add image support (with proxying) (closes #38)

pages/dirview.go

@@ -61,7 +61,7 @@ func DirView(c *fiber.Ctx) error {
 	})
 	sc.OnHTML("div#readme div.Box-body", func(e *colly.HTMLElement) {
 		Content, _ := e.DOM.Html()
-		readmeOutput = strings.Replace(strings.Replace(string(utils.UGCPolicy().SanitizeBytes([]byte(Content))), "https://github.com", "", -1), "user-content-", "", -1)
+		readmeOutput = strings.Replace(strings.Replace(strings.Replace(strings.Replace(string(utils.UGCPolicy().SanitizeBytes([]byte(Content))), "https://github.com", "", -1), "user-content-", "", -1), "https://camo.githubusercontent.com", "/camo", -1), "https://raw.githubusercontent.com", "/raw", -1)
 	})
 	sc.OnHTML("div.js-details-container div.Details-content--hidden-not-important", func(e *colly.HTMLElement) {
 		e.ForEach("div.js-navigation-item", func(i int, el *colly.HTMLElement) {

pages/repo.go

@@ -86,7 +86,7 @@ func HandleRepo(c *fiber.Ctx) error {
 	})
 	sc.OnHTML("div#readme div.Box-body", func(e *colly.HTMLElement) {
 		Content, _ := e.DOM.Html()
-		readmeOutput = strings.Replace(strings.Replace(string(utils.UGCPolicy().SanitizeBytes([]byte(Content))), "https://github.com", "", -1), "user-content-", "", -1)
+		readmeOutput = strings.Replace(strings.Replace(strings.Replace(strings.Replace(string(utils.UGCPolicy().SanitizeBytes([]byte(Content))), "https://github.com", "", -1), "user-content-", "", -1), "https://camo.githubusercontent.com", "/camo", -1), "https://raw.githubusercontent.com", "/raw", -1)
 	})
 	sc.OnHTML("div.BorderGrid-cell ul.list-style-none", func(e *colly.HTMLElement) {
 		e.ForEach("li.d-inline .d-inline-flex", func(i int, el *colly.HTMLElement) {

pages/user.go

@@ -157,7 +157,7 @@ func HandleUser(c *fiber.Ctx) error {
 	})
 	sc.OnHTML("article.markdown-body", func(e *colly.HTMLElement) {
 		Content, _ := e.DOM.Html()
-		Scrape.Readme = strings.Replace(string(utils.UGCPolicy().SanitizeBytes([]byte(Content))), "https://github.com", "", -1)
+		Scrape.Readme = strings.Replace(strings.Replace(strings.Replace(strings.Replace(string(utils.UGCPolicy().SanitizeBytes([]byte(Content))), "https://github.com", "", -1), "user-content-", "", -1), "https://camo.githubusercontent.com", "/camo", -1), "https://raw.githubusercontent.com", "/raw", -1)
 	})
 	sc.OnHTML("div.text-mono", func(e *colly.HTMLElement) {
 		Scrape.ReadmeUrl = strings.Replace(e.ChildAttr("a", "href"), "tree", "blob", -1)

serve/serve.go

@@ -116,6 +116,10 @@ func Serve(port string) {
 		utils.ProxyRequest(c, "https://github.com/"+c.Params("user")+"/"+c.Params("repo")+"/archive/"+c.Params("branch")+".zip")
 		return nil
 	})
+	app.Get("/camo/:p1/:p2", func(c *fiber.Ctx) error {
+		utils.ProxyRequest(c, "https://camo.githubusercontent.com/"+c.Params("p1")+"/"+c.Params("p2"))
+		return nil
+	})
 	app.Get("/gist/:user/:gistID", pages.HandleGist)
 	app.Get("/download/gist/:user/:gistID/:revision", func(c *fiber.Ctx) error {
 		utils.ProxyRequest(c, "https://gist.github.com/"+c.Params("user")+"/"+c.Params("gistID")+"/archive/"+c.Params("revision")+".zip")

utils/ugcpolicy.go

@@ -110,9 +110,17 @@ func UGCPolicy() *bluemonday.Policy {
 	p.AllowAttrs("shape").Matching(
 		regexp.MustCompile(`(?i)^(default|circle|rect|poly)$`),
 	).OnElements("area")
+
+	// "img" is permitted
+	p.AllowImages()
 	p.AllowAttrs("usemap").Matching(
 		regexp.MustCompile(`(?i)^#[\p{L}\p{N}_-]+$`),
 	).OnElements("img")
+	p.AllowAttrs("src").Matching(
+		regexp.MustCompile(`(?i)^\/[\p{L}\p{N}\/\.]+$`),
+	).OnElements("img")
+	p.AllowAttrs("style").OnElements("img")
+	p.AllowAttrs("alt").OnElements("img")
 
 	// "link" is not permitted