Initial commit

1 files changed, 30 insertions, 0 deletions

diff --git a/utils.go b/utils.go
new file mode 100644
index 0000000..cc99d93
--- /dev/null
+++ b/utils.go
@@ -0,0 +1,30 @@
+package main
+
+import (
+	"crypto/sha256"
+	"io"
+	"log"
+	"os"
+)
+
+const invalidHashString = "invalid"
+
+func Sha256Sum(fileName string) (string, error) {
+	f, err := os.Open(fileName)
+	if err != nil {
+		return invalidHashString, err
+	}
+	defer func() {
+		err = f.Close()
+		if err != nil {
+			log.Println("Cannot close file " + fileName)
+		}
+	}()
+
+	h := sha256.New()
+	if _, err := io.Copy(h, f); err != nil {
+		return invalidHashString, err
+	}
+
+	return string(h.Sum(nil)), nil
+}