tailscale/ipn/ipnlocal/network-lock.go

1344 lines
40 KiB
Go

// Copyright (c) Tailscale Inc & AUTHORS
// SPDX-License-Identifier: BSD-3-Clause
package ipnlocal
import (
"bytes"
"context"
"crypto/ed25519"
"crypto/rand"
"encoding/base64"
"encoding/binary"
"encoding/json"
"errors"
"fmt"
"io"
"net/http"
"net/netip"
"os"
"path/filepath"
"time"
"tailscale.com/health"
"tailscale.com/health/healthmsg"
"tailscale.com/ipn"
"tailscale.com/ipn/ipnstate"
"tailscale.com/net/tsaddr"
"tailscale.com/tailcfg"
"tailscale.com/tka"
"tailscale.com/types/key"
"tailscale.com/types/netmap"
"tailscale.com/types/persist"
"tailscale.com/types/tkatype"
"tailscale.com/util/mak"
)
// TODO(tom): RPC retry/backoff was broken and has been removed. Fix?
var (
errMissingNetmap = errors.New("missing netmap: verify that you are logged in")
errNetworkLockNotActive = errors.New("network-lock is not active")
tkaCompactionDefaults = tka.CompactionOptions{
MinChain: 24, // Keep at minimum 24 AUMs since head.
MinAge: 14 * 24 * time.Hour, // Keep 2 weeks of AUMs.
}
)
type tkaState struct {
profile ipn.ProfileID
authority *tka.Authority
storage *tka.FS
filtered []ipnstate.TKAFilteredPeer
}
// tkaFilterNetmapLocked checks the signatures on each node key, dropping
// nodes from the netmap whose signature does not verify.
//
// b.mu must be held.
func (b *LocalBackend) tkaFilterNetmapLocked(nm *netmap.NetworkMap) {
if b.tka == nil && !b.capTailnetLock {
health.SetTKAHealth(nil)
return
}
if b.tka == nil {
health.SetTKAHealth(nil)
return // TKA not enabled.
}
var toDelete map[int]bool // peer index => true
for i, p := range nm.Peers {
if p.UnsignedPeerAPIOnly() {
// Not subject to tailnet lock.
continue
}
if p.KeySignature().Len() == 0 {
b.logf("Network lock is dropping peer %v(%v) due to missing signature", p.ID(), p.StableID())
mak.Set(&toDelete, i, true)
} else {
if err := b.tka.authority.NodeKeyAuthorized(p.Key(), p.KeySignature().AsSlice()); err != nil {
b.logf("Network lock is dropping peer %v(%v) due to failed signature check: %v", p.ID(), p.StableID(), err)
mak.Set(&toDelete, i, true)
}
}
}
// nm.Peers is ordered, so deletion must be order-preserving.
if len(toDelete) > 0 {
peers := make([]tailcfg.NodeView, 0, len(nm.Peers))
filtered := make([]ipnstate.TKAFilteredPeer, 0, len(toDelete))
for i, p := range nm.Peers {
if !toDelete[i] {
peers = append(peers, p)
} else {
// Record information about the node we filtered out.
fp := ipnstate.TKAFilteredPeer{
Name: p.Name(),
ID: p.ID(),
StableID: p.StableID(),
TailscaleIPs: make([]netip.Addr, p.Addresses().Len()),
NodeKey: p.Key(),
}
for i := range p.Addresses().LenIter() {
addr := p.Addresses().At(i)
if addr.IsSingleIP() && tsaddr.IsTailscaleIP(addr.Addr()) {
fp.TailscaleIPs[i] = addr.Addr()
}
}
filtered = append(filtered, fp)
}
}
nm.Peers = peers
b.tka.filtered = filtered
} else {
b.tka.filtered = nil
}
// Check that we ourselves are not locked out, report a health issue if so.
if nm.SelfNode.Valid() && b.tka.authority.NodeKeyAuthorized(nm.SelfNode.Key(), nm.SelfNode.KeySignature().AsSlice()) != nil {
health.SetTKAHealth(errors.New(healthmsg.LockedOut))
} else {
health.SetTKAHealth(nil)
}
}
// tkaSyncIfNeeded examines TKA info reported from the control plane,
// performing the steps necessary to synchronize local tka state.
//
// There are 4 scenarios handled here:
// - Enablement: nm.TKAEnabled but b.tka == nil
// ∴ reach out to /machine/tka/bootstrap to get the genesis AUM, then
// initialize TKA.
// - Disablement: !nm.TKAEnabled but b.tka != nil
// ∴ reach out to /machine/tka/bootstrap to read the disablement secret,
// then verify and clear tka local state.
// - Sync needed: b.tka.Head != nm.TKAHead
// ∴ complete multi-step synchronization flow.
// - Everything up to date: All other cases.
// ∴ no action necessary.
//
// tkaSyncIfNeeded immediately takes b.takeSyncLock which is held throughout,
// and may take b.mu as required.
func (b *LocalBackend) tkaSyncIfNeeded(nm *netmap.NetworkMap, prefs ipn.PrefsView) error {
b.tkaSyncLock.Lock() // take tkaSyncLock to make this function an exclusive section.
defer b.tkaSyncLock.Unlock()
b.mu.Lock() // take mu to protect access to synchronized fields.
defer b.mu.Unlock()
if b.tka == nil && !b.capTailnetLock {
return nil
}
if b.tka != nil || nm.TKAEnabled {
b.logf("tkaSyncIfNeeded: enabled=%v, head=%v", nm.TKAEnabled, nm.TKAHead)
}
ourNodeKey := prefs.Persist().PublicNodeKey()
isEnabled := b.tka != nil
wantEnabled := nm.TKAEnabled
didJustEnable := false
if isEnabled != wantEnabled {
var ourHead tka.AUMHash
if b.tka != nil {
ourHead = b.tka.authority.Head()
}
// Regardless of whether we are moving to disabled or enabled, we
// need information from the tka bootstrap endpoint.
b.mu.Unlock()
bs, err := b.tkaFetchBootstrap(ourNodeKey, ourHead)
b.mu.Lock()
if err != nil {
return fmt.Errorf("fetching bootstrap: %w", err)
}
if wantEnabled && !isEnabled {
if err := b.tkaBootstrapFromGenesisLocked(bs.GenesisAUM, prefs.Persist()); err != nil {
return fmt.Errorf("bootstrap: %w", err)
}
isEnabled = true
didJustEnable = true
} else if !wantEnabled && isEnabled {
if err := b.tkaApplyDisablementLocked(bs.DisablementSecret); err != nil {
// We log here instead of returning an error (which itself would be
// logged), so that sync will continue even if control gives us an
// incorrect disablement secret.
b.logf("Disablement failed, leaving TKA enabled. Error: %v", err)
} else {
isEnabled = false
health.SetTKAHealth(nil)
}
} else {
return fmt.Errorf("[bug] unreachable invariant of wantEnabled w/ isEnabled")
}
}
// We always transmit the sync RPCs if TKA was just enabled.
// This informs the control plane that our TKA state is now
// initialized to the transmitted TKA head hash.
if isEnabled && (b.tka.authority.Head() != nm.TKAHead || didJustEnable) {
if err := b.tkaSyncLocked(ourNodeKey); err != nil {
return fmt.Errorf("tka sync: %w", err)
}
}
return nil
}
func toSyncOffer(head string, ancestors []string) (tka.SyncOffer, error) {
var out tka.SyncOffer
if err := out.Head.UnmarshalText([]byte(head)); err != nil {
return tka.SyncOffer{}, fmt.Errorf("head.UnmarshalText: %v", err)
}
out.Ancestors = make([]tka.AUMHash, len(ancestors))
for i, a := range ancestors {
if err := out.Ancestors[i].UnmarshalText([]byte(a)); err != nil {
return tka.SyncOffer{}, fmt.Errorf("ancestor[%d].UnmarshalText: %v", i, err)
}
}
return out, nil
}
// tkaSyncLocked synchronizes TKA state with control. b.mu must be held
// and tka must be initialized. b.mu will be stepped out of (and back into)
// during network RPCs.
//
// b.mu must be held.
func (b *LocalBackend) tkaSyncLocked(ourNodeKey key.NodePublic) error {
offer, err := b.tka.authority.SyncOffer(b.tka.storage)
if err != nil {
return fmt.Errorf("offer: %w", err)
}
b.mu.Unlock()
offerResp, err := b.tkaDoSyncOffer(ourNodeKey, offer)
b.mu.Lock()
if err != nil {
return fmt.Errorf("offer RPC: %w", err)
}
controlOffer, err := toSyncOffer(offerResp.Head, offerResp.Ancestors)
if err != nil {
return fmt.Errorf("control offer: %v", err)
}
if controlOffer.Head == offer.Head {
// We are up to date.
return nil
}
// Compute missing AUMs before we apply any AUMs from the control-plane,
// so we still submit AUMs to control even if they are not part of the
// active chain.
toSendAUMs, err := b.tka.authority.MissingAUMs(b.tka.storage, controlOffer)
if err != nil {
return fmt.Errorf("computing missing AUMs: %w", err)
}
// If we got this far, then we are not up to date. Either the control-plane
// has updates for us, or we have updates for the control plane.
//
// TODO(tom): Do we want to keep processing even if the Inform fails? Need
// to think through if theres holdback concerns here or not.
if len(offerResp.MissingAUMs) > 0 {
aums := make([]tka.AUM, len(offerResp.MissingAUMs))
for i, a := range offerResp.MissingAUMs {
if err := aums[i].Unserialize(a); err != nil {
return fmt.Errorf("MissingAUMs[%d]: %v", i, err)
}
}
if err := b.tka.authority.Inform(b.tka.storage, aums); err != nil {
return fmt.Errorf("inform failed: %v", err)
}
}
// NOTE(tom): We always send this RPC so control knows what TKA
// head we landed at.
head := b.tka.authority.Head()
b.mu.Unlock()
sendResp, err := b.tkaDoSyncSend(ourNodeKey, head, toSendAUMs, false)
b.mu.Lock()
if err != nil {
return fmt.Errorf("send RPC: %v", err)
}
var remoteHead tka.AUMHash
if err := remoteHead.UnmarshalText([]byte(sendResp.Head)); err != nil {
return fmt.Errorf("head unmarshal: %v", err)
}
if remoteHead != b.tka.authority.Head() {
b.logf("TKA desync: expected consensus after sync but our head is %v and the control plane's is %v", b.tka.authority.Head(), remoteHead)
}
return nil
}
// tkaApplyDisablementLocked checks a disablement secret and locally disables
// TKA (if correct). An error is returned if disablement failed.
//
// b.mu must be held & TKA must be initialized.
func (b *LocalBackend) tkaApplyDisablementLocked(secret []byte) error {
if b.tka.authority.ValidDisablement(secret) {
if err := os.RemoveAll(b.chonkPathLocked()); err != nil {
return err
}
b.tka = nil
return nil
}
return errors.New("incorrect disablement secret")
}
// chonkPathLocked returns the absolute path to the directory in which TKA
// state (the 'tailchonk') is stored.
//
// b.mu must be held.
func (b *LocalBackend) chonkPathLocked() string {
return filepath.Join(b.TailscaleVarRoot(), "tka-profiles", string(b.pm.CurrentProfile().ID))
}
// tkaBootstrapFromGenesisLocked initializes the local (on-disk) state of the
// tailnet key authority, based on the given genesis AUM.
//
// b.mu must be held.
func (b *LocalBackend) tkaBootstrapFromGenesisLocked(g tkatype.MarshaledAUM, persist persist.PersistView) error {
if err := b.CanSupportNetworkLock(); err != nil {
return err
}
var genesis tka.AUM
if err := genesis.Unserialize(g); err != nil {
return fmt.Errorf("reading genesis: %v", err)
}
if persist.Valid() && persist.DisallowedTKAStateIDs().Len() > 0 {
if genesis.State == nil {
return errors.New("invalid genesis: missing State")
}
bootstrapStateID := fmt.Sprintf("%d:%d", genesis.State.StateID1, genesis.State.StateID2)
for i := 0; i < persist.DisallowedTKAStateIDs().Len(); i++ {
stateID := persist.DisallowedTKAStateIDs().At(i)
if stateID == bootstrapStateID {
return fmt.Errorf("TKA with stateID of %q is disallowed on this node", stateID)
}
}
}
chonkDir := b.chonkPathLocked()
if err := os.Mkdir(filepath.Dir(chonkDir), 0755); err != nil && !os.IsExist(err) {
return fmt.Errorf("creating chonk root dir: %v", err)
}
if err := os.Mkdir(chonkDir, 0755); err != nil && !os.IsExist(err) {
return fmt.Errorf("mkdir: %v", err)
}
chonk, err := tka.ChonkDir(chonkDir)
if err != nil {
return fmt.Errorf("chonk: %v", err)
}
authority, err := tka.Bootstrap(chonk, genesis)
if err != nil {
return fmt.Errorf("tka bootstrap: %v", err)
}
b.tka = &tkaState{
profile: b.pm.CurrentProfile().ID,
authority: authority,
storage: chonk,
}
return nil
}
// CanSupportNetworkLock returns nil if tailscaled is able to operate
// a local tailnet key authority (and hence enforce network lock).
func (b *LocalBackend) CanSupportNetworkLock() error {
if b.tka != nil {
// If the TKA is being used, it is supported.
return nil
}
if b.TailscaleVarRoot() == "" {
return errors.New("network-lock is not supported in this configuration, try setting --statedir")
}
// There's a var root (aka --statedir), so if network lock gets
// initialized we have somewhere to store our AUMs. That's all
// we need.
return nil
}
// NetworkLockStatus returns a structure describing the state of the
// tailnet key authority, if any.
func (b *LocalBackend) NetworkLockStatus() *ipnstate.NetworkLockStatus {
b.mu.Lock()
defer b.mu.Unlock()
var (
nodeKey *key.NodePublic
nlPriv key.NLPrivate
)
if p := b.pm.CurrentPrefs(); p.Valid() && p.Persist().Valid() && !p.Persist().PrivateNodeKey().IsZero() {
nkp := p.Persist().PublicNodeKey()
nodeKey = &nkp
nlPriv = p.Persist().NetworkLockKey()
}
if nlPriv.IsZero() {
return &ipnstate.NetworkLockStatus{
Enabled: false,
NodeKey: nodeKey,
}
}
if b.tka == nil {
return &ipnstate.NetworkLockStatus{
Enabled: false,
NodeKey: nodeKey,
PublicKey: nlPriv.Public(),
}
}
var head [32]byte
h := b.tka.authority.Head()
copy(head[:], h[:])
var selfAuthorized bool
if b.netMap != nil {
selfAuthorized = b.tka.authority.NodeKeyAuthorized(b.netMap.SelfNode.Key(), b.netMap.SelfNode.KeySignature().AsSlice()) == nil
}
keys := b.tka.authority.Keys()
outKeys := make([]ipnstate.TKAKey, len(keys))
for i, k := range keys {
outKeys[i] = ipnstate.TKAKey{
Key: key.NLPublicFromEd25519Unsafe(k.Public),
Metadata: k.Meta,
Votes: k.Votes,
}
}
filtered := make([]*ipnstate.TKAFilteredPeer, len(b.tka.filtered))
for i := 0; i < len(filtered); i++ {
filtered[i] = b.tka.filtered[i].Clone()
}
stateID1, _ := b.tka.authority.StateIDs()
return &ipnstate.NetworkLockStatus{
Enabled: true,
Head: &head,
PublicKey: nlPriv.Public(),
NodeKey: nodeKey,
NodeKeySigned: selfAuthorized,
TrustedKeys: outKeys,
FilteredPeers: filtered,
StateID: stateID1,
}
}
// NetworkLockInit enables network-lock for the tailnet, with the tailnets'
// key authority initialized to trust the provided keys.
//
// Initialization involves two RPCs with control, termed 'begin' and 'finish'.
// The Begin RPC transmits the genesis Authority Update Message, which
// encodes the initial state of the authority, and the list of all nodes
// needing signatures is returned as a response.
// The Finish RPC submits signatures for all these nodes, at which point
// Control has everything it needs to atomically enable network lock.
func (b *LocalBackend) NetworkLockInit(keys []tka.Key, disablementValues [][]byte, supportDisablement []byte) error {
if err := b.CanSupportNetworkLock(); err != nil {
return err
}
var ourNodeKey key.NodePublic
var nlPriv key.NLPrivate
b.mu.Lock()
if !b.capTailnetLock {
b.mu.Unlock()
return errors.New("not permitted to enable tailnet lock")
}
if p := b.pm.CurrentPrefs(); p.Valid() && p.Persist().Valid() && !p.Persist().PrivateNodeKey().IsZero() {
ourNodeKey = p.Persist().PublicNodeKey()
nlPriv = p.Persist().NetworkLockKey()
}
b.mu.Unlock()
if ourNodeKey.IsZero() || nlPriv.IsZero() {
return errors.New("no node-key: is tailscale logged in?")
}
var entropy [16]byte
if _, err := rand.Read(entropy[:]); err != nil {
return err
}
// Generates a genesis AUM representing trust in the provided keys.
// We use an in-memory tailchonk because we don't want to commit to
// the filesystem until we've finished the initialization sequence,
// just in case something goes wrong.
_, genesisAUM, err := tka.Create(&tka.Mem{}, tka.State{
Keys: keys,
// TODO(tom): s/tka.State.DisablementSecrets/tka.State.DisablementValues
// This will center on consistent nomenclature:
// - DisablementSecret: value needed to disable.
// - DisablementValue: the KDF of the disablement secret, a public value.
DisablementSecrets: disablementValues,
StateID1: binary.LittleEndian.Uint64(entropy[:8]),
StateID2: binary.LittleEndian.Uint64(entropy[8:]),
}, nlPriv)
if err != nil {
return fmt.Errorf("tka.Create: %v", err)
}
b.logf("Generated genesis AUM to initialize network lock, trusting the following keys:")
for i, k := range genesisAUM.State.Keys {
b.logf(" - key[%d] = tlpub:%x with %d votes", i, k.Public, k.Votes)
}
// Phase 1/2 of initialization: Transmit the genesis AUM to Control.
initResp, err := b.tkaInitBegin(ourNodeKey, genesisAUM)
if err != nil {
return fmt.Errorf("tka init-begin RPC: %w", err)
}
// Our genesis AUM was accepted but before Control turns on enforcement of
// node-key signatures, we need to sign keys for all the existing nodes.
// If we don't get these signatures ahead of time, everyone will loose
// connectivity because control won't have any signatures to send which
// satisfy network-lock checks.
sigs := make(map[tailcfg.NodeID]tkatype.MarshaledSignature, len(initResp.NeedSignatures))
for _, nodeInfo := range initResp.NeedSignatures {
nks, err := signNodeKey(nodeInfo, nlPriv)
if err != nil {
return fmt.Errorf("generating signature: %v", err)
}
sigs[nodeInfo.NodeID] = nks.Serialize()
}
// Finalize enablement by transmitting signature for all nodes to Control.
_, err = b.tkaInitFinish(ourNodeKey, sigs, supportDisablement)
return err
}
// Only use is in tests.
func (b *LocalBackend) NetworkLockVerifySignatureForTest(nks tkatype.MarshaledSignature, nodeKey key.NodePublic) error {
b.mu.Lock()
defer b.mu.Unlock()
if b.tka == nil {
return errNetworkLockNotActive
}
return b.tka.authority.NodeKeyAuthorized(nodeKey, nks)
}
// Only use is in tests.
func (b *LocalBackend) NetworkLockKeyTrustedForTest(keyID tkatype.KeyID) bool {
b.mu.Lock()
defer b.mu.Unlock()
if b.tka == nil {
panic("network lock not initialized")
}
return b.tka.authority.KeyTrusted(keyID)
}
// NetworkLockForceLocalDisable shuts down TKA locally, and denylists the current
// TKA from being initialized locally in future.
func (b *LocalBackend) NetworkLockForceLocalDisable() error {
b.mu.Lock()
defer b.mu.Unlock()
if b.tka == nil {
return errNetworkLockNotActive
}
id1, id2 := b.tka.authority.StateIDs()
stateID := fmt.Sprintf("%d:%d", id1, id2)
newPrefs := b.pm.CurrentPrefs().AsStruct().Clone() // .Persist should always be initialized here.
newPrefs.Persist.DisallowedTKAStateIDs = append(newPrefs.Persist.DisallowedTKAStateIDs, stateID)
if err := b.pm.SetPrefs(newPrefs.View()); err != nil {
return fmt.Errorf("saving prefs: %w", err)
}
if err := os.RemoveAll(b.chonkPathLocked()); err != nil {
return fmt.Errorf("deleting TKA state: %w", err)
}
b.tka = nil
return nil
}
// NetworkLockSign signs the given node-key and submits it to the control plane.
// rotationPublic, if specified, must be an ed25519 public key.
func (b *LocalBackend) NetworkLockSign(nodeKey key.NodePublic, rotationPublic []byte) error {
ourNodeKey, sig, err := func(nodeKey key.NodePublic, rotationPublic []byte) (key.NodePublic, tka.NodeKeySignature, error) {
b.mu.Lock()
defer b.mu.Unlock()
var nlPriv key.NLPrivate
if p := b.pm.CurrentPrefs(); p.Valid() && p.Persist().Valid() {
nlPriv = p.Persist().NetworkLockKey()
}
if nlPriv.IsZero() {
return key.NodePublic{}, tka.NodeKeySignature{}, errMissingNetmap
}
if b.tka == nil {
return key.NodePublic{}, tka.NodeKeySignature{}, errNetworkLockNotActive
}
if !b.tka.authority.KeyTrusted(nlPriv.KeyID()) {
return key.NodePublic{}, tka.NodeKeySignature{}, errors.New("this node is not trusted by network lock")
}
p, err := nodeKey.MarshalBinary()
if err != nil {
return key.NodePublic{}, tka.NodeKeySignature{}, err
}
sig := tka.NodeKeySignature{
SigKind: tka.SigDirect,
KeyID: nlPriv.KeyID(),
Pubkey: p,
WrappingPubkey: rotationPublic,
}
sig.Signature, err = nlPriv.SignNKS(sig.SigHash())
if err != nil {
return key.NodePublic{}, tka.NodeKeySignature{}, fmt.Errorf("signature failed: %w", err)
}
return b.pm.CurrentPrefs().Persist().PublicNodeKey(), sig, nil
}(nodeKey, rotationPublic)
if err != nil {
return err
}
b.logf("Generated network-lock signature for %v, submitting to control plane", nodeKey)
if _, err := b.tkaSubmitSignature(ourNodeKey, sig.Serialize()); err != nil {
return err
}
return nil
}
// NetworkLockModify adds and/or removes keys in the tailnet's key authority.
func (b *LocalBackend) NetworkLockModify(addKeys, removeKeys []tka.Key) (err error) {
defer func() {
if err != nil {
err = fmt.Errorf("modify network-lock keys: %w", err)
}
}()
b.mu.Lock()
defer b.mu.Unlock()
var ourNodeKey key.NodePublic
if p := b.pm.CurrentPrefs(); p.Valid() && p.Persist().Valid() && !p.Persist().PrivateNodeKey().IsZero() {
ourNodeKey = p.Persist().PublicNodeKey()
}
if ourNodeKey.IsZero() {
return errors.New("no node-key: is tailscale logged in?")
}
var nlPriv key.NLPrivate
if p := b.pm.CurrentPrefs(); p.Valid() && p.Persist().Valid() {
nlPriv = p.Persist().NetworkLockKey()
}
if nlPriv.IsZero() {
return errMissingNetmap
}
if b.tka == nil {
return errNetworkLockNotActive
}
if !b.tka.authority.KeyTrusted(nlPriv.KeyID()) {
return errors.New("this node does not have a trusted tailnet lock key")
}
updater := b.tka.authority.NewUpdater(nlPriv)
for _, addKey := range addKeys {
if err := updater.AddKey(addKey); err != nil {
return err
}
}
for _, removeKey := range removeKeys {
keyID, err := removeKey.ID()
if err != nil {
return err
}
if err := updater.RemoveKey(keyID); err != nil {
return err
}
}
aums, err := updater.Finalize(b.tka.storage)
if err != nil {
return err
}
if len(aums) == 0 {
return nil
}
head := b.tka.authority.Head()
b.mu.Unlock()
resp, err := b.tkaDoSyncSend(ourNodeKey, head, aums, true)
b.mu.Lock()
if err != nil {
return err
}
var controlHead tka.AUMHash
if err := controlHead.UnmarshalText([]byte(resp.Head)); err != nil {
return err
}
lastHead := aums[len(aums)-1].Hash()
if controlHead != lastHead {
return errors.New("central tka head differs from submitted AUM, try again")
}
return nil
}
// NetworkLockDisable disables network-lock using the provided disablement secret.
func (b *LocalBackend) NetworkLockDisable(secret []byte) error {
var (
ourNodeKey key.NodePublic
head tka.AUMHash
err error
)
b.mu.Lock()
if p := b.pm.CurrentPrefs(); p.Valid() && p.Persist().Valid() && !p.Persist().PrivateNodeKey().IsZero() {
ourNodeKey = p.Persist().PublicNodeKey()
}
if b.tka == nil {
err = errNetworkLockNotActive
} else {
head = b.tka.authority.Head()
if !b.tka.authority.ValidDisablement(secret) {
err = errors.New("incorrect disablement secret")
}
}
b.mu.Unlock()
if err != nil {
return err
}
if ourNodeKey.IsZero() {
return errors.New("no node-key: is tailscale logged in?")
}
_, err = b.tkaDoDisablement(ourNodeKey, head, secret)
return err
}
// NetworkLockLog returns the changelog of TKA state up to maxEntries in size.
func (b *LocalBackend) NetworkLockLog(maxEntries int) ([]ipnstate.NetworkLockUpdate, error) {
b.mu.Lock()
defer b.mu.Unlock()
if b.tka == nil {
return nil, errNetworkLockNotActive
}
var out []ipnstate.NetworkLockUpdate
cursor := b.tka.authority.Head()
for i := 0; i < maxEntries; i++ {
aum, err := b.tka.storage.AUM(cursor)
if err != nil {
if err == os.ErrNotExist {
break
}
return out, fmt.Errorf("reading AUM: %w", err)
}
update := ipnstate.NetworkLockUpdate{
Hash: cursor,
Change: aum.MessageKind.String(),
Raw: aum.Serialize(),
}
out = append(out, update)
parent, hasParent := aum.Parent()
if !hasParent {
break
}
cursor = parent
}
return out, nil
}
// NetworkLockAffectedSigs returns the signatures which would be invalidated
// by removing trust in the specified KeyID.
func (b *LocalBackend) NetworkLockAffectedSigs(keyID tkatype.KeyID) ([]tkatype.MarshaledSignature, error) {
var (
ourNodeKey key.NodePublic
err error
)
b.mu.Lock()
if p := b.pm.CurrentPrefs(); p.Valid() && p.Persist().Valid() && !p.Persist().PrivateNodeKey().IsZero() {
ourNodeKey = p.Persist().PublicNodeKey()
}
if b.tka == nil {
err = errNetworkLockNotActive
}
b.mu.Unlock()
if err != nil {
return nil, err
}
resp, err := b.tkaReadAffectedSigs(ourNodeKey, keyID)
if err != nil {
return nil, err
}
b.mu.Lock()
defer b.mu.Unlock()
if b.tka == nil {
return nil, errNetworkLockNotActive
}
// Confirm for ourselves tha the signatures would actually be invalidated
// by removal of trusted in the specified key.
for i, sigBytes := range resp.Signatures {
var sig tka.NodeKeySignature
if err := sig.Unserialize(sigBytes); err != nil {
return nil, fmt.Errorf("failed decoding signature %d: %w", i, err)
}
sigKeyID, err := sig.UnverifiedAuthorizingKeyID()
if err != nil {
return nil, fmt.Errorf("extracting SigID from signature %d: %w", i, err)
}
if !bytes.Equal(keyID, sigKeyID) {
return nil, fmt.Errorf("got signature with keyID %X from request for %X", sigKeyID, keyID)
}
var nodeKey key.NodePublic
if err := nodeKey.UnmarshalBinary(sig.Pubkey); err != nil {
return nil, fmt.Errorf("failed decoding pubkey for signature %d: %w", i, err)
}
if err := b.tka.authority.NodeKeyAuthorized(nodeKey, sigBytes); err != nil {
return nil, fmt.Errorf("signature %d is not valid: %w", i, err)
}
}
return resp.Signatures, nil
}
// NetworkLockGenerateRecoveryAUM generates an AUM which retroactively removes trust in the
// specified keys. This AUM is signed by the current node and returned.
//
// If forkFrom is specified, it is used as the parent AUM to fork from. If the zero value,
// the parent AUM is determined automatically.
func (b *LocalBackend) NetworkLockGenerateRecoveryAUM(removeKeys []tkatype.KeyID, forkFrom tka.AUMHash) (*tka.AUM, error) {
b.mu.Lock()
defer b.mu.Unlock()
if b.tka == nil {
return nil, errNetworkLockNotActive
}
var nlPriv key.NLPrivate
if p := b.pm.CurrentPrefs(); p.Valid() && p.Persist().Valid() {
nlPriv = p.Persist().NetworkLockKey()
}
if nlPriv.IsZero() {
return nil, errMissingNetmap
}
aum, err := b.tka.authority.MakeRetroactiveRevocation(b.tka.storage, removeKeys, nlPriv.KeyID(), forkFrom)
if err != nil {
return nil, err
}
// Sign it ourselves.
aum.Signatures, err = nlPriv.SignAUM(aum.SigHash())
if err != nil {
return nil, fmt.Errorf("signing failed: %w", err)
}
return aum, nil
}
// NetworkLockCosignRecoveryAUM co-signs the provided recovery AUM and returns
// the updated structure.
//
// The recovery AUM provided should be the output from a previous call to
// NetworkLockGenerateRecoveryAUM or NetworkLockCosignRecoveryAUM.
func (b *LocalBackend) NetworkLockCosignRecoveryAUM(aum *tka.AUM) (*tka.AUM, error) {
b.mu.Lock()
defer b.mu.Unlock()
if b.tka == nil {
return nil, errNetworkLockNotActive
}
var nlPriv key.NLPrivate
if p := b.pm.CurrentPrefs(); p.Valid() && p.Persist().Valid() {
nlPriv = p.Persist().NetworkLockKey()
}
if nlPriv.IsZero() {
return nil, errMissingNetmap
}
for _, sig := range aum.Signatures {
if bytes.Equal(sig.KeyID, nlPriv.KeyID()) {
return nil, errors.New("this node has already signed this recovery AUM")
}
}
// Sign it ourselves.
sigs, err := nlPriv.SignAUM(aum.SigHash())
if err != nil {
return nil, fmt.Errorf("signing failed: %w", err)
}
aum.Signatures = append(aum.Signatures, sigs...)
return aum, nil
}
func (b *LocalBackend) NetworkLockSubmitRecoveryAUM(aum *tka.AUM) error {
b.mu.Lock()
defer b.mu.Unlock()
if b.tka == nil {
return errNetworkLockNotActive
}
var ourNodeKey key.NodePublic
if p := b.pm.CurrentPrefs(); p.Valid() && p.Persist().Valid() && !p.Persist().PrivateNodeKey().IsZero() {
ourNodeKey = p.Persist().PublicNodeKey()
}
if ourNodeKey.IsZero() {
return errors.New("no node-key: is tailscale logged in?")
}
b.mu.Unlock()
_, err := b.tkaDoSyncSend(ourNodeKey, aum.Hash(), []tka.AUM{*aum}, false)
b.mu.Lock()
return err
}
var tkaSuffixEncoder = base64.RawStdEncoding
// NetworkLockWrapPreauthKey wraps a pre-auth key with information to
// enable unattended bringup in the locked tailnet.
//
// The provided trusted tailnet-lock key is used to sign
// a SigCredential structure, which is encoded along with the
// private key and appended to the pre-auth key.
func (b *LocalBackend) NetworkLockWrapPreauthKey(preauthKey string, tkaKey key.NLPrivate) (string, error) {
b.mu.Lock()
defer b.mu.Unlock()
if b.tka == nil {
return "", errNetworkLockNotActive
}
pub, priv, err := ed25519.GenerateKey(nil) // nil == crypto/rand
if err != nil {
return "", err
}
sig := tka.NodeKeySignature{
SigKind: tka.SigCredential,
KeyID: tkaKey.KeyID(),
WrappingPubkey: pub,
}
sig.Signature, err = tkaKey.SignNKS(sig.SigHash())
if err != nil {
return "", fmt.Errorf("signing failed: %w", err)
}
b.logf("Generated network-lock credential signature using %s", tkaKey.Public().CLIString())
return fmt.Sprintf("%s--TL%s-%s", preauthKey, tkaSuffixEncoder.EncodeToString(sig.Serialize()), tkaSuffixEncoder.EncodeToString(priv)), nil
}
// NetworkLockVerifySigningDeeplink asks the authority to verify the given deeplink
// URL. See the comment for ValidateDeeplink for details.
func (b *LocalBackend) NetworkLockVerifySigningDeeplink(url string) tka.DeeplinkValidationResult {
b.mu.Lock()
defer b.mu.Unlock()
if b.tka == nil {
return tka.DeeplinkValidationResult{IsValid: false, Error: errNetworkLockNotActive.Error()}
}
return b.tka.authority.ValidateDeeplink(url)
}
func signNodeKey(nodeInfo tailcfg.TKASignInfo, signer key.NLPrivate) (*tka.NodeKeySignature, error) {
p, err := nodeInfo.NodePublic.MarshalBinary()
if err != nil {
return nil, err
}
sig := tka.NodeKeySignature{
SigKind: tka.SigDirect,
KeyID: signer.KeyID(),
Pubkey: p,
WrappingPubkey: nodeInfo.RotationPubkey,
}
sig.Signature, err = signer.SignNKS(sig.SigHash())
if err != nil {
return nil, fmt.Errorf("signature failed: %w", err)
}
return &sig, nil
}
func (b *LocalBackend) tkaInitBegin(ourNodeKey key.NodePublic, aum tka.AUM) (*tailcfg.TKAInitBeginResponse, error) {
var req bytes.Buffer
if err := json.NewEncoder(&req).Encode(tailcfg.TKAInitBeginRequest{
Version: tailcfg.CurrentCapabilityVersion,
NodeKey: ourNodeKey,
GenesisAUM: aum.Serialize(),
}); err != nil {
return nil, fmt.Errorf("encoding request: %v", err)
}
ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
defer cancel()
req2, err := http.NewRequestWithContext(ctx, "GET", "https://unused/machine/tka/init/begin", &req)
if err != nil {
return nil, fmt.Errorf("req: %w", err)
}
res, err := b.DoNoiseRequest(req2)
if err != nil {
return nil, fmt.Errorf("resp: %w", err)
}
if res.StatusCode != 200 {
body, _ := io.ReadAll(res.Body)
res.Body.Close()
return nil, fmt.Errorf("request returned (%d): %s", res.StatusCode, string(body))
}
a := new(tailcfg.TKAInitBeginResponse)
err = json.NewDecoder(&io.LimitedReader{R: res.Body, N: 10 * 1024 * 1024}).Decode(a)
res.Body.Close()
if err != nil {
return nil, fmt.Errorf("decoding JSON: %w", err)
}
return a, nil
}
func (b *LocalBackend) tkaInitFinish(ourNodeKey key.NodePublic, nks map[tailcfg.NodeID]tkatype.MarshaledSignature, supportDisablement []byte) (*tailcfg.TKAInitFinishResponse, error) {
var req bytes.Buffer
if err := json.NewEncoder(&req).Encode(tailcfg.TKAInitFinishRequest{
Version: tailcfg.CurrentCapabilityVersion,
NodeKey: ourNodeKey,
Signatures: nks,
SupportDisablement: supportDisablement,
}); err != nil {
return nil, fmt.Errorf("encoding request: %v", err)
}
ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
defer cancel()
req2, err := http.NewRequestWithContext(ctx, "GET", "https://unused/machine/tka/init/finish", &req)
if err != nil {
return nil, fmt.Errorf("req: %w", err)
}
res, err := b.DoNoiseRequest(req2)
if err != nil {
return nil, fmt.Errorf("resp: %w", err)
}
if res.StatusCode != 200 {
body, _ := io.ReadAll(res.Body)
res.Body.Close()
return nil, fmt.Errorf("request returned (%d): %s", res.StatusCode, string(body))
}
a := new(tailcfg.TKAInitFinishResponse)
err = json.NewDecoder(&io.LimitedReader{R: res.Body, N: 1024 * 1024}).Decode(a)
res.Body.Close()
if err != nil {
return nil, fmt.Errorf("decoding JSON: %w", err)
}
return a, nil
}
// tkaFetchBootstrap sends a /machine/tka/bootstrap RPC to the control plane
// over noise. This is used to get values necessary to enable or disable TKA.
func (b *LocalBackend) tkaFetchBootstrap(ourNodeKey key.NodePublic, head tka.AUMHash) (*tailcfg.TKABootstrapResponse, error) {
bootstrapReq := tailcfg.TKABootstrapRequest{
Version: tailcfg.CurrentCapabilityVersion,
NodeKey: ourNodeKey,
}
if !head.IsZero() {
head, err := head.MarshalText()
if err != nil {
return nil, fmt.Errorf("head.MarshalText failed: %v", err)
}
bootstrapReq.Head = string(head)
}
var req bytes.Buffer
if err := json.NewEncoder(&req).Encode(bootstrapReq); err != nil {
return nil, fmt.Errorf("encoding request: %v", err)
}
ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
defer cancel()
if err := ctx.Err(); err != nil {
return nil, fmt.Errorf("ctx: %w", err)
}
req2, err := http.NewRequestWithContext(ctx, "GET", "https://unused/machine/tka/bootstrap", &req)
if err != nil {
return nil, fmt.Errorf("req: %w", err)
}
res, err := b.DoNoiseRequest(req2)
if err != nil {
return nil, fmt.Errorf("resp: %w", err)
}
if res.StatusCode != 200 {
body, _ := io.ReadAll(res.Body)
res.Body.Close()
return nil, fmt.Errorf("request returned (%d): %s", res.StatusCode, string(body))
}
a := new(tailcfg.TKABootstrapResponse)
err = json.NewDecoder(&io.LimitedReader{R: res.Body, N: 1024 * 1024}).Decode(a)
res.Body.Close()
if err != nil {
return nil, fmt.Errorf("decoding JSON: %w", err)
}
return a, nil
}
func fromSyncOffer(offer tka.SyncOffer) (head string, ancestors []string, err error) {
headBytes, err := offer.Head.MarshalText()
if err != nil {
return "", nil, fmt.Errorf("head.MarshalText: %v", err)
}
ancestors = make([]string, len(offer.Ancestors))
for i, ancestor := range offer.Ancestors {
hash, err := ancestor.MarshalText()
if err != nil {
return "", nil, fmt.Errorf("ancestor[%d].MarshalText: %v", i, err)
}
ancestors[i] = string(hash)
}
return string(headBytes), ancestors, nil
}
// tkaDoSyncOffer sends a /machine/tka/sync/offer RPC to the control plane
// over noise. This is the first of two RPCs implementing tka synchronization.
func (b *LocalBackend) tkaDoSyncOffer(ourNodeKey key.NodePublic, offer tka.SyncOffer) (*tailcfg.TKASyncOfferResponse, error) {
head, ancestors, err := fromSyncOffer(offer)
if err != nil {
return nil, fmt.Errorf("encoding offer: %v", err)
}
syncReq := tailcfg.TKASyncOfferRequest{
Version: tailcfg.CurrentCapabilityVersion,
NodeKey: ourNodeKey,
Head: head,
Ancestors: ancestors,
}
var req bytes.Buffer
if err := json.NewEncoder(&req).Encode(syncReq); err != nil {
return nil, fmt.Errorf("encoding request: %v", err)
}
ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
defer cancel()
req2, err := http.NewRequestWithContext(ctx, "GET", "https://unused/machine/tka/sync/offer", &req)
if err != nil {
return nil, fmt.Errorf("req: %w", err)
}
res, err := b.DoNoiseRequest(req2)
if err != nil {
return nil, fmt.Errorf("resp: %w", err)
}
if res.StatusCode != 200 {
body, _ := io.ReadAll(res.Body)
res.Body.Close()
return nil, fmt.Errorf("request returned (%d): %s", res.StatusCode, string(body))
}
a := new(tailcfg.TKASyncOfferResponse)
err = json.NewDecoder(&io.LimitedReader{R: res.Body, N: 10 * 1024 * 1024}).Decode(a)
res.Body.Close()
if err != nil {
return nil, fmt.Errorf("decoding JSON: %w", err)
}
return a, nil
}
// tkaDoSyncSend sends a /machine/tka/sync/send RPC to the control plane
// over noise. This is the second of two RPCs implementing tka synchronization.
func (b *LocalBackend) tkaDoSyncSend(ourNodeKey key.NodePublic, head tka.AUMHash, aums []tka.AUM, interactive bool) (*tailcfg.TKASyncSendResponse, error) {
headBytes, err := head.MarshalText()
if err != nil {
return nil, fmt.Errorf("head.MarshalText: %w", err)
}
sendReq := tailcfg.TKASyncSendRequest{
Version: tailcfg.CurrentCapabilityVersion,
NodeKey: ourNodeKey,
Head: string(headBytes),
MissingAUMs: make([]tkatype.MarshaledAUM, len(aums)),
Interactive: interactive,
}
for i, a := range aums {
sendReq.MissingAUMs[i] = a.Serialize()
}
var req bytes.Buffer
if err := json.NewEncoder(&req).Encode(sendReq); err != nil {
return nil, fmt.Errorf("encoding request: %v", err)
}
ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
defer cancel()
req2, err := http.NewRequestWithContext(ctx, "GET", "https://unused/machine/tka/sync/send", &req)
if err != nil {
return nil, fmt.Errorf("req: %w", err)
}
res, err := b.DoNoiseRequest(req2)
if err != nil {
return nil, fmt.Errorf("resp: %w", err)
}
if res.StatusCode != 200 {
body, _ := io.ReadAll(res.Body)
res.Body.Close()
return nil, fmt.Errorf("request returned (%d): %s", res.StatusCode, string(body))
}
a := new(tailcfg.TKASyncSendResponse)
err = json.NewDecoder(&io.LimitedReader{R: res.Body, N: 10 * 1024 * 1024}).Decode(a)
res.Body.Close()
if err != nil {
return nil, fmt.Errorf("decoding JSON: %w", err)
}
return a, nil
}
func (b *LocalBackend) tkaDoDisablement(ourNodeKey key.NodePublic, head tka.AUMHash, secret []byte) (*tailcfg.TKADisableResponse, error) {
headBytes, err := head.MarshalText()
if err != nil {
return nil, fmt.Errorf("head.MarshalText: %w", err)
}
var req bytes.Buffer
if err := json.NewEncoder(&req).Encode(tailcfg.TKADisableRequest{
Version: tailcfg.CurrentCapabilityVersion,
NodeKey: ourNodeKey,
Head: string(headBytes),
DisablementSecret: secret,
}); err != nil {
return nil, fmt.Errorf("encoding request: %v", err)
}
ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
defer cancel()
req2, err := http.NewRequestWithContext(ctx, "GET", "https://unused/machine/tka/disable", &req)
if err != nil {
return nil, fmt.Errorf("req: %w", err)
}
res, err := b.DoNoiseRequest(req2)
if err != nil {
return nil, fmt.Errorf("resp: %w", err)
}
if res.StatusCode != 200 {
body, _ := io.ReadAll(res.Body)
res.Body.Close()
return nil, fmt.Errorf("request returned (%d): %s", res.StatusCode, string(body))
}
a := new(tailcfg.TKADisableResponse)
err = json.NewDecoder(&io.LimitedReader{R: res.Body, N: 1024 * 1024}).Decode(a)
res.Body.Close()
if err != nil {
return nil, fmt.Errorf("decoding JSON: %w", err)
}
return a, nil
}
func (b *LocalBackend) tkaSubmitSignature(ourNodeKey key.NodePublic, sig tkatype.MarshaledSignature) (*tailcfg.TKASubmitSignatureResponse, error) {
var req bytes.Buffer
if err := json.NewEncoder(&req).Encode(tailcfg.TKASubmitSignatureRequest{
Version: tailcfg.CurrentCapabilityVersion,
NodeKey: ourNodeKey,
Signature: sig,
}); err != nil {
return nil, fmt.Errorf("encoding request: %v", err)
}
ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
defer cancel()
req2, err := http.NewRequestWithContext(ctx, "GET", "https://unused/machine/tka/sign", &req)
if err != nil {
return nil, fmt.Errorf("req: %w", err)
}
res, err := b.DoNoiseRequest(req2)
if err != nil {
return nil, fmt.Errorf("resp: %w", err)
}
if res.StatusCode != 200 {
body, _ := io.ReadAll(res.Body)
res.Body.Close()
return nil, fmt.Errorf("request returned (%d): %s", res.StatusCode, string(body))
}
a := new(tailcfg.TKASubmitSignatureResponse)
err = json.NewDecoder(&io.LimitedReader{R: res.Body, N: 1024 * 1024}).Decode(a)
res.Body.Close()
if err != nil {
return nil, fmt.Errorf("decoding JSON: %w", err)
}
return a, nil
}
func (b *LocalBackend) tkaReadAffectedSigs(ourNodeKey key.NodePublic, key tkatype.KeyID) (*tailcfg.TKASignaturesUsingKeyResponse, error) {
var encodedReq bytes.Buffer
if err := json.NewEncoder(&encodedReq).Encode(tailcfg.TKASignaturesUsingKeyRequest{
Version: tailcfg.CurrentCapabilityVersion,
NodeKey: ourNodeKey,
KeyID: key,
}); err != nil {
return nil, fmt.Errorf("encoding request: %v", err)
}
ctx, cancel := context.WithTimeout(context.Background(), time.Minute)
defer cancel()
req, err := http.NewRequestWithContext(ctx, "GET", "https://unused/machine/tka/affected-sigs", &encodedReq)
if err != nil {
return nil, fmt.Errorf("req: %w", err)
}
resp, err := b.DoNoiseRequest(req)
if err != nil {
return nil, fmt.Errorf("resp: %w", err)
}
if resp.StatusCode != 200 {
body, _ := io.ReadAll(resp.Body)
resp.Body.Close()
return nil, fmt.Errorf("request returned (%d): %s", resp.StatusCode, string(body))
}
a := new(tailcfg.TKASignaturesUsingKeyResponse)
err = json.NewDecoder(&io.LimitedReader{R: resp.Body, N: 1024 * 1024}).Decode(a)
resp.Body.Close()
if err != nil {
return nil, fmt.Errorf("decoding JSON: %w", err)
}
return a, nil
}