security: fix full audit findings (v0.32.0)

Full list of the audit's confirmed findings and their fixes:

- Stored XSS via unescaped JSON-LD on the public recipe page
  (app/r/[id]/page.tsx) — escape < before injecting.
- CSP allowed unsafe-eval in production — now dev-only (Next prod
  never eval()s; only its HMR does).
- avatarUrl accepted any URL with no ownership check — now takes an
  avatarKey issued by avatar-presign, validated server-side, same
  pattern as recipe/review photos.
- No session revocation on password change/reset — both now revoke
  other sessions (revokeOtherSessions: true, revokeSessionsOnPasswordReset).
- Rate-limit bypass via spoofable X-Forwarded-For — take the last
  (proxy-appended) hop instead of the first (client-supplied) one,
  matching the single-Traefik-hop topology.
- Webhook signing secrets stored plaintext — now AES-256-GCM
  encrypted like every other secret in this app, with a legacy-
  plaintext fallback for pre-existing rows (bare hex has no ":", our
  ciphertext format always does).
- Better Auth's own rate limiter defaulted to in-memory storage,
  ineffective across replicas — now backed by the same Redis as
  lib/rate-limit.ts (secondaryStorage), with storeSessionInDatabase
  explicit so session storage itself doesn't move as a side effect.
- Presigned upload URLs didn't bind the declared file size to the
  actual upload, letting a client under-declare size (and quota
  charge) then PUT an arbitrarily large object — switched to S3
  presigned POST with a signed content-length-range condition,
  enforced by the storage server itself.
- generateMetadata() on the recipe page skipped the visibility
  filter the page body uses, leaking a private recipe's title via
  <title> to any signed-in user with the id.
- Block/unblock had no rate limit, unlike follow/unfollow.
- AI quota was charged even when a user's own BYOK key was used
  (their own credentials/billing) — added an isByok flag through
  the config-resolution chain and skip the charge when set. Also
  wired BYOK into generate/generate-from-idea/translate/import-url,
  which never looked it up at all before.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

apps/web/app/api/v1/ai/adapt/[id]/route.ts

@@ -65,7 +65,7 @@ export async function POST(req: NextRequest, { params }: Params) {
       },
       { ...aiConfig, userContext: privateBio ?? undefined },
       (session!.user as { locale?: string }).locale ?? "en"
-    )
+    ), { skipQuota: aiConfig.isByok }
   );
   if (!result.ok) return result.response;
   const adapted = result.data;

apps/web/app/api/v1/ai/batch-cook/generate/route.ts

@@ -55,7 +55,7 @@ export async function POST(req: NextRequest) {
       },
       { ...config, userContext: privateBio ?? undefined },
       locale
-    )
+    ), { skipQuota: config.isByok }
   );
   if (!result.ok) return result.response;
   const plan = result.data;

apps/web/app/api/v1/ai/cooking-chat/route.ts

@@ -33,7 +33,8 @@ export async function POST(req: NextRequest) {
     getUserPrivateBio(session!.user.id),
   ]);
   if (!configResult.ok) return configResult.response;
-  const model = resolveModel(configResult.data);
+  const aiConfig = configResult.data;
+  const model = resolveModel(aiConfig);
   const bioContext = buildUserBioContext(privateBio);
   const locale = (session!.user as { locale?: string }).locale ?? "en";
   const lang = LANG[locale] ?? "English";
@@ -43,7 +44,7 @@ export async function POST(req: NextRequest) {
       model,
       system: `You are Epicure, a helpful culinary assistant answering general cooking questions — not tied to any specific recipe (techniques, substitutions, timing, equipment, food safety, etc). If asked who you are or what model/AI you're built on, say you're Epicure — never name the underlying model or provider. If a question has nothing to do with cooking or food, politely redirect. Keep answers under 200 words. Respond in ${lang}.${bioContext}`,
       prompt: parsed.data.question,
-    })
+    }), { skipQuota: aiConfig.isByok }
   );
   if (!result.ok) return result.response;
 

apps/web/app/api/v1/ai/drinks/[id]/route.ts

@@ -55,7 +55,7 @@ export async function POST(req: NextRequest, { params }: Params) {
       parsed.data.count,
       { ...aiConfig, userContext: privateBio ?? undefined },
       (session!.user as { locale?: string }).locale ?? "en"
-    )
+    ), { skipQuota: aiConfig.isByok }
   );
   if (!result.ok) return result.response;
 

apps/web/app/api/v1/ai/generate-from-idea/route.ts

@@ -2,9 +2,10 @@ import { NextRequest, NextResponse } from "next/server";
 import { z } from "zod";
 import { requireSessionOrApiKey } from "@/lib/api-auth";
 import { applyRateLimit } from "@/lib/rate-limit";
-import { withAiQuota } from "@/lib/ai/ai-error";
+import { withAiQuota, resolveAiConfigOrError } from "@/lib/ai/ai-error";
 import { generateRecipe } from "@/lib/ai/features/generate-recipe";
 import { getUserPrivateBio } from "@/lib/ai/user-bio";
+import { withUserKey } from "@/lib/ai/resolve-user-key";
 import { db, recipes, recipeIngredients, recipeSteps } from "@epicure/db";
 import { parseQuantity } from "@/lib/parse-quantity";
 
@@ -32,13 +33,18 @@ export async function POST(req: NextRequest) {
   const privateBio = await getUserPrivateBio(session!.user.id);
   const locale = (session!.user as { locale?: string }).locale ?? "en";
 
+  const configResult = await resolveAiConfigOrError(() =>
+    withUserKey(session!.user.id, { provider: parsed.data.provider, model: parsed.data.model })
+  );
+  if (!configResult.ok) return configResult.response;
+  const aiConfig = configResult.data;
+
   const result = await withAiQuota(session!.user.id, session!.user.tier as "free" | "pro", () =>
     generateRecipe(parsed.data.title, {
-      provider: parsed.data.provider,
-      model: parsed.data.model,
+      ...aiConfig,
       userContext: privateBio ?? undefined,
       language: LANG[locale] ?? "English",
-    })
+    }), { skipQuota: aiConfig.isByok }
   );
   if (!result.ok) return result.response;
   const recipe = result.data;

apps/web/app/api/v1/ai/generate/route.ts

@@ -2,9 +2,10 @@ import { NextRequest, NextResponse } from "next/server";
 import { z } from "zod";
 import { requireSessionOrApiKey } from "@/lib/api-auth";
 import { applyRateLimit } from "@/lib/rate-limit";
-import { withAiQuota } from "@/lib/ai/ai-error";
+import { withAiQuota, resolveAiConfigOrError } from "@/lib/ai/ai-error";
 import { generateRecipe } from "@/lib/ai/features/generate-recipe";
 import { getUserPrivateBio } from "@/lib/ai/user-bio";
+import { withUserKey } from "@/lib/ai/resolve-user-key";
 
 const Schema = z.object({
   prompt: z.string().min(3).max(500),
@@ -29,14 +30,19 @@ export async function POST(req: NextRequest) {
 
   const privateBio = await getUserPrivateBio(session!.user.id);
 
+  const configResult = await resolveAiConfigOrError(() =>
+    withUserKey(session!.user.id, { provider: parsed.data.provider, model: parsed.data.model })
+  );
+  if (!configResult.ok) return configResult.response;
+  const aiConfig = configResult.data;
+
   const result = await withAiQuota(session!.user.id, session!.user.tier as "free" | "pro", () =>
     generateRecipe(parsed.data.prompt, {
-      provider: parsed.data.provider,
-      model: parsed.data.model,
+      ...aiConfig,
       language: parsed.data.language,
       difficulty: parsed.data.difficulty,
       userContext: privateBio ?? undefined,
-    })
+    }), { skipQuota: aiConfig.isByok }
   );
   if (!result.ok) return result.response;
 

apps/web/app/api/v1/ai/import-photo/route.ts

@@ -39,7 +39,8 @@ export async function POST(req: NextRequest) {
   }
 
   const result = await withAiQuota(userId, session!.user.tier as "free" | "pro", () =>
-    importFromPhoto(parsed.data.imageBase64, parsed.data.mimeType, aiConfig, locale)
+    importFromPhoto(parsed.data.imageBase64, parsed.data.mimeType, aiConfig, locale),
+    { skipQuota: aiConfig.isByok }
   );
   if (!result.ok) return result.response;
   const recipe = result.data;

apps/web/app/api/v1/ai/import-url/route.ts

@@ -2,9 +2,10 @@ import { NextRequest, NextResponse } from "next/server";
 import { z } from "zod";
 import { requireSessionOrApiKey } from "@/lib/api-auth";
 import { applyRateLimit } from "@/lib/rate-limit";
-import { withAiQuota } from "@/lib/ai/ai-error";
+import { withAiQuota, resolveAiConfigOrError } from "@/lib/ai/ai-error";
 import { importFromUrl } from "@/lib/ai/features/import-url";
 import { validateWebhookUrl } from "@/lib/validate-webhook-url";
+import { withUserKey } from "@/lib/ai/resolve-user-key";
 
 const Schema = z.object({
   url: z.string().url(),
@@ -30,11 +31,14 @@ export async function POST(req: NextRequest) {
   const limited = await applyRateLimit(`rl:ai:${session!.user.id}`, 10, 60);
   if (limited) return limited;
 
+  const configResult = await resolveAiConfigOrError(() =>
+    withUserKey(session!.user.id, { provider: parsed.data.provider, model: parsed.data.model })
+  );
+  if (!configResult.ok) return configResult.response;
+  const aiConfig = configResult.data;
+
   const result = await withAiQuota(session!.user.id, session!.user.tier as "free" | "pro", () =>
-    importFromUrl(parsed.data.url, {
-      provider: parsed.data.provider,
-      model: parsed.data.model,
-    })
+    importFromUrl(parsed.data.url, aiConfig), { skipQuota: aiConfig.isByok }
   );
   if (!result.ok) return result.response;
 

apps/web/app/api/v1/ai/meal-plan/generate/route.ts

@@ -88,7 +88,7 @@ export async function POST(req: NextRequest) {
       },
       { ...config, userContext: privateBio ?? undefined },
       locale
-    )
+    ), { skipQuota: config.isByok }
   );
   if (!result.ok) return result.response;
   const plan = result.data;

apps/web/app/api/v1/ai/pairings/[id]/route.ts

@@ -56,7 +56,7 @@ export async function POST(req: NextRequest, { params }: Params) {
       parsed.data.count,
       { ...aiConfig, userContext: privateBio ?? undefined },
       (session!.user as { locale?: string }).locale ?? "en"
-    )
+    ), { skipQuota: aiConfig.isByok }
   );
   if (!result.ok) return result.response;
 

apps/web/app/api/v1/ai/recipe-chat/route.ts

@@ -68,7 +68,8 @@ ${stepList || "None listed"}
     getUserPrivateBio(session!.user.id),
   ]);
   if (!configResult.ok) return configResult.response;
-  const model = resolveModel(configResult.data);
+  const aiConfig = configResult.data;
+  const model = resolveModel(aiConfig);
   const bioContext = buildUserBioContext(privateBio);
   const locale = (session!.user as { locale?: string }).locale ?? "en";
   const lang = LANG[locale] ?? "English";
@@ -80,7 +81,7 @@ ${stepList || "None listed"}
 
 ${recipeContext}${bioContext}`,
       prompt: parsed.data.question,
-    })
+    }), { skipQuota: aiConfig.isByok }
   );
   if (!result.ok) return result.response;
 

apps/web/app/api/v1/ai/recipe-ideas/route.ts

@@ -42,7 +42,8 @@ export async function POST(req: NextRequest) {
     getUserPrivateBio(session!.user.id),
   ]);
   if (!configResult.ok) return configResult.response;
-  const model = resolveModel(configResult.data);
+  const aiConfig = configResult.data;
+  const model = resolveModel(aiConfig);
   const bioContext = buildUserBioContext(privateBio);
 
   const userContext = bioContext
@@ -62,7 +63,7 @@ export async function POST(req: NextRequest) {
       schema: IdeasSchema,
       system: `Respond in ${lang}.`,
       prompt,
-    })
+    }), { skipQuota: aiConfig.isByok }
   );
   if (!result.ok) return result.response;
 

apps/web/app/api/v1/ai/scale/route.ts

@@ -55,7 +55,7 @@ export async function POST(req: NextRequest) {
       recipe.baseServings,
       aiConfig,
       (session!.user as { locale?: string }).locale ?? "en"
-    )
+    ), { skipQuota: aiConfig.isByok }
   );
   if (!result.ok) return result.response;
 

apps/web/app/api/v1/ai/substitute/route.ts

@@ -5,6 +5,7 @@ import { withAiQuota, resolveAiConfigOrError } from "@/lib/ai/ai-error";
 import { applyRateLimit } from "@/lib/rate-limit";
 import { getDefaultProviderWithKey } from "@/lib/ai/resolve-user-key";
 import { substituteIngredient } from "@/lib/ai/features/substitute-ingredient";
+import type { AiConfig } from "@/lib/ai/factory";
 
 const Schema = z.object({
   ingredient: z.string().min(1).max(200),
@@ -28,7 +29,7 @@ export async function POST(req: NextRequest) {
     ? `recipe "${parsed.data.recipeTitle}"`
     : "a general recipe";
 
-  let aiConfig;
+  let aiConfig: AiConfig;
   if (parsed.data.provider) {
     aiConfig = { provider: parsed.data.provider, model: parsed.data.model };
   } else {
@@ -40,7 +41,8 @@ export async function POST(req: NextRequest) {
   const locale = (session!.user as { locale?: string }).locale ?? "en";
 
   const result = await withAiQuota(session!.user.id, session!.user.tier as "free" | "pro", () =>
-    substituteIngredient(parsed.data.ingredient, context, aiConfig, locale)
+    substituteIngredient(parsed.data.ingredient, context, aiConfig, locale),
+    { skipQuota: aiConfig.isByok }
   );
   if (!result.ok) return result.response;
 

apps/web/app/api/v1/ai/translate/[id]/route.ts

@@ -3,8 +3,9 @@ import { z } from "zod";
 import { and, eq } from "@epicure/db";
 import { db, recipes, recipeIngredients, recipeSteps } from "@epicure/db";
 import { requireSessionOrApiKey } from "@/lib/api-auth";
-import { withAiQuota } from "@/lib/ai/ai-error";
+import { withAiQuota, resolveAiConfigOrError } from "@/lib/ai/ai-error";
 import { translateRecipe } from "@/lib/ai/features/translate-recipe";
+import { withUserKey } from "@/lib/ai/resolve-user-key";
 
 const Schema = z.object({
   targetLanguage: z.string().min(2).max(50),
@@ -35,6 +36,12 @@ export async function POST(req: NextRequest, { params }: Params) {
     return NextResponse.json({ error: "Validation error", issues: parsed.error.issues }, { status: 400 });
   }
 
+  const configResult = await resolveAiConfigOrError(() =>
+    withUserKey(session!.user.id, { provider: parsed.data.provider, model: parsed.data.model })
+  );
+  if (!configResult.ok) return configResult.response;
+  const aiConfig = configResult.data;
+
   const result = await withAiQuota(session!.user.id, session!.user.tier as "free" | "pro", () =>
     translateRecipe(
       {
@@ -44,8 +51,8 @@ export async function POST(req: NextRequest, { params }: Params) {
         steps: recipe.steps,
       },
       parsed.data.targetLanguage,
-      { provider: parsed.data.provider, model: parsed.data.model }
-    )
+      aiConfig
+    ), { skipQuota: aiConfig.isByok }
   );
   if (!result.ok) return result.response;
   const translation = result.data;

apps/web/app/api/v1/ai/variations/[id]/route.ts

@@ -59,7 +59,7 @@ export async function POST(req: NextRequest, { params }: Params) {
       { ...aiConfig, userContext: privateBio ?? undefined },
       parsed.data.directions,
       (session!.user as { locale?: string }).locale ?? "en"
-    )
+    ), { skipQuota: aiConfig.isByok }
   );
   if (!result.ok) return result.response;
 

apps/web/app/api/v1/upload/avatar-presign/route.ts

@@ -1,7 +1,7 @@
 import { NextRequest, NextResponse } from "next/server";
 import { z } from "zod";
 import { requireSession } from "@/lib/api-auth";
-import { createPresignedUploadUrl } from "@/lib/storage";
+import { createPresignedUploadPost } from "@/lib/storage";
 import { checkAndIncrementTierLimit, TierLimitError } from "@/lib/tiers";
 
 const ALLOWED_TYPES = ["image/jpeg", "image/png", "image/webp", "image/avif"] as const;
@@ -39,7 +39,7 @@ export async function POST(req: NextRequest) {
 
   const ext = contentType.split("/")[1] ?? "jpg";
   const key = `user-avatars/${session!.user.id}/${crypto.randomUUID()}.${ext}`;
-  const url = await createPresignedUploadUrl(key, contentType);
+  const { url, fields } = await createPresignedUploadPost(key, contentType, MAX_FILE_SIZE);
 
-  return NextResponse.json({ url, key });
+  return NextResponse.json({ url, fields, key });
 }

apps/web/app/api/v1/upload/presign/route.ts

@@ -1,7 +1,7 @@
 import { NextRequest, NextResponse } from "next/server";
 import { z } from "zod";
 import { requireSession } from "@/lib/api-auth";
-import { createPresignedUploadUrl } from "@/lib/storage";
+import { createPresignedUploadPost } from "@/lib/storage";
 import { db, recipes, eq, and } from "@epicure/db";
 import { checkAndIncrementTierLimit, TierLimitError } from "@/lib/tiers";
 
@@ -53,7 +53,7 @@ export async function POST(req: NextRequest) {
   const ext = contentType.split("/")[1] ?? "jpg";
   const folder = purpose === "review" ? "reviews" : "photos";
   const key = `recipes/${recipeId}/${folder}/${session!.user.id}-${crypto.randomUUID()}.${ext}`;
-  const url = await createPresignedUploadUrl(key, contentType);
+  const { url, fields } = await createPresignedUploadPost(key, contentType, MAX_FILE_SIZE);
 
-  return NextResponse.json({ url, key });
+  return NextResponse.json({ url, fields, key });
 }

apps/web/app/api/v1/users/[username]/block/route.ts

@@ -1,12 +1,17 @@
 import { NextRequest, NextResponse } from "next/server";
 import { db, users, userBlocks, userFollows, eq, and, or } from "@epicure/db";
 import { requireSession } from "@/lib/api-auth";
+import { applyRateLimit } from "@/lib/rate-limit";
 
 type Params = { params: Promise<{ username: string }> };
 
 export async function POST(_req: NextRequest, { params }: Params) {
   const { session, response } = await requireSession();
   if (response) return response;
+
+  const limited = await applyRateLimit(`rl:block:${session!.user.id}`, 30, 60);
+  if (limited) return limited;
+
   const { username } = await params;
 
   const target = await db.query.users.findFirst({ where: eq(users.username, username) });
@@ -31,6 +36,10 @@ export async function POST(_req: NextRequest, { params }: Params) {
 export async function DELETE(_req: NextRequest, { params }: Params) {
   const { session, response } = await requireSession();
   if (response) return response;
+
+  const limited = await applyRateLimit(`rl:block:${session!.user.id}`, 30, 60);
+  if (limited) return limited;
+
   const { username } = await params;
 
   const target = await db.query.users.findFirst({ where: eq(users.username, username) });

apps/web/app/api/v1/users/me/route.ts

@@ -5,6 +5,7 @@ import { db, users, eq } from "@epicure/db";
 import { z } from "zod";
 import { gravatarUrl } from "@/lib/gravatar";
 import { USERNAME_PATTERN, isUsernameTaken } from "@/lib/username";
+import { isOwnedAvatarKey, getPublicUrl } from "@/lib/storage";
 
 const PatchSchema = z.object({
   name: z.string().min(1).max(100).optional(),
@@ -13,9 +14,12 @@ const PatchSchema = z.object({
   privateBio: z.string().max(2000).optional().nullable(),
   isPrivate: z.boolean().optional(),
   username: z.string().trim().toLowerCase().regex(USERNAME_PATTERN, "3-20 characters, lowercase letters, numbers, and underscores only").optional(),
-  // A custom-uploaded avatar URL, or null to revert to the initials fallback
-  // (or Gravatar, if useGravatar is on — see below).
-  avatarUrl: z.string().url().max(2048).optional().nullable(),
+  // The storage key returned by /api/v1/upload/avatar-presign (not a URL) —
+  // the server validates it was actually issued to this user and builds the
+  // public URL itself, so a client can't point avatarUrl at an arbitrary or
+  // another user's object. `null` reverts to the initials fallback (or
+  // Gravatar, if useGravatar is on — see below).
+  avatarKey: z.string().max(500).optional().nullable(),
   // Off by default (Settings → Profile) — Gravatar is looked up by an MD5
   // hash of the user's email, sent to a third party.
   useGravatar: z.boolean().optional(),
@@ -32,7 +36,7 @@ export async function PATCH(req: Request) {
     return NextResponse.json({ error: "Username already taken" }, { status: 409 });
   }
 
-  const { avatarUrl, useGravatar, ...rest } = body.data;
+  const { avatarKey, useGravatar, ...rest } = body.data;
   const updates: Partial<typeof users.$inferInsert> = { ...rest };
 
   // useGravatar is only ever toggled from the settings form, never alongside
@@ -45,13 +49,16 @@ export async function PATCH(req: Request) {
     }
   }
 
-  if (avatarUrl !== undefined) {
-    if (avatarUrl === null) {
+  if (avatarKey !== undefined) {
+    if (avatarKey === null) {
       const gravatarOptedIn = useGravatar ?? (await getUseGravatar(session.user.id));
       updates.avatarUrl = gravatarOptedIn ? gravatarUrl(session.user.email) : null;
       updates.hasCustomAvatar = false;
     } else {
-      updates.avatarUrl = avatarUrl;
+      if (!isOwnedAvatarKey(avatarKey, session.user.id)) {
+        return NextResponse.json({ error: "Invalid avatar key" }, { status: 400 });
+      }
+      updates.avatarUrl = getPublicUrl(avatarKey);
       updates.hasCustomAvatar = true;
     }
   }

apps/web/app/api/v1/webhooks/route.ts

@@ -5,6 +5,7 @@ import { db, webhooks, eq } from "@epicure/db";
 import { requireSession } from "@/lib/api-auth";
 import { validateWebhookUrl } from "@/lib/validate-webhook-url";
 import { WEBHOOK_EVENTS } from "@/lib/webhooks";
+import { encrypt } from "@/lib/encrypt";
 
 const CreateWebhookBody = z.object({
   url: z.string().min(1).max(2048),
@@ -64,7 +65,7 @@ export async function POST(req: NextRequest) {
     userId: session!.user.id,
     url: parsed.data.url,
     events: parsed.data.events,
-    secret,
+    secret: encrypt(secret),
     active: true,
     createdAt: now,
   });