#399

frontend/src/lib/postImportStorage.ts

@@ -11,6 +11,9 @@ const SESSION_VERSION = 3
 const SESSION_PREFIX = 'post-import-session:'
 const SOURCE_DRAFT_KEY = 'post-import-source-draft'
 const SESSION_MAX_AGE_MS = 24 * 60 * 60 * 1000
+const MAX_SESSION_JSON_BYTES = 262_144
+const MAX_SESSION_ROWS = 100
+const MAX_SOURCE_BYTES = 262_144
 const SESSION_ID_PATTERN =
     /^[0-9a-f]{8}-[0-9a-f]{4}-[1-5][0-9a-f]{3}-[89ab][0-9a-f]{3}-[0-9a-f]{12}$/i
 const ATTRIBUTE_KEYS = [
@@ -50,11 +53,15 @@ const SESSION_KEYS = [
     'source',
     'rows',
     'repairMode'] as const
+const textEncoder = new TextEncoder ()
 
 
 const isPlainObject = (value: unknown): value is Record<string, unknown> =>
     typeof value === 'object' && value != null && !(Array.isArray (value))
 
+const byteLength = (value: string): number =>
+    textEncoder.encode (value).byteLength
+
 
 export const validatePostImportSessionId = (value: unknown): string | null => {
     if (typeof value !== 'string')
@@ -184,6 +191,14 @@ const hasOnlyKeys = (
 const sanitiseResetSnapshot = (value: unknown): PostImportResetSnapshot | null => {
     if (!(isPlainObject (value)))
       return null
+    if (!(hasOnlyKeys (value, ['url',
+			       'attributes',
+			       'provenance',
+			       'tagSources',
+			       'fieldWarnings',
+			       'baseWarnings',
+			       'metadataUrl'])))
+      return null
     if (typeof value.url !== 'string')
       return null
     if (!(isPlainObject (value.attributes)))
@@ -353,6 +368,8 @@ const sanitiseRow = (value: unknown): PostImportRow | null => {
       return null
     if (typeof value.url !== 'string')
       return null
+    if (byteLength (value.url) > 20_480)
+      return null
     if (!(isPlainObject (value.attributes)))
       return null
     if (!(isPlainObject (value.provenance)))
@@ -450,17 +467,23 @@ const sanitiseSession = (value: unknown): PostImportSession | null => {
       return null
     if (value.version !== SESSION_VERSION || !(Array.isArray (value.rows)))
       return null
+    if (value.rows.length === 0 || value.rows.length > MAX_SESSION_ROWS)
+      return null
     if (typeof value.expiresAt !== 'string' || isExpiredSession (value.expiresAt))
       return null
+    if (typeof value.source !== 'string' || byteLength (value.source) > MAX_SOURCE_BYTES)
+      return null
 
     const rows = value.rows.map (sanitiseRow)
     if (rows.some (row => row == null))
       return null
+    if ((new Set (rows.map (row => row?.sourceRow))).size !== rows.length)
+      return null
 
     return {
         version: SESSION_VERSION,
         expiresAt: value.expiresAt,
-        source: typeof value.source === 'string' ? value.source : '',
+        source: value.source,
         rows: (rows as PostImportRow[]).map (row => recalculateThumbnailWarning (row)),
         repairMode: value.repairMode === 'failed' ? 'failed' : 'all' }
 }
@@ -497,6 +520,12 @@ export const cleanupExpiredPostImportSessions = (
           const raw = sessionStorage.getItem (key)
           if (raw == null)
             continue
+          if (byteLength (raw) > MAX_SESSION_JSON_BYTES)
+            {
+              sessionStorage.removeItem (key)
+              --i
+              continue
+            }
 
           try
           {
@@ -585,6 +614,11 @@ export const loadPostImportSession = (
     const raw = readStorage (sessionKey (validatedId), onError)
     if (raw == null)
       return null
+    if (byteLength (raw) > MAX_SESSION_JSON_BYTES)
+      {
+        removeStorage (sessionKey (validatedId), onError)
+        return null
+      }
 
     try
     {
@@ -598,6 +632,7 @@ export const loadPostImportSession = (
     }
     catch
     {
+      removeStorage (sessionKey (validatedId), onError)
       return null
     }
 }