pyhanko.sign.diff_analysis.rules.file_structure_rules module

class pyhanko.sign.diff_analysis.rules.file_structure_rules.CatalogModificationRule(ignored_keys=None)

Bases: QualifiedWhitelistRule

Rule that adjudicates modifications to the document catalog.

Parameters

ignored_keys –

Values in the document catalog that may change between revisions. The default ones are /AcroForm, /DSS, /Extensions, /Metadata, /MarkInfo and /Version.

Checking for /AcroForm, /DSS and /Metadata is delegated to FormUpdatingRule, DSSCompareRule and MetadataUpdateRule, respectively.

apply_qualified(old: HistoricalResolver, new: HistoricalResolver) → Iterable[Tuple[ModificationLevel, Reference]]

Apply the rule to the changes between two revisions.

Parameters

  • old – The older, base revision.

  • new – The newer revision to be vetted.

class pyhanko.sign.diff_analysis.rules.file_structure_rules.ObjectStreamRule

Bases: WhitelistRule

Rule that allows object streams to be added.

Note that this rule only whitelists the object streams themselves (provided they do not override any existing objects, obviously), not the objects in them.

apply(old: HistoricalResolver, new: HistoricalResolver) → Iterable[Reference]

Apply the rule to the changes between two revisions.

Parameters

  • old – The older, base revision.

  • new – The newer revision to be vetted.

class pyhanko.sign.diff_analysis.rules.file_structure_rules.XrefStreamRule

Bases: WhitelistRule

Rule that allows new cross-reference streams to be defined.

apply(old: HistoricalResolver, new: HistoricalResolver) → Iterable[Reference]

Apply the rule to the changes between two revisions.

Parameters

  • old – The older, base revision.

  • new – The newer revision to be vetted.