func queueFile(src string) error {
// refuse huge files, this is for assertions
fi, err := os.Stat(src)
if err != nil {
return err
}
// 640kb ought be to enough for anyone
if fi.Size() > 640*1024 {
msg := fmt.Errorf("cannot queue %s, file size too big: %v", src, fi.Size())
logger.Noticef("error: %v", msg)
return msg
}
// ensure name is predictable, weak hash is ok
hash, _, err := osutil.FileDigest(src, crypto.SHA3_384)
if err != nil {
return err
}
dst := filepath.Join(dirs.SnapAssertsSpoolDir, fmt.Sprintf("%s.assert", base64.URLEncoding.EncodeToString(hash)))
if err := os.MkdirAll(filepath.Dir(dst), 0755); err != nil {
return err
}
return osutil.CopyFile(src, dst, osutil.CopyFlagOverwrite)
}
// SnapFileSHA3_384 computes the SHA3-384 digest of the given snap file.
// It also returns its size.
func SnapFileSHA3_384(snapPath string) (digest string, size uint64, err error) {
sha3_384Dgst, size, err := osutil.FileDigest(snapPath, crypto.SHA3_384)
if err != nil {
return "", 0, fmt.Errorf("cannot compute snap %q digest: %v", snapPath, err)
}
sha3_384, err := EncodeDigest(crypto.SHA3_384, sha3_384Dgst)
if err != nil {
return "", 0, fmt.Errorf("cannot encode snap %q digest: %v", snapPath, err)
}
return sha3_384, size, nil
}
func (ts *FileDigestSuite) TestFileDigest(c *C) {
exData := []byte("hashmeplease")
tempdir := c.MkDir()
fn := filepath.Join(tempdir, "ex.file")
err := ioutil.WriteFile(fn, exData, 0644)
c.Assert(err, IsNil)
digest, size, err := osutil.FileDigest(fn, crypto.SHA512)
c.Assert(err, IsNil)
c.Check(size, Equals, uint64(len(exData)))
h512 := sha512.Sum512(exData)
c.Check(digest, DeepEquals, h512[:])
}
return fmt.Errorf("cannot apply unsupported delta format %q (only xdelta3 currently)", deltaInfo.Format)
}
partialTargetPath := targetPath + ".partial"
xdelta3Args := []string{"-d", "-s", snapPath, deltaPath, partialTargetPath}
cmd := exec.Command("xdelta3", xdelta3Args...)
if err := cmd.Run(); err != nil {
if err := os.Remove(partialTargetPath); err != nil {
logger.Noticef("failed to remove partial delta target %q: %s", partialTargetPath, err)
}
return err
}
bsha3_384, _, err := osutil.FileDigest(partialTargetPath, crypto.SHA3_384)
if err != nil {
return err
}
sha3_384 := fmt.Sprintf("%x", bsha3_384)
if targetSha3_384 != "" && sha3_384 != targetSha3_384 {
if err := os.Remove(partialTargetPath); err != nil {
logger.Noticef("failed to remove partial delta target %q: %s", partialTargetPath, err)
}
return HashError{name, sha3_384, targetSha3_384}
}
if err := os.Rename(partialTargetPath, targetPath); err != nil {
return osutil.CopyFile(partialTargetPath, targetPath, 0)
}
