mirror of
https://github.com/ergochat/ergo.git
synced 2024-12-28 13:42:35 +01:00
36 lines
1.1 KiB
Go
36 lines
1.1 KiB
Go
// Copyright (c) 2018 Shivaram Lingamneni <slingamn@cs.stanford.edu>
|
|
// released under the MIT license
|
|
|
|
package utils
|
|
|
|
import (
|
|
"crypto/rand"
|
|
"crypto/subtle"
|
|
"encoding/base32"
|
|
)
|
|
|
|
var (
|
|
// standard b32 alphabet, but in lowercase for silly aesthetic reasons
|
|
b32encoder = base32.NewEncoding("abcdefghijklmnopqrstuvwxyz234567").WithPadding(base32.NoPadding)
|
|
)
|
|
|
|
// generate a secret token that cannot be brute-forced via online attacks
|
|
func GenerateSecretToken() string {
|
|
// 128 bits of entropy are enough to resist any online attack:
|
|
var buf [16]byte
|
|
rand.Read(buf[:])
|
|
// 26 ASCII characters, should be fine for most purposes
|
|
return b32encoder.EncodeToString(buf[:])
|
|
}
|
|
|
|
// securely check if a supplied token matches a stored token
|
|
func SecretTokensMatch(storedToken string, suppliedToken string) bool {
|
|
// XXX fix a potential gotcha: if the stored token is uninitialized,
|
|
// then nothing should match it, not even supplying an empty token.
|
|
if len(storedToken) == 0 {
|
|
return false
|
|
}
|
|
|
|
return subtle.ConstantTimeCompare([]byte(storedToken), []byte(suppliedToken)) == 1
|
|
}
|