// decodeTimestamp decodes and verifies timestamp metadata, and returns the
// new snapshot file meta.
func (c *Client) decodeTimestamp(b json.RawMessage) (data.FileMeta, error) {
timestamp := &data.Timestamp{}
if err := signed.Unmarshal(b, timestamp, "timestamp", c.timestampVer, c.db); err != nil {
return data.FileMeta{}, ErrDecodeFailed{"timestamp.json", err}
}
c.timestampVer = timestamp.Version
return timestamp.Meta["snapshot.json"], nil
}
// decodeSnapshot decodes and verifies snapshot metadata, and returns the new
// root and targets file meta.
func (c *Client) decodeSnapshot(b json.RawMessage) (data.FileMeta, data.FileMeta, error) {
snapshot := &data.Snapshot{}
if err := signed.Unmarshal(b, snapshot, "snapshot", c.snapshotVer, c.db); err != nil {
return data.FileMeta{}, data.FileMeta{}, ErrDecodeFailed{"snapshot.json", err}
}
c.snapshotVer = snapshot.Version
return snapshot.Meta["root.json"], snapshot.Meta["targets.json"], nil
}
// decodeRoot decodes and verifies root metadata.
func (c *Client) decodeRoot(b json.RawMessage) error {
root := &data.Root{}
if err := signed.Unmarshal(b, root, "root", c.rootVer, c.db); err != nil {
return ErrDecodeFailed{"root.json", err}
}
c.rootVer = root.Version
c.consistentSnapshot = root.ConsistentSnapshot
return nil
}
// decodeTargets decodes and verifies targets metadata, sets c.targets and
// returns updated targets.
func (c *Client) decodeTargets(b json.RawMessage) (data.Files, error) {
targets := &data.Targets{}
if err := signed.Unmarshal(b, targets, "targets", c.targetsVer, c.db); err != nil {
return nil, ErrDecodeFailed{"targets.json", err}
}
updatedTargets := make(data.Files)
for path, meta := range targets.Targets {
if local, ok := c.targets[path]; ok {
if err := util.FileMetaEqual(local, meta); err == nil {
continue
}
}
updatedTargets[path] = meta
}
c.targetsVer = targets.Version
c.targets = targets.Targets
return updatedTargets, nil
}