diff --git a/internal/backend/utils.go b/internal/backend/utils.go index 7d319402c..64af705ac 100644 --- a/internal/backend/utils.go +++ b/internal/backend/utils.go @@ -3,14 +3,33 @@ package backend import ( "bytes" "context" + "encoding/hex" "fmt" "io" + "github.com/minio/sha256-simd" + "github.com/restic/restic/internal/debug" "github.com/restic/restic/internal/errors" "github.com/restic/restic/internal/restic" ) +func verifyContentMatchesName(s string, data []byte) (bool, error) { + if len(s) != hex.EncodedLen(sha256.Size) { + return false, fmt.Errorf("invalid length for ID: %q", s) + } + + b, err := hex.DecodeString(s) + if err != nil { + return false, fmt.Errorf("invalid ID: %s", err) + } + var id [sha256.Size]byte + copy(id[:], b) + + hashed := sha256.Sum256(data) + return id == hashed, nil +} + // LoadAll reads all data stored in the backend for the handle into the given // buffer, which is truncated. If the buffer is not large enough or nil, a new // one is allocated. @@ -29,8 +48,7 @@ func LoadAll(ctx context.Context, buf []byte, be restic.Backend, h restic.Handle // the second time, then it is likely corrupted at the backend. Return the data // to the caller in that case to let it decide what to do with the data. if !retriedInvalidData && h.Type != restic.ConfigFile { - id, err := restic.ParseID(h.Name) - if err == nil && !restic.Hash(buf).Equal(id) { + if matches, err := verifyContentMatchesName(h.Name, buf); err == nil && !matches { debug.Log("retry loading broken blob %v", h) retriedInvalidData = true return errors.Errorf("loadAll(%v): invalid data returned", h)