Fix error message sanitiziation (#3082)

modules/util/sanitize.go

@@ -0,0 +1,48 @@
+// Copyright 2017 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package util
+
+import (
+	"net/url"
+	"strings"
+)
+
+// urlSafeError wraps an error whose message may contain a sensitive URL
+type urlSafeError struct {
+	err            error
+	unsanitizedURL string
+}
+
+func (err urlSafeError) Error() string {
+	return SanitizeMessage(err.err.Error(), err.unsanitizedURL)
+}
+
+// URLSanitizedError returns the sanitized version an error whose message may
+// contain a sensitive URL
+func URLSanitizedError(err error, unsanitizedURL string) error {
+	return urlSafeError{err: err, unsanitizedURL: unsanitizedURL}
+}
+
+// SanitizeMessage sanitizes a message which may contains a sensitive URL
+func SanitizeMessage(message, unsanitizedURL string) string {
+	sanitizedURL := SanitizeURLCredentials(unsanitizedURL, true)
+	return strings.Replace(message, unsanitizedURL, sanitizedURL, -1)
+}
+
+// SanitizeURLCredentials sanitizes a url, either removing user credentials
+// or replacing them with a placeholder.
+func SanitizeURLCredentials(unsanitizedURL string, usePlaceholder bool) string {
+	u, err := url.Parse(unsanitizedURL)
+	if err != nil {
+		// don't log the error, since it might contain unsanitized URL.
+		return "(unparsable url)"
+	}
+	if u.User != nil && usePlaceholder {
+		u.User = url.User("<credentials>")
+	} else {
+		u.User = nil
+	}
+	return u.String()
+}