X-Git-Url: https://git.r.bdr.sh/rbdr/mobius/blobdiff_plain/b1658a46aebe8aceb23af187de956ef91452f48a..dcd23d5355badf66c34ffd63d3c44734e87ebf17:/hotline/user.go

diff --git a/hotline/user.go b/hotline/user.go
index 34fe1ab..c4e0790 100644
--- a/hotline/user.go
+++ b/hotline/user.go
@@ -2,6 +2,9 @@ package hotline
 
 import (
 	"encoding/binary"
+	"io"
+	"math/big"
+	"slices"
 )
 
 // User flags are stored as a 2 byte bitmap and represent various user states
@@ -12,21 +15,36 @@ const (
 	UserFlagRefusePChat = 3 // User refuses private chat
 )
 
-// FieldOptions flags are sent from v1.5+ clients as part of TranAgreed
+// User options are sent from clients and represent options set in the client's preferences.
 const (
-	refusePM     = 0 // User has "Refuse private messages" pref set
-	refuseChat   = 1 // User has "Refuse private chat" pref set
-	autoResponse = 2 // User has "Automatic response" pref set
+	UserOptRefusePM     = 0 // User has "Refuse private messages" pref set
+	UserOptRefuseChat   = 1 // User has "Refuse private chat" pref set
+	UserOptAutoResponse = 2 // User has "Automatic response" pref set
 )
 
+type UserFlags [2]byte
+
+func (f *UserFlags) IsSet(i int) bool {
+	flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(f[:])))
+	return flagBitmap.Bit(i) == 1
+}
+
+func (f *UserFlags) Set(i int, newVal uint) {
+	flagBitmap := big.NewInt(int64(binary.BigEndian.Uint16(f[:])))
+	flagBitmap.SetBit(flagBitmap, i, newVal)
+	binary.BigEndian.PutUint16(f[:], uint16(flagBitmap.Int64()))
+}
+
 type User struct {
-	ID    []byte // Size 2
+	ID    [2]byte
 	Icon  []byte // Size 2
 	Flags []byte // Size 2
 	Name  string // Variable length user name
+
+	readOffset int // Internal offset to track read progress
 }
 
-func (u User) Payload() []byte {
+func (u *User) Read(p []byte) (int, error) {
 	nameLen := make([]byte, 2)
 	binary.BigEndian.PutUint16(nameLen, uint16(len(u.Name)))
 
@@ -38,37 +56,38 @@ func (u User) Payload() []byte {
 		u.Flags = u.Flags[2:]
 	}
 
-	out := append(u.ID[:2], u.Icon[:2]...)
-	out = append(out, u.Flags[:2]...)
-	out = append(out, nameLen...)
-	out = append(out, u.Name...)
+	b := slices.Concat(
+		u.ID[:],
+		u.Icon,
+		u.Flags,
+		nameLen,
+		[]byte(u.Name),
+	)
 
-	return out
-}
-
-func ReadUser(b []byte) (*User, error) {
-	u := &User{
-		ID:    b[0:2],
-		Icon:  b[2:4],
-		Flags: b[4:6],
-		Name:  string(b[8:]),
+	if u.readOffset >= len(b) {
+		return 0, io.EOF // All bytes have been read
 	}
-	return u, nil
+
+	n := copy(p, b)
+	u.readOffset = n
+
+	return n, nil
 }
 
-// DecodeUserString decodes an obfuscated user string from a client
-// e.g. 98 8a 9a 8c 8b => "guest"
-func DecodeUserString(obfuText []byte) (clearText string) {
-	for _, char := range obfuText {
-		clearText += string(rune(255 - uint(char)))
-	}
-	return clearText
+func (u *User) Write(p []byte) (int, error) {
+	namelen := int(binary.BigEndian.Uint16(p[6:8]))
+	u.ID = [2]byte(p[0:2])
+	u.Icon = p[2:4]
+	u.Flags = p[4:6]
+	u.Name = string(p[8 : 8+namelen])
+
+	return 8 + namelen, nil
 }
 
-// negateString takes []byte s containing cleartext and rotates by 255 into obfuscated cleartext.
+// EncodeString takes []byte s containing cleartext and rotates by 255 into obfuscated cleartext.
 // The Hotline protocol uses this format for sending passwords over network.
 // Not secure, but hey, it was the 90s!
-func negateString(clearText []byte) []byte {
+func EncodeString(clearText []byte) []byte {
 	obfuText := make([]byte, len(clearText))
 	for i := 0; i < len(clearText); i++ {
 		obfuText[i] = 255 - clearText[i]