mirror of
https://github.com/netbirdio/netbird.git
synced 2026-10-19 20:09:07 +02:00
60 lines
2.1 KiB
Go
60 lines
2.1 KiB
Go
package rosenpass
|
|
|
|
import (
|
|
"crypto/sha256"
|
|
"fmt"
|
|
|
|
"golang.zx2c4.com/wireguard/wgctrl/wgtypes"
|
|
)
|
|
|
|
// ratchetLabel domain-separates the expiry ratchet from other uses of the
|
|
// rosenpass output key.
|
|
const ratchetLabel = "netbird-rosenpass-expiry-ratchet"
|
|
|
|
// RatchetKey derives the successor preshared key from the previous Rosenpass
|
|
// output key. When a key expires without a completed renewal, both peers
|
|
// advance their last shared key by one ratchet step: the expired key is
|
|
// rotated out while both ends still converge on an identical, non-public
|
|
// replacement without communicating.
|
|
func RatchetKey(prev wgtypes.Key) wgtypes.Key {
|
|
input := make([]byte, 0, len(ratchetLabel)+len(prev))
|
|
input = append(input, ratchetLabel...)
|
|
input = append(input, prev[:]...)
|
|
return sha256.Sum256(input)
|
|
}
|
|
|
|
// DeterministicSeedKey derives a 32-byte WireGuard preshared key from a pair
|
|
// of peer public keys. Both peers, given the same key pair, produce the same
|
|
// output regardless of which side runs the function: the inputs are ordered
|
|
// lexicographically before concatenation.
|
|
//
|
|
// NetBird uses this value as the initial Rosenpass-side preshared key when no
|
|
// explicit account-level PSK is configured, so both peers converge on the same
|
|
// PSK before the first post-quantum handshake completes.
|
|
//
|
|
// The resulting key MUST NOT be treated as quantum-safe: it is deterministic
|
|
// from public keys and exists only to seed WireGuard until Rosenpass rotates
|
|
// in a real post-quantum PSK.
|
|
func DeterministicSeedKey(localKey, remoteKey string) (*wgtypes.Key, error) {
|
|
lk := []byte(localKey)
|
|
rk := []byte(remoteKey)
|
|
if len(lk) < 16 || len(rk) < 16 {
|
|
return nil, fmt.Errorf("rosenpass: peer keys must be at least 16 bytes (got local=%d, remote=%d)", len(lk), len(rk))
|
|
}
|
|
|
|
var keyInput []byte
|
|
if localKey > remoteKey {
|
|
keyInput = append(keyInput, lk[:16]...)
|
|
keyInput = append(keyInput, rk[:16]...)
|
|
} else {
|
|
keyInput = append(keyInput, rk[:16]...)
|
|
keyInput = append(keyInput, lk[:16]...)
|
|
}
|
|
|
|
key, err := wgtypes.NewKey(keyInput)
|
|
if err != nil {
|
|
return nil, fmt.Errorf("rosenpass: deterministic seed key: %w", err)
|
|
}
|
|
return &key, nil
|
|
}
|