Admit kiosk callers by network position, not only by device token

The device token assumes a handful of fixed screens an administrator
provisions once. That is not how these kiosks are used: most people open the
page on their own PC, and there is no login, so per-browser provisioning would
mean touching every PC on the floor and losing it again on the next reimage or
cleared profile. A screen in that state did not look refused either - the USB
kiosk rendered a working page whose every call answered 404.

Both kiosks now admit a caller on either ground, the same shape the GE-Enforce
client endpoints already use: the per-device token, or a source address inside
an allowlist. Wall screens keep the token and are not confined to the
allowlist; everyone else is admitted by where they are on the network. Still
gated on the site's enable flag, so nothing opens by itself, and both
allowlists ship empty - token-only until a site enters its ranges.

- shopdb.api gains ip_in_cidrs and request_ip_allowlisted (contract 0.35.0).
  On the surface because both plugins need the identical gate, and a CIDR
  parser copied into two of them is where a fail-open creeps in later. They
  fail closed on an empty setting, an unparseable caller address and a
  malformed entry, and they read remote_addr rather than raw X-Forwarded-For -
  so the IIS rewrite rule is what makes them meaningful, which the module says
  at length.
- Separate settings per kiosk, usb_kiosk_allowed_cidrs and
  printedparts_kiosk_allowed_cidrs. One must not grant the other, for the same
  reason the tokens are separate.
- Both settings pages get a picker listing the network plugin's subnets with
  their VLANs. It stores resolved CIDR strings, not subnet ids: the setting has
  to work at a site that does not run that plugin and must not break when an
  inventory row is deleted. Entries matching no subnet are shown rather than
  hidden, since a stale one left by an inventory edit looks exactly like a
  hand-typed range.
- USBKiosk says it was not admitted instead of pretending to work, which
  PartsKiosk already did.
- The USB settings page keyed text-vs-boolean off the token alone. Adding a
  second text setting to the boolean path would have saved it as the word
  'true' - the bug that replaced the kiosk token and 404'd every provisioned
  screen. Both load and save now key off a list, with a spec on it.

The trade, stated plainly in the admin UI: anyone on an allowed network can
check a drive in or out against a badge number they guess, and the record
carries that person's name. Badges are attribution, not authorization. Keeping
the ranges narrow is what bounds it; login is the alternative and was ruled out
because these users do not sign in.

frontend/src/components/NetworkAllowlistPicker.vue

@@ -0,0 +1,129 @@
+<template>
+  <div class="allowlist-picker">
+    <div v-if="loading" class="picker-note">Loading networks...</div>
+
+    <div v-else-if="subnets.length" class="subnet-list">
+      <label v-for="subnet in subnets" :key="subnet.subnetid" class="subnet-row">
+        <input type="checkbox" :value="subnet.cidr"
+               :checked="isSelected(subnet.cidr)"
+               @change="toggle(subnet.cidr)" />
+        <span class="subnet-cidr">{{ subnet.cidr }}</span>
+        <span class="subnet-name">{{ subnet.name }}</span>
+        <span v-if="subnet.vlannumber" class="subnet-vlan">
+          VLAN {{ subnet.vlannumber }}<template v-if="subnet.vlanname"> - {{ subnet.vlanname }}</template>
+        </span>
+      </label>
+    </div>
+
+    <p v-else class="picker-note">
+      {{ unavailableMessage }}
+    </p>
+
+    <label class="manual-label">Allowed networks (CIDR, comma separated)</label>
+    <input :value="modelValue" type="text" class="form-control"
+           placeholder="empty = device token only"
+           @input="$emit('update:modelValue', $event.target.value)" />
+
+    <p v-if="extraEntries.length" class="picker-note">
+      Not from the network inventory: {{ extraEntries.join(', ') }}
+    </p>
+    <p v-if="invalidEntries.length" class="picker-warn">
+      Not valid CIDR and will never match: {{ invalidEntries.join(', ') }}
+    </p>
+  </div>
+</template>
+
+<script setup>
+// Picks networks for a kiosk allowlist from the network plugin's subnet
+// inventory, and stays usable without it.
+//
+// Stores resolved CIDR STRINGS, not subnet ids. The setting has to keep working
+// at a site that does not run the network plugin, and must not break when an
+// inventory row is edited or deleted. The trade is that a CIDR edited in the
+// inventory leaves a stale copy here - which is why entries that match no
+// subnet are listed back to the administrator rather than hidden.
+import { ref, computed, onMounted } from 'vue'
+import { fetchAllPages } from '@/api'
+
+const props = defineProps({
+  modelValue: { type: String, default: '' },
+})
+const emit = defineEmits(['update:modelValue'])
+
+const subnets = ref([])
+const loading = ref(true)
+const unavailableMessage = ref('No subnets found. Enter networks by hand below.')
+
+function entries (raw) {
+  return String(raw || '').split(',').map(part => part.trim()).filter(Boolean)
+}
+
+const selected = computed(() => entries(props.modelValue))
+
+function isSelected (cidr) {
+  return selected.value.includes(cidr)
+}
+
+function toggle (cidr) {
+  const current = selected.value
+  const next = current.includes(cidr)
+    ? current.filter(entry => entry !== cidr)
+    : [...current, cidr]
+  emit('update:modelValue', next.join(', '))
+}
+
+// Entries the administrator typed that no subnet record matches. Not an error -
+// a range may simply not be inventoried - but worth showing, because a stale
+// entry left behind by an inventory edit looks exactly like this.
+const extraEntries = computed(() => {
+  const known = new Set(subnets.value.map(subnet => subnet.cidr))
+  return selected.value.filter(entry => !known.has(entry))
+})
+
+// Shape check only, mirroring the server: anything the server cannot parse is
+// skipped there, so it silently admits nobody. Better to say so here.
+const CIDR_SHAPE = /^\d{1,3}(\.\d{1,3}){3}\/\d{1,2}$/
+const invalidEntries = computed(
+  () => selected.value.filter(entry => !CIDR_SHAPE.test(entry) && !entry.includes(':')))
+
+onMounted(async () => {
+  try {
+    subnets.value = await fetchAllPages('/network/subnets')
+  } catch (error) {
+    // The network plugin may be disabled at this site, or the signed-in user
+    // may not hold network.view. Neither stops an administrator configuring
+    // the allowlist by hand, so degrade instead of failing.
+    subnets.value = []
+    unavailableMessage.value =
+      'Network inventory unavailable. Enter networks by hand below.'
+  } finally {
+    loading.value = false
+  }
+})
+</script>
+
+<style scoped>
+.subnet-list {
+  display: flex;
+  flex-direction: column;
+  gap: 0.25rem;
+  max-height: 220px;
+  overflow-y: auto;
+  border: 1px solid var(--border-color, #ccc);
+  border-radius: 4px;
+  padding: 0.5rem;
+  margin-bottom: 0.5rem;
+}
+.subnet-row {
+  display: flex;
+  align-items: baseline;
+  gap: 0.5rem;
+  font-weight: 400;
+}
+.subnet-cidr { font-family: monospace; min-width: 12rem; }
+.subnet-name { font-weight: 600; }
+.subnet-vlan { color: var(--text-light); font-size: 0.85rem; }
+.manual-label { display: block; font-weight: 600; margin-top: 0.5rem; }
+.picker-note { color: var(--text-light); font-size: 0.85rem; margin: 0.25rem 0; }
+.picker-warn { color: var(--warning-dark); font-size: 0.85rem; margin: 0.25rem 0; }
+</style>

plugins/printedparts/api/routes.py

@@ -518,16 +518,15 @@ def adjust_item(item_id: int):
 
 import hmac
 
+from shopdb.api import request_ip_allowlisted
+
 # Largest single take the kiosk records. A shop-floor grab is single digits; 25
 # leaves real use untouched and denies draining a bin in one request.
 KIOSK_MAX_TAKE_QUANTITY = 25
 
 
-def _kiosk_open():
-    """True when this site has the kiosk on AND the caller carries its token."""
-    enabled = Setting.get('printedparts_kiosk_enabled', default=False)
-    if not (enabled is True or str(enabled).strip().lower() in ('true', '1', 'yes', 'on')):
-        return False
+def _kiosk_token_presented():
+    """True when the caller carries this kiosk's device token."""
     expected = (Setting.get('printedparts_kiosk_token') or '').strip()
     presented = (request.headers.get('X-Kiosk-Token') or '').strip()
     if not expected or not presented:
@@ -537,6 +536,27 @@ def _kiosk_open():
     return hmac.compare_digest(presented, expected)
 
 
+def _kiosk_open():
+    """True when this site has the kiosk on AND the caller is admitted.
+
+    Two ways in, either sufficient:
+      1. the per-device token, for the unattended screen by the printers, and
+      2. a source address inside printedparts_kiosk_allowed_cidrs, for people
+         who open the page on their own PC and never log in.
+
+    Its own setting, not the USB kiosk's: the two are separate screens in
+    separate rooms, and one allowlist granting the other is exactly the sharing
+    the separate tokens exist to prevent.
+    """
+    enabled = Setting.get('printedparts_kiosk_enabled', default=False)
+    if not (enabled is True or str(enabled).strip().lower() in ('true', '1', 'yes', 'on')):
+        return False
+    if _kiosk_token_presented():
+        return True
+    return request_ip_allowlisted(
+        request, Setting.get('printedparts_kiosk_allowed_cidrs'))
+
+
 def _kiosk_shut():
     """404, not 403 - a caller without the token does not learn the door exists."""
     return error_response(ErrorCodes.NOT_FOUND, 'Not found', http_code=404)

plugins/printedparts/frontend/views/PrintedPartsSettings.vue

@@ -68,6 +68,18 @@
         </p>
       </div>
 
+      <div class="form-group">
+        <label>Networks allowed without the token</label>
+        <NetworkAllowlistPicker v-model="values.printedparts_kiosk_allowed_cidrs" />
+        <p class="field-hint">
+          For people who open the kiosk on their own PC rather than at the
+          screen. A browser on one of these networks is admitted with no token
+          and no login, so keep this to the shop-floor ranges. Leave empty to
+          require the token from every caller. Separate from the USB kiosk
+          allowlist: one does not grant the other.
+        </p>
+      </div>
+
       <div class="form-group">
         <label>Unknown badge at the kiosk</label>
         <select v-model="values.printedparts_unknown_badge" class="form-control">
@@ -143,6 +155,7 @@
 <script setup>
 import { ref, computed, onMounted } from 'vue'
 import { settingsApi, usersApi, supportteamsApi } from '@/api'
+import NetworkAllowlistPicker from '@/components/NetworkAllowlistPicker.vue'
 
 const KEYS = [
   'printedparts_code_prefix',
@@ -150,6 +163,7 @@ const KEYS = [
   'printedparts_default_threshold',
   'printedparts_kiosk_enabled',
   'printedparts_kiosk_token',
+  'printedparts_kiosk_allowed_cidrs',
   'printedparts_unknown_badge',
   'printedparts_alert_email',
   'printedparts_alert_userids',
@@ -163,6 +177,7 @@ const values = ref({
   printedparts_default_threshold: 5,
   printedparts_kiosk_enabled: 'false',
   printedparts_kiosk_token: '',
+  printedparts_kiosk_allowed_cidrs: '',
   printedparts_unknown_badge: 'deny',
   printedparts_alert_email: '',
   printedparts_alert_userids: '',

plugins/printedparts/plugin.py

@@ -172,6 +172,21 @@ class PrintedpartsPlugin(BasePlugin):
                                'Generate one, then open the kiosk once as '
                                '/parts-kiosk?token=<value> on each screen',
             },
+            {
+                'key': 'printedparts_kiosk_allowed_cidrs',
+                'value': '',
+                'valuetype': 'string',
+                'category': 'printedparts',
+                'description': 'Networks allowed to use the kiosk WITHOUT the '
+                               'device token, as comma-separated CIDRs (for '
+                               'example 192.0.2.0/24). For people who open '
+                               'the kiosk on their own PC and never log in. '
+                               'Empty = token only. Separate from the USB '
+                               'kiosk allowlist on purpose. Requires the IIS '
+                               'X-Forwarded-For rewrite rule to be live, or the '
+                               'app sees the proxy address and this matches '
+                               'nothing.',
+            },
             {
                 'key': 'printedparts_unknown_badge',
                 'value': 'deny',

plugins/usb/api/routes.py

@@ -39,7 +39,7 @@ from shopdb.api import (
     get_pagination_params,
     require_permission,
 )
-from shopdb.api import Setting
+from shopdb.api import Setting, request_ip_allowlisted
 
 from . import selfhosted
 
@@ -743,22 +743,14 @@ def _kiosk_enabled():
     return _kiosk_setting('usb_kiosk_enabled', False)
 
 
-def _kiosk_open():
-    """True when the kiosk is on for this site AND the caller has its token.
-
-    The flag alone was the whole gate, and a flag is a decision, not a
-    credential: with the kiosk on, anyone who could reach the app could move a
-    device between checked-out and checked-in and have it recorded against a
-    badge they guessed. A badge is a short numeric SSO, so it is attribution,
-    never authorization - the same reasoning that closed the parts kiosk.
+def _kiosk_token_presented():
+    """True when the caller presents the configured device token.
 
     The token is per-DEVICE. A kiosk is a browser on a screen by the cabinet, so
     a token served inside the page would be readable by anyone who could load
     it. An admin opens the screen once as /usb-kiosk?token=..., the page keeps
     it in that browser and sends it as X-Kiosk-Token.
     """
-    if not _kiosk_enabled():
-        return False
     expected = (Setting.get('usb_kiosk_token') or '').strip()
     presented = (request.headers.get('X-Kiosk-Token') or '').strip()
     if not expected or not presented:
@@ -768,6 +760,46 @@ def _kiosk_open():
     return hmac.compare_digest(presented, expected)
 
 
+def _kiosk_ip_allowlisted():
+    """True when the caller sits in the configured kiosk network allowlist.
+
+    Why this exists alongside the token: the token model assumes a handful of
+    fixed screens provisioned once. Most people reach this kiosk from their own
+    PC instead, and there is no login - so per-browser provisioning would mean
+    provisioning every PC on the floor, and losing it on every reimage or
+    cleared profile. Network position is what those callers actually have in
+    common.
+
+    Fail-closed behaviour and the IIS rewrite-rule dependency that makes the
+    caller address trustworthy are documented on request_ip_allowlisted.
+    """
+    return request_ip_allowlisted(
+        request, Setting.get('usb_kiosk_allowed_cidrs'))
+
+
+def _kiosk_open():
+    """True when the kiosk is on for this site AND the caller is admitted.
+
+    The flag alone was the whole gate, and a flag is a decision, not a
+    credential: with the kiosk on, anyone who could reach the app could move a
+    device between checked-out and checked-in and have it recorded against a
+    badge they guessed. A badge is a short numeric SSO, so it is attribution,
+    never authorization - the same reasoning that closed the parts kiosk.
+
+    Two ways in, either sufficient, mirroring what the GE-Enforce client
+    endpoints already do:
+      1. the per-device token, for unattended screens by the cabinet, and
+      2. a source address inside usb_kiosk_allowed_cidrs, for the people who
+         open this page on their own PC and never log in.
+
+    Both are still gated on usb_kiosk_enabled, so the door stays shut until a
+    site opens it deliberately.
+    """
+    if not _kiosk_enabled():
+        return False
+    return _kiosk_token_presented() or _kiosk_ip_allowlisted()
+
+
 def _kiosk_disabled_response():
     # 404, not 403: when the kiosk is off these routes should not read as
     # "there is a door here and you may not use it".

plugins/usb/frontend/views/USBKiosk.vue

@@ -12,6 +12,16 @@
       <p class="kiosk-hint">An administrator enables it in Settings under USB.</p>
     </div>
 
+    <div v-else-if="refused" class="kiosk-step">
+      <p class="kiosk-prompt">This screen is not set up for the kiosk.</p>
+      <p class="kiosk-hint">
+        The kiosk is on, but this browser was not admitted. A wall screen is
+        provisioned once by opening it with its device token; a PC is admitted
+        by being on an allowed network. An administrator sets both in Settings
+        under USB.
+      </p>
+    </div>
+
     <template v-else>
       <div v-if="error" class="kiosk-error">{{ error }}</div>
 
@@ -145,6 +155,12 @@ const error = ref('')
 const doneMessage = ref('')
 const busy = ref(false)
 const disabled = ref(false)
+// The kiosk is on, but the server refused THIS caller: no device token in this
+// browser and no allowed network. The server answers 404 rather than 403 so the
+// route does not advertise itself, which means the client cannot know until it
+// asks. Without this the page rendered as a working kiosk whose every call
+// failed - the parts kiosk already says so, and this one did not.
+const refused = ref(false)
 const manualBadge = ref('')
 const entryInput = ref(null)
 let resetTimer = null
@@ -214,7 +230,11 @@ async function startSession (value) {
     step.value = 'pick'
     focusFilter()
   } catch (sessionError) {
-    error.value = messageFrom(sessionError, 'Could not look that badge up')
+    if (sessionError.response?.status === 404) {
+      refused.value = true
+    } else {
+      error.value = messageFrom(sessionError, 'Could not look that badge up')
+    }
   } finally {
     busy.value = false
     focusEntry()

plugins/usb/frontend/views/USBSettings.vue

@@ -55,6 +55,23 @@
         </p>
       </div>
 
+      <div class="form-group">
+        <label>Networks allowed without the token</label>
+        <NetworkAllowlistPicker v-model="values.usb_kiosk_allowed_cidrs" />
+        <p class="field-hint">
+          For people who open the kiosk on their own PC. A browser on one of
+          these networks is admitted with no token and no login, so keep this to
+          the shop-floor ranges rather than everything. Leave empty to require
+          the token from every caller. Wall screens keep using the token either
+          way.
+        </p>
+        <p class="field-hint token-warn">
+          Anyone on an allowed network can check a drive in or out against a
+          badge number they guess, and the record carries that person's name.
+          Badges are attribution, not authorization.
+        </p>
+      </div>
+
       <div class="form-group">
         <label class="check-row">
           <input type="checkbox" v-model="values.usb_kiosk_allow_return_for_others"
@@ -82,12 +99,19 @@
 import { ref, onMounted } from 'vue'
 import { settingsApi } from '@/api'
 import { withBase } from '@/utils/basePath'
+import NetworkAllowlistPicker from '@/components/NetworkAllowlistPicker.vue'
 
 const KEYS = ['usb_kiosk_enabled', 'usb_kiosk_allow_return_for_others',
-              'usb_kiosk_token']
+              'usb_kiosk_token', 'usb_kiosk_allowed_cidrs']
+
+// Keys whose value is text. Everything else is a switch stored as true/false.
+// Saving a text setting through the boolean path is what replaced the kiosk
+// token with the word 'true' and 404'd every provisioned screen.
+const TEXTKEYS = ['usb_kiosk_token', 'usb_kiosk_allowed_cidrs']
 
 const values = ref({
   usb_kiosk_enabled: false,
+  usb_kiosk_allowed_cidrs: '',
   usb_kiosk_allow_return_for_others: true,
   usb_kiosk_token: '',
 })
@@ -115,9 +139,9 @@ async function load () {
     const response = await settingsApi.list({ category: 'usb' })
     for (const row of (response.data.data || [])) {
       if (!KEYS.includes(row.key)) continue
-      // The token is text (the server sends a mask once set); only the two
-      // switches are booleans.
-      values.value[row.key] = row.key === 'usb_kiosk_token'
+      // Text settings stay text (the server sends a mask for the token once it
+      // is set); only the switches are booleans.
+      values.value[row.key] = TEXTKEYS.includes(row.key)
         ? (row.value || '')
         : asBool(row.value)
     }
@@ -132,10 +156,10 @@ async function save () {
   error.value = ''
   try {
     for (const key of KEYS) {
-      // Saving the token as true/false replaced the real token with the word
-      // 'true', and every provisioned kiosk then got 404. The server keeps the
-      // stored token when it receives the mask back unchanged.
-      const value = key === 'usb_kiosk_token'
+      // Saving a text setting through the boolean path replaced the real token
+      // with the word 'true', and every provisioned kiosk then got 404. The
+      // server keeps the stored token when it receives the mask back unchanged.
+      const value = TEXTKEYS.includes(key)
         ? String(values.value[key] ?? '')
         : (values.value[key] ? 'true' : 'false')
       await settingsApi.update(key, value)

plugins/usb/frontend/views/usbSettings.spec.js

@@ -49,9 +49,23 @@ describe('USBSettings save', () => {
       usb_kiosk_enabled: 'true',
       usb_kiosk_allow_return_for_others: 'false',
       usb_kiosk_token: MASK,
+      usb_kiosk_allowed_cidrs: '',
     })
   })
 
+  it('saves the network allowlist as text, not as true/false', async () => {
+    // Same trap the token fell into: a text setting sent through the boolean
+    // path becomes the word 'true', and the gate then admits nobody while the
+    // settings page still shows something plausible.
+    const wrapper = await render([
+      { key: 'usb_kiosk_enabled', value: 'true' },
+      { key: 'usb_kiosk_allowed_cidrs', value: '192.0.2.0/24, 198.51.100.0/24' },
+    ])
+    await wrapper.find('button.btn-primary').trigger('click')
+    await flushPromises()
+    expect(saved().usb_kiosk_allowed_cidrs).toBe('192.0.2.0/24, 198.51.100.0/24')
+  })
+
   it('saves a generated token as the token itself', async () => {
     const wrapper = await render([
       { key: 'usb_kiosk_enabled', value: 'true' },

plugins/usb/plugin.py

@@ -150,6 +150,22 @@ class USBPlugin(BasePlugin):
                                'kiosk once as /usb-kiosk?token=<value> on each '
                                'screen',
             },
+            {
+                'key': 'usb_kiosk_allowed_cidrs',
+                'value': '',
+                'valuetype': 'string',
+                'category': 'usb',
+                'description': 'Networks allowed to use the kiosk WITHOUT the '
+                               'device token, as comma-separated CIDRs (for '
+                               'example 192.0.2.0/24). For people who open '
+                               'the kiosk on their own PC and never log in - '
+                               'provisioning a token into every browser is not '
+                               'workable. Empty = token only. Wall screens keep '
+                               'using the token either way. Requires the IIS '
+                               'X-Forwarded-For rewrite rule to be live, or the '
+                               'app sees the proxy address and this matches '
+                               'nothing.',
+            },
             {
                 'key': 'usb_kiosk_allow_return_for_others',
                 'value': 'true',

shopdb/__init__.py

@@ -139,7 +139,17 @@ from .plugins import plugin_manager
 # bump can catch, and it is the kind of thing that gets copied. Exposing the
 # model closes the gap instead of leaving the workaround as the worked example.
 # Additive name on the surface, minor bump.
-__contract_version__ = '0.34.0'
+# 0.35.0 adds ip_in_cidrs and request_ip_allowlisted to shopdb.api: network
+# position as an admission check for routes that run without a login. The two
+# kiosks needed the identical gate - a device token suits an unattended screen
+# provisioned once, and suits nothing about somebody opening the same page on
+# their own PC - and a CIDR parser copied into two plugins is exactly where a
+# fail-open creeps in later. Both fail closed on an empty setting, an
+# unparseable caller address and a malformed entry. Caller trustworthiness is a
+# deployment property: they read remote_addr, never raw X-Forwarded-For, so the
+# IIS rewrite rule is what makes them meaningful. Additive names on the surface,
+# minor bump.
+__contract_version__ = '0.35.0'
 
 # Product release version (see ADR-007). The product version and the
 # plugin-contract version above are distinct series with independent

shopdb/api/__init__.py

@@ -187,6 +187,11 @@ from shopdb.utils.uploads import send_upload, harden_upload_response
 # nothing. See shopdb/utils/clientip.py.
 from shopdb.utils.clientip import client_ip, strip_port
 
+# Network-position allowlists for the unauthenticated kiosk routes. On the
+# contract surface because two plugins need the identical gate and a
+# copy-pasted CIDR parser is exactly where a fail-open creeps in.
+from shopdb.utils.ipallowlist import ip_in_cidrs, request_ip_allowlisted
+
 # Strict date parsing. On the contract surface because every plugin that stores
 # a date needs it and the two that rolled their own both swallowed the error.
 from shopdb.utils.queryargs import QueryArgError, intarg, intargs
@@ -477,6 +482,8 @@ __all__ = [
     'harden_upload_response',
     'client_ip',
     'strip_port',
+    'ip_in_cidrs',
+    'request_ip_allowlisted',
     # Import-mode helpers
     'apply_import_timestamps',
     'import_mode_active',

shopdb/utils/ipallowlist.py

@@ -0,0 +1,64 @@
+"""Network-position allowlists for unauthenticated kiosk routes.
+
+A kiosk route writes without a login. The device token (see the kiosk views)
+covers unattended screens an administrator provisions once, but it does not fit
+the other caller: somebody opening the kiosk page on their own PC, who never
+logs in and whose browser nobody provisioned. Per-browser provisioning would
+mean touching every PC on the floor and losing it again on the next reimage.
+What those callers have in common is where they are on the network.
+
+Fails closed, in every direction that matters:
+  - an empty or absent setting matches nothing (the feature is off),
+  - an unparseable caller address matches nothing,
+  - a malformed entry in the list is skipped rather than widening the match.
+
+SPOOF RESISTANCE IS A DEPLOYMENT PROPERTY, NOT A PROPERTY OF THIS CODE.
+The caller address comes from client_ip(), which reads remote_addr and never
+the raw X-Forwarded-For header - reading that header directly would let any
+caller send 'X-Forwarded-For: <allowlisted-ip>' and walk straight through.
+remote_addr is only the real client because of what sits in front of the app:
+behind IIS the URL-Rewrite rule overwrites X-Forwarded-For with the real TCP
+peer and ProxyFix resolves it into remote_addr (TRUSTED_PROXY_COUNT). Remove
+that rule and IIS forwards whatever the caller sent; waitress trusts it because
+it arrives from 127.0.0.1, remote_addr becomes attacker-controlled, and every
+allowlist built on this becomes bypassable from anywhere on the network. It
+does NOT fail closed in that case. The rewrite rule is the control. The
+GE-Enforce client allowlist carries the same dependency.
+
+Callers store plain CIDR strings rather than references to subnet records: a
+site that does not run the network plugin still has to be able to configure
+this, and a stored allowlist must not break when an inventory row is deleted.
+"""
+
+import ipaddress
+
+from shopdb.utils.clientip import client_ip
+
+
+def ip_in_cidrs(address, rawcidrs):
+    """True when `address` falls inside any CIDR in the comma-separated list.
+
+    Pure and side-effect free so it can be tested without a request context.
+    """
+    raw = (rawcidrs or '').strip()
+    if not raw:
+        return False
+    try:
+        caller = ipaddress.ip_address((address or '').strip())
+    except ValueError:
+        return False
+    for part in raw.split(','):
+        part = part.strip()
+        if not part:
+            continue
+        try:
+            if caller in ipaddress.ip_network(part, strict=False):
+                return True
+        except ValueError:
+            continue
+    return False
+
+
+def request_ip_allowlisted(request_obj, rawcidrs):
+    """True when the request's client address is inside the allowlist."""
+    return ip_in_cidrs(client_ip(request_obj), rawcidrs)

tests/test_plugins/test_kiosk_network_allowlist.py

@@ -0,0 +1,138 @@
+"""Network-position admission for the two unauthenticated kiosks.
+
+The device token covers unattended screens an administrator provisions once. It
+does not cover the other caller: somebody opening the kiosk page on their own
+PC, who never logs in and whose browser nobody provisioned. Per-browser
+provisioning would mean touching every PC on the floor and losing it on the next
+reimage, so those callers are admitted by where they are on the network instead.
+
+What these tests hold down:
+  - the allowlist actually admits a caller with no token (the feature),
+  - it stays shut when unset, when the caller is outside it, and when the kiosk
+    itself is off (the flag still wins),
+  - a malformed entry is skipped rather than widening the match, and
+  - the two kiosks do not share an allowlist.
+"""
+
+import pytest
+
+from shopdb.core.models import Setting
+from shopdb.api import ip_in_cidrs
+
+
+PLANT = '10.134.48.17'
+PLANT_CIDR = '10.134.48.0/23'
+ELSEWHERE = '10.9.100.5'
+
+
+# -- the pure matcher ---------------------------------------------------------
+# Separated from the request so the fail-closed edges can be stated plainly.
+
+@pytest.mark.parametrize('address, cidrs, expected', [
+    (PLANT, PLANT_CIDR, True),
+    (PLANT, ' 10.48.249.0/26 , 10.134.48.0/23 ', True),
+    (ELSEWHERE, PLANT_CIDR, False),
+    # Empty or absent setting means the feature is off, not "allow everyone".
+    (PLANT, '', False),
+    (PLANT, None, False),
+    # A malformed entry must be skipped, never treated as a wildcard.
+    (PLANT, 'not-a-cidr', False),
+    (PLANT, 'not-a-cidr, 10.134.48.0/23', True),
+    # An unparseable caller address matches nothing.
+    ('', PLANT_CIDR, False),
+    ('unknown', PLANT_CIDR, False),
+])
+def test_ip_in_cidrs(address, cidrs, expected):
+    assert ip_in_cidrs(address, cidrs) is expected
+
+
+# -- USB kiosk ----------------------------------------------------------------
+
+@pytest.fixture
+def usbkiosk(db):
+    """Self-hosted USB, kiosk ON, a token set, one employee and one drive."""
+    from plugins.employees.models import DirectoryEmployee
+    from plugins.usb.models import USBDevice
+
+    db.session.add(Setting(key='usb_directory_mode', value='selfhosted',
+                           valuetype='string', category='site'))
+    db.session.add(Setting(key='usb_kiosk_enabled', value='true',
+                           valuetype='boolean', category='usb'))
+    db.session.add(Setting(key='usb_kiosk_token', value='a-real-token',
+                           valuetype='string', category='usb'))
+    db.session.add(DirectoryEmployee(sso=270015376, firstname='Dana',
+                                     lastname='Reyes'))
+    db.session.add(USBDevice(serialnumber='USB-1', label='Blue Kingston',
+                             ischeckedout=False))
+    db.session.commit()
+    return db
+
+
+def _allow(db, key, value):
+    row = Setting.query.filter_by(key=key).first()
+    if row is None:
+        db.session.add(Setting(key=key, value=value, valuetype='string',
+                               category='usb'))
+    else:
+        row.value = value
+    db.session.commit()
+
+
+def _session(client, address):
+    """A kiosk call carrying NO token, from `address`."""
+    return client.post('/api/usb/kiosk/session', json={'badge': '270015376'},
+                       environ_base={'REMOTE_ADDR': address})
+
+
+def test_usb_kiosk_refuses_tokenless_caller_when_no_allowlist(usbkiosk, client):
+    """The state before this feature: no token, no way in."""
+    assert _session(client, PLANT).status_code == 404
+
+
+def test_usb_kiosk_admits_tokenless_caller_on_allowed_network(usbkiosk, client):
+    """THE FEATURE. Fails without the allowlist branch in _kiosk_open."""
+    _allow(usbkiosk, 'usb_kiosk_allowed_cidrs', PLANT_CIDR)
+    assert _session(client, PLANT).status_code == 200
+
+
+def test_usb_kiosk_refuses_caller_outside_the_allowlist(usbkiosk, client):
+    """The PXE LAN is also 10.x, which is why the range has to be narrow."""
+    _allow(usbkiosk, 'usb_kiosk_allowed_cidrs', PLANT_CIDR)
+    assert _session(client, ELSEWHERE).status_code == 404
+
+
+def test_usb_kiosk_allowlist_does_not_override_the_off_switch(usbkiosk, client):
+    """Turning the kiosk off closes it to everyone, allowlisted or not.
+
+    The flag is the site's decision to have this door at all; the allowlist only
+    decides who walks through an open one.
+    """
+    _allow(usbkiosk, 'usb_kiosk_allowed_cidrs', PLANT_CIDR)
+    Setting.query.filter_by(key='usb_kiosk_enabled').first().value = 'false'
+    usbkiosk.session.commit()
+    assert _session(client, PLANT).status_code == 404
+
+
+def test_usb_kiosk_token_still_works_from_any_network(usbkiosk, client):
+    """Wall screens keep working, and are not confined to the allowlist."""
+    response = client.post('/api/usb/kiosk/session',
+                           json={'badge': '270015376'},
+                           headers={'X-Kiosk-Token': 'a-real-token'},
+                           environ_base={'REMOTE_ADDR': ELSEWHERE})
+    assert response.status_code == 200
+
+
+def test_usb_allowlist_does_not_open_the_parts_kiosk(usbkiosk, client):
+    """Separate screens, separate rooms, separate settings.
+
+    The tokens are deliberately separate so provisioning one does not grant the
+    other. An allowlist shared between them would hand back exactly that.
+    """
+    _allow(usbkiosk, 'usb_kiosk_allowed_cidrs', PLANT_CIDR)
+    Setting.query.filter_by(key='usb_kiosk_enabled').first().value = 'true'
+    usbkiosk.session.add(Setting(key='printedparts_kiosk_enabled', value='true',
+                                 valuetype='boolean', category='printedparts'))
+    usbkiosk.session.commit()
+    response = client.get('/api/printedparts/kiosk/lookup?code=ANY',
+                          environ_base={'REMOTE_ADDR': PLANT})
+    assert response.status_code == 404