Root class

class Root(version=None, spec_version=None, expires=None, keys=None, roles=None, consistent_snapshot=True, unrecognized_fields=None)

A container for the signed part of root metadata.

Parameters listed below are 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.

  • keys (dict[str, Key] | None) – Dictionary of keyids to Keys. Defines the keys used in roles. Default is empty dictionary.

  • roles (dict[str, Role] | None) – Dictionary of role names to Roles. Defines which keys are required to sign the metadata for a specific role. Default is a dictionary of top level roles without keys and threshold of 1.

  • consistent_snapshot (bool | None) – True if repository supports consistent

  • True. (snapshots. Default is)

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

Raises:

ValueError – Invalid arguments.

add_key(key, role)

Add new signing key for delegated role role.

Parameters:

  • key (Key) – Signing key to be added for role.

  • role (str) – Name of the role, for which key is added.

Raises:

ValueError – If the argument order is wrong or if role doesn’t exist.

Return type:

None

property expires: datetime

Get the metadata expiry date.

get_delegated_role(delegated_role)

Return the role object for the given delegated role.

Raises ValueError if delegated_role is not actually delegated.

Parameters:

delegated_role (str)

Return type:

Role

get_key(keyid)

Return the key object for the given keyid.

Raises ValueError if key is not found.

Parameters:

keyid (str)

Return type:

Key

get_root_verification_result(previous, payload, signatures)

Return signature threshold verification result for two root roles.

Verify root metadata with two roles (self and optionally previous).

If the repository has no root role versions yet, previous can be left None. In all other cases, previous must be the previous version of the Root.

NOTE: Unlike verify_delegate() this method does not raise, if the root metadata is not fully verified.

Parameters:

  • previous (Root | None) – The previous Root to verify payload with, or None

  • payload (bytes) – Signed payload bytes for root

  • signatures (dict[str, Signature]) – Signatures over payload bytes

Raises:

ValueError – no delegation was found for root or given Root versions are not sequential.

Return type:

RootVerificationResult

get_verification_result(delegated_role, payload, signatures)

Return signature threshold verification result for delegated role.

NOTE: Unlike verify_delegate() this method does not raise, if the role metadata is not fully verified.

Parameters:

  • delegated_role (str) – Name of the delegated role to verify

  • payload (bytes) – Signed payload bytes for the delegated role

  • signatures (dict[str, Signature]) – Signatures over payload bytes

Raises:

ValueError – no delegation was found for delegated_role.

Return type:

VerificationResult

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

revoke_key(keyid, role)

Revoke key from role and updates the key store.

Parameters:

  • keyid (str) – Identifier of the key to be removed for role.

  • role (str) – Name of the role, for which a signing key is removed.

Raises:

ValueError – If role doesn’t exist or if role doesn’t include the key.

Return type:

None

verify_delegate(delegated_role, payload, signatures)

Verify signature threshold for delegated role.

Verify that there are enough valid signatures over payload, to meet the threshold of keys for delegated_role, as defined by the delegator (self).

Parameters:

  • delegated_role (str) – Name of the delegated role to verify

  • payload (bytes) – Signed payload bytes for the delegated role

  • signatures (dict[str, Signature]) – Signatures over payload bytes

Raises:

  • UnsignedMetadataError – delegated_role was not signed with required threshold of keys for role_name.

  • ValueError – no delegation was found for delegated_role.

Return type:

None