Snapshot class

class Snapshot(version=None, spec_version=None, expires=None, meta=None, unrecognized_fields=None)

A container for the signed part of snapshot metadata.

Snapshot contains information about all target Metadata files.

All parameters named below are not just constructor arguments but also instance attributes.

Parameters:
  • version (int | None) – Metadata version number. Default is 1.

  • spec_version (str | None) – Supported TUF specification version. Default is the version currently supported by the library.

  • expires (datetime | None) – Metadata expiry date. Default is current date and time.

  • unrecognized_fields (Dict[str, Any] | None) – Dictionary of all attributes that are not managed by TUF Metadata API

  • meta (Dict[str, MetaFile] | None) – Dictionary of targets filenames to MetaFile objects. Default is a dictionary with a Metafile for “snapshot.json” version 1.

Raises:

ValueError – Invalid arguments.

property expires: datetime

Get the metadata expiry date.

# Use ‘datetime’ module to e.g. expire in seven days from now obj.expires = utcnow() + timedelta(days=7)

is_expired(reference_time=None)

Check metadata expiration against a reference time.

Parameters:

reference_time (datetime | None) – Time to check expiration date against. A naive datetime in UTC expected. Default is current UTC date and time.

Returns:

True if expiration time is less than the reference time.

Return type:

bool