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tka: implement consensus & state computation internals
Signed-off-by: Tom DNetto <tom@tailscale.com>
This commit is contained in:
Tom DNetto
Tom
parent
af412e8874
commit
4f1374ec9e
365
tka/chaintest_test.go
Normal file
365
tka/chaintest_test.go
Normal file
@ -0,0 +1,365 @@
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// Copyright (c) 2022 Tailscale Inc & AUTHORS All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package tka
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import (
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"bytes"
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"crypto/ed25519"
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"fmt"
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"strconv"
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"strings"
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"testing"
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"text/scanner"
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"github.com/google/go-cmp/cmp"
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"github.com/google/go-cmp/cmp/cmpopts"
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)
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// chaintest_test.go implements test helpers for concisely describing
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// chains of possibly signed AUMs, to assist in making tests shorter and
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// easier to read.
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// parsed representation of a named AUM in a test chain.
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type testchainNode struct {
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Name string
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Parent string
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Uses []scanner.Position
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HashSeed int
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Template string
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SignedWith string
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}
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// testChain represents a constructed web of AUMs for testing purposes.
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type testChain struct {
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Nodes map[string]*testchainNode
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AUMs map[string]AUM
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AUMHashes map[string]AUMHash
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// Configured by options to NewTestchain()
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Template map[string]AUM
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Key map[string]*Key
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KeyPrivs map[string]ed25519.PrivateKey
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SignAllKeys []string
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}
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// newTestchain constructs a web of AUMs based on the provided input and
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// options.
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//
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// Input is expected to be a graph & tweaks, looking like this:
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//
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// G1 -> A -> B
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// | -> C
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//
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// which defines AUMs G1, A, B, and C; with G1 having no parent, A having
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// G1 as a parent, and both B & C having A as a parent.
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//
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// Tweaks are specified like this:
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//
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// <AUM>.<tweak> = <value>
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//
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// for example: G1.hashSeed = 2
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//
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// There are 3 available tweaks:
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// - hashSeed: Set to an integer to tweak the AUM hash of that AUM.
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// - template: Set to the name of a template provided via optTemplate().
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// The template is copied and use as the content for that AUM.
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// - signedWith: Set to the name of a key provided via optKey(). This
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// key is used to sign that AUM.
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func newTestchain(t *testing.T, input string, options ...testchainOpt) *testChain {
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t.Helper()
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var (
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s scanner.Scanner
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out = testChain{
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Nodes: map[string]*testchainNode{},
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Template: map[string]AUM{},
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Key: map[string]*Key{},
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KeyPrivs: map[string]ed25519.PrivateKey{},
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}
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)
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// Process any options
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for _, o := range options {
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if o.Template != nil {
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out.Template[o.Name] = *o.Template
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}
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if o.Key != nil {
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out.Key[o.Name] = o.Key
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out.KeyPrivs[o.Name] = o.Private
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}
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if o.SignAllWith {
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out.SignAllKeys = append(out.SignAllKeys, o.Name)
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}
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}
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s.Init(strings.NewReader(input))
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s.Mode = scanner.ScanIdents | scanner.SkipComments | scanner.ScanComments | scanner.ScanChars | scanner.ScanInts
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s.Whitespace ^= 1 << '\t' // clear tabs
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var (
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lastIdent string
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lastWasChain bool // if the last token was '->'
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)
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for tok := s.Scan(); tok != scanner.EOF; tok = s.Scan() {
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switch tok {
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case '\t':
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t.Fatalf("tabs disallowed, use spaces (seen at %v)", s.Pos())
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case '.': // tweaks, like <ident>.hashSeed = <val>
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s.Scan()
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tweak := s.TokenText()
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if tok := s.Scan(); tok == '=' {
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s.Scan()
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switch tweak {
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case "hashSeed":
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out.Nodes[lastIdent].HashSeed, _ = strconv.Atoi(s.TokenText())
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case "template":
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out.Nodes[lastIdent].Template = s.TokenText()
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case "signedWith":
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out.Nodes[lastIdent].SignedWith = s.TokenText()
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}
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}
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case scanner.Ident:
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out.recordPos(s.TokenText(), s.Pos())
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// If the last token was '->', that means
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// that the next identifier has a child relationship
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// with the identifier preceeding '->'.
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if lastWasChain {
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out.recordParent(t, s.TokenText(), lastIdent)
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}
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lastIdent = s.TokenText()
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case '-': // handle '->'
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switch s.Peek() {
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case '>':
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s.Scan()
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lastWasChain = true
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continue
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}
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case '|': // handle '|'
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line, col := s.Pos().Line, s.Pos().Column
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nodeLoop:
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for _, n := range out.Nodes {
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for _, p := range n.Uses {
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// Find the identifier used right here on the line above.
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if p.Line == line-1 && col <= p.Column && col > p.Column-len(n.Name) {
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lastIdent = n.Name
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out.recordPos(n.Name, s.Pos())
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break nodeLoop
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}
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}
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}
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}
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lastWasChain = false
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// t.Logf("tok = %v, %q", tok, s.TokenText())
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}
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out.buildChain()
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return &out
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}
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// called from the parser to record the location of an
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// identifier (a named AUM).
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func (c *testChain) recordPos(ident string, pos scanner.Position) {
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n := c.Nodes[ident]
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if n == nil {
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n = &testchainNode{Name: ident}
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}
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n.Uses = append(n.Uses, pos)
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c.Nodes[ident] = n
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}
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// called from the parser to record a parent relationship between
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// two AUMs.
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func (c *testChain) recordParent(t *testing.T, child, parent string) {
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if p := c.Nodes[child].Parent; p != "" && p != parent {
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t.Fatalf("differing parent specified for %s: %q != %q", child, p, parent)
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}
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c.Nodes[child].Parent = parent
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}
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// called after parsing to build the web of AUM structures.
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// This method populates c.AUMs and c.AUMHashes.
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func (c *testChain) buildChain() {
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pending := make(map[string]*testchainNode, len(c.Nodes))
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for k, v := range c.Nodes {
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pending[k] = v
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}
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// AUMs with a parent need to know their hash, so we
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// only compute AUMs who's parents have been computed
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// each iteration. Since at least the genesis AUM
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// had no parent, theres always a path to completion
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// in O(n+1) where n is the number of AUMs.
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c.AUMs = make(map[string]AUM, len(c.Nodes))
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c.AUMHashes = make(map[string]AUMHash, len(c.Nodes))
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for i := 0; i < len(c.Nodes)+1; i++ {
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if len(pending) == 0 {
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return
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}
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next := make([]*testchainNode, 0, 10)
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for _, v := range pending {
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if _, parentPending := pending[v.Parent]; !parentPending {
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next = append(next, v)
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}
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}
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for _, v := range next {
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aum := c.makeAUM(v)
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h := aum.Hash()
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c.AUMHashes[v.Name] = h
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c.AUMs[v.Name] = aum
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delete(pending, v.Name)
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}
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}
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panic("unexpected: incomplete despite len(Nodes)+1 iterations")
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}
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func (c *testChain) makeAUM(v *testchainNode) AUM {
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// By default, the AUM used is just a no-op AUM
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// with a parent hash set (if any).
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//
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// If <AUM>.template is set to the same name as in
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// a provided optTemplate(), the AUM is built
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// from a copy of that instead.
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//
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// If <AUM>.hashSeed = <int> is set, the KeyID is
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// tweaked to effect tweaking the hash. This is useful
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// if you want one AUM to have a lower hash than another.
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aum := AUM{MessageKind: AUMNoOp}
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if template := v.Template; template != "" {
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aum = c.Template[template]
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}
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if v.Parent != "" {
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parentHash := c.AUMHashes[v.Parent]
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aum.PrevAUMHash = parentHash[:]
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}
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if seed := v.HashSeed; seed != 0 {
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aum.KeyID = []byte{byte(seed)}
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}
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if err := aum.StaticValidate(); err != nil {
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// Usually caused by a test writer specifying a template
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// AUM which is ultimately invalid.
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panic(fmt.Sprintf("aum %+v failed static validation: %v", aum, err))
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}
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sigHash := aum.SigHash()
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for _, key := range c.SignAllKeys {
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aum.Signatures = append(aum.Signatures, Signature{
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KeyID: c.Key[key].ID(),
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Signature: ed25519.Sign(c.KeyPrivs[key], sigHash[:]),
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})
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}
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// If the aum was specified as being signed by some key, then
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// sign it using that key.
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if key := v.SignedWith; key != "" {
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aum.Signatures = append(aum.Signatures, Signature{
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KeyID: c.Key[key].ID(),
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Signature: ed25519.Sign(c.KeyPrivs[key], sigHash[:]),
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})
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}
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return aum
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}
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// Chonk returns a tailchonk containing all AUMs.
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func (c *testChain) Chonk() Chonk {
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var out Mem
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for _, update := range c.AUMs {
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if err := out.CommitVerifiedAUMs([]AUM{update}); err != nil {
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panic(err)
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}
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}
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return &out
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}
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// ChonkWith returns a tailchonk containing the named AUMs.
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func (c *testChain) ChonkWith(names ...string) Chonk {
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var out Mem
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for _, name := range names {
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update := c.AUMs[name]
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if err := out.CommitVerifiedAUMs([]AUM{update}); err != nil {
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panic(err)
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}
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}
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return &out
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}
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type testchainOpt struct {
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Name string
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Template *AUM
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Key *Key
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Private ed25519.PrivateKey
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SignAllWith bool
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}
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func optTemplate(name string, template AUM) testchainOpt {
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return testchainOpt{
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Name: name,
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Template: &template,
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}
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}
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func optKey(name string, key Key, priv ed25519.PrivateKey) testchainOpt {
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return testchainOpt{
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Name: name,
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Key: &key,
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Private: priv,
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}
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}
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func optSignAllUsing(keyName string) testchainOpt {
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return testchainOpt{
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Name: keyName,
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SignAllWith: true,
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}
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}
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func TestNewTestchain(t *testing.T) {
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c := newTestchain(t, `
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genesis -> B -> C
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| -> D
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| -> E -> F
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E.hashSeed = 12 // tweak E to have the lowest hash so its chosen
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F.template = test
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`, optTemplate("test", AUM{MessageKind: AUMNoOp, KeyID: []byte{10}}))
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want := map[string]*testchainNode{
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"genesis": &testchainNode{Name: "genesis", Uses: []scanner.Position{{Line: 2, Column: 16}}},
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"B": &testchainNode{
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Name: "B",
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Parent: "genesis",
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Uses: []scanner.Position{{Line: 2, Column: 21}, {Line: 3, Column: 21}, {Line: 4, Column: 21}},
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},
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"C": &testchainNode{Name: "C", Parent: "B", Uses: []scanner.Position{{Line: 2, Column: 26}}},
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"D": &testchainNode{Name: "D", Parent: "B", Uses: []scanner.Position{{Line: 3, Column: 26}}},
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"E": &testchainNode{Name: "E", Parent: "B", HashSeed: 12, Uses: []scanner.Position{{Line: 4, Column: 26}, {Line: 6, Column: 10}}},
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"F": &testchainNode{Name: "F", Parent: "E", Template: "test", Uses: []scanner.Position{{Line: 4, Column: 31}, {Line: 7, Column: 10}}},
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}
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if diff := cmp.Diff(want, c.Nodes, cmpopts.IgnoreFields(scanner.Position{}, "Offset")); diff != "" {
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t.Errorf("decoded state differs (-want, +got):\n%s", diff)
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}
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if !bytes.Equal(c.AUMs["F"].KeyID, []byte{10}) {
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t.Errorf("AUM 'F' missing KeyID from template: %v", c.AUMs["F"])
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}
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// chonk := c.Chonk()
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// authority, err := Open(chonk)
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// if err != nil {
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// t.Errorf("failed to initialize from chonk: %v", err)
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// }
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// if authority.Head() != c.AUMHashes["F"] {
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// t.Errorf("head = %X, want %X", authority.Head(), c.AUMHashes["F"])
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// }
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}
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332
tka/tka.go
332
tka/tka.go
@ -4,3 +4,335 @@
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// Package tka (WIP) implements the Tailnet Key Authority.
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package tka
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import (
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"bytes"
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"errors"
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"fmt"
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"os"
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"sort"
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)
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// A chain describes a linear sequence of updates from Oldest to Head,
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// resulting in some State at Head.
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type chain struct {
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Oldest AUM
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Head AUM
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state State
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// Set to true if the AUM chain intersects with the active
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// chain from a previous run.
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chainsThroughActive bool
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}
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// computeChainCandidates returns all possible chains based on AUMs stored
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// in the given tailchonk. A chain is defined as a unique (oldest, newest)
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// AUM tuple. chain.state is not yet populated in returned chains.
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//
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// If lastKnownOldest is provided, any chain that includes the given AUM
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// has the chainsThroughActive field set to true. This bit is leveraged
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// in computeActiveAncestor() to filter out irrelevant chains when determining
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// the active ancestor from a list of distinct chains.
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func computeChainCandidates(storage Chonk, lastKnownOldest *AUMHash, maxIter int) ([]chain, error) {
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heads, err := storage.Heads()
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if err != nil {
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return nil, fmt.Errorf("reading heads: %v", err)
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}
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candidates := make([]chain, len(heads))
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for i := range heads {
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// Oldest is iteratively computed below.
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candidates[i] = chain{Oldest: heads[i], Head: heads[i]}
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}
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// Not strictly necessary, but simplifies checks in tests.
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sort.Slice(candidates, func(i, j int) bool {
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ih, jh := candidates[i].Oldest.Hash(), candidates[j].Oldest.Hash()
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return bytes.Compare(ih[:], jh[:]) < 0
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})
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// candidates.Oldest needs to be computed by working backwards from
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// head as far as we can.
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iterAgain := true // if theres still work to be done.
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for i := 0; iterAgain; i++ {
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if i >= maxIter {
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return nil, fmt.Errorf("iteration limit exceeded (%d)", maxIter)
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}
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iterAgain = false
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for j := range candidates {
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parent, hasParent := candidates[j].Oldest.Parent()
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if hasParent {
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parent, err := storage.AUM(parent)
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if err != nil {
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if err == os.ErrNotExist {
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continue
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}
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return nil, fmt.Errorf("reading parent: %v", err)
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}
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candidates[j].Oldest = parent
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if lastKnownOldest != nil && *lastKnownOldest == parent.Hash() {
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candidates[j].chainsThroughActive = true
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}
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iterAgain = true
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}
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}
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}
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return candidates, nil
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}
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// pickNextAUM returns the AUM which should be used as the next
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// AUM in the chain, possibly applying fork resolution logic.
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//
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// In other words: given an AUM with 3 children like this:
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// / - 1
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// P - 2
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// \ - 3
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//
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// pickNextAUM will determine and return the correct branch.
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//
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// This method takes ownership of the provided slice.
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func pickNextAUM(state State, candidates []AUM) AUM {
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switch len(candidates) {
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case 0:
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panic("pickNextAUM called with empty candidate set")
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case 1:
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return candidates[0]
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}
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// Oooof, we have some forks in the chain. We need to pick which
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// one to use by applying the Fork Resolution Algorithm ✨
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//
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// The rules are this:
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// 1. The child with the highest signature weight is chosen.
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// 2. If equal, the child which is a RemoveKey AUM is chosen.
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// 3. If equal, the child with the lowest AUM hash is chosen.
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sort.Slice(candidates, func(j, i int) bool {
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// Rule 1.
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iSigWeight, jSigWeight := candidates[i].Weight(state), candidates[j].Weight(state)
|
||||
if iSigWeight != jSigWeight {
|
||||
return iSigWeight < jSigWeight
|
||||
}
|
||||
|
||||
// Rule 2.
|
||||
if iKind, jKind := candidates[i].MessageKind, candidates[j].MessageKind; iKind != jKind &&
|
||||
(iKind == AUMRemoveKey || jKind == AUMRemoveKey) {
|
||||
return jKind == AUMRemoveKey
|
||||
}
|
||||
|
||||
// Rule 3.
|
||||
iHash, jHash := candidates[i].Hash(), candidates[j].Hash()
|
||||
return bytes.Compare(iHash[:], jHash[:]) > 0
|
||||
})
|
||||
|
||||
return candidates[0]
|
||||
}
|
||||
|
||||
// advanceChain computes the next AUM to advance with based on all child
|
||||
// AUMs, returning the chosen AUM & the state obtained by applying that
|
||||
// AUM.
|
||||
//
|
||||
// The return value for next is nil if there are no children AUMs, hence
|
||||
// the provided state is at head (up to date).
|
||||
func advanceChain(state State, candidates []AUM) (next *AUM, out State, err error) {
|
||||
if len(candidates) == 0 {
|
||||
return nil, state, nil
|
||||
}
|
||||
|
||||
aum := pickNextAUM(state, candidates)
|
||||
if state, err = state.applyVerifiedAUM(aum); err != nil {
|
||||
return nil, State{}, fmt.Errorf("advancing state: %v", err)
|
||||
}
|
||||
return &aum, state, nil
|
||||
}
|
||||
|
||||
// fastForward iteratively advances the current state based on known AUMs until
|
||||
// the given termination function returns true or there is no more progress possible.
|
||||
//
|
||||
// The last-processed AUM, and the state computed after applying the last AUM,
|
||||
// are returned.
|
||||
func fastForward(storage Chonk, maxIter int, startState State, done func(curAUM AUM, curState State) bool) (AUM, State, error) {
|
||||
if startState.LastAUMHash == nil {
|
||||
return AUM{}, State{}, errors.New("invalid initial state")
|
||||
}
|
||||
nextAUM, err := storage.AUM(*startState.LastAUMHash)
|
||||
if err != nil {
|
||||
return AUM{}, State{}, fmt.Errorf("reading next: %v", err)
|
||||
}
|
||||
|
||||
curs := nextAUM
|
||||
state := startState
|
||||
for i := 0; i < maxIter; i++ {
|
||||
if done != nil && done(curs, state) {
|
||||
return curs, state, nil
|
||||
}
|
||||
|
||||
children, err := storage.ChildAUMs(curs.Hash())
|
||||
if err != nil {
|
||||
return AUM{}, State{}, fmt.Errorf("getting children of %X: %v", curs.Hash(), err)
|
||||
}
|
||||
next, nextState, err := advanceChain(state, children)
|
||||
if err != nil {
|
||||
return AUM{}, State{}, fmt.Errorf("advance %X: %v", curs.Hash(), err)
|
||||
}
|
||||
if next == nil {
|
||||
// There were no more children, we are at 'head'.
|
||||
return curs, state, nil
|
||||
}
|
||||
curs = *next
|
||||
state = nextState
|
||||
}
|
||||
|
||||
return AUM{}, State{}, fmt.Errorf("iteration limit exceeded (%d)", maxIter)
|
||||
}
|
||||
|
||||
// computeStateAt returns the State at wantHash.
|
||||
func computeStateAt(storage Chonk, maxIter int, wantHash AUMHash) (State, error) {
|
||||
// TODO(tom): This is going to get expensive for really long
|
||||
// chains. We should make nodes emit a checkpoint every
|
||||
// X updates or something.
|
||||
|
||||
topAUM, err := storage.AUM(wantHash)
|
||||
if err != nil {
|
||||
return State{}, err
|
||||
}
|
||||
|
||||
// Iterate backwards till we find a starting point to compute
|
||||
// the state from.
|
||||
//
|
||||
// Valid starting points are either a checkpoint AUM, or a
|
||||
// genesis AUM.
|
||||
curs := topAUM
|
||||
var state State
|
||||
for i := 0; true; i++ {
|
||||
if i > maxIter {
|
||||
return State{}, fmt.Errorf("iteration limit exceeded (%d)", maxIter)
|
||||
}
|
||||
|
||||
// Checkpoints encapsulate the state at that point, dope.
|
||||
if curs.MessageKind == AUMCheckpoint {
|
||||
state = curs.State.cloneForUpdate(&curs)
|
||||
break
|
||||
}
|
||||
parent, hasParent := curs.Parent()
|
||||
if !hasParent {
|
||||
// This is a 'genesis' update: there are none before it, so
|
||||
// this AUM can be applied to the empty state to determine
|
||||
// the state at this AUM.
|
||||
//
|
||||
// It is only valid for NoOp, AddKey, and Checkpoint AUMs
|
||||
// to be a genesis update. Checkpoint was handled earlier.
|
||||
if mk := curs.MessageKind; mk == AUMNoOp || mk == AUMAddKey {
|
||||
var err error
|
||||
if state, err = (State{}).applyVerifiedAUM(curs); err != nil {
|
||||
return State{}, fmt.Errorf("applying genesis (%+v): %v", curs, err)
|
||||
}
|
||||
break
|
||||
}
|
||||
return State{}, fmt.Errorf("invalid genesis update: %+v", curs)
|
||||
}
|
||||
|
||||
// If we got here, the current state is dependent on the previous.
|
||||
// Keep iterating backwards till thats not the case.
|
||||
if curs, err = storage.AUM(parent); err != nil {
|
||||
return State{}, fmt.Errorf("reading parent: %v", err)
|
||||
}
|
||||
}
|
||||
|
||||
// We now know some starting point state. Iterate forward till we
|
||||
// are at the AUM we want state for.
|
||||
_, state, err = fastForward(storage, maxIter, state, func(curs AUM, _ State) bool {
|
||||
return curs.Hash() == wantHash
|
||||
})
|
||||
// fastForward only terminates before the done condition if it
|
||||
// doesnt have any later AUMs to process. This cant be the case
|
||||
// as we've already iterated through them above so they must exist,
|
||||
// but we check anyway to be super duper sure.
|
||||
if err == nil && *state.LastAUMHash != wantHash {
|
||||
panic("unexpected fastForward outcome")
|
||||
}
|
||||
return state, err
|
||||
}
|
||||
|
||||
// computeActiveAncestor determines which ancestor AUM to use as the
|
||||
// ancestor of the valid chain.
|
||||
//
|
||||
// If all the chains end up having the same ancestor, then thats the
|
||||
// only possible ancestor, ezpz. However if there are multiple distinct
|
||||
// ancestors, that means there are distinct chains, and we need some
|
||||
// hint to choose what to use. For that, we rely on the chainsThroughActive
|
||||
// bit, which signals to us that that ancestor was part of the
|
||||
// chain in a previous run.
|
||||
func computeActiveAncestor(storage Chonk, chains []chain) (AUMHash, error) {
|
||||
// Dedupe possible ancestors, tracking if they were part of
|
||||
// the active chain on a previous run.
|
||||
ancestors := make(map[AUMHash]bool, len(chains))
|
||||
for _, c := range chains {
|
||||
ancestors[c.Oldest.Hash()] = c.chainsThroughActive
|
||||
}
|
||||
|
||||
if len(ancestors) == 1 {
|
||||
// There's only one. DOPE.
|
||||
for k, _ := range ancestors {
|
||||
return k, nil
|
||||
}
|
||||
}
|
||||
|
||||
// Theres more than one, so we need to use the ancestor that was
|
||||
// part of the active chain in a previous iteration.
|
||||
// Note that there can only be one distinct ancestor that was
|
||||
// formerly part of the active chain, because AUMs can only have
|
||||
// one parent and would have converged to a common ancestor.
|
||||
for k, chainsThroughActive := range ancestors {
|
||||
if chainsThroughActive {
|
||||
return k, nil
|
||||
}
|
||||
}
|
||||
|
||||
return AUMHash{}, errors.New("multiple distinct chains")
|
||||
}
|
||||
|
||||
// computeActiveChain bootstraps the runtime state of the Authority when
|
||||
// starting entirely off stored state.
|
||||
//
|
||||
// TODO(tom): Don't look at head states, just iterate forward from
|
||||
// the ancestor.
|
||||
//
|
||||
// The algorithm is as follows:
|
||||
// 1. Determine all possible 'head' (like in git) states.
|
||||
// 2. Filter these possible chains based on whether the ancestor was
|
||||
// formerly (in a previous run) part of the chain.
|
||||
// 3. Compute the state of the state machine at this ancestor. This is
|
||||
// needed for fast-forward, as each update operates on the state of
|
||||
// the update preceeding it.
|
||||
// 4. Iteratively apply updates till we reach head ('fast forward').
|
||||
func computeActiveChain(storage Chonk, lastKnownOldest *AUMHash, maxIter int) (chain, error) {
|
||||
chains, err := computeChainCandidates(storage, lastKnownOldest, maxIter)
|
||||
if err != nil {
|
||||
return chain{}, fmt.Errorf("computing candidates: %v", err)
|
||||
}
|
||||
|
||||
// Find the right ancestor.
|
||||
oldestHash, err := computeActiveAncestor(storage, chains)
|
||||
if err != nil {
|
||||
return chain{}, fmt.Errorf("computing ancestor: %v", err)
|
||||
}
|
||||
ancestor, err := storage.AUM(oldestHash)
|
||||
if err != nil {
|
||||
return chain{}, err
|
||||
}
|
||||
|
||||
// At this stage we know the ancestor AUM, so we have excluded distinct
|
||||
// chains but we might still have forks (so we don't know the head AUM).
|
||||
//
|
||||
// We iterate forward from the ancestor AUM, handling any forks as we go
|
||||
// till we arrive at a head.
|
||||
out := chain{Oldest: ancestor, Head: ancestor}
|
||||
if out.state, err = computeStateAt(storage, maxIter, oldestHash); err != nil {
|
||||
return chain{}, fmt.Errorf("bootstrapping state: %v", err)
|
||||
}
|
||||
out.Head, out.state, err = fastForward(storage, maxIter, out.state, nil)
|
||||
if err != nil {
|
||||
return chain{}, fmt.Errorf("fast forward: %v", err)
|
||||
}
|
||||
return out, nil
|
||||
}
|
||||
|
||||
187
tka/tka_test.go
Normal file
187
tka/tka_test.go
Normal file
@ -0,0 +1,187 @@
|
||||
// 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)
|
||||
}
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user