package repository import ( "bytes" "crypto/sha256" "encoding/json" "errors" "fmt" "io" "io/ioutil" "sync" "github.com/restic/restic/backend" "github.com/restic/restic/chunker" "github.com/restic/restic/crypto" "github.com/restic/restic/debug" "github.com/restic/restic/pack" ) // Repository is used to access a repository in a backend. type Repository struct { be backend.Backend Config Config key *crypto.Key keyName string idx *Index pm sync.Mutex packs []*pack.Packer } // New returns a new repository with backend be. func New(be backend.Backend) *Repository { return &Repository{ be: be, idx: NewIndex(), } } // Find loads the list of all blobs of type t and searches for names which start // with prefix. If none is found, nil and ErrNoIDPrefixFound is returned. If // more than one is found, nil and ErrMultipleIDMatches is returned. func (r *Repository) Find(t backend.Type, prefix string) (string, error) { return backend.Find(r.be, t, prefix) } // PrefixLength returns the number of bytes required so that all prefixes of // all IDs of type t are unique. func (r *Repository) PrefixLength(t backend.Type) (int, error) { return backend.PrefixLength(r.be, t) } // LoadAndDecrypt loads and decrypts data identified by t and id from the // backend. func (r *Repository) LoadAndDecrypt(t backend.Type, id backend.ID) ([]byte, error) { debug.Log("Repo.Load", "load %v with id %v", t, id.Str()) // load blob from pack rd, err := r.be.Get(t, id.String()) if err != nil { debug.Log("Repo.Load", "error loading %v: %v", id.Str(), err) return nil, err } buf, err := ioutil.ReadAll(rd) if err != nil { return nil, err } err = rd.Close() if err != nil { return nil, err } // check hash if !backend.Hash(buf).Equal(id) { return nil, errors.New("invalid data returned") } // decrypt plain, err := r.Decrypt(buf) if err != nil { return nil, err } return plain, nil } // LoadBlob tries to load and decrypt content identified by t and id from a // pack from the backend. func (r *Repository) LoadBlob(t pack.BlobType, id backend.ID) ([]byte, error) { debug.Log("Repo.LoadBlob", "load %v with id %v", t, id.Str()) // lookup pack packID, tpe, offset, length, err := r.idx.Lookup(id) if err != nil { debug.Log("Repo.LoadBlob", "id %v not found in index: %v", id.Str(), err) return nil, err } if tpe != t { debug.Log("Repo.LoadBlob", "wrong type returned for %v: wanted %v, got %v", id.Str(), t, tpe) return nil, fmt.Errorf("blob has wrong type %v (wanted: %v)", tpe, t) } debug.Log("Repo.LoadBlob", "id %v found in pack %v at offset %v (length %d)", id.Str(), packID.Str(), offset, length) // load blob from pack rd, err := r.be.GetReader(backend.Data, packID.String(), offset, length) if err != nil { debug.Log("Repo.LoadBlob", "error loading pack %v for %v: %v", packID.Str(), id.Str(), err) return nil, err } buf, err := ioutil.ReadAll(rd) if err != nil { return nil, err } err = rd.Close() if err != nil { return nil, err } // decrypt plain, err := r.Decrypt(buf) if err != nil { return nil, err } // check hash if !backend.Hash(plain).Equal(id) { return nil, errors.New("invalid data returned") } return plain, nil } // LoadJSONUnpacked decrypts the data and afterwards calls json.Unmarshal on // the item. func (r *Repository) LoadJSONUnpacked(t backend.Type, id backend.ID, item interface{}) error { // load blob from backend rd, err := r.be.Get(t, id.String()) if err != nil { return err } defer rd.Close() // decrypt decryptRd, err := crypto.DecryptFrom(r.key, rd) defer decryptRd.Close() if err != nil { return err } // decode decoder := json.NewDecoder(decryptRd) err = decoder.Decode(item) if err != nil { return err } return nil } // LoadJSONPack calls LoadBlob() to load a blob from the backend, decrypt the // data and afterwards call json.Unmarshal on the item. func (r *Repository) LoadJSONPack(t pack.BlobType, id backend.ID, item interface{}) error { // lookup pack packID, _, offset, length, err := r.idx.Lookup(id) if err != nil { return err } // load blob from pack rd, err := r.be.GetReader(backend.Data, packID.String(), offset, length) if err != nil { return err } defer rd.Close() // decrypt decryptRd, err := crypto.DecryptFrom(r.key, rd) defer decryptRd.Close() if err != nil { return err } // decode decoder := json.NewDecoder(decryptRd) err = decoder.Decode(item) if err != nil { return err } return nil } const minPackSize = 4 * chunker.MiB const maxPackSize = 16 * chunker.MiB const maxPackers = 200 // findPacker returns a packer for a new blob of size bytes. Either a new one is // created or one is returned that already has some blobs. func (r *Repository) findPacker(size uint) (*pack.Packer, error) { r.pm.Lock() defer r.pm.Unlock() // search for a suitable packer if len(r.packs) > 0 { debug.Log("Repo.findPacker", "searching packer for %d bytes\n", size) for i, p := range r.packs { if p.Size()+size < maxPackSize { debug.Log("Repo.findPacker", "found packer %v", p) // remove from list r.packs = append(r.packs[:i], r.packs[i+1:]...) return p, nil } } } // no suitable packer found, return new blob, err := r.be.Create() if err != nil { return nil, err } debug.Log("Repo.findPacker", "create new pack %p", blob) return pack.NewPacker(r.key, blob), nil } // insertPacker appends p to s.packs. func (r *Repository) insertPacker(p *pack.Packer) { r.pm.Lock() defer r.pm.Unlock() r.packs = append(r.packs, p) debug.Log("Repo.insertPacker", "%d packers\n", len(r.packs)) } // savePacker stores p in the backend. func (r *Repository) savePacker(p *pack.Packer) error { debug.Log("Repo.savePacker", "save packer with %d blobs\n", p.Count()) _, err := p.Finalize() if err != nil { return err } // move file to the final location sid := p.ID() err = p.Writer().(backend.Blob).Finalize(backend.Data, sid.String()) if err != nil { debug.Log("Repo.savePacker", "blob Finalize() error: %v", err) return err } debug.Log("Repo.savePacker", "saved as %v", sid.Str()) // update blobs in the index for _, b := range p.Blobs() { debug.Log("Repo.savePacker", " updating blob %v to pack %v", b.ID.Str(), sid.Str()) r.idx.Store(b.Type, b.ID, sid, b.Offset, uint(b.Length)) } return nil } // countPacker returns the number of open (unfinished) packers. func (r *Repository) countPacker() int { r.pm.Lock() defer r.pm.Unlock() return len(r.packs) } // SaveAndEncrypt encrypts data and stores it to the backend as type t. If data is small // enough, it will be packed together with other small blobs. func (r *Repository) SaveAndEncrypt(t pack.BlobType, data []byte, id backend.ID) (backend.ID, error) { if id == nil { // compute plaintext hash id = backend.Hash(data) } debug.Log("Repo.Save", "save id %v (%v, %d bytes)", id.Str(), t, len(data)) // get buf from the pool ciphertext := getBuf() defer freeBuf(ciphertext) // encrypt blob ciphertext, err := r.Encrypt(ciphertext, data) if err != nil { return nil, err } // find suitable packer and add blob packer, err := r.findPacker(uint(len(ciphertext))) if err != nil { return nil, err } // save ciphertext packer.Add(t, id, bytes.NewReader(ciphertext)) // add this id to the index, although we don't know yet in which pack it // will be saved, the entry will be updated when the pack is written. r.idx.Store(t, id, nil, 0, 0) debug.Log("Repo.Save", "saving stub for %v (%v) in index", id.Str, t) // if the pack is not full enough and there are less than maxPackers // packers, put back to the list if packer.Size() < minPackSize && r.countPacker() < maxPackers { debug.Log("Repo.Save", "pack is not full enough (%d bytes)", packer.Size()) r.insertPacker(packer) return id, nil } // else write the pack to the backend return id, r.savePacker(packer) } // SaveFrom encrypts data read from rd and stores it in a pack in the backend as type t. func (r *Repository) SaveFrom(t pack.BlobType, id backend.ID, length uint, rd io.Reader) error { debug.Log("Repo.SaveFrom", "save id %v (%v, %d bytes)", id.Str(), t, length) if id == nil { return errors.New("id is nil") } buf, err := ioutil.ReadAll(rd) if err != nil { return err } _, err = r.SaveAndEncrypt(t, buf, id) if err != nil { return err } return nil } // SaveJSON serialises item as JSON and encrypts and saves it in a pack in the // backend as type t. func (r *Repository) SaveJSON(t pack.BlobType, item interface{}) (backend.ID, error) { debug.Log("Repo.SaveJSON", "save %v blob", t) buf := getBuf()[:0] defer freeBuf(buf) wr := bytes.NewBuffer(buf) enc := json.NewEncoder(wr) err := enc.Encode(item) if err != nil { return nil, fmt.Errorf("json.Encode: %v", err) } buf = wr.Bytes() return r.SaveAndEncrypt(t, buf, nil) } // SaveJSONUnpacked serialises item as JSON and encrypts and saves it in the // backend as type t, without a pack. It returns the storage hash. func (r *Repository) SaveJSONUnpacked(t backend.Type, item interface{}) (backend.ID, error) { // create file blob, err := r.be.Create() if err != nil { return nil, err } debug.Log("Repo.SaveJSONUnpacked", "create new blob %v", t) // hash hw := backend.NewHashingWriter(blob, sha256.New()) // encrypt blob ewr := crypto.EncryptTo(r.key, hw) enc := json.NewEncoder(ewr) err = enc.Encode(item) if err != nil { return nil, fmt.Errorf("json.Encode: %v", err) } err = ewr.Close() if err != nil { return nil, err } // finalize blob in the backend sid := backend.ID(hw.Sum(nil)) err = blob.Finalize(t, sid.String()) if err != nil { debug.Log("Repo.SaveJSONUnpacked", "error saving blob %v as %v: %v", t, sid, err) return nil, err } debug.Log("Repo.SaveJSONUnpacked", "new blob %v saved as %v", t, sid) return sid, nil } // Flush saves all remaining packs. func (r *Repository) Flush() error { r.pm.Lock() defer r.pm.Unlock() debug.Log("Repo.Flush", "manually flushing %d packs", len(r.packs)) for _, p := range r.packs { err := r.savePacker(p) if err != nil { return err } } r.packs = r.packs[:0] return nil } // Backend returns the backend for the repository. func (r *Repository) Backend() backend.Backend { return r.be } // Index returns the currently loaded Index. func (r *Repository) Index() *Index { return r.idx } // SetIndex instructs the repository to use the given index. func (r *Repository) SetIndex(i *Index) { r.idx = i } // SaveIndex saves all new packs in the index in the backend, returned is the // storage ID. func (r *Repository) SaveIndex() (backend.ID, error) { debug.Log("Repo.SaveIndex", "Saving index") // create blob blob, err := r.be.Create() if err != nil { return nil, err } debug.Log("Repo.SaveIndex", "create new pack %p", blob) // hash hw := backend.NewHashingWriter(blob, sha256.New()) // encrypt blob ewr := crypto.EncryptTo(r.key, hw) err = r.idx.Encode(ewr) if err != nil { return nil, err } err = ewr.Close() if err != nil { return nil, err } // finalize blob in the backend sid := backend.ID(hw.Sum(nil)) err = blob.Finalize(backend.Index, sid.String()) if err != nil { return nil, err } debug.Log("Repo.SaveIndex", "Saved index as %v", sid.Str()) return sid, nil } const loadIndexParallelism = 20 // LoadIndex loads all index files from the backend in parallel and merges them // with the current index. The first error that occurred is returned. func (r *Repository) LoadIndex() error { debug.Log("Repo.LoadIndex", "Loading index") errCh := make(chan error, 1) indexes := make(chan *Index) worker := func(id string, done <-chan struct{}) error { idx, err := LoadIndex(r, id) if err != nil { return err } select { case indexes <- idx: case <-done: } return nil } go func() { defer close(indexes) errCh <- FilesInParallel(r.be, backend.Index, loadIndexParallelism, worker) }() for idx := range indexes { r.idx.Merge(idx) } if err := <-errCh; err != nil { return err } return nil } // LoadIndex loads the index id from backend and returns it. func LoadIndex(repo *Repository, id string) (*Index, error) { debug.Log("LoadIndex", "Loading index %v", id[:8]) rd, err := repo.be.Get(backend.Index, id) defer rd.Close() if err != nil { return nil, err } // decrypt decryptRd, err := crypto.DecryptFrom(repo.key, rd) defer decryptRd.Close() if err != nil { return nil, err } idx, err := DecodeIndex(decryptRd) if err != nil { debug.Log("LoadIndex", "error while decoding index %v: %v", id, err) return nil, err } return idx, nil } // SearchKey finds a key with the supplied password, afterwards the config is // read and parsed. func (r *Repository) SearchKey(password string) error { key, err := SearchKey(r, password) if err != nil { return err } r.key = key.master r.keyName = key.Name() r.Config, err = LoadConfig(r) return err } // Init creates a new master key with the supplied password, initializes and // saves the repository config. func (r *Repository) Init(password string) error { has, err := r.be.Test(backend.Config, "") if err != nil { return err } if has { return errors.New("repository master key and config already initialized") } key, err := createMasterKey(r, password) if err != nil { return err } r.key = key.master r.keyName = key.Name() r.Config, err = CreateConfig(r) return err } // Decrypt authenticates and decrypts ciphertext and returns the plaintext. func (r *Repository) Decrypt(ciphertext []byte) ([]byte, error) { if r.key == nil { return nil, errors.New("key for repository not set") } return crypto.Decrypt(r.key, nil, ciphertext) } // Encrypt encrypts and authenticates the plaintext and saves the result in // ciphertext. func (r *Repository) Encrypt(ciphertext, plaintext []byte) ([]byte, error) { if r.key == nil { return nil, errors.New("key for repository not set") } return crypto.Encrypt(r.key, ciphertext, plaintext) } // Key returns the current master key. func (r *Repository) Key() *crypto.Key { return r.key } // KeyName returns the name of the current key in the backend. func (r *Repository) KeyName() string { return r.keyName } // Count returns the number of blobs of a given type in the backend. func (r *Repository) Count(t backend.Type) (n uint) { for _ = range r.be.List(t, nil) { n++ } return } func (r *Repository) list(t backend.Type, done <-chan struct{}, out chan<- backend.ID) { defer close(out) in := r.be.List(t, done) var ( // disable sending on the outCh until we received a job outCh chan<- backend.ID // enable receiving from in inCh = in id backend.ID err error ) for { select { case <-done: return case strID, ok := <-inCh: if !ok { // input channel closed, we're done return } id, err = backend.ParseID(strID) if err != nil { // ignore invalid IDs continue } inCh = nil outCh = out case outCh <- id: outCh = nil inCh = in } } } // List returns a channel that yields all IDs of type t in the backend. func (r *Repository) List(t backend.Type, done <-chan struct{}) <-chan backend.ID { outCh := make(chan backend.ID) go r.list(t, done, outCh) return outCh } // Delete calls backend.Delete() if implemented, and returns an error // otherwise. func (r *Repository) Delete() error { if b, ok := r.be.(backend.Deleter); ok { return b.Delete() } return errors.New("Delete() called for backend that does not implement this method") } // Close closes the repository by closing the backend. func (r *Repository) Close() error { return r.be.Close() }