Fin Proxy

\n \n \n

\n \n \n\n`, {\n headers: { \"Content-Type\": \"text/html; charset=utf-8\" },\n });\n }\n\n let target: URL;\n try {\n target = new URL(normalizeInput(rawTarget));\n } catch {\n return new Response(\"Invalid url\", { status: 400 });\n }\n\n const proxyUrl = (u: string) => {\n try {\n const abs = new URL(u, target).toString();\n return `${proxyRoot}?url=${encodeURIComponent(abs)}`;\n } catch {\n return u;\n }\n };\n\n const hopByHop = new Set([\n \"connection\",\n \"keep-alive\",\n \"proxy-authenticate\",\n \"proxy-authorization\",\n \"te\",\n \"trailer\",\n \"transfer-encoding\",\n \"upgrade\",\n \"content-length\",\n ]);\n\n const stripHeaders = new Set([\n \"content-security-policy\",\n \"content-security-policy-report-only\",\n \"x-frame-options\",\n \"frame-options\",\n \"permissions-policy\",\n \"cross-origin-opener-policy\",\n \"cross-origin-resource-policy\",\n \"cross-origin-embedder-policy\",\n ]);\n\n const reqHeaders = new Headers();\n reqHeaders.set(\n \"user-agent\",\n req.headers.get(\"user-agent\") ||\n \"Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/124.0.0.0 Safari/537.36\"\n );\n reqHeaders.set(\n \"accept\",\n req.headers.get(\"accept\") ||\n \"text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8\"\n );\n reqHeaders.set(\n \"accept-language\",\n req.headers.get(\"accept-language\") || \"en-GB,en;q=0.9\"\n );\n\n const range = req.headers.get(\"range\");\n if (range) reqHeaders.set(\"range\", range);\n\n const cookie = req.headers.get(\"cookie\");\n if (cookie) reqHeaders.set(\"cookie\", cookie);\n\n const referer = req.headers.get(\"referer\");\n if (referer) {\n try {\n const ref = new URL(referer);\n const refTarget = ref.searchParams.get(\"url\");\n if (refTarget) reqHeaders.set(\"referer\", refTarget);\n else reqHeaders.set(\"referer\", target.toString());\n } catch {\n reqHeaders.set(\"referer\", target.toString());\n }\n }\n\n const body =\n req.method === \"GET\" || req.method === \"HEAD\"\n ? undefined\n : await req.arrayBuffer();\n\n const upstream = await fetch(target.toString(), {\n method: req.method,\n headers: reqHeaders,\n body,\n redirect: \"manual\",\n });\n\n const ct = upstream.headers.get(\"content-type\") || \"\";\n const outHeaders = new Headers();\n\n for (const [k, v] of upstream.headers) {\n const lk = k.toLowerCase();\n if (hopByHop.has(lk) || stripHeaders.has(lk)) continue;\n if (lk === \"location\") {\n outHeaders.set(\"location\", proxyUrl(v));\n continue;\n }\n if (lk === \"set-cookie\") {\n outHeaders.append(\"set-cookie\", v);\n continue;\n }\n outHeaders.set(k, v);\n }\n\n outHeaders.set(\"cache-control\", \"no-store\");\n outHeaders.set(\"x-proxy\", \"val-town\");\n\n const isText = /text\\/html|text\\/css|javascript|json|xml|svg|application\\/xhtml\\+xml/i.test(ct);\n\n if (!isText) {\n return new Response(upstream.body, {\n status: upstream.status,\n headers: outHeaders,\n });\n }\n\n let text = await upstream.text();\n\n const rewriteUrl = (u: string) => {\n const s = u.trim().replace(/^['\"]|['\"]$/g, \"\");\n if (\n !s ||\n s.startsWith(\"data:\") ||\n s.startsWith(\"blob:\") ||\n s.startsWith(\"javascript:\") ||\n s.startsWith(\"mailto:\") ||\n s.startsWith(\"#\")\n ) return s;\n return proxyUrl(s);\n };\n\n const rewriteAttrs = (html: string, attrs: string[]) => {\n for (const attr of attrs) {\n const re = new RegExp(`\\\\b${attr}=[\"']([^\"']+)[\"']`, \"gi\");\n html = html.replace(re, (_, v) => `${attr}=\"${rewriteUrl(v)}\"`);\n }\n return html;\n };\n\n if (/text\\/css/i.test(ct)) {\n text = text\n .replace(/@import\\s+(['\"])([^'\"]+)\\1/gi, (_, q, u) => `@import ${q}${rewriteUrl(u)}${q}`)\n .replace(/url\$([^)]+)\$/gi, (_, raw) => `url(\"${rewriteUrl(raw)}\")`);\n\n return new Response(text, {\n status: upstream.status,\n headers: {\n \"content-type\": \"text/css; charset=utf-8\",\n \"cache-control\": \"no-store\",\n },\n });\n }\n\n text = text\n .replace(/]*>/gi, ``)\n .replace(/]+http-equiv=[\"']refresh[\"'][^>]*>/gi, (m) =>\n m.replace(/url=([^\"';]+)/i, (_, u) => `url=${rewriteUrl(u)}`)\n );\n\n text = rewriteAttrs(text, [\n \"href\",\n \"src\",\n \"action\",\n \"poster\",\n \"data-src\",\n \"data-href\",\n \"formaction\",\n \"ping\",\n ]);\n\n text = text.replace(/srcset=[\"']([^\"']+)[\"']/gi, (_, v) => {\n const parts = v.split(\",\").map((part: string) => {\n const t = part.trim();\n const [u, ...rest] = t.split(/\\s+/);\n return [rewriteUrl(u), ...rest].join(\" \");\n });\n return `srcset=\"${parts.join(\", \")}\"`;\n });\n\n text = text.replace(/url\$([^)]+)\$/gi, (_, raw) => `url(\"${rewriteUrl(raw)}\")`);\n text = text.replace(/https?:\\/\\/[^\"' <>()]+/g, (u) => proxyUrl(u));\n\n text = text.replace(\n /]*)>/i,\n ``\n );\n\n return new Response(text, {\n status: upstream.status,\n headers: outHeaders,\n });\n}","deleted","label",[102],"permalink","https://www.val.town/x/finlaym/perplex/code/HTTP","extension","actionData","errors"]