == 0 {
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cache, remain = rand2.Int63(), letterIdxMax
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}
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if idx := int(cache & letterIdxMask); idx < len(letterBytes) {
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b[i] = letterBytes[idx]
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i--
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}
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cache >>= letterIdxBits
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remain--
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}
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return string(b)
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}
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func GenerateSaltKey() string {
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return uuid.New().String()
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}
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