pack: Handle more invalid header cases

This commit is contained in:
Alexander Neumann 2017-06-08 21:04:07 +02:00
parent eb767ab15f
commit 48fecd791d

View file

@ -8,6 +8,7 @@ import (
"restic"
"sync"
"restic/debug"
"restic/errors"
"restic/crypto"
@ -195,17 +196,14 @@ var minFileSize = entrySize + crypto.Extension
// readHeader reads the header at the end of rd. size is the length of the
// whole data accessible in rd.
func readHeader(rd io.ReaderAt, size int64) ([]byte, error) {
debug.Log("size: %v", size)
if size == 0 {
err := InvalidFileError{
Message: "file is empty",
}
err := InvalidFileError{Message: "file is empty"}
return nil, errors.Wrap(err, "readHeader")
}
if size < int64(minFileSize) {
err := InvalidFileError{
Message: "file is too small",
}
err := InvalidFileError{Message: "file is too small"}
return nil, errors.Wrap(err, "readHeader")
}
@ -214,6 +212,23 @@ func readHeader(rd io.ReaderAt, size int64) ([]byte, error) {
return nil, err
}
debug.Log("header length: %v", size)
if hl == 0 {
err := InvalidFileError{Message: "header length is zero"}
return nil, errors.Wrap(err, "readHeader")
}
if hl < crypto.Extension {
err := InvalidFileError{Message: "header length is too small"}
return nil, errors.Wrap(err, "readHeader")
}
if (hl-crypto.Extension)%uint32(entrySize) != 0 {
err := InvalidFileError{Message: "header length is invalid"}
return nil, errors.Wrap(err, "readHeader")
}
if int64(hl) > size-int64(binary.Size(hl)) {
return nil, errors.New("header is larger than file")
}