Files
openp2p/totp.go
2021-11-24 22:40:07 +08:00

31 lines
743 B
Go

// Time-based One-time Password
package main
import (
"crypto/hmac"
"crypto/sha256"
"encoding/binary"
)
const TOTPStep = 30 // 30s
func GenTOTP(user string, password string, ts int64) uint64 {
step := ts / TOTPStep
mac := hmac.New(sha256.New, []byte(user+password))
b := make([]byte, 8)
binary.LittleEndian.PutUint64(b, uint64(step))
mac.Write(b)
num := binary.LittleEndian.Uint64(mac.Sum(nil)[:8])
// fmt.Printf("%x\n", mac.Sum(nil))
return num
}
func VerifyTOTP(code uint64, user string, password string, ts int64) bool {
if code == 0 {
return false
}
if code == GenTOTP(user, password, ts) || code == GenTOTP(user, password, ts-TOTPStep) || code == GenTOTP(user, password, ts+TOTPStep) {
return true
}
return false
}