3 files changed, 14 insertions, 16 deletions
diff --git a/modules/base/markdown.go b/modules/base/markdown.go
index 8b3c8f43..dac51ebc 100644
--- a/modules/base/markdown.go
+++ b/modules/base/markdown.go
@@ -31,16 +31,10 @@ func isalnum(c byte) bool {
 	return (c >= '0' && c <= '9') || isletter(c)
 }
 
-var validLinks = [][]byte{[]byte("http://"), []byte("https://"), []byte("ftp://"), []byte("mailto://")}
+var validLinksPattern = regexp.MustCompile(`^[a-z][\w-]+://`)
 
 func isLink(link []byte) bool {
-	for _, prefix := range validLinks {
-		if len(link) > len(prefix) && bytes.Equal(bytes.ToLower(link[:len(prefix)]), prefix) && isalnum(link[len(prefix)]) {
-			return true
-		}
-	}
-
-	return false
+	return validLinksPattern.Match(link)
 }
 
 func IsMarkdownFile(name string) bool {
diff --git a/modules/base/tool.go b/modules/base/tool.go
index f98ae28b..ad39db89 100644
--- a/modules/base/tool.go
+++ b/modules/base/tool.go
@@ -31,16 +31,19 @@ import (
 	"github.com/gogits/gogs/modules/setting"
 )
 
-func BuildSanitizer() (p *bluemonday.Policy) {
-	p = bluemonday.UGCPolicy()
-	p.AllowAttrs("class").Matching(regexp.MustCompile(`[\p{L}\p{N}\s\-_',:\[\]!\./\\\(\)&]*`)).OnElements("code")
+var Sanitizer = bluemonday.UGCPolicy()
 
-	p.AllowAttrs("type").Matching(regexp.MustCompile(`^checkbox$`)).OnElements("input")
-	p.AllowAttrs("checked", "disabled").OnElements("input")
-	return p
-}
+func BuildSanitizer() {
+	// Normal markdown-stuff
+	Sanitizer.AllowAttrs("class").Matching(regexp.MustCompile(`[\p{L}\p{N}\s\-_',:\[\]!\./\\\(\)&]*`)).OnElements("code")
+
+	// Checkboxes
+	Sanitizer.AllowAttrs("type").Matching(regexp.MustCompile(`^checkbox$`)).OnElements("input")
+	Sanitizer.AllowAttrs("checked", "disabled").OnElements("input")
 
-var Sanitizer = BuildSanitizer()
+	// Custom URL-Schemes
+	Sanitizer.AllowURLSchemes(setting.Markdown.CustomURLSchemes...)
+}
 
 // EncodeMD5 encodes string to md5 hex value.
 func EncodeMD5(str string) string {
diff --git a/modules/setting/setting.go b/modules/setting/setting.go
index 3936546c..99b968c8 100644
--- a/modules/setting/setting.go
+++ b/modules/setting/setting.go
@@ -118,6 +118,7 @@ var (
 	// Markdown sttings
 	Markdown struct {
 		EnableHardLineBreak bool
+		CustomURLSchemes    []string `ini:"CUSTOM_URL_SCHEMES"`
 	}
 
 	// Picture settings