49 lines
1 KiB
Go
49 lines
1 KiB
Go
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package types
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import (
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"crypto/md5"
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"crypto/rand"
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"fmt"
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"io"
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"strings"
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)
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// standard characters allowed in token string.
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var chars = []byte("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789")
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// default token length
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var length = 40
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// GenerateToken generates random strings good for use in URIs to
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// identify unique objects.
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func GenerateToken() string {
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b := make([]byte, length)
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r := make([]byte, length+(length/4)) // storage for random bytes.
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clen := byte(len(chars))
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maxrb := byte(256 - (256 % len(chars)))
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i := 0
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for {
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io.ReadFull(rand.Reader, r)
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for _, c := range r {
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if c >= maxrb {
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// Skip this number to avoid modulo bias.
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continue
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}
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b[i] = chars[c%clen]
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i++
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if i == length {
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return string(b)
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}
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}
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}
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}
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// helper function to create a Gravatar Hash
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// for the given Email address.
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func CreateGravatar(email string) string {
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email = strings.ToLower(strings.TrimSpace(email))
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hash := md5.New()
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hash.Write([]byte(email))
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return fmt.Sprintf("%x", hash.Sum(nil))
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}
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