From 71a0376962633e102d6e20484b70065f148aad63 Mon Sep 17 00:00:00 2001
From: nato <nato@grahamgit.6ax.org>
Date: Sun, 5 Feb 2023 15:11:17 -0800
Subject: [PATCH] Host.go: move /nick command and add nick registration check.

---
 auth.go         |  5 +++++
 chat/command.go | 30 ---------------------------
 host.go         | 54 +++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 59 insertions(+), 30 deletions(-)

diff --git a/auth.go b/auth.go
index 05c1bcf..e54bcca 100644
--- a/auth.go
+++ b/auth.go
@@ -109,6 +109,11 @@ func (a *Auth) Keyname(key ssh.PublicKey) string {
 	return name
 }
 
+func (a *Auth) KeynameFingerprint(keyname string) string {
+	fingerprint := a.fingerprintsByKeyname[keyname]
+	return fingerprint
+}
+
 // SetPassphrase enables passphrase authentication with the given passphrase.
 // If an empty passphrase is given, disable passphrase authentication.
 func (a *Auth) SetPassphrase(passphrase string) {
diff --git a/chat/command.go b/chat/command.go
index 6a8fcd2..5d27cf1 100644
--- a/chat/command.go
+++ b/chat/command.go
@@ -142,36 +142,6 @@ func InitCommands(c *Commands) {
 	})
 	c.Alias("/exit", "/quit")
 
-	c.Add(Command{
-		Prefix:     "/nick",
-		PrefixHelp: "NAME",
-		Help:       "Rename yourself.",
-		Handler: func(room *Room, msg message.CommandMsg) error {
-			args := msg.Args()
-			if len(args) != 1 {
-				return ErrMissingArg
-			}
-			u := msg.From()
-
-			member, ok := room.MemberByID(u.ID())
-			if !ok {
-				return errors.New("failed to find member")
-			}
-
-			oldID := member.ID()
-			newID := sanitize.Name(args[0])
-			if newID == oldID {
-				return errors.New("new name is the same as the original")
-			}
-			member.SetID(newID)
-			err := room.Rename(oldID, member)
-			if err != nil {
-				member.SetID(oldID)
-				return err
-			}
-			return nil
-		},
-	})
 
 	c.Add(Command{
 		Prefix: "/names",
diff --git a/host.go b/host.go
index 0da784e..17b32df 100644
--- a/host.go
+++ b/host.go
@@ -387,6 +387,60 @@ func (h *Host) InitCommands(c *chat.Commands) {
 		},
 	})
 
+	c.Add(chat.Command{
+		Prefix:     "/nick",
+		PrefixHelp: "NAME",
+		Help:       "Rename yourself.",
+		Handler: func(room *chat.Room, msg message.CommandMsg) error {
+			args := msg.Args()
+			if len(args) != 1 {
+				return errors.New("missing argument")
+			}
+			u := msg.From()
+
+			member, ok := room.MemberByID(u.ID())
+			if !ok {
+				return errors.New("failed to find member")
+			}
+
+			oldID := member.ID()
+			newID := sanitize.Name(args[0])
+
+			if newID == oldID {
+				return errors.New("new name is the same as the original")
+			}
+
+			// check nick registration
+			if h.auth.keynamesMode {
+				identity, identified := member.Identifier.(*Identity)
+				if identified {
+					identity.SetSymbol(strings.Replace(identity.symbol, "✓", "", -1 ))
+				}
+				registeredFingerprint := h.auth.KeynameFingerprint(newID)
+				if registeredFingerprint != "" {
+					if ! identified {
+						errors.New("this nick is registered to different key")
+					}
+					fingerprint := sshd.Fingerprint(identity.PublicKey())
+					if registeredFingerprint != fingerprint {
+						return errors.New("this nick is registered to different key")
+					}
+					if identified {
+						identity.SetSymbol("✓"+ identity.symbol)
+					}
+				}
+			}
+
+			member.SetID(newID)
+			err := room.Rename(oldID, member)
+			if err != nil {
+				member.SetID(oldID)
+				return err
+			}
+			return nil
+		},
+	})
+
 	c.Add(chat.Command{
 		Prefix:     "/reply",
 		PrefixHelp: "MESSAGE",