|
| 1 | +from html.parser import HTMLParser |
| 2 | + |
| 3 | +from django.utils.translation import gettext_lazy as _ |
| 4 | + |
| 5 | +from debug_toolbar.panels import Panel |
| 6 | + |
| 7 | + |
| 8 | +class FormParser(HTMLParser): |
| 9 | + """ |
| 10 | + HTML form parser, used to check for invalid configurations of forms that |
| 11 | + take file inputs. |
| 12 | + """ |
| 13 | + |
| 14 | + def __init__(self): |
| 15 | + super().__init__() |
| 16 | + self.in_form = False |
| 17 | + self.current_form = {} |
| 18 | + self.forms = [] |
| 19 | + self.form_ids = [] |
| 20 | + self.referenced_file_inputs = [] |
| 21 | + |
| 22 | + def handle_starttag(self, tag, attrs): |
| 23 | + attrs = dict(attrs) |
| 24 | + if tag == "form": |
| 25 | + self.in_form = True |
| 26 | + form_id = attrs.get("id") |
| 27 | + if form_id: |
| 28 | + self.form_ids.append(form_id) |
| 29 | + self.current_form = { |
| 30 | + "file_form": False, |
| 31 | + "form_attrs": attrs, |
| 32 | + "submit_element_attrs": [], |
| 33 | + } |
| 34 | + elif ( |
| 35 | + self.in_form |
| 36 | + and tag == "input" |
| 37 | + and attrs.get("type") == "file" |
| 38 | + and (not attrs.get("form") or attrs.get("form") == "") |
| 39 | + ): |
| 40 | + self.current_form["file_form"] = True |
| 41 | + elif ( |
| 42 | + self.in_form |
| 43 | + and ( |
| 44 | + (tag == "input" and attrs.get("type") in {"submit", "image"}) |
| 45 | + or tag == "button" |
| 46 | + ) |
| 47 | + and (not attrs.get("form") or attrs.get("form") == "") |
| 48 | + ): |
| 49 | + self.current_form["submit_element_attrs"].append(attrs) |
| 50 | + elif tag == "input" and attrs.get("form"): |
| 51 | + self.referenced_file_inputs.append(attrs) |
| 52 | + |
| 53 | + def handle_endtag(self, tag): |
| 54 | + if tag == "form" and self.in_form: |
| 55 | + self.forms.append(self.current_form) |
| 56 | + self.in_form = False |
| 57 | + |
| 58 | + |
| 59 | +class AlertsPanel(Panel): |
| 60 | + """ |
| 61 | + A panel to alert users to issues. |
| 62 | + """ |
| 63 | + |
| 64 | + messages = { |
| 65 | + "form_id_missing_enctype": _( |
| 66 | + 'Form with id "{form_id}" contains file input, but does not have the attribute enctype="multipart/form-data".' |
| 67 | + ), |
| 68 | + "form_missing_enctype": _( |
| 69 | + 'Form contains file input, but does not have the attribute enctype="multipart/form-data".' |
| 70 | + ), |
| 71 | + "input_refs_form_missing_enctype": _( |
| 72 | + 'Input element references form with id "{form_id}", but the form does not have the attribute enctype="multipart/form-data".' |
| 73 | + ), |
| 74 | + } |
| 75 | + |
| 76 | + title = _("Alerts") |
| 77 | + |
| 78 | + template = "debug_toolbar/panels/alerts.html" |
| 79 | + |
| 80 | + def __init__(self, *args, **kwargs): |
| 81 | + super().__init__(*args, **kwargs) |
| 82 | + self.alerts = [] |
| 83 | + |
| 84 | + @property |
| 85 | + def nav_subtitle(self): |
| 86 | + alerts = self.get_stats()["alerts"] |
| 87 | + if alerts: |
| 88 | + alert_text = "alert" if len(alerts) == 1 else "alerts" |
| 89 | + return f"{len(alerts)} {alert_text}" |
| 90 | + else: |
| 91 | + return "" |
| 92 | + |
| 93 | + def add_alert(self, alert): |
| 94 | + self.alerts.append(alert) |
| 95 | + |
| 96 | + def check_invalid_file_form_configuration(self, html_content): |
| 97 | + """ |
| 98 | + Inspects HTML content for a form that includes a file input but does |
| 99 | + not have the encoding type set to multipart/form-data, and warns the |
| 100 | + user if so. |
| 101 | + """ |
| 102 | + parser = FormParser() |
| 103 | + parser.feed(html_content) |
| 104 | + |
| 105 | + # Check for file inputs directly inside a form that do not reference |
| 106 | + # any form through the form attribute |
| 107 | + for form in parser.forms: |
| 108 | + if ( |
| 109 | + form["file_form"] |
| 110 | + and form["form_attrs"].get("enctype") != "multipart/form-data" |
| 111 | + and not any( |
| 112 | + elem.get("formenctype") == "multipart/form-data" |
| 113 | + for elem in form["submit_element_attrs"] |
| 114 | + ) |
| 115 | + ): |
| 116 | + if form_id := form["form_attrs"].get("id"): |
| 117 | + alert = self.messages["form_id_missing_enctype"].format( |
| 118 | + form_id=form_id |
| 119 | + ) |
| 120 | + else: |
| 121 | + alert = self.messages["form_missing_enctype"] |
| 122 | + self.add_alert({"alert": alert}) |
| 123 | + |
| 124 | + # Check for file inputs that reference a form |
| 125 | + form_attrs_by_id = { |
| 126 | + form["form_attrs"].get("id"): form["form_attrs"] for form in parser.forms |
| 127 | + } |
| 128 | + |
| 129 | + for attrs in parser.referenced_file_inputs: |
| 130 | + form_id = attrs.get("form") |
| 131 | + if form_id and attrs.get("type") == "file": |
| 132 | + form_attrs = form_attrs_by_id.get(form_id) |
| 133 | + if form_attrs and form_attrs.get("enctype") != "multipart/form-data": |
| 134 | + alert = self.messages["input_refs_form_missing_enctype"].format( |
| 135 | + form_id=form_id |
| 136 | + ) |
| 137 | + self.add_alert({"alert": alert}) |
| 138 | + |
| 139 | + return self.alerts |
| 140 | + |
| 141 | + def generate_stats(self, request, response): |
| 142 | + html_content = response.content.decode(response.charset) |
| 143 | + self.check_invalid_file_form_configuration(html_content) |
| 144 | + |
| 145 | + # Further alert checks can go here |
| 146 | + |
| 147 | + # Write all alerts to record_stats |
| 148 | + self.record_stats({"alerts": self.alerts}) |
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