lib: add FixedXORBytes

* lib/xor.go (FixedXORBytes): New function.

1 files changed, 12 insertions, 0 deletions

diff --git a/lib/xor.go b/lib/xor.go
index 0d1f3d7..7b57d82 100644
--- a/lib/xor.go
+++ b/lib/xor.go
@@ -22,6 +22,18 @@ func FixedXOR(a, b string) string {
 	return cs
 }
 
+func FixedXORBytes(as, bs []byte) []byte {
+	if len(as) != len(bs) {
+		return make([]byte, 0)
+	}
+
+	cs := make([]byte, len(as))
+	for i := 0; i < len(as); i++ {
+		cs[i] = as[i] ^ bs[i]
+	}
+	return cs
+}
+
 // Both 'data' and 'key' need to be plain ascii string.
 func RepeatingXOR(data, key string) string {
 	xs := ""