diff --git a/backend/app.js b/backend/app.js index 7d554898..f7e957c8 100644 --- a/backend/app.js +++ b/backend/app.js @@ -70,6 +70,17 @@ app.use(cookieParser()); app.use((req, res, next) => { req.requestId = req.headers["x-request-id"] || randomUUID(); res.setHeader("x-request-id", req.requestId); + // SECURITY: Content-Security-Policy header to mitigate XSS attacks. + // Blocks inline scripts, restricts sources, and prevents clickjacking. + res.setHeader( + "Content-Security-Policy", + "default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; img-src 'self' data: https: blob:; connect-src 'self' https://*.supabase.co wss://*.supabase.co; font-src 'self'; object-src 'none'; frame-ancestors 'none'; form-action 'self'; base-uri 'self'" + ); + // Additional security headers + res.setHeader("X-Content-Type-Options", "nosniff"); + res.setHeader("X-Frame-Options", "DENY"); + res.setHeader("X-XSS-Protection", "1; mode=block"); + res.setHeader("Referrer-Policy", "strict-origin-when-cross-origin"); next(); }); diff --git a/package-lock.json b/package-lock.json index 9695b0d5..fb0c0575 100644 --- a/package-lock.json +++ b/package-lock.json @@ -47,7 +47,7 @@ "clsx": "^2.1.1", "cmdk": "^1.1.1", "date-fns": "^3.6.0", - "dompurify": "^3.4.7", + "dompurify": "^3.4.12", "embla-carousel-react": "^8.6.0", "framer-motion": "^11.18.2", "input-otp": "^1.4.2", @@ -358,7 +358,6 @@ } ], "license": "MIT", - "peer": true, "engines": { "node": ">=20.19.0" }, @@ -407,7 +406,6 @@ } ], "license": "MIT", - "peer": true, "engines": { "node": ">=20.19.0" } @@ -3534,7 +3532,6 @@ "integrity": "sha512-o4PXJQidqJl82ckFaXUeoAW+XysPLauYI43Abki5hABd853iMhitooc6znOnczgbTYmEP6U6/y1ZyKAIsvMKGg==", "dev": true, "license": "MIT", - "peer": true, "dependencies": { "@babel/code-frame": "^7.10.4", "@babel/runtime": "^7.12.5", @@ -3616,6 +3613,7 @@ "resolved": "https://registry.npmjs.org/@types/body-parser/-/body-parser-1.19.6.tgz", "integrity": "sha512-HLFeCYgz89uk22N5Qg3dvGvsv46B8GLvKKo1zKG4NybA8U2DiEO3w9lqGg29t/tfLRJpJ6iQxnVw4OnB7MoM9g==", "license": "MIT", + "peer": true, "dependencies": { "@types/connect": "*", "@types/node": "*" @@ -3637,6 +3635,7 @@ "resolved": "https://registry.npmjs.org/@types/connect/-/connect-3.4.38.tgz", "integrity": "sha512-K6uROf1LD88uDQqJCktA4yzL1YYAK6NgfsI0v/mTgyPKWsX1CnJ0XPSDhViejru1GcRkLWb8RlzFYJRqGUbaug==", "license": "MIT", + "peer": true, "dependencies": { "@types/node": "*" } @@ -3771,6 +3770,7 @@ "resolved": "https://registry.npmjs.org/@types/express-serve-static-core/-/express-serve-static-core-5.1.1.tgz", "integrity": "sha512-v4zIMr/cX7/d2BpAEX3KNKL/JrT1s43s96lLvvdTmza1oEvDudCqK9aF/djc/SWgy8Yh0h30TZx5VpzqFCxk5A==", "license": "MIT", + "peer": true, "dependencies": { "@types/node": "*", "@types/qs": "*", @@ -3791,7 +3791,8 @@ "version": "2.0.5", "resolved": "https://registry.npmjs.org/@types/http-errors/-/http-errors-2.0.5.tgz", "integrity": "sha512-r8Tayk8HJnX0FztbZN7oVqGccWgw98T/0neJphO91KkmOzug1KkofZURD4UaD5uH8AqcFLfdPErnBod0u71/qg==", - "license": "MIT" + "license": "MIT", + "peer": true }, "node_modules/@types/json-schema": { "version": "7.0.15", @@ -3840,20 +3841,21 @@ "version": "6.15.1", "resolved": "https://registry.npmjs.org/@types/qs/-/qs-6.15.1.tgz", "integrity": "sha512-GZHUBZR9hckSUhrxmp1nG6NwdpM9fCunJwyThLW1X3AyHgd9IlHb6VANpQQqDr2o/qQp6McZ3y/IA2rVzKzSbw==", - "license": "MIT" + "license": "MIT", + "peer": true }, "node_modules/@types/range-parser": { "version": "1.2.7", "resolved": "https://registry.npmjs.org/@types/range-parser/-/range-parser-1.2.7.tgz", "integrity": "sha512-hKormJbkJqzQGhziax5PItDUTMAM9uE2XXQmM37dyd4hVM+5aVl7oVxMVUiVQn2oCQFN/LKCZdvSM0pFRqbSmQ==", - "license": "MIT" + "license": "MIT", + "peer": true }, "node_modules/@types/react": { "version": "18.3.31", "resolved": "https://registry.npmjs.org/@types/react/-/react-18.3.31.tgz", "integrity": "sha512-vfEqpXTvwT91yhmwdfouStN2hSKwTvyRs8qpLfADyrq/kxDw0hZM7Wk9Ug1FELj8hIby+S/+kQCSRFF32nv2Qw==", "license": "MIT", - "peer": true, "dependencies": { "@types/prop-types": "*", "csstype": "^3.2.2" @@ -3865,7 +3867,6 @@ "integrity": "sha512-MEe3UeoENYVFXzoXEWsvcpg6ZvlrFNlOQ7EOsvhI3CfAXwzPfO8Qwuxd40nepsYKqyyVQnTdEfv68q91yLcKrQ==", "devOptional": true, "license": "MIT", - "peer": true, "peerDependencies": { "@types/react": "^18.0.0" } @@ -3875,6 +3876,7 @@ "resolved": "https://registry.npmjs.org/@types/send/-/send-1.2.1.tgz", "integrity": "sha512-arsCikDvlU99zl1g69TcAB3mzZPpxgw0UQnaHeC1Nwb015xp8bknZv5rIfri9xTOcMuaVgvabfIRA7PSZVuZIQ==", "license": "MIT", + "peer": true, "dependencies": { "@types/node": "*" } @@ -3884,6 +3886,7 @@ "resolved": "https://registry.npmjs.org/@types/serve-static/-/serve-static-2.2.0.tgz", "integrity": "sha512-8mam4H1NHLtu7nmtalF7eyBH14QyOASmcxHhSfEoRyr0nP/YdoesEtU+uSRvMe96TW/HPTtkoKqQLl53N7UXMQ==", "license": "MIT", + "peer": true, "dependencies": { "@types/http-errors": "*", "@types/node": "*" @@ -3947,7 +3950,6 @@ "integrity": "sha512-PJ5vePq5/ognBbrIcoC5+SHO5dfpeLPzP9FpLkzWrguoYQEeeSjlJpVwOpo1JRSTEi7dRcwNy4h4dzV70PqHcg==", "dev": true, "license": "MIT", - "peer": true, "dependencies": { "@typescript-eslint/scope-manager": "8.61.1", "@typescript-eslint/types": "8.61.1", @@ -4211,7 +4213,6 @@ "integrity": "sha512-G9/lgqibheLVBDRuya45EbsEXTYcWoSG+TLg7i2axuzx0Eq62eXn+aWXyaVdV5vKvFSWd6ywcX8hA7la9Pvu8g==", "dev": true, "license": "MIT", - "peer": true, "dependencies": { "@bcoe/v8-coverage": "^1.0.2", "@vitest/utils": "4.1.9", @@ -4356,7 +4357,6 @@ "integrity": "sha512-xRQbDb9BnwDafYNn6Vwl839DYVjqXYb1XVGtWAZ1kcDc6iwAL4hg3B1dZlRiuENFeO2H53gFG3in621AdERVAg==", "dev": true, "license": "MIT", - "peer": true, "bin": { "acorn": "bin/acorn" }, @@ -4671,7 +4671,6 @@ } ], "license": "MIT", - "peer": true, "dependencies": { "baseline-browser-mapping": "^2.10.12", "caniuse-lite": "^1.0.30001782", @@ -4814,7 +4813,6 @@ "resolved": "https://registry.npmjs.org/chart.js/-/chart.js-4.5.1.tgz", "integrity": "sha512-GIjfiT9dbmHRiYi6Nl2yFCq7kkwdkp1W/lp2J99rX0yo9tgJGn3lKQATztIjb5tVtevcBtIdICNWqlq5+E8/Pw==", "license": "MIT", - "peer": true, "dependencies": { "@kurkle/color": "^0.3.0" }, @@ -5142,7 +5140,6 @@ "resolved": "https://registry.npmjs.org/date-fns/-/date-fns-3.6.0.tgz", "integrity": "sha512-fRHTG8g/Gif+kSh50gaGEdToemgfj74aRX3swtiouboip5JDLAyDE9F11nHMIcvOaXeOC6D7SpNhi7uFyB7Uww==", "license": "MIT", - "peer": true, "funding": { "type": "github", "url": "https://github.com/sponsors/kossnocorp" @@ -5256,9 +5253,9 @@ } }, "node_modules/dompurify": { - "version": "3.4.11", - "resolved": "https://registry.npmjs.org/dompurify/-/dompurify-3.4.11.tgz", - "integrity": "sha512-zhlUV12GsaRzMsf9q5M254YhA4+VuF0fG+QFqu6aYpoGlKtz+w8//jBcGVYBgQkR5GHjUomejY84AV+/uPbWdw==", + "version": "3.4.12", + "resolved": "https://registry.npmjs.org/dompurify/-/dompurify-3.4.12.tgz", + "integrity": "sha512-zQvGet8Z2sWbQhCmfFz/T5QWH2oBmjnqK3qvOjaqaNLrLEF912WamU+ohnTp0TCep/MFVHpdJuCZEdFOdTnEFg==", "license": "(MPL-2.0 OR Apache-2.0)", "optionalDependencies": { "@types/trusted-types": "^2.0.7" @@ -5284,8 +5281,7 @@ "version": "8.6.0", "resolved": "https://registry.npmjs.org/embla-carousel/-/embla-carousel-8.6.0.tgz", "integrity": "sha512-SjWyZBHJPbqxHOzckOfo8lHisEaJWmwd23XppYFYVh10bU66/Pn5tkVkbkCMZVdbUE5eTCI2nD8OyIP4Z+uwkA==", - "license": "MIT", - "peer": true + "license": "MIT" }, "node_modules/embla-carousel-react": { "version": "8.6.0", @@ -5409,7 +5405,6 @@ "integrity": "sha512-XoMjdBOwe/esVgEvLmNsD3IRHkm7fbKIUGvrleloJXUZgDHig2IPWNniv+GwjyJXzuNqVjlr5+4yVUZjycJwfQ==", "dev": true, "license": "MIT", - "peer": true, "dependencies": { "@eslint-community/eslint-utils": "^4.8.0", "@eslint-community/regexpp": "^4.12.1", @@ -6321,7 +6316,6 @@ "resolved": "https://registry.npmjs.org/jiti/-/jiti-1.21.7.tgz", "integrity": "sha512-/imKNG4EbWNrVjoNC/1H5/9GFy+tqjGBHCaSsN+P2RnPqjsLmv6UD3Ej+Kj8nBWaRAwyk7kK5ZUc+OEatnTR3A==", "license": "MIT", - "peer": true, "bin": { "jiti": "bin/jiti.js" } @@ -6361,7 +6355,6 @@ "integrity": "sha512-ECi4Fi2f7BdJtUKTflYRTiaMxIB0O6zfR1fX0GXpUrf6flp8QIYn1UT20YQqdSOfk2dfkCwS8LAFoJDEppNK5Q==", "dev": true, "license": "MIT", - "peer": true, "dependencies": { "@asamuzakjp/css-color": "^5.1.11", "@asamuzakjp/dom-selector": "^7.1.1", @@ -6642,6 +6635,7 @@ "resolved": "https://registry.npmjs.org/marked/-/marked-14.0.0.tgz", "integrity": "sha512-uIj4+faQ+MgHgwUW1l2PsPglZLOLOT1uErt06dAPtx2kjteLAkbsd/0FiYg/MGS+i7ZKLb7w2WClxHkzOOuryQ==", "license": "MIT", + "peer": true, "bin": { "marked": "bin/marked.js" }, @@ -7578,6 +7572,7 @@ "resolved": "https://registry.npmjs.org/monaco-editor/-/monaco-editor-0.55.1.tgz", "integrity": "sha512-jz4x+TJNFHwHtwuV9vA9rMujcZRb0CEilTEwG2rRSpe/A7Jdkuj8xPKttCgOh+v/lkHy7HsZ64oj+q3xoAFl9A==", "license": "MIT", + "peer": true, "dependencies": { "dompurify": "3.2.7", "marked": "14.0.0" @@ -7588,6 +7583,7 @@ "resolved": "https://registry.npmjs.org/dompurify/-/dompurify-3.2.7.tgz", "integrity": "sha512-WhL/YuveyGXJaerVlMYGWhvQswa7myDG17P7Vu65EWC05o8vfeNbvNf4d/BOvH99+ZW+LlQsc1GDKMa1vNK6dw==", "license": "(MPL-2.0 OR Apache-2.0)", + "peer": true, "optionalDependencies": { "@types/trusted-types": "^2.0.7" } @@ -7855,7 +7851,6 @@ "resolved": "https://registry.npmjs.org/picomatch/-/picomatch-4.0.4.tgz", "integrity": "sha512-QP88BAKvMam/3NxH6vj2o21R6MjxZUAd6nlwAS/pnGvN9IVLocLHxGYIzFhg6fUQ+5th6P4dv4eW9jX3DSIj7A==", "license": "MIT", - "peer": true, "engines": { "node": ">=12" }, @@ -7932,7 +7927,6 @@ } ], "license": "MIT", - "peer": true, "dependencies": { "nanoid": "^3.3.12", "picocolors": "^1.1.1", @@ -8193,7 +8187,6 @@ "resolved": "https://registry.npmjs.org/react/-/react-18.3.1.tgz", "integrity": "sha512-wS+hAgJShR0KhEvPJArfuPVN1+Hz1t0Y6n5jLrGQbkb4urgPE/0Rve+1kMB1v/oWgHgm4WIcV+i7F2pTVj+2iQ==", "license": "MIT", - "peer": true, "dependencies": { "loose-envify": "^1.1.0" }, @@ -8253,7 +8246,6 @@ "resolved": "https://registry.npmjs.org/react-dom/-/react-dom-18.3.1.tgz", "integrity": "sha512-5m4nQKp+rZRb09LNH59GM4BxTh9251/ylbKIbpe7TpGxfJ+9kv6BLkLBXIjjspbgbnIBNqlI23tRnTWT0snUIw==", "license": "MIT", - "peer": true, "dependencies": { "loose-envify": "^1.1.0", "scheduler": "^0.23.2" @@ -8279,7 +8271,6 @@ "resolved": "https://registry.npmjs.org/react-hook-form/-/react-hook-form-7.79.0.tgz", "integrity": "sha512-mhYp/MTmXvzYX6AJcJVko0rktoIhhmRnEouObj4wF5i/tCttgJvnp1+9wRkpITZjDTqpo4IOSJqu0dBlPlV/Lw==", "license": "MIT", - "peer": true, "engines": { "node": ">=18.0.0" }, @@ -9081,7 +9072,6 @@ "resolved": "https://registry.npmjs.org/tailwindcss/-/tailwindcss-3.4.19.tgz", "integrity": "sha512-3ofp+LL8E+pK/JuPLPggVAIaEuhvIz4qNcf3nA1Xn2o/7fb7s/TYpHhwGDv1ZU3PkBluUVaF8PyCHcm48cKLWQ==", "license": "MIT", - "peer": true, "dependencies": { "@alloc/quick-lru": "^5.2.0", "arg": "^5.0.2", @@ -9328,7 +9318,6 @@ "integrity": "sha512-jl1vZzPDinLr9eUt3J/t7V6FgNEw9QjvBPdysz9KfQDD41fQrC2Y4vKQdiaUpFT4bXlb1RHhLpp8wtm6M5TgSw==", "dev": true, "license": "Apache-2.0", - "peer": true, "bin": { "tsc": "bin/tsc", "tsserver": "bin/tsserver" @@ -9623,7 +9612,6 @@ "integrity": "sha512-KuOaNhcnGFN2zIPGA7wRmzF+lJA1sea7rHq17aiJ++9lzY1WWG6Jpwqwe1KNbRVPIqHmr8GLYx7jbrQcN/7/ww==", "dev": true, "license": "MIT", - "peer": true, "dependencies": { "esbuild": "^0.27.0", "fdir": "^6.5.0", @@ -9714,7 +9702,6 @@ "integrity": "sha512-nE3/LEyc0z87uHYLZebqCUOaJr2hdtuPp7BQ4BosVFnfltxgAvMG08NyrSGlPpOUWvR27c5flSmYFTNr78L9GQ==", "dev": true, "license": "MIT", - "peer": true, "dependencies": { "@vitest/expect": "4.1.9", "@vitest/mocker": "4.1.9", diff --git a/package.json b/package.json index 303aa5dc..fdadfc5c 100644 --- a/package.json +++ b/package.json @@ -54,7 +54,7 @@ "clsx": "^2.1.1", "cmdk": "^1.1.1", "date-fns": "^3.6.0", - "dompurify": "^3.4.7", + "dompurify": "^3.4.12", "embla-carousel-react": "^8.6.0", "framer-motion": "^11.18.2", "input-otp": "^1.4.2", diff --git a/src/components/chat/MessageBubble.tsx b/src/components/chat/MessageBubble.tsx index 116616a0..9680c490 100644 --- a/src/components/chat/MessageBubble.tsx +++ b/src/components/chat/MessageBubble.tsx @@ -1,4 +1,5 @@ -import { memo } from "react"; +import { memo, useMemo } from "react"; +import { sanitizeMessageContent } from "@/utils/sanitize"; interface MessageBubbleProps { text: string; @@ -12,6 +13,8 @@ const MessageBubble = ({ time, }: MessageBubbleProps) => { const isUser = sender === "user"; + // SECURITY (#1852): Sanitize message content to prevent XSS on render + const safeText = useMemo(() => sanitizeMessageContent(text), [text]); return (
@@ -22,7 +25,7 @@ const MessageBubble = ({ : "bg-white text-black rounded-bl-none" }`} > -

{text}

+

{safeText}

{time}
diff --git a/src/components/messages/utils.ts b/src/components/messages/utils.ts index b1dbc503..eb59ca59 100644 --- a/src/components/messages/utils.ts +++ b/src/components/messages/utils.ts @@ -1,4 +1,5 @@ import { ProfileSummary, MessageRow } from "@/hooks/useMessages"; +import { sanitizeMessageContent } from "@/utils/sanitize"; export const getDisplayName = (profile?: Pick | null) => profile?.name?.trim() || profile?.email?.split("@")[0] || "Learner"; @@ -6,8 +7,11 @@ export const getDisplayName = (profile?: Pick export const getInitial = (profile?: Pick | null) => getDisplayName(profile).charAt(0).toUpperCase(); -export const getMessageBody = (message: MessageRow) => - message.content || message.text || message.message || ""; +/** SECURITY (#1852): Sanitize message body to prevent Stored XSS on render */ +export const getMessageBody = (message: MessageRow) => { + const raw = message.content || message.text || message.message || ""; + return sanitizeMessageContent(raw); +}; export const getRoleLabel = (profile: ProfileSummary) => { if (profile.is_mentor && profile.is_learner) return "Mentor + Learner"; diff --git a/src/hooks/useMessages.ts b/src/hooks/useMessages.ts index 3beb06b9..1ae38dac 100644 --- a/src/hooks/useMessages.ts +++ b/src/hooks/useMessages.ts @@ -3,6 +3,7 @@ import { supabase } from "@/integrations/supabase/client"; import { useAwardXP } from "@/hooks/useAwardXP"; import { toast } from "@/hooks/use-toast"; import { logError } from "@/utils/logger"; +import { validateMessageContent } from "@/utils/sanitize"; export type ProfileSummary = { id: string; @@ -567,14 +568,17 @@ export function useMessages( const sendMessage = useCallback(async (content: string) => { if (!content || !selectedUser || !currentUserId) return false; - if (content.length > 1000) { + // SECURITY (#1852): Validate and sanitize message content to prevent Stored XSS + const validation = validateMessageContent(content); + if (!validation.valid) { toast({ - title: "Message too long", - description: "Message exceeds the 1000 character limit.", + title: "Invalid message", + description: validation.error, variant: "destructive", }); return false; } + const sanitizedContent = validation.content; try { const { data, error: insertError } = await supabase @@ -582,8 +586,8 @@ export function useMessages( .insert({ sender_id: currentUserId, receiver_id: selectedUser.id, - content, - text: content, + content: sanitizedContent, + text: sanitizedContent, }) .select("id,sender_id,receiver_id,content,text,message,created_at,read_at") .single(); diff --git a/src/hooks/useRoomChat.ts b/src/hooks/useRoomChat.ts index 062bc1af..efa13db0 100644 --- a/src/hooks/useRoomChat.ts +++ b/src/hooks/useRoomChat.ts @@ -2,6 +2,7 @@ import { useState, useEffect, useCallback } from "react"; import { toast } from "sonner"; import { supabase } from "@/integrations/supabase/client"; import { User } from "@supabase/supabase-js"; +import { validateMessageContent } from "@/utils/sanitize"; export function useRoomChat(id: string | undefined, user: User | null) { // eslint-disable-next-line @typescript-eslint/no-explicit-any @@ -30,9 +31,17 @@ export function useRoomChat(id: string | undefined, user: User | null) { const handleSendMessage = useCallback(async (newMessage: string) => { if (!newMessage.trim() || !user || !id) return false; + // SECURITY (#1852): Validate and sanitize message content to prevent Stored XSS + const validation = validateMessageContent(newMessage); + if (!validation.valid) { + toast.error(validation.error); + return false; + } + const sanitizedMessage = validation.content; + // eslint-disable-next-line @typescript-eslint/no-explicit-any const { error } = await supabase.from('study_room_messages' as any).insert([ - { room_id: id, profile_id: user.id, content: newMessage } + { room_id: id, profile_id: user.id, content: sanitizedMessage } ]); if (error) { diff --git a/src/hooks/useSessions.ts b/src/hooks/useSessions.ts index 1cff6961..3ec61a09 100644 --- a/src/hooks/useSessions.ts +++ b/src/hooks/useSessions.ts @@ -3,6 +3,7 @@ import { supabase } from "@/integrations/supabase/client"; import { useAwardXP } from "@/hooks/useAwardXP"; import { useToast } from "@/hooks/use-toast"; import { API_BASE_URL } from "@/config/api"; +import { validateMessageContent } from "@/utils/sanitize"; // UI tab labels don't match the DB's session status values, so each tab // must be translated to the status (or statuses) it represents before filtering. const TAB_TO_STATUS: Record = { @@ -305,6 +306,14 @@ export function useSessions(user: any) { const sendMessage = useCallback(async (msgText: string) => { if (!msgText.trim() || !selectedSession) return; + // SECURITY (#1852): Validate and sanitize message content to prevent Stored XSS + const validation = validateMessageContent(msgText); + if (!validation.valid) { + toast({ title: "Invalid message", description: validation.error, variant: "destructive" }); + return; + } + const sanitizedText = validation.content; + const activity = { id: Date.now(), text: `${user?.user_metadata?.full_name || "Someone"} sent a message`, @@ -326,7 +335,7 @@ export function useSessions(user: any) { session_id: selectedSession.id, user_id: user?.id, username: user?.user_metadata?.full_name || "Anonymous", - message: msgText, + message: sanitizedText, }); if (error) throw error; diff --git a/src/utils/sanitize.ts b/src/utils/sanitize.ts new file mode 100644 index 00000000..54a1f9ef --- /dev/null +++ b/src/utils/sanitize.ts @@ -0,0 +1,65 @@ +import DOMPurify from 'dompurify'; + +// NOTE: DOMPurify requires a browser DOM environment (window/document). +// This module is browser-only and must NOT be imported in Node.js/server contexts. + +/** + * Sanitize user-generated content to prevent Stored XSS attacks. + * + * - Strips all HTML tags, scripts, event handlers, and dangerous attributes. + * - Returns plain text safe for rendering in React components. + * + * @param dirty - Raw user input that may contain HTML/JS payloads + * @returns Sanitized plain text string + */ +export function sanitizeMessageContent(dirty: string): string { + if (!dirty || typeof dirty !== 'string') return ''; + + // Use DOMPurify to strip ALL HTML — peer messages should be plain text. + // ALLOWED_TAGS and ALLOWED_ATTR are empty so every tag is removed. + const clean = DOMPurify.sanitize(dirty, { + ALLOWED_TAGS: [], + ALLOWED_ATTR: [], + KEEP_CONTENT: true, // keep the text content of stripped tags + }); + + return clean.trim(); +} + +/** + * Validate and enforce limits on message content before storage. + * + * @param content - The message content to validate + * @param maxLength - Maximum allowed character length (default 1000) + * @returns An object with `valid` flag and either the sanitized `content` or an `error` message + */ +export function validateMessageContent( + content: string, + maxLength = 1000 +): { valid: true; content: string } | { valid: false; error: string } { + if (!content || typeof content !== 'string') { + return { valid: false, error: 'Message content is required.' }; + } + + const trimmed = content.trim(); + if (trimmed.length === 0) { + return { valid: false, error: 'Message cannot be empty.' }; + } + + if (trimmed.length > maxLength) { + return { + valid: false, + error: `Message exceeds the ${maxLength} character limit.`, + }; + } + + const sanitized = sanitizeMessageContent(trimmed); + if (sanitized.length === 0) { + return { + valid: false, + error: 'Message contains only disallowed content.', + }; + } + + return { valid: true, content: sanitized }; +}