Quote regex meta characters in Rewrite (#1541)

Currently there is a half and half situation where the user can't use regex (fully) because * will be replaced with (.*), yet they also can't just enter any old string, because meta chars like . would need escaping.

e.g. currently *.html wouldn't work as intended, and instead *\.html should be used.

Work around this by using regexp's QuoteMeta function to sanitise the input before handling it.

Author: LeafHacker

middleware/rewrite.go

@@ -57,7 +57,8 @@ func RewriteWithConfig(config RewriteConfig) echo.MiddlewareFunc {
 
 	// Initialize
 	for k, v := range config.Rules {
-		k = strings.Replace(k, "*", "(.*)", -1)
+		k = regexp.QuoteMeta(k)
+		k = strings.Replace(k, `\*`, "(.*)", -1)
 		k = k + "$"
 		config.rulesRegex[regexp.MustCompile(k)] = v
 	}