feat: better card ascii art

2 files changed, 42 insertions, 0 deletions

diff --git a/internal/net/remote_host_test.go b/internal/net/remote_host_test.go
new file mode 100644
index 0000000..690e758
--- /dev/null
+++ b/internal/net/remote_host_test.go
@@ -0,0 +1,34 @@
+package net
+
+import (
+	"testing"
+	"time"
+)
+
+// remoteAddrConn is a minimal Conn that also reports a peer address, so the
+// Session.RemoteHost port-stripping contract can be tested without a socket.
+type remoteAddrConn struct{ addr string }
+
+func (c remoteAddrConn) ReadMessage() (string, error)     { return "", nil }
+func (c remoteAddrConn) Write(b []byte) (int, error)      { return len(b), nil }
+func (c remoteAddrConn) Close() error                     { return nil }
+func (c remoteAddrConn) SetWriteDeadline(time.Time) error { return nil }
+func (c remoteAddrConn) SetEcho(bool) error               { return nil }
+func (c remoteAddrConn) RemoteAddr() string               { return c.addr }
+
+// TestSessionRemoteHostStripsPort: login throttling keys on the client host,
+// so RemoteHost must drop the ephemeral source port (RemoteAddr keeps it).
+// Keying on the raw address would let a reconnect reset the limiter.
+func TestSessionRemoteHostStripsPort(t *testing.T) {
+	for _, tc := range []struct{ in, want string }{
+		{"203.0.113.7:54321", "203.0.113.7"},
+		{"[2001:db8::1]:443", "2001:db8::1"},
+		{"203.0.113.7", "203.0.113.7"},
+		{"", ""},
+	} {
+		sess := &Session{Conn: remoteAddrConn{addr: tc.in}}
+		if got := sess.RemoteHost(); got != tc.want {
+			t.Fatalf("RemoteHost(%q) = %q, want %q", tc.in, got, tc.want)
+		}
+	}
+}
diff --git a/internal/net/server.go b/internal/net/server.go
index c818eef..daf3e47 100644
--- a/internal/net/server.go
+++ b/internal/net/server.go
@@ -151,6 +151,14 @@ func (sess *Session) RemoteAddr() string {
 	return ""
 }
 
+// RemoteHost returns the client's IP/host without the ephemeral source port.
+// Rate-limit keys must use this: RemoteAddr includes a fresh port on every
+// reconnect, so keying on it lets a reconnecting attacker reset the limiter.
+// Synthetic/test connections without a transport address return "".
+func (sess *Session) RemoteHost() string {
+	return remoteHost(sess.RemoteAddr())
+}
+
 // sessionSeq is the source of Session.seq values. It is incremented under the
 // adding Hub's mutex, so no extra atomicity is needed for correctness; atomic
 // access keeps the package-level default counter safe if Hub.Add is ever