From 661d8311330ad372c666efe7c7da9aae42834a76 Mon Sep 17 00:00:00 2001
From: Evan Chen <evanchen@kumoly.io>
Date: Wed, 17 Nov 2021 09:44:15 +0800
Subject: [PATCH] init

---
 README.md          |  0
 go.mod             |  3 +++
 xorencrypt.go      | 25 +++++++++++++++++++++++++
 xorencrypt_test.go | 25 +++++++++++++++++++++++++
 4 files changed, 53 insertions(+)
 create mode 100644 README.md
 create mode 100644 go.mod
 create mode 100644 xorencrypt.go
 create mode 100644 xorencrypt_test.go

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..e69de29
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..1e378cd
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module kumoly.io/lib/xorencrypt
+
+go 1.17
diff --git a/xorencrypt.go b/xorencrypt.go
new file mode 100644
index 0000000..a2fed56
--- /dev/null
+++ b/xorencrypt.go
@@ -0,0 +1,25 @@
+package xorencrypt
+
+import "encoding/base64"
+
+func Decrypt(msg, key string) (string, error) {
+	deb64, err := base64.StdEncoding.DecodeString(msg)
+	if err != nil {
+		return "", err
+	}
+	dec := xor(deb64, []byte(key))
+	return string(dec), nil
+}
+
+func Encrypt(msg, key string) string {
+	enc := xor([]byte(msg), []byte(key))
+	return base64.StdEncoding.EncodeToString(enc)
+}
+
+func xor(msg, key []byte) []byte {
+	ret := make([]byte, len(msg))
+	for i := 0; i < len(msg); i++ {
+		ret[i] = msg[i] ^ key[i%len(key)]
+	}
+	return ret
+}
diff --git a/xorencrypt_test.go b/xorencrypt_test.go
new file mode 100644
index 0000000..49b6ae1
--- /dev/null
+++ b/xorencrypt_test.go
@@ -0,0 +1,25 @@
+package xorencrypt
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestXOR(t *testing.T) {
+	msg := "test"
+	key := "key"
+	enc := xor([]byte(msg), []byte(key))
+	dec := xor([]byte(enc), []byte(key))
+	fmt.Printf("%s -> %d -> %s\n", msg, enc, dec)
+}
+
+func TestEncrypt(t *testing.T) {
+	msg := "test"
+	key := "key"
+	enc := Encrypt(msg, key)
+	dec, _ := Decrypt(enc, key)
+	fmt.Printf("%s -> %s -> %s\n", msg, enc, dec)
+
+	decErr, _ := Decrypt(enc, "wrongKey")
+	fmt.Printf("%s -> %s -> %s\n", msg, enc, decErr)
+}