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-rw-r--r--pkg/state/single.go203
1 files changed, 106 insertions, 97 deletions
diff --git a/pkg/state/single.go b/pkg/state/single.go
index d02b86f..5c69232 100644
--- a/pkg/state/single.go
+++ b/pkg/state/single.go
@@ -5,152 +5,161 @@ import (
"crypto"
"crypto/ed25519"
"fmt"
- "reflect"
"sync"
"time"
"git.sigsum.org/sigsum-lib-go/pkg/types"
"git.sigsum.org/sigsum-log-go/pkg/db"
"github.com/golang/glog"
- "github.com/google/certificate-transparency-go/schedule"
)
-// StateManagerSingle implements a single-instance StateManager. In other
-// words, there's no other state that needs to be synced on any remote machine.
+// StateManagerSingle implements a single-instance StateManager
type StateManagerSingle struct {
- client db.Client
- signer crypto.Signer
- interval time.Duration
- deadline time.Duration
+ client db.Client
+ signer crypto.Signer
+ namespace types.Hash
+ interval time.Duration
+ deadline time.Duration
+
+ // Lock-protected access to pointers. A write lock is only obtained once
+ // per interval when doing pointer rotation. All endpoints are readers.
sync.RWMutex
+ signedTreeHead *types.SignedTreeHead
+ cosignedTreeHead *types.CosignedTreeHead
- // cosigned is the current cosigned tree head that is being served
- cosigned types.CosignedTreeHead
-
- // toSign is the current tree head that is being cosigned by witnesses
- toSign types.SignedTreeHead
-
- // cosignatures keep track of all cosignatures for the toSign tree head
+ // Syncronized and deduplicated witness cosignatures for signedTreeHead
+ events chan *event
cosignatures map[types.Hash]*types.Signature
}
func NewStateManagerSingle(client db.Client, signer crypto.Signer, interval, deadline time.Duration) (*StateManagerSingle, error) {
sm := &StateManagerSingle{
- client: client,
- signer: signer,
- interval: interval,
- deadline: deadline,
+ client: client,
+ signer: signer,
+ namespace: *types.HashFn(signer.Public().(ed25519.PublicKey)),
+ interval: interval,
+ deadline: deadline,
}
- ctx, cancel := context.WithTimeout(context.Background(), sm.deadline)
- defer cancel()
-
- sth, err := sm.Latest(ctx)
- if err != nil {
- return nil, fmt.Errorf("Latest: %v", err)
- }
- sm.toSign = *sth
- sm.cosignatures = make(map[types.Hash]*types.Signature)
- sm.cosigned = types.CosignedTreeHead{
- SignedTreeHead: *sth,
- Cosignature: make([]types.Signature, 0),
- KeyHash: make([]types.Hash, 0),
- }
- return sm, nil
+ sth, err := sm.latestSTH(context.Background())
+ sm.setCosignedTreeHead()
+ sm.setToCosignTreeHead(sth)
+ return sm, err
}
func (sm *StateManagerSingle) Run(ctx context.Context) {
- schedule.Every(ctx, sm.interval, func(ctx context.Context) {
- ictx, cancel := context.WithTimeout(ctx, sm.deadline)
- defer cancel()
-
- nextSTH, err := sm.Latest(ictx)
+ rotation := func() {
+ nextSTH, err := sm.latestSTH(ctx)
if err != nil {
- glog.Warningf("rotate failed: Latest: %v", err)
+ glog.Warningf("cannot rotate without tree head: %v", err)
return
}
-
- sm.Lock()
- defer sm.Unlock()
sm.rotate(nextSTH)
- })
-}
-
-func (sm *StateManagerSingle) Latest(ctx context.Context) (*types.SignedTreeHead, error) {
- th, err := sm.client.GetTreeHead(ctx)
- if err != nil {
- return nil, fmt.Errorf("LatestTreeHead: %v", err)
}
+ sm.events = make(chan *event, 4096)
+ defer close(sm.events)
+ ticker := time.NewTicker(sm.interval)
+ defer ticker.Stop()
+
+ rotation()
+ for {
+ select {
+ case <-ticker.C:
+ rotation()
+ case ev := <-sm.events:
+ sm.handleEvent(ev)
+ case <-ctx.Done():
+ return
+ }
+ }
+}
- namespace := types.HashFn(sm.signer.Public().(ed25519.PublicKey))
- return th.Sign(sm.signer, namespace)
+func (sm *StateManagerSingle) ToCosignTreeHead(_ context.Context) (*types.SignedTreeHead, error) {
+ sm.RLock()
+ defer sm.RUnlock()
+ return sm.signedTreeHead, nil
}
-func (sm *StateManagerSingle) ToSign(_ context.Context) (*types.SignedTreeHead, error) {
+func (sm *StateManagerSingle) CosignedTreeHead(_ context.Context) (*types.CosignedTreeHead, error) {
sm.RLock()
defer sm.RUnlock()
- return &sm.toSign, nil
+ if sm.cosignedTreeHead == nil {
+ return nil, fmt.Errorf("no cosignatures available")
+ }
+ return sm.cosignedTreeHead, nil
}
-func (sm *StateManagerSingle) Cosigned(_ context.Context) (*types.CosignedTreeHead, error) {
+func (sm *StateManagerSingle) AddCosignature(ctx context.Context, pub *types.PublicKey, sig *types.Signature) error {
sm.RLock()
defer sm.RUnlock()
- if len(sm.cosigned.Cosignature) == 0 {
- return nil, fmt.Errorf("no witness cosignatures available")
+
+ msg := sm.signedTreeHead.TreeHead.ToBinary(&sm.namespace)
+ if !ed25519.Verify(ed25519.PublicKey(pub[:]), msg, sig[:]) {
+ return fmt.Errorf("invalid cosignature")
+ }
+ select {
+ case sm.events <- &event{types.HashFn(pub[:]), sig}:
+ return nil
+ case <-ctx.Done():
+ return fmt.Errorf("request timeout")
}
- return &sm.cosigned, nil
}
-func (sm *StateManagerSingle) AddCosignature(_ context.Context, vk *types.PublicKey, sig *types.Signature) error {
+func (sm *StateManagerSingle) rotate(nextSTH *types.SignedTreeHead) {
sm.Lock()
defer sm.Unlock()
- namespace := types.HashFn(sm.signer.Public().(ed25519.PublicKey))
- msg := sm.toSign.TreeHead.ToBinary(namespace)
- if !ed25519.Verify(ed25519.PublicKey(vk[:]), msg, sig[:]) {
- return fmt.Errorf("invalid tree head signature")
- }
+ glog.V(3).Infof("rotating tree heads")
+ sm.handleEvents()
+ sm.setCosignedTreeHead()
+ sm.setToCosignTreeHead(nextSTH)
+}
- witness := types.HashFn(vk[:])
- if _, ok := sm.cosignatures[*witness]; ok {
- return fmt.Errorf("signature-signer pair is a duplicate") // TODO: maybe not an error
+func (sm *StateManagerSingle) handleEvents() {
+ glog.V(3).Infof("handling any outstanding events")
+ for i, n := 0, len(sm.events); i < n; i++ {
+ sm.handleEvent(<-sm.events)
}
- sm.cosignatures[*witness] = sig
+}
- glog.V(3).Infof("accepted new cosignature from witness: %x", *witness)
- return nil
+func (sm *StateManagerSingle) handleEvent(ev *event) {
+ glog.V(3).Infof("handling event from witness %x", ev.keyHash[:])
+ sm.cosignatures[*ev.keyHash] = ev.cosignature
}
-// rotate rotates the log's cosigned and stable STH. The caller must aquire the
-// source's read-write lock if there are concurrent reads and/or writes.
-func (sm *StateManagerSingle) rotate(next *types.SignedTreeHead) {
- if reflect.DeepEqual(sm.cosigned.SignedTreeHead, sm.toSign) {
- // cosigned and toSign are the same. So, we need to merge all
- // cosignatures that we already had with the new collected ones.
- for i := 0; i < len(sm.cosigned.Cosignature); i++ {
- kh := sm.cosigned.KeyHash[i]
- sig := sm.cosigned.Cosignature[i]
-
- if _, ok := sm.cosignatures[kh]; !ok {
- sm.cosignatures[kh] = &sig
- }
- }
- glog.V(3).Infof("cosigned tree head repeated, merged signatures")
+func (sm *StateManagerSingle) setCosignedTreeHead() {
+ n := len(sm.cosignatures)
+ if n == 0 {
+ sm.cosignedTreeHead = nil
+ return
}
- var cosignatures []types.Signature
- var keyHashes []types.Hash
+ var cth types.CosignedTreeHead
+ cth.SignedTreeHead = *sm.signedTreeHead
+ cth.Cosignature = make([]types.Signature, 0, n)
+ cth.KeyHash = make([]types.Hash, 0, n)
for keyHash, cosignature := range sm.cosignatures {
- cosignatures = append(cosignatures, *cosignature)
- keyHashes = append(keyHashes, keyHash)
+ cth.KeyHash = append(cth.KeyHash, keyHash)
+ cth.Cosignature = append(cth.Cosignature, *cosignature)
}
+ sm.cosignedTreeHead = &cth
+}
- // Update cosigned tree head
- sm.cosigned.SignedTreeHead = sm.toSign
- sm.cosigned.Cosignature = cosignatures
- sm.cosigned.KeyHash = keyHashes
+func (sm *StateManagerSingle) setToCosignTreeHead(nextSTH *types.SignedTreeHead) {
+ sm.cosignatures = make(map[types.Hash]*types.Signature)
+ sm.signedTreeHead = nextSTH
+}
+
+func (sm *StateManagerSingle) latestSTH(ctx context.Context) (*types.SignedTreeHead, error) {
+ ictx, cancel := context.WithTimeout(ctx, sm.deadline)
+ defer cancel()
- // Update to-sign tree head
- sm.toSign = *next
- sm.cosignatures = make(map[types.Hash]*types.Signature, 0) // TODO: on repeat we might want to not zero this
- glog.V(3).Infof("rotated tree heads")
+ th, err := sm.client.GetTreeHead(ictx)
+ if err != nil {
+ return nil, fmt.Errorf("failed fetching tree head: %v", err)
+ }
+ sth, err := th.Sign(sm.signer, &sm.namespace)
+ if err != nil {
+ return nil, fmt.Errorf("failed signing tree head: %v", err)
+ }
+ return sth, nil
}
generated by cgit v1.2.3 (git 2.25.1) at 2024-05-19 17:10:48 +0000