mirror of https://gitlab.crans.org/bde/nk20
43 lines
1.5 KiB
Python
43 lines
1.5 KiB
Python
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import re
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from functools import lru_cache
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from rest_framework.filters import SearchFilter
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class RegexSafeSearchFilter(SearchFilter):
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@lru_cache
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def validate_regex(self, search_term) -> bool:
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try:
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re.compile(search_term)
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return True
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except re.error:
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return False
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def get_search_fields(self, view, request):
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"""
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Ensure that given regex are valid.
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If not, we consider that the user is trying to search by substring.
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"""
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search_fields = super().get_search_fields(view, request)
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search_terms = self.get_search_terms(request)
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for search_term in search_terms:
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if not self.validate_regex(search_term):
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# Invalid regex. We assume we don't query by regex but by substring.
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search_fields = [f.replace('$', '') for f in search_fields]
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break
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return search_fields
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def get_search_terms(self, request):
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"""
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Ensure that search field is a valid regex query. If not, we remove extra characters.
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"""
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terms = super().get_search_terms(request)
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if not all(self.validate_regex(term) for term in terms):
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# Invalid regex. If a ^ is prefixed to the search term, we remove it.
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terms = [term[1:] if term[0] == '^' else term for term in terms]
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# Same for dollars.
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terms = [term[:-1] if term[-1] == '$' else term for term in terms]
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return terms
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