3 files changed, 111 insertions, 0 deletions
diff --git a/workhorse/internal/utils/svg/LICENSE b/workhorse/internal/utils/svg/LICENSE
new file mode 100644
index 00000000000..f67807d0070
--- /dev/null
+++ b/workhorse/internal/utils/svg/LICENSE
@@ -0,0 +1,24 @@
+The MIT License
+
+Copyright (c) 2016 Tomas Aparicio
+
+Permission is hereby granted, free of charge, to any person
+obtaining a copy of this software and associated documentation
+files (the "Software"), to deal in the Software without
+restriction, including without limitation the rights to use,
+copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the
+Software is furnished to do so, subject to the following
+conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
diff --git a/workhorse/internal/utils/svg/README.md b/workhorse/internal/utils/svg/README.md
new file mode 100644
index 00000000000..e5531f47473
--- /dev/null
+++ b/workhorse/internal/utils/svg/README.md
@@ -0,0 +1,45 @@
+# go-is-svg
+
+Tiny package to verify if a given file buffer is an SVG image in Go (golang).
+
+## Installation
+
+```bash
+go get -u github.com/h2non/go-is-svg
+```
+
+## Example
+
+```go
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+
+	svg "github.com/h2non/go-is-svg"
+)
+
+func main() {
+	buf, err := ioutil.ReadFile("_example/example.svg")
+	if err != nil {
+		fmt.Printf("Error: %s\n", err)
+		return
+	}
+
+	if svg.Is(buf) {
+		fmt.Println("File is an SVG")
+	} else {
+		fmt.Println("File is NOT an SVG")
+	}
+}
+```
+
+Run example:
+```bash
+go run _example/example.go
+```
+
+## License
+
+MIT - Tomas Aparicio
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)
+}