From 47bacfd5c5d22470340e0823c4ad37b45914b68e Mon Sep 17 00:00:00 2001 From: Rasmus Dahlberg Date: Sun, 6 Jun 2021 15:59:35 +0200 Subject: started using the refactored packages in siglog server --- pkg/state/state_manager.go | 154 ++++++++++++++++ pkg/state/state_manager_test.go | 393 ++++++++++++++++++++++++++++++++++++++++ 2 files changed, 547 insertions(+) create mode 100644 pkg/state/state_manager.go create mode 100644 pkg/state/state_manager_test.go (limited to 'pkg/state') 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) + } +} -- cgit v1.2.3