60 lines
1.7 KiB
Go
60 lines
1.7 KiB
Go
package security
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import (
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cryptoRand "crypto/rand"
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"math/big"
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mathRand "math/rand" // @todo replace with rand/v2?
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)
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const defaultRandomAlphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
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// RandomString generates a cryptographically random string with the specified length.
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//
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// The generated string matches [A-Za-z0-9]+ and it's transparent to URL-encoding.
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func RandomString(length int) string {
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return RandomStringWithAlphabet(length, defaultRandomAlphabet)
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}
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// RandomStringWithAlphabet generates a cryptographically random string
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// with the specified length and characters set.
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//
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// It panics if for some reason rand.Int returns a non-nil error.
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func RandomStringWithAlphabet(length int, alphabet string) string {
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b := make([]byte, length)
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max := big.NewInt(int64(len(alphabet)))
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for i := range b {
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n, err := cryptoRand.Int(cryptoRand.Reader, max)
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if err != nil {
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panic(err)
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}
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b[i] = alphabet[n.Int64()]
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}
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return string(b)
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}
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// PseudorandomString generates a pseudorandom string with the specified length.
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//
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// The generated string matches [A-Za-z0-9]+ and it's transparent to URL-encoding.
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//
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// For a cryptographically random string (but a little bit slower) use RandomString instead.
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func PseudorandomString(length int) string {
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return PseudorandomStringWithAlphabet(length, defaultRandomAlphabet)
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}
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// PseudorandomStringWithAlphabet generates a pseudorandom string
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// with the specified length and characters set.
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//
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// For a cryptographically random (but a little bit slower) use RandomStringWithAlphabet instead.
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func PseudorandomStringWithAlphabet(length int, alphabet string) string {
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b := make([]byte, length)
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max := len(alphabet)
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for i := range b {
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b[i] = alphabet[mathRand.Intn(max)]
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}
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return string(b)
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}
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