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mirror of https://github.com/octoleo/restic.git synced 2024-11-27 15:26:37 +00:00

backup: verify blobs before upload

This only covers the blobs themselves, the pack header is not verified
so far. Unpacked files are also not covered by the integrity check.
This commit is contained in:
Michael Eischer 2024-02-02 21:15:39 +01:00
parent 0ea62b5ac6
commit 2f30c940b2

View File

@ -423,6 +423,11 @@ func (r *Repository) saveAndEncrypt(ctx context.Context, t restic.BlobType, data
// encrypt blob
ciphertext = r.key.Seal(ciphertext, nonce, data, nil)
if err := r.verifyCiphertext(ciphertext, uncompressedLength, id); err != nil {
// FIXME call to action
return 0, fmt.Errorf("detected data corruption while saving blob %v: %w", id, err)
}
// find suitable packer and add blob
var pm *packerManager
@ -438,6 +443,27 @@ func (r *Repository) saveAndEncrypt(ctx context.Context, t restic.BlobType, data
return pm.SaveBlob(ctx, t, id, ciphertext, uncompressedLength)
}
func (r *Repository) verifyCiphertext(buf []byte, uncompressedLength int, id restic.ID) error {
nonce, ciphertext := buf[:r.key.NonceSize()], buf[r.key.NonceSize():]
plaintext, err := r.key.Open(nil, nonce, ciphertext, nil)
if err != nil {
return fmt.Errorf("decryption failed: %w", err)
}
if uncompressedLength != 0 {
// DecodeAll will allocate a slice if it is not large enough since it
// knows the decompressed size (because we're using EncodeAll)
plaintext, err = r.getZstdDecoder().DecodeAll(plaintext, nil)
if err != nil {
return fmt.Errorf("decompression failed: %w", err)
}
}
if !restic.Hash(plaintext).Equal(id) {
return errors.New("hash mismatch")
}
return nil
}
func (r *Repository) compressUnpacked(p []byte) ([]byte, error) {
// compression is only available starting from version 2
if r.cfg.Version < 2 {