1 files changed, 42 insertions, 0 deletions
diff --git a/workhorse/internal/utils/svg/svg.go b/workhorse/internal/utils/svg/svg.go
new file mode 100644
index 00000000000..b209cb5bf33
--- /dev/null
+++ b/workhorse/internal/utils/svg/svg.go
@@ -0,0 +1,42 @@
+// Copyright (c) 2016 Tomas Aparicio. All rights reserved.
+//
+// Use of this source code is governed by a MIT License
+// license that can be found in the LICENSE file or at
+// https://github.com/h2non/go-is-svg/blob/master/LICENSE.
+
+package svg
+
+import (
+	"regexp"
+	"unicode/utf8"
+)
+
+var (
+	htmlCommentRegex = regexp.MustCompile(`(?i)<!--([\s\S]*?)-->`)
+	svgRegex         = regexp.MustCompile(`(?i)^\s*(?:<\?xml[^>]*>\s*)?(?:<!doctype svg[^>]*>\s*)?<svg[^>]*>`)
+)
+
+// isBinary checks if the given buffer is a binary file.
+func isBinary(buf []byte) bool {
+	if len(buf) < 24 {
+		return false
+	}
+	for i := 0; i < 24; i++ {
+		charCode, _ := utf8.DecodeRuneInString(string(buf[i]))
+		if charCode == 65533 || charCode <= 8 {
+			return true
+		}
+	}
+	return false
+}
+
+// Is returns true if the given buffer is a valid SVG image.
+func Is(buf []byte) bool {
+	return !isBinary(buf) && svgRegex.Match(htmlCommentRegex.ReplaceAll(buf, []byte{}))
+}
+
+// IsSVG returns true if the given buffer is a valid SVG image.
+// Alias to: Is()
+func IsSVG(buf []byte) bool {
+	return Is(buf)
+}