44 lines
922 B
Go
44 lines
922 B
Go
package jess
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import (
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"crypto/rand"
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"io"
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"github.com/tevino/abool"
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)
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var (
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customRandReader io.Reader
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customRandReaderFlag = abool.NewBool(false)
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)
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// Random returns the io.Reader for reading randomness. By default, it uses crypto/rand.Reader.
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func Random() io.Reader {
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if customRandReaderFlag.IsSet() {
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return customRandReader
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}
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return rand.Reader
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}
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// RandomBytes returns the specified amount of random bytes in a []byte slice. By default, it uses crypto/rand.Reader.
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func RandomBytes(n int) ([]byte, error) {
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rBytes := make([]byte, n)
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bytesRead, err := Random().Read(rBytes)
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if err != nil {
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return nil, err
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}
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if bytesRead != n {
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return nil, ErrInsufficientRandom
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}
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return rBytes, nil
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}
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// SetCustomRNG sets a custom RNG to be used with jess.
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func SetCustomRNG(randReader io.Reader) {
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if !customRandReaderFlag.IsSet() {
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customRandReader = randReader
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customRandReaderFlag.Set()
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}
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}
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