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-rw-r--r--pkg/state/state_manager.go154
-rw-r--r--pkg/state/state_manager_test.go393
2 files changed, 547 insertions, 0 deletions
diff --git a/pkg/state/state_manager.go b/pkg/state/state_manager.go
new file mode 100644
index 0000000..dfa73f4
--- /dev/null
+++ b/pkg/state/state_manager.go
@@ -0,0 +1,154 @@
+package state
+
+import (
+ "context"
+ "crypto"
+ "fmt"
+ "reflect"
+ "sync"
+ "time"
+
+ "github.com/golang/glog"
+ "github.com/google/certificate-transparency-go/schedule"
+ "github.com/system-transparency/stfe/pkg/trillian"
+ "github.com/system-transparency/stfe/pkg/types"
+)
+
+// StateManager coordinates access to the log's tree heads and (co)signatures
+type StateManager interface {
+ Latest(context.Context) (*types.SignedTreeHead, error)
+ ToSign(context.Context) (*types.SignedTreeHead, error)
+ Cosigned(context.Context) (*types.SignedTreeHead, error)
+ AddCosignature(context.Context, *[types.VerificationKeySize]byte, *[types.SignatureSize]byte) error
+ Run(context.Context)
+}
+
+// StateManagerSingle implements the StateManager interface. It is assumed that
+// the log server is running on a single-instance machine. So, no coordination.
+type StateManagerSingle struct {
+ client trillian.Client
+ signer crypto.Signer
+ interval time.Duration
+ deadline time.Duration
+ sync.RWMutex
+
+ // cosigned is the current cosigned tree head that is being served
+ cosigned types.SignedTreeHead
+
+ // tosign is the current tree head that is being cosigned by witnesses
+ tosign types.SignedTreeHead
+
+ // cosignature keeps track of all cosignatures for the tosign tree head
+ cosignature map[[types.HashSize]byte]*types.SigIdent
+}
+
+func NewStateManagerSingle(client trillian.Client, signer crypto.Signer, interval, deadline time.Duration) (*StateManagerSingle, error) {
+ sm := &StateManagerSingle{
+ client: client,
+ signer: signer,
+ interval: interval,
+ deadline: deadline,
+ }
+
+ ctx, _ := context.WithTimeout(context.Background(), sm.deadline)
+ sth, err := sm.Latest(ctx)
+ if err != nil {
+ return nil, fmt.Errorf("Latest: %v", err)
+ }
+
+ sm.cosigned = *sth
+ sm.tosign = *sth
+ sm.cosignature = map[[types.HashSize]byte]*types.SigIdent{
+ *sth.SigIdent[0].KeyHash: sth.SigIdent[0], // log signature
+ }
+ return sm, nil
+}
+
+func (sm *StateManagerSingle) Run(ctx context.Context) {
+ schedule.Every(ctx, sm.interval, func(ctx context.Context) {
+ ictx, _ := context.WithTimeout(ctx, sm.deadline)
+ nextTreeHead, err := sm.Latest(ictx)
+ if err != nil {
+ glog.Warningf("rotate failed: Latest: %v", err)
+ return
+ }
+
+ sm.Lock()
+ defer sm.Unlock()
+ sm.rotate(nextTreeHead)
+ })
+}
+
+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)
+ }
+ sth, err := th.Sign(sm.signer)
+ if err != nil {
+ return nil, fmt.Errorf("sign: %v", err)
+ }
+ return sth, nil
+}
+
+func (sm *StateManagerSingle) ToSign(_ context.Context) (*types.SignedTreeHead, error) {
+ sm.RLock()
+ defer sm.RUnlock()
+ return &sm.tosign, nil
+}
+
+func (sm *StateManagerSingle) Cosigned(_ context.Context) (*types.SignedTreeHead, error) {
+ sm.RLock()
+ defer sm.RUnlock()
+ return &sm.cosigned, nil
+}
+
+func (sm *StateManagerSingle) AddCosignature(_ context.Context, vk *[types.VerificationKeySize]byte, sig *[types.SignatureSize]byte) error {
+ sm.Lock()
+ defer sm.Unlock()
+
+ if err := sm.tosign.TreeHead.Verify(vk, sig); err != nil {
+ return fmt.Errorf("Verify: %v", err)
+ }
+ witness := types.Hash(vk[:])
+ if _, ok := sm.cosignature[*witness]; ok {
+ return fmt.Errorf("signature-signer pair is a duplicate")
+ }
+ sm.cosignature[*witness] = &types.SigIdent{
+ Signature: sig,
+ KeyHash: witness,
+ }
+
+ glog.V(3).Infof("accepted new cosignature from witness: %x", *witness)
+ return nil
+}
+
+// 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.TreeHead, sm.tosign.TreeHead) {
+ // cosigned and tosign are the same. So, we need to merge all
+ // cosignatures that we already had with the new collected ones.
+ for _, sigident := range sm.cosigned.SigIdent {
+ if _, ok := sm.cosignature[*sigident.KeyHash]; !ok {
+ sm.cosignature[*sigident.KeyHash] = sigident
+ }
+ }
+ glog.V(3).Infof("cosigned tree head repeated, merged signatures")
+ }
+ var cosignatures []*types.SigIdent
+ for _, sigident := range sm.cosignature {
+ cosignatures = append(cosignatures, sigident)
+ }
+
+ // Update cosigned tree head
+ sm.cosigned.TreeHead = sm.tosign.TreeHead
+ sm.cosigned.SigIdent = cosignatures
+
+ // Update to-sign tree head
+ sm.tosign = *next
+ sm.cosignature = map[[types.HashSize]byte]*types.SigIdent{
+ *next.SigIdent[0].KeyHash: next.SigIdent[0], // log signature
+ }
+ glog.V(3).Infof("rotated tree heads")
+}
diff --git a/pkg/state/state_manager_test.go b/pkg/state/state_manager_test.go
new file mode 100644
index 0000000..08990cc
--- /dev/null
+++ b/pkg/state/state_manager_test.go
@@ -0,0 +1,393 @@
+package state
+
+import (
+ "bytes"
+ "context"
+ "crypto"
+ "crypto/ed25519"
+ "crypto/rand"
+ "fmt"
+ "reflect"
+ "testing"
+ "time"
+
+ "github.com/golang/mock/gomock"
+ "github.com/system-transparency/stfe/pkg/mocks"
+ "github.com/system-transparency/stfe/pkg/types"
+)
+
+var (
+ testSig = &[types.SignatureSize]byte{}
+ testPub = &[types.VerificationKeySize]byte{}
+ testTH = &types.TreeHead{
+ Timestamp: 0,
+ TreeSize: 0,
+ RootHash: types.Hash(nil),
+ }
+ testSigIdent = &types.SigIdent{
+ Signature: testSig,
+ KeyHash: types.Hash(testPub[:]),
+ }
+ testSTH = &types.SignedTreeHead{
+ TreeHead: *testTH,
+ SigIdent: []*types.SigIdent{testSigIdent},
+ }
+ testSignerOK = &mocks.TestSigner{testPub, testSig, nil}
+ testSignerErr = &mocks.TestSigner{testPub, testSig, fmt.Errorf("something went wrong")}
+)
+
+func TestNewStateManagerSingle(t *testing.T) {
+ for _, table := range []struct {
+ description string
+ signer crypto.Signer
+ rsp *types.TreeHead
+ err error
+ wantErr bool
+ wantSth *types.SignedTreeHead
+ }{
+ {
+ description: "invalid: backend failure",
+ signer: testSignerOK,
+ err: fmt.Errorf("something went wrong"),
+ wantErr: true,
+ },
+ {
+ description: "valid",
+ signer: testSignerOK,
+ rsp: testTH,
+ wantSth: testSTH,
+ },
+ } {
+ // Run deferred functions at the end of each iteration
+ func() {
+ ctrl := gomock.NewController(t)
+ defer ctrl.Finish()
+ client := mocks.NewMockClient(ctrl)
+ client.EXPECT().GetTreeHead(gomock.Any()).Return(table.rsp, table.err)
+
+ sm, err := NewStateManagerSingle(client, table.signer, time.Duration(0), time.Duration(0))
+ if got, want := err != nil, table.wantErr; got != want {
+ t.Errorf("got error %v but wanted %v in test %q: %v", got, want, table.description, err)
+ }
+ if err != nil {
+ return
+ }
+ if got, want := &sm.cosigned, table.wantSth; !reflect.DeepEqual(got, want) {
+ t.Errorf("got cosigned tree head\n\t%v\nbut wanted\n\t%v\nin test %q", got, want, table.description)
+ }
+ if got, want := &sm.tosign, table.wantSth; !reflect.DeepEqual(got, want) {
+ t.Errorf("got tosign tree head\n\t%v\nbut wanted\n\t%v\nin test %q", got, want, table.description)
+ }
+ // we only have log signature on startup
+ if got, want := len(sm.cosignature), 1; got != want {
+ t.Errorf("got %d cosignatures but wanted %d in test %q", got, want, table.description)
+ }
+ }()
+ }
+}
+
+func TestLatest(t *testing.T) {
+ for _, table := range []struct {
+ description string
+ signer crypto.Signer
+ rsp *types.TreeHead
+ err error
+ wantErr bool
+ wantSth *types.SignedTreeHead
+ }{
+ {
+ description: "invalid: backend failure",
+ signer: testSignerOK,
+ err: fmt.Errorf("something went wrong"),
+ wantErr: true,
+ },
+ {
+ description: "invalid: signature failure",
+ rsp: testTH,
+ signer: testSignerErr,
+ wantErr: true,
+ },
+ {
+ description: "valid",
+ signer: testSignerOK,
+ rsp: testTH,
+ wantSth: testSTH,
+ },
+ } {
+ // Run deferred functions at the end of each iteration
+ func() {
+ ctrl := gomock.NewController(t)
+ defer ctrl.Finish()
+ client := mocks.NewMockClient(ctrl)
+ client.EXPECT().GetTreeHead(gomock.Any()).Return(table.rsp, table.err)
+ sm := StateManagerSingle{
+ client: client,
+ signer: table.signer,
+ }
+
+ sth, err := sm.Latest(context.Background())
+ if got, want := err != nil, table.wantErr; got != want {
+ t.Errorf("got error %v but wanted %v in test %q: %v", got, want, table.description, err)
+ }
+ if err != nil {
+ return
+ }
+ if got, want := sth, table.wantSth; !reflect.DeepEqual(got, want) {
+ t.Errorf("got signed tree head\n\t%v\nbut wanted\n\t%v\nin test %q", got, want, table.description)
+ }
+ }()
+ }
+}
+
+func TestToSign(t *testing.T) {
+ description := "valid"
+ sm := StateManagerSingle{
+ tosign: *testSTH,
+ }
+ sth, err := sm.ToSign(context.Background())
+ if err != nil {
+ t.Errorf("ToSign should not fail with error: %v", err)
+ return
+ }
+ if got, want := sth, testSTH; !reflect.DeepEqual(got, want) {
+ t.Errorf("got signed tree head\n\t%v\nbut wanted\n\t%v\nin test %q", got, want, description)
+ }
+}
+
+func TestCosigned(t *testing.T) {
+ description := "valid"
+ sm := StateManagerSingle{
+ cosigned: *testSTH,
+ }
+ sth, err := sm.Cosigned(context.Background())
+ if err != nil {
+ t.Errorf("Cosigned should not fail with error: %v", err)
+ return
+ }
+ if got, want := sth, testSTH; !reflect.DeepEqual(got, want) {
+ t.Errorf("got signed tree head\n\t%v\nbut wanted\n\t%v\nin test %q", got, want, description)
+ }
+}
+
+func TestAddCosignature(t *testing.T) {
+ vk, sk, err := ed25519.GenerateKey(rand.Reader)
+ if err != nil {
+ t.Fatalf("GenerateKey: %v", err)
+ }
+ if bytes.Equal(vk[:], testPub[:]) {
+ t.Fatalf("Sampled same key as testPub, aborting...")
+ }
+ var vkArray [types.VerificationKeySize]byte
+ copy(vkArray[:], vk[:])
+
+ for _, table := range []struct {
+ description string
+ signer crypto.Signer
+ vk *[types.VerificationKeySize]byte
+ th *types.TreeHead
+ wantErr bool
+ }{
+ {
+ description: "invalid: signature error",
+ signer: sk,
+ vk: testPub, // wrong key for message
+ th: testTH,
+ wantErr: true,
+ },
+ {
+ description: "valid",
+ signer: sk,
+ vk: &vkArray,
+ th: testTH,
+ },
+ } {
+ sth, _ := table.th.Sign(testSignerOK)
+ logKeyHash := sth.SigIdent[0].KeyHash
+ logSigIdent := sth.SigIdent[0]
+ sm := &StateManagerSingle{
+ signer: testSignerOK,
+ cosigned: *sth,
+ tosign: *sth,
+ cosignature: map[[types.HashSize]byte]*types.SigIdent{
+ *logKeyHash: logSigIdent,
+ },
+ }
+
+ // Prepare witness signature
+ sth, err := table.th.Sign(table.signer)
+ if err != nil {
+ t.Fatalf("Sign: %v", err)
+ }
+ witnessKeyHash := sth.SigIdent[0].KeyHash
+ witnessSigIdent := sth.SigIdent[0]
+
+ // Add witness signature
+ err = sm.AddCosignature(context.Background(), table.vk, witnessSigIdent.Signature)
+ if got, want := err != nil, table.wantErr; got != want {
+ t.Errorf("got error %v but wanted %v in test %q: %v", got, want, table.description, err)
+ }
+ if err != nil {
+ continue
+ }
+
+ // We should have two signatures (log + witness)
+ if got, want := len(sm.cosignature), 2; got != want {
+ t.Errorf("got %d cosignatures but wanted %v in test %q", got, want, table.description)
+ continue
+ }
+ // check that log signature is there
+ sigident, ok := sm.cosignature[*logKeyHash]
+ if !ok {
+ t.Errorf("log signature is missing")
+ continue
+ }
+ if got, want := sigident, logSigIdent; !reflect.DeepEqual(got, want) {
+ t.Errorf("got log sigident\n\t%v\nbut wanted\n\t%v\nin test %q", got, want, table.description)
+ }
+ // check that witness signature is there
+ sigident, ok = sm.cosignature[*witnessKeyHash]
+ if !ok {
+ t.Errorf("witness signature is missing")
+ continue
+ }
+ if got, want := sigident, witnessSigIdent; !reflect.DeepEqual(got, want) {
+ t.Errorf("got witness sigident\n\t%v\nbut wanted\n\t%v\nin test %q", got, want, table.description)
+ continue
+ }
+
+ // Adding a duplicate signature should give an error
+ if err := sm.AddCosignature(context.Background(), table.vk, witnessSigIdent.Signature); err == nil {
+ t.Errorf("duplicate witness signature accepted as valid")
+ }
+ }
+}
+
+func TestRotate(t *testing.T) {
+ log := testSigIdent
+ wit1 := &types.SigIdent{
+ Signature: testSig,
+ KeyHash: types.Hash([]byte("wit1 key")),
+ }
+ wit2 := &types.SigIdent{
+ Signature: testSig,
+ KeyHash: types.Hash([]byte("wit2 key")),
+ }
+ th0 := testTH
+ th1 := &types.TreeHead{
+ Timestamp: 1,
+ TreeSize: 1,
+ RootHash: types.Hash([]byte("1")),
+ }
+ th2 := &types.TreeHead{
+ Timestamp: 2,
+ TreeSize: 2,
+ RootHash: types.Hash([]byte("2")),
+ }
+
+ for _, table := range []struct {
+ description string
+ before, after *StateManagerSingle
+ next *types.SignedTreeHead
+ }{
+ {
+ description: "tosign tree head repated, but got one new witnes signature",
+ before: &StateManagerSingle{
+ cosigned: types.SignedTreeHead{
+ TreeHead: *th0,
+ SigIdent: []*types.SigIdent{log, wit1},
+ },
+ tosign: types.SignedTreeHead{
+ TreeHead: *th0,
+ SigIdent: []*types.SigIdent{log},
+ },
+ cosignature: map[[types.HashSize]byte]*types.SigIdent{
+ *log.KeyHash: log,
+ *wit2.KeyHash: wit2, // the new witness signature
+ },
+ },
+ next: &types.SignedTreeHead{
+ TreeHead: *th1,
+ SigIdent: []*types.SigIdent{log},
+ },
+ after: &StateManagerSingle{
+ cosigned: types.SignedTreeHead{
+ TreeHead: *th0,
+ SigIdent: []*types.SigIdent{log, wit1, wit2},
+ },
+ tosign: types.SignedTreeHead{
+ TreeHead: *th1,
+ SigIdent: []*types.SigIdent{log},
+ },
+ cosignature: map[[types.HashSize]byte]*types.SigIdent{
+ *log.KeyHash: log, // after rotate we always have log sig
+ },
+ },
+ },
+ {
+ description: "tosign tree head did not repeat, it got one witness signature",
+ before: &StateManagerSingle{
+ cosigned: types.SignedTreeHead{
+ TreeHead: *th0,
+ SigIdent: []*types.SigIdent{log, wit1},
+ },
+ tosign: types.SignedTreeHead{
+ TreeHead: *th1,
+ SigIdent: []*types.SigIdent{log},
+ },
+ cosignature: map[[types.HashSize]byte]*types.SigIdent{
+ *log.KeyHash: log,
+ *wit2.KeyHash: wit2, // the only witness that signed tosign
+ },
+ },
+ next: &types.SignedTreeHead{
+ TreeHead: *th2,
+ SigIdent: []*types.SigIdent{log},
+ },
+ after: &StateManagerSingle{
+ cosigned: types.SignedTreeHead{
+ TreeHead: *th1,
+ SigIdent: []*types.SigIdent{log, wit2},
+ },
+ tosign: types.SignedTreeHead{
+ TreeHead: *th2,
+ SigIdent: []*types.SigIdent{log},
+ },
+ cosignature: map[[types.HashSize]byte]*types.SigIdent{
+ *log.KeyHash: log, // after rotate we always have log sig
+ },
+ },
+ },
+ } {
+ table.before.rotate(table.next)
+ if got, want := table.before.cosigned.TreeHead, table.after.cosigned.TreeHead; !reflect.DeepEqual(got, want) {
+ t.Errorf("got cosigned tree head\n\t%v\nbut wanted\n\t%v\nin test %q", got, want, table.description)
+ }
+ checkWitnessList(t, table.description, table.before.cosigned.SigIdent, table.after.cosigned.SigIdent)
+ if got, want := table.before.tosign.TreeHead, table.after.tosign.TreeHead; !reflect.DeepEqual(got, want) {
+ t.Errorf("got tosign tree head\n\t%v\nbut wanted\n\t%v\nin test %q", got, want, table.description)
+ }
+ checkWitnessList(t, table.description, table.before.tosign.SigIdent, table.after.tosign.SigIdent)
+ if got, want := table.before.cosignature, table.after.cosignature; !reflect.DeepEqual(got, want) {
+ t.Errorf("got cosignature map\n\t%v\nbut wanted\n\t%v\nin test %q", got, want, table.description)
+ }
+ }
+}
+
+func checkWitnessList(t *testing.T, description string, got, want []*types.SigIdent) {
+ t.Helper()
+ for _, si := range got {
+ found := false
+ for _, sj := range want {
+ if reflect.DeepEqual(si, sj) {
+ found = true
+ break
+ }
+ }
+ if !found {
+ t.Errorf("got unexpected signature-signer pair with key hash in test %q: %x", description, si.KeyHash[:])
+ }
+ }
+ if len(got) != len(want) {
+ t.Errorf("got %d signature-signer pairs but wanted %d in test %q", len(got), len(want), description)
+ }
+}
generated by cgit v1.2.3 (git 2.46.0) at 2025-10-31 11:40:45 +0000