// OpenBundle opens the provided key in the given store, and wraps it in a
// bagit reader.
func OpenBundle(s store.Store, key string) (*BagreaderCloser, error) {
stream, size, err := s.Open(key)
if err != nil {
return nil, err
}
var result *BagreaderCloser
r, err := bagit.NewReader(stream, size)
if err == nil {
result = &BagreaderCloser{
Reader: r,
f: stream,
}
} else {
stream.Close()
}
return result, err
}
// Validate the given item. Returns the total amount checksummed (in bytes),
// a list of issues which will be empty if everything is fine, and an error
// if an error happened during the validation. In particular, err does not
// show validation errors, only if a system error happened while validating.
//
// Things checked (not all are implemented yet):
// * Each blob has the correct checksum
// * Each blob appears in exactly one bundle
// * Every blob is assigned to at least one slot in at least one version
// * Each slot points to an existing (possibly deleted) blob
// * Each bundle is readable and in the correct format
// * There are no extra files in a bundle
// * All required metadata fields are present for each blob
// * All required metadata fields are present for each version
//
// This is a method on the Store instead of an Item since it needs access
// to the underlying bundle files.
func (s *Store) Validate(id string) (nb int64, problems []string, err error) {
// First verify each bundle file
var bundleNames []string
bundleNames, err = s.S.ListPrefix(id)
if err != nil {
return
}
for _, name := range bundleNames {
// open the bundle directly since we need access to the size
var stream store.ReadAtCloser
var size int64
stream, size, err = s.S.Open(name)
if err != nil {
return
}
var bag *bagit.Reader
bag, err = bagit.NewReader(stream, size)
if err != nil {
stream.Close()
return
}
err = bag.Verify()
_ = stream.Close()
nb += size
if err != nil {
if _, ok := err.(bagit.BagError); ok {
// there was a failed verification
problems = append(problems, err.Error())
err = nil
} else {
// there was an actual error in doing the verification
return
}
}
}
// then validate the metadata
var item *Item
item, err = s.Item(id)
if err != nil {
return
}
// First validate blob metadata
for _, blob := range item.Blobs {
if blob.SaveDate.IsZero() {
problems = append(problems, fmt.Sprintf("Blob (%s,%d) has a zero save date", id, blob.ID))
}
switch {
case blob.Size > 0:
if blob.Bundle <= 0 {
problems = append(problems, fmt.Sprintf("Blob (%s,%d) has non-positve bundle ID", id, blob.ID))
}
if len(blob.MD5) != 16 {
problems = append(problems, fmt.Sprintf("Blob (%s,%d) has malformed MD5 hash", id, blob.ID))
}
if len(blob.SHA256) != 32 {
problems = append(problems, fmt.Sprintf("Blob (%s,%d) has malformed SHA-256 hash", id, blob.ID))
}
if !blob.DeleteDate.IsZero() {
problems = append(problems, fmt.Sprintf("Blob (%s,%d) has non-zero delete date", id, blob.ID))
}
if blob.Deleter != "" {
problems = append(problems, fmt.Sprintf("Blob (%s,%d) has a deleter", id, blob.ID))
}
if blob.DeleteNote != "" {
problems = append(problems, fmt.Sprintf("Blob (%s,%d) has a delete note", id, blob.ID))
}
// now verify these hashes match what is stored in the manifest
// TODO(dbrower): Make the checksum verification more efficient.
var bag *BagreaderCloser
bag, err = OpenBundle(s.S, sugar(id, blob.Bundle))
if err != nil {
return
}
checksum := bag.Checksum(fmt.Sprintf("blob/%d", blob.ID))
_ = bag.Close()
if bytes.Compare(blob.MD5, checksum.MD5) != 0 {
problems = append(problems, fmt.Sprintf("Blob (%s,%d) has MD5 mismatch", id, blob.ID))
}
if bytes.Compare(blob.SHA256, checksum.SHA256) != 0 {
problems = append(problems, fmt.Sprintf("Blob (%s,%d) has SHA-256 mismatch", id, blob.ID))
}
case blob.Size == 0:
// blob is deleted
if blob.Bundle != 0 {
problems = append(problems, fmt.Sprintf("Blob (%s,%d) is deleted and has non-zero bundle ID", id, blob.ID))
}
if blob.DeleteDate.IsZero() {
problems = append(problems, fmt.Sprintf("Blob (%s,%d) is deleted and has no delete date", id, blob.ID))
}
if blob.Deleter == "" {
problems = append(problems, fmt.Sprintf("Blob (%s,%d) is deleted and has no deleter", id, blob.ID))
}
case blob.Size < 0:
problems = append(problems, fmt.Sprintf("Blob (%s,%d) has negative size", id, blob.ID))
}
}
// TODO(dbrower): validate version metadata
return
}