o Pcy @sldZddlZddlmZmZmZmZmZmZddl m Z m Z ddl m Z mZddlmZddlmZmZdd lmZeeZgd Zeee j ee j fZd d Zd edeeddffddZd ede jde jdeedeffddZedZedZ ddfdedee defdee gefdeeeefdeffddZ!e"dfde de dee#de$fd d!Z%dS)"z Module defining common helpers for use by rules and policies. In principle, these aren't relevant to the high-level validation API. N)Callable GeneratorOptionalSetTupleTypeVar)genericmisc) PdfObject Reference)HistoricalResolver)ModificationLevelSuspiciousModification)ReferenceUpdate)qualifysafe_whitelistcompare_key_refs compare_dictsassert_not_streamcCs"t|tjrtd|jddS)zT Throw :class:`.SuspiciousModification` if the argument is a stream object. z!Unexpected stream encountered at !N) isinstancer StreamObjectr container_ref)objr`/var/www/milkbook_backend/env/lib/python3.10/site-packages/pyhanko/sign/diff_analysis/commons.pyrs  roldreturnccsT|r t|||krt||VdS||r"|VdStd|d)a~ Checks whether an indirect reference in a PDF structure can be updated without clobbering an older object in a way that causes ramifications at the PDF syntax level. The following are verified: - Does the old reference point to a non-stream object? - If the new reference is equal to the old one, does the new reference point to a non-stream object? - If the new reference is not equal to the old one, is the new reference a newly defined object? This is a generator for syntactical convenience and integration with internal APIs, but it will always yield at most one element. zUpdate clobbers or reuses z in an unexpected way.N)r get_objectis_ref_availabler)rold_refnew_refrrrr&s      rold_dictnew_dictccsz||}t|tjr|j}|}nd}Wn ty%d}}Ynwz||}t|tjr:|j}|}nd}WntyS|durPtd|dYdSw|durat|||EdH||fS)aj Ensure that updating a key in a dictionary has no undesirable side effects. The following scenarios are allowed: 1. adding a key in new_dict 2. replacing a direct value in old_dict with a reference in new_dict 3. the reverse (allowed by default) 4. replacing a reference with another reference (that doesn't override anything else) The restrictions of `safe_whitelist` apply to this function as well. Note: this routine is only safe to use if the structure of the resulting values is also checked. Otherwise, it can lead to reference leaks if one is not careful. NzKey z was deleted from dictionary)NN) raw_getrrIndirectObject referencerKeyErrorrr)keyrr#r$ old_value old_value_ref new_value new_value_refrrrrGs8          rRXcCs|SNr)xrrrsr2level rule_result transformcst|fddS)aL This is a helper function for rule implementors. It attaches a fixed modification level to an existing reference update generator, respecting the original generator's return value (if relevant). A prototypical use would be of the following form: .. code-block:: python def some_generator_function(): # do stuff for ref in some_list: # do stuff yield ref # do more stuff return summary_value # ... def some_qualified_generator_function(): summary_value = yield from qualify( ModificationLevel.FORM_FILLING, some_generator_function() ) Provided that ``some_generator_function`` yields :class:`~.generic.ReferenceUpdate` objects, the yield type of the resulting generator will be tuples of the form ``(level, ref)``. :param level: The modification level to set. :param rule_result: A generator that outputs references to be whitelisted. :param transform: Function to apply to the reference object before appending the modification level and yielding it. Defaults to the identity. :return: A converted generator that outputs references qualified at the modification level specified. cs |fSr0r)refr3r5rrr2s zqualify..)r map_with_return)r3r4r5rr7rr~s.rTignoredc Cst|tjs tdt|tjstdt|t|t||}t||}||kr@|r>td|d|ddS|D]"}| |}| |}||krd|ratd|d|d |dSqBd S) zP Compare entries in two dictionaries, optionally ignoring certain keys. z?Encountered unexpected non-dictionary object in prior revision.z.Dict is overridden by non-dict in new revisionzDict keys differ: z vs. .FzValues for dict key z differ:z changed to T) rrDictionaryObjectr PdfReadErrorrrsetkeysr%) r#r$r9 raise_exc new_dict_keys old_dict_keysknew_valold_valrrrrsF     r)&__doc__loggingtypingrrrrrrpyhanko.pdf_utilsrr pyhanko.pdf_utils.genericr r pyhanko.pdf_utils.readerr policy_apirr rules_apir getLogger__name__logger__all__ TwoVersionsrrr;rr.r/r frozensetstrboolrrrrrsL      !  3   4