diff options
Diffstat (limited to 'sth.go')
| -rw-r--r-- | sth.go | 155 |
1 files changed, 0 insertions, 155 deletions
@@ -1,155 +0,0 @@ -package stfe - -import ( - "context" - "fmt" - "reflect" - "sync" - - "github.com/golang/glog" - "github.com/google/certificate-transparency-go/schedule" - "github.com/google/trillian" - ttypes "github.com/google/trillian/types" - "github.com/system-transparency/stfe/types" -) - -// SthSource provides access to the log's STHs. -type SthSource interface { - // Latest returns the most reccent signed_tree_head_v*. - Latest(context.Context) (*types.StItem, error) - // Stable returns the most recent signed_tree_head_v* that is stable for - // some period of time, e.g., 10 minutes. - Stable(context.Context) (*types.StItem, error) - // Cosigned returns the most recent cosigned_tree_head_v*. - Cosigned(context.Context) (*types.StItem, error) - // AddCosignature attempts to add a cosignature to the stable STH. The - // passed cosigned_tree_head_v* must have a single verified cosignature. - AddCosignature(context.Context, *types.StItem) error - // Run keeps the STH source updated until cancelled - Run(context.Context) -} - -// ActiveSthSource implements the SthSource interface for an STFE instance that -// accepts new logging requests, i.e., the log is running in read+write mode. -type ActiveSthSource struct { - client trillian.TrillianLogClient - logParameters *LogParameters - currCosth *types.StItem // current cosigned_tree_head_v1 (already finalized) - nextCosth *types.StItem // next cosigned_tree_head_v1 (under preparation) - cosignatureFrom map[[types.NamespaceFingerprintSize]byte]bool // track who we got cosignatures from in nextCosth - mutex sync.RWMutex -} - -// NewActiveSthSource returns an initialized ActiveSthSource -func NewActiveSthSource(cli trillian.TrillianLogClient, lp *LogParameters) (*ActiveSthSource, error) { - s := ActiveSthSource{ - client: cli, - logParameters: lp, - } - - ctx, _ := context.WithTimeout(context.Background(), lp.Deadline) - sth, err := s.Latest(ctx) - if err != nil { - return nil, fmt.Errorf("Latest: %v", err) - } - - // TODO: load persisted cosigned STH? - s.currCosth = types.NewCosignedTreeHeadV1(sth.SignedTreeHeadV1, nil) - s.nextCosth = types.NewCosignedTreeHeadV1(sth.SignedTreeHeadV1, nil) - s.cosignatureFrom = make(map[[types.NamespaceFingerprintSize]byte]bool) - return &s, nil -} - -func (s *ActiveSthSource) Run(ctx context.Context) { - schedule.Every(ctx, s.logParameters.Interval, func(ctx context.Context) { - // get the next stable sth - ictx, _ := context.WithTimeout(ctx, s.logParameters.Deadline) - sth, err := s.Latest(ictx) - if err != nil { - glog.Warningf("cannot rotate without new sth: Latest: %v", err) - return - } - // rotate - s.mutex.Lock() - defer s.mutex.Unlock() - if err := s.rotate(sth); err != nil { - glog.Warningf("rotate failed: %v", err) - } - // TODO: persist cosigned STH? - }) -} - -func (s *ActiveSthSource) Latest(ctx context.Context) (*types.StItem, error) { - trsp, err := s.client.GetLatestSignedLogRoot(ctx, &trillian.GetLatestSignedLogRootRequest{ - LogId: s.logParameters.TreeId, - }) - var lr ttypes.LogRootV1 - if errInner := checkGetLatestSignedLogRoot(s.logParameters, trsp, err, &lr); errInner != nil { - return nil, fmt.Errorf("invalid signed log root response: %v", errInner) - } - return s.logParameters.SignTreeHeadV1(NewTreeHeadV1FromLogRoot(&lr)) -} - -func (s *ActiveSthSource) Stable(_ context.Context) (*types.StItem, error) { - s.mutex.RLock() - defer s.mutex.RUnlock() - if s.nextCosth == nil { - return nil, fmt.Errorf("no stable sth available") - } - return types.NewSignedTreeHeadV1(&s.nextCosth.CosignedTreeHeadV1.SignedTreeHead.TreeHead, &s.nextCosth.CosignedTreeHeadV1.SignedTreeHead.Signature), nil -} - -func (s *ActiveSthSource) Cosigned(_ context.Context) (*types.StItem, error) { - s.mutex.RLock() - defer s.mutex.RUnlock() - if s.currCosth == nil { - return nil, fmt.Errorf("no cosigned sth available") - } - return s.currCosth, nil -} - -func (s *ActiveSthSource) AddCosignature(_ context.Context, costh *types.StItem) error { - s.mutex.Lock() - defer s.mutex.Unlock() - if !reflect.DeepEqual(s.nextCosth.CosignedTreeHeadV1.SignedTreeHead, costh.CosignedTreeHeadV1.SignedTreeHead) { - return fmt.Errorf("cosignature covers a different tree head") - } - witness, err := costh.CosignedTreeHeadV1.Cosignatures[0].Namespace.Fingerprint() - if err != nil { - return fmt.Errorf("namespace without fingerprint: %v", err) - } - if _, ok := s.cosignatureFrom[*witness]; ok { - return nil // duplicate - } - s.cosignatureFrom[*witness] = true - s.nextCosth.CosignedTreeHeadV1.Cosignatures = append(s.nextCosth.CosignedTreeHeadV1.Cosignatures, costh.CosignedTreeHeadV1.Cosignatures[0]) - 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 (s *ActiveSthSource) rotate(fixedSth *types.StItem) error { - // rotate stable -> cosigned - if reflect.DeepEqual(&s.currCosth.CosignedTreeHeadV1.SignedTreeHead, &s.nextCosth.CosignedTreeHeadV1.SignedTreeHead) { - for _, sigv1 := range s.currCosth.CosignedTreeHeadV1.Cosignatures { - witness, err := sigv1.Namespace.Fingerprint() - if err != nil { - return fmt.Errorf("namespace without fingerprint: %v", err) - } - if _, ok := s.cosignatureFrom[*witness]; !ok { - s.cosignatureFrom[*witness] = true - s.nextCosth.CosignedTreeHeadV1.Cosignatures = append(s.nextCosth.CosignedTreeHeadV1.Cosignatures, sigv1) - } - } - } - s.currCosth.CosignedTreeHeadV1.SignedTreeHead = s.nextCosth.CosignedTreeHeadV1.SignedTreeHead - s.currCosth.CosignedTreeHeadV1.Cosignatures = make([]types.SignatureV1, len(s.nextCosth.CosignedTreeHeadV1.Cosignatures)) - copy(s.currCosth.CosignedTreeHeadV1.Cosignatures, s.nextCosth.CosignedTreeHeadV1.Cosignatures) - - // rotate new stable -> stable - if !reflect.DeepEqual(&s.nextCosth.CosignedTreeHeadV1.SignedTreeHead, fixedSth.SignedTreeHeadV1) { - s.nextCosth = types.NewCosignedTreeHeadV1(fixedSth.SignedTreeHeadV1, nil) - s.cosignatureFrom = make(map[[types.NamespaceFingerprintSize]byte]bool) - } - return nil -} |