Refactor filetype is not allowed errors (#7309)

1 files changed, 49 insertions, 0 deletions

diff --git a/modules/upload/filetype.go b/modules/upload/filetype.go
new file mode 100644
index 0000000000..1ec7324ed3
--- /dev/null
+++ b/modules/upload/filetype.go
@@ -0,0 +1,49 @@
+// Copyright 2019 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 upload
+
+import (
+	"fmt"
+	"net/http"
+	"strings"
+
+	"code.gitea.io/gitea/modules/log"
+)
+
+// ErrFileTypeForbidden not allowed file type error
+type ErrFileTypeForbidden struct {
+	Type string
+}
+
+// IsErrFileTypeForbidden checks if an error is a ErrFileTypeForbidden.
+func IsErrFileTypeForbidden(err error) bool {
+	_, ok := err.(ErrFileTypeForbidden)
+	return ok
+}
+
+func (err ErrFileTypeForbidden) Error() string {
+	return fmt.Sprintf("File type is not allowed: %s", err.Type)
+}
+
+// VerifyAllowedContentType validates a file is allowed to be uploaded.
+func VerifyAllowedContentType(buf []byte, allowedTypes []string) error {
+	fileType := http.DetectContentType(buf)
+
+	allowed := false
+	for _, t := range allowedTypes {
+		t := strings.Trim(t, " ")
+		if t == "*/*" || t == fileType {
+			allowed = true
+			break
+		}
+	}
+
+	if !allowed {
+		log.Info("Attachment with type %s blocked from upload", fileType)
+		return ErrFileTypeForbidden{Type: fileType}
+	}
+
+	return nil
+}