fluxer/tests/integration/helper_totp_code_at.go
2026-01-01 21:05:54 +00:00

59 lines
1.7 KiB
Go

/*
* Copyright (C) 2026 Fluxer Contributors
*
* This file is part of Fluxer.
*
* Fluxer is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Fluxer is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with Fluxer. If not, see <https://www.gnu.org/licenses/>.
*/
package integration
import (
"crypto/hmac"
"crypto/sha1"
"encoding/base32"
"encoding/binary"
"fmt"
"strings"
"testing"
"time"
)
func totpCodeAt(t testing.TB, secret string, at time.Time) string {
t.Helper()
decoder := base32.StdEncoding.WithPadding(base32.NoPadding)
normalized := strings.ToUpper(strings.ReplaceAll(secret, " ", ""))
key, err := decoder.DecodeString(normalized)
if err != nil {
t.Fatalf("failed to decode totp secret: %v", err)
}
counter := uint64(at.Unix() / 30)
var counterBytes [8]byte
binary.BigEndian.PutUint64(counterBytes[:], counter)
mac := hmac.New(sha1.New, key)
if _, err := mac.Write(counterBytes[:]); err != nil {
t.Fatalf("failed to compute totp hmac: %v", err)
}
sum := mac.Sum(nil)
offset := sum[len(sum)-1] & 0x0f
code := ((int(sum[offset]) & 0x7f) << 24) |
((int(sum[offset+1]) & 0xff) << 16) |
((int(sum[offset+2]) & 0xff) << 8) |
(int(sum[offset+3]) & 0xff)
code %= 1000000
return fmt.Sprintf("%06d", code)
}