feat(munch): :star:

3 files changed, 125 insertions, 0 deletions

diff --git a/pkg/server/utils/decode.go b/pkg/server/utils/decode.go
new file mode 100644
index 0000000..e819b31
--- /dev/null
+++ b/pkg/server/utils/decode.go
@@ -0,0 +1,24 @@
+// Copyright (C) 2021-2021 The Whirlsplash Collective
+// SPDX-License-Identifier: GPL-3.0-only
+
+package utils
+
+import "strconv"
+
+type Text struct {
+	Author  string
+	Message string
+}
+
+// Decode a TEXT command from hexadecimal to a Text struct
+func DecodeText(data []byte) Text {
+	authorLength, _ := strconv.ParseInt(strconv.Itoa(int(data[4])), 16, 32)
+	authorLast := authorLength + 5
+	messageLength, _ := strconv.ParseInt(strconv.Itoa(int(data[authorLast])), 16, 32)
+	messageStart := authorLast + 1
+
+	return Text{
+		Author:  string(data[5:(authorLast)]),
+		Message: string(data[messageStart : messageStart+(messageLength)]),
+	}
+}
diff --git a/pkg/server/utils/encode.go b/pkg/server/utils/encode.go
new file mode 100644
index 0000000..86e5500
--- /dev/null
+++ b/pkg/server/utils/encode.go
@@ -0,0 +1,70 @@
+// Copyright (C) 2021-2021 The Whirlsplash Collective
+// SPDX-License-Identifier: GPL-3.0-only
+
+package utils
+
+const (
+	AutoServer = iota
+	RoomServer
+)
+
+func EncodeSessionInitialization(username string, password string, serverType int) []byte {
+	data := ""
+
+	// Data length
+	if serverType == AutoServer {
+		data += "\x2b"
+	} else {
+		data += "\x2c"
+	}
+
+	// Command header and other stuff we don't need to worry about
+	data += "\x01\x06\x03\x02\x32\x34\x09\x0a\x32\x30\x32\x30\x30\x33\x31" +
+		"\x32\x30\x30"
+
+	if serverType == RoomServer {
+		data += "\x07\x02\x32\x34"
+	}
+
+	data +=
+		// Username
+		"\x02" + string(rune(len(username))) + ISO88591ToString(username) +
+
+			// Password
+			"\x06" + string(rune(len(password))) + ISO88591ToString(password)
+
+	if serverType == AutoServer {
+		data += "\x0c\x01\x31"
+	}
+
+	return []byte(data)
+}
+
+func EncodeBuddyListUpdate(buddy string) []byte {
+	// Command header
+	data := "\x01\x1d"
+
+	// Buddy UTF-8 length and UTF-8
+	data += string(rune(len(buddy))) + ISO88591ToString(buddy)
+
+	// Buddy "add"
+	data += "\x01"
+
+	// Data length
+	data = (string(rune(len(data) + 1))) + data
+
+	return []byte(data)
+}
+
+func EncodePropertyUpdate(avatar string) []byte {
+	// Command header and extra stuff we don't need to worry about
+	data := "\x01\x0f\x00\x05\x40\x01"
+
+	// Avatar UTF-8 length and UTF-8
+	data += string(rune(len("avatar:"+avatar))) + ISO88591ToString("avatar:"+avatar)
+
+	// Data length
+	data = (string(rune(len(data) + 1))) + data
+
+	return []byte(data)
+}
diff --git a/pkg/server/utils/hex.go b/pkg/server/utils/hex.go
new file mode 100644
index 0000000..a5393aa
--- /dev/null
+++ b/pkg/server/utils/hex.go
@@ -0,0 +1,31 @@
+package utils
+
+import "unicode/utf8"
+
+// https://stackoverflow.com/a/43461796/14452787
+//
+// I cannot explain the joy that flew through me once I found this ISO-8859-1
+// (Latin-1) to UTF-8 converter. I was looking for a valid solution on how to
+// insert the username and password into a hex-escaped string sequence for
+// EncodeSessionInitialization for hours and this finally solved all of my
+// problems.
+func ISO88591ToString(iso string) string {
+	var utf []rune
+	for i := 0; i < len(iso); i++ {
+		r := iso[i]
+		if utf == nil {
+			if r < utf8.RuneSelf {
+				continue
+			}
+			utf = make([]rune, len(iso))
+			for j, r := range iso[:i] {
+				utf[j] = rune(r)
+			}
+		}
+		utf[i] = rune(r)
+	}
+	if utf == nil {
+		return string(iso)
+	}
+	return string(utf)
+}