From e81db1f0bda930f50b5c3e47627770299ec3e19b Mon Sep 17 00:00:00 2001
From: Andrea Franz <andrea@gravityblast.com>
Date: Thu, 27 Sep 2018 11:39:35 +0200
Subject: [PATCH] add appendDESPadding function

---
 globalplatform/crypto/crypto.go      | 12 ++++++++++++
 globalplatform/crypto/crypto_test.go |  7 +++++++
 2 files changed, 19 insertions(+)

diff --git a/globalplatform/crypto/crypto.go b/globalplatform/crypto/crypto.go
index 2e37402..e362a58 100644
--- a/globalplatform/crypto/crypto.go
+++ b/globalplatform/crypto/crypto.go
@@ -37,3 +37,15 @@ func resizeKey24(key []byte) []byte {
 
 	return data
 }
+
+func appendDESPadding(data []byte) []byte {
+	length := len(data) + 1
+	for ; length%8 != 0; length++ {
+	}
+
+	newData := make([]byte, length)
+	copy(newData, data)
+	copy(newData[len(data):], []byte{0x80})
+
+	return newData
+}
diff --git a/globalplatform/crypto/crypto_test.go b/globalplatform/crypto/crypto_test.go
index bbf40b4..3378266 100644
--- a/globalplatform/crypto/crypto_test.go
+++ b/globalplatform/crypto/crypto_test.go
@@ -24,3 +24,10 @@ func TestResizeKey24(t *testing.T) {
 	expected := "404142434445464748494A4B4C4D4E4F4041424344454647"
 	assert.Equal(t, expected, hexutils.BytesToHex(resized))
 }
+
+func TestAppendDESPadding(t *testing.T) {
+	data := hexutils.HexToBytes("AABB")
+	result := appendDESPadding(data)
+	expected := "AABB800000000000"
+	assert.Equal(t, expected, hexutils.BytesToHex(result))
+}