feat: imgur proxying for blocked countries (#7104)

packages/api-client/src/modules/index.ts

@@ -32,6 +32,7 @@ import { LabrinthCollectionsModule } from './labrinth/collections'
 import { LabrinthContentV3Module } from './labrinth/content/v3'
 import { LabrinthExternalProjectsInternalModule } from './labrinth/external-projects/internal'
 import { LabrinthFriendsV3Module } from './labrinth/friends/v3'
+import { LabrinthGeoIpModule } from './labrinth/geoip'
 import { LabrinthGlobalsInternalModule } from './labrinth/globals/internal'
 import { LabrinthImagesV3Module } from './labrinth/images/v3'
 import { LabrinthLimitsV3Module } from './labrinth/limits/v3'
@@ -111,6 +112,7 @@ export const MODULE_REGISTRY = {
 	labrinth_content_v3: LabrinthContentV3Module,
 	labrinth_external_projects_internal: LabrinthExternalProjectsInternalModule,
 	labrinth_friends_v3: LabrinthFriendsV3Module,
+	labrinth_geoip: LabrinthGeoIpModule,
 	labrinth_globals_internal: LabrinthGlobalsInternalModule,
 	labrinth_images_v3: LabrinthImagesV3Module,
 	labrinth_moderation_internal: LabrinthModerationInternalModule,

packages/api-client/src/modules/labrinth/geoip.ts

@@ -0,0 +1,23 @@
+import { AbstractModule } from '../../core/abstract-module'
+
+export class LabrinthGeoIpModule extends AbstractModule {
+	public getModuleID(): string {
+		return 'labrinth_geoip'
+	}
+
+	public async getCountry(): Promise<string | undefined> {
+		const trace = await this.client.request<string>('/trace', {
+			api: 'https://api.modrinth.com',
+			version: 'cdn-cgi',
+			method: 'GET',
+			skipAuth: true,
+		})
+		const country = trace
+			.split('\n')
+			.find((line) => line.startsWith('loc='))
+			?.slice(4)
+			.toUpperCase()
+
+		return country?.match(/^[A-Z]{2}$/) ? country : undefined
+	}
+}

packages/api-client/src/modules/labrinth/index.ts

@@ -8,6 +8,7 @@ export * from './collections'
 export * from './content/v3'
 export * from './external-projects/internal'
 export * from './friends/v3'
+export * from './geoip'
 export * from './globals/internal'
 export * from './images/v3'
 export * from './limits/v3'

packages/ui/src/providers/index.ts

@@ -18,4 +18,5 @@ export * from './project-page-new'
 export * from './server-context'
 export * from './server-settings-modal'
 export * from './tags'
+export * from './user-country'
 export * from './web-notifications'

packages/ui/src/providers/user-country.ts

@@ -0,0 +1,28 @@
+import { setMarkdownUserCountryResolver } from '@modrinth/utils'
+import type { Ref } from 'vue'
+import { hasInjectionContext } from 'vue'
+
+import { createContext } from './create-context'
+
+const [injectUserCountryContext, provideUserCountryContext] = createContext<Ref<string>>(
+	'root',
+	'userCountry',
+)
+
+let clientCountry: Ref<string> | null = null
+
+export const injectUserCountry = injectUserCountryContext
+export const useUserCountry = injectUserCountryContext
+
+export function provideUserCountry(country: Ref<string>) {
+	if (typeof window !== 'undefined') {
+		clientCountry = country
+	}
+
+	return provideUserCountryContext(country)
+}
+
+setMarkdownUserCountryResolver(() => {
+	const injectedCountry = hasInjectionContext() ? injectUserCountryContext(null) : null
+	return injectedCountry?.value ?? clientCountry?.value
+})

packages/utils/parse.ts

@@ -4,6 +4,39 @@ import xss from 'xss'
 // @ts-expect-error xss types don't reflect CJS default export shape
 const { escapeAttrValue, FilterXSS, safeAttrValue, whiteList } = xss
 
+// Imgur is blocked in UK and Indonesia
+const imgurProxyCountries = new Set(['GB', 'ID'])
+
+type MarkdownUserCountryResolver = () => string | null | undefined
+
+let resolveMarkdownUserCountry: MarkdownUserCountryResolver = () => undefined
+
+export const setMarkdownUserCountryResolver = (resolver: MarkdownUserCountryResolver) => {
+	resolveMarkdownUserCountry = resolver
+}
+
+const shouldProxyImgur = () => {
+	try {
+		const country = resolveMarkdownUserCountry()
+		return country ? imgurProxyCountries.has(country.toUpperCase()) : false
+	} catch {
+		return false
+	}
+}
+
+const getImgurProxyUrl = (value: string) => {
+	try {
+		const url = new URL(value.replaceAll('&', '&'))
+		if (url.hostname !== 'imgur.com' && !url.hostname.endsWith('.imgur.com')) {
+			return undefined
+		}
+
+		return `https://external-content.duckduckgo.com/iu/?u=${encodeURIComponent(url.toString())}.png`
+	} catch {
+		return undefined
+	}
+}
+
 export const configuredXss = new FilterXSS({
 	whiteList: {
 		...whiteList,
@@ -84,6 +117,18 @@ export const configuredXss = new FilterXSS({
 		}
 	},
 	safeAttrValue(tag, name, value, cssFilter) {
+		if (
+			shouldProxyImgur() &&
+			((tag === 'a' && name === 'href') ||
+				((tag === 'img' || tag === 'video' || tag === 'audio' || tag === 'source') &&
+					(name === 'src' || name === 'srcset' || name === 'poster')))
+		) {
+			const proxiedUrl = getImgurProxyUrl(value)
+			if (proxiedUrl) {
+				return safeAttrValue(tag, name, proxiedUrl, cssFilter)
+			}
+		}
+
 		if (
 			(tag === 'img' || tag === 'video' || tag === 'audio' || tag === 'source') &&
 			(name === 'src' || name === 'srcset' || name === 'poster') &&