tailscale/tka/tka_test.go

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// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package tka
import (
"bytes"
"testing"
"github.com/google/go-cmp/cmp"
)
func TestComputeChainCandidates(t *testing.T) {
c := newTestchain(t, `
G1 -> I1 -> I2 -> I3 -> L2
| -> L1 | -> L3
G2 -> L4
// We tweak these AUMs so they are different hashes.
G2.hashSeed = 2
L1.hashSeed = 2
L3.hashSeed = 2
L4.hashSeed = 3
`)
// Should result in 4 chains:
// G1->L1, G1->L2, G1->L3, G2->L4
i1H := c.AUMHashes["I1"]
got, err := computeChainCandidates(c.Chonk(), &i1H, 50)
if err != nil {
t.Fatalf("computeChainCandidates() failed: %v", err)
}
want := []chain{
{Oldest: c.AUMs["G1"], Head: c.AUMs["L1"], chainsThroughActive: true},
{Oldest: c.AUMs["G1"], Head: c.AUMs["L3"], chainsThroughActive: true},
{Oldest: c.AUMs["G1"], Head: c.AUMs["L2"], chainsThroughActive: true},
{Oldest: c.AUMs["G2"], Head: c.AUMs["L4"]},
}
if diff := cmp.Diff(want, got, cmp.AllowUnexported(chain{})); diff != "" {
t.Errorf("chains differ (-want, +got):\n%s", diff)
}
}
func TestForkResolutionHash(t *testing.T) {
c := newTestchain(t, `
G1 -> L1
| -> L2
// tweak hashes so L1 & L2 are not identical
L1.hashSeed = 2
L2.hashSeed = 3
`)
got, err := computeActiveChain(c.Chonk(), nil, 50)
if err != nil {
t.Fatalf("computeActiveChain() failed: %v", err)
}
// The fork with the lowest AUM hash should have been chosen.
l1H := c.AUMHashes["L1"]
l2H := c.AUMHashes["L2"]
want := l1H
if bytes.Compare(l2H[:], l1H[:]) < 0 {
want = l2H
}
if got := got.Head.Hash(); got != want {
t.Errorf("head was %x, want %x", got, want)
}
}
func TestForkResolutionSigWeight(t *testing.T) {
pub, priv := testingKey25519(t, 1)
key := Key{Kind: Key25519, Public: pub, Votes: 2}
c := newTestchain(t, `
G1 -> L1
| -> L2
G1.template = addKey
L1.hashSeed = 2
L2.signedWith = key
`,
optTemplate("addKey", AUM{MessageKind: AUMAddKey, Key: &key}),
optKey("key", key, priv))
l1H := c.AUMHashes["L1"]
l2H := c.AUMHashes["L2"]
if bytes.Compare(l2H[:], l1H[:]) < 0 {
t.Fatal("failed assert: h(l1) > h(l2)\nTweak hashSeed till this passes")
}
got, err := computeActiveChain(c.Chonk(), nil, 50)
if err != nil {
t.Fatalf("computeActiveChain() failed: %v", err)
}
// Based on the hash, l1H should be chosen.
// But based on the signature weight (which has higher
// precedence), it should be l2H
want := l2H
if got := got.Head.Hash(); got != want {
t.Errorf("head was %x, want %x", got, want)
}
}
func TestForkResolutionMessageType(t *testing.T) {
pub, _ := testingKey25519(t, 1)
key := Key{Kind: Key25519, Public: pub, Votes: 2}
c := newTestchain(t, `
G1 -> L1
| -> L2
| -> L3
G1.template = addKey
L1.hashSeed = 11
L2.template = removeKey
L3.hashSeed = 18
`,
optTemplate("addKey", AUM{MessageKind: AUMAddKey, Key: &key}),
optTemplate("removeKey", AUM{MessageKind: AUMRemoveKey, KeyID: key.ID()}))
l1H := c.AUMHashes["L1"]
l2H := c.AUMHashes["L2"]
l3H := c.AUMHashes["L3"]
if bytes.Compare(l2H[:], l1H[:]) < 0 {
t.Fatal("failed assert: h(l1) > h(l2)\nTweak hashSeed till this passes")
}
if bytes.Compare(l2H[:], l3H[:]) < 0 {
t.Fatal("failed assert: h(l3) > h(l2)\nTweak hashSeed till this passes")
}
got, err := computeActiveChain(c.Chonk(), nil, 50)
if err != nil {
t.Fatalf("computeActiveChain() failed: %v", err)
}
// Based on the hash, L1 or L3 should be chosen.
// But based on the preference for AUMRemoveKey messages,
// it should be L2.
want := l2H
if got := got.Head.Hash(); got != want {
t.Errorf("head was %x, want %x", got, want)
}
}
func TestComputeStateAt(t *testing.T) {
pub, _ := testingKey25519(t, 1)
key := Key{Kind: Key25519, Public: pub, Votes: 2}
c := newTestchain(t, `
G1 -> I1 -> I2
I1.template = addKey
`,
optTemplate("addKey", AUM{MessageKind: AUMAddKey, Key: &key}))
// G1 is before the key, so there shouldn't be a key there.
state, err := computeStateAt(c.Chonk(), 500, c.AUMHashes["G1"])
if err != nil {
t.Fatalf("computeStateAt(G1) failed: %v", err)
}
if _, err := state.GetKey(key.ID()); err != ErrNoSuchKey {
t.Errorf("expected key to be missing: err = %v", err)
}
if *state.LastAUMHash != c.AUMHashes["G1"] {
t.Errorf("LastAUMHash = %x, want %x", *state.LastAUMHash, c.AUMHashes["G1"])
}
// I1 & I2 are after the key, so the computed state should contain
// the key.
for _, wantHash := range []AUMHash{c.AUMHashes["I1"], c.AUMHashes["I2"]} {
state, err = computeStateAt(c.Chonk(), 500, wantHash)
if err != nil {
t.Fatalf("computeStateAt(%X) failed: %v", wantHash, err)
}
if *state.LastAUMHash != wantHash {
t.Errorf("LastAUMHash = %x, want %x", *state.LastAUMHash, wantHash)
}
if _, err := state.GetKey(key.ID()); err != nil {
t.Errorf("expected key to be present at state: err = %v", err)
}
}
}
// fakeAUM generates an AUM structure based on the template.
// If parent is provided, PrevAUMHash is set to that value.
//
// If template is an AUM, the returned AUM is based on that.
// If template is an int, a NOOP AUM is returned, and the
// provided int can be used to tweak the resulting hash (needed
// for tests you want one AUM to be 'lower' than another, so that
// that chain is taken based on fork resolution rules).
func fakeAUM(t *testing.T, template interface{}, parent *AUMHash) (AUM, AUMHash) {
if seed, ok := template.(int); ok {
a := AUM{MessageKind: AUMNoOp, KeyID: []byte{byte(seed)}}
if parent != nil {
a.PrevAUMHash = (*parent)[:]
}
h := a.Hash()
return a, h
}
if a, ok := template.(AUM); ok {
if parent != nil {
a.PrevAUMHash = (*parent)[:]
}
h := a.Hash()
return a, h
}
panic("template must be an int or an AUM")
}
func TestOpenAuthority(t *testing.T) {
pub, _ := testingKey25519(t, 1)
key := Key{Kind: Key25519, Public: pub, Votes: 2}
// /- L1
// G1 - I1 - I2 - I3 -L2
// \-L3
// G2 - L4
//
// We set the previous-known ancestor to G1, so the
// ancestor to start from should be G1.
g1, g1H := fakeAUM(t, AUM{MessageKind: AUMAddKey, Key: &key}, nil)
i1, i1H := fakeAUM(t, 2, &g1H) // AUM{MessageKind: AUMAddKey, Key: &key2}
l1, l1H := fakeAUM(t, 13, &i1H)
i2, i2H := fakeAUM(t, 2, &i1H)
i3, i3H := fakeAUM(t, 5, &i2H)
l2, l2H := fakeAUM(t, AUM{MessageKind: AUMNoOp, KeyID: []byte{7}, Signatures: []Signature{{KeyID: key.ID()}}}, &i3H)
l3, l3H := fakeAUM(t, 4, &i3H)
g2, g2H := fakeAUM(t, 8, nil)
l4, _ := fakeAUM(t, 9, &g2H)
// We make sure that I2 has a lower hash than L1, so
// it should take that path rather than L1.
if bytes.Compare(l1H[:], i2H[:]) < 0 {
t.Fatal("failed assert: h(i2) > h(l1)\nTweak parameters to fakeAUM till this passes")
}
// We make sure L2 has a signature with key, so it should
// take that path over L3. We assert that the L3 hash
// is less than L2 so the test will fail if the signature
// preference logic is broken.
if bytes.Compare(l2H[:], l3H[:]) < 0 {
t.Fatal("failed assert: h(l3) > h(l2)\nTweak parameters to fakeAUM till this passes")
}
// Construct the state of durable storage.
chonk := &Mem{}
err := chonk.CommitVerifiedAUMs([]AUM{g1, i1, l1, i2, i3, l2, l3, g2, l4})
if err != nil {
t.Fatal(err)
}
chonk.SetLastActiveAncestor(i1H)
a, err := Open(chonk)
if err != nil {
t.Fatalf("New() failed: %v", err)
}
// Should include the key added in G1
if _, err := a.state.GetKey(key.ID()); err != nil {
t.Errorf("missing G1 key: %v", err)
}
// The head of the chain should be L2.
if a.Head() != l2H {
t.Errorf("head was %x, want %x", a.state.LastAUMHash, l2H)
}
}
func TestOpenAuthority_EmptyErrors(t *testing.T) {
_, err := Open(&Mem{})
if err == nil {
t.Error("Expected an error initializing an empty authority, got nil")
}
}
func TestAuthorityHead(t *testing.T) {
c := newTestchain(t, `
G1 -> L1
| -> L2
L1.hashSeed = 2
`)
a, _ := Open(c.Chonk())
if got, want := a.head.Hash(), a.Head(); got != want {
t.Errorf("Hash() returned %x, want %x", got, want)
}
}
func TestCreateBootstrapAuthority(t *testing.T) {
pub, priv := testingKey25519(t, 1)
key := Key{Kind: Key25519, Public: pub, Votes: 2}
a1, genesisAUM, err := Create(&Mem{}, State{
Keys: []Key{key},
DisablementSecrets: [][]byte{disablementKDF([]byte{1, 2, 3})},
}, priv)
if err != nil {
t.Fatalf("Create() failed: %v", err)
}
a2, err := Bootstrap(&Mem{}, genesisAUM)
if err != nil {
t.Fatalf("Bootstrap() failed: %v", err)
}
if a1.Head() != a2.Head() {
t.Fatal("created and bootstrapped authority differ")
}
// Both authorities should trust the key laid down in the genesis state.
if _, err := a1.state.GetKey(key.ID()); err != nil {
t.Errorf("reading genesis key from a1: %v", err)
}
if _, err := a2.state.GetKey(key.ID()); err != nil {
t.Errorf("reading genesis key from a2: %v", err)
}
}
func TestAuthorityInform(t *testing.T) {
pub, priv := testingKey25519(t, 1)
key := Key{Kind: Key25519, Public: pub, Votes: 2}
c := newTestchain(t, `
G1 -> L1
| -> L2 -> L3
| -> L4 -> L5
G1.template = genesis
L2.hashSeed = 1
L4.hashSeed = 2
`,
optTemplate("genesis", AUM{MessageKind: AUMCheckpoint, State: &State{
Keys: []Key{key},
DisablementSecrets: [][]byte{disablementKDF([]byte{1, 2, 3})},
}}),
optKey("key", key, priv),
optSignAllUsing("key"))
storage := &Mem{}
a, err := Bootstrap(storage, c.AUMs["G1"])
if err != nil {
t.Fatalf("Bootstrap() failed: %v", err)
}
informAUMs := []AUM{c.AUMs["L1"], c.AUMs["L2"], c.AUMs["L3"], c.AUMs["L4"], c.AUMs["L5"]}
if err := a.Inform(informAUMs); err != nil {
t.Fatalf("Inform() failed: %v", err)
}
for i, update := range informAUMs {
stored, err := storage.AUM(update.Hash())
if err != nil {
t.Errorf("reading stored update %d: %v", i, err)
continue
}
if diff := cmp.Diff(update, stored); diff != "" {
t.Errorf("update %d differs (-want, +got):\n%s", i, diff)
}
}
if a.Head() != c.AUMHashes["L3"] {
t.Fatal("authority did not converge to correct AUM")
}
}