SQLite support for user info

.gitignore

@@ -23,3 +23,6 @@ go.work.sum
 
 # SSH
 .ssh/
+
+# SQLite
+*.db

go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/charmbracelet/log v0.4.1
 	github.com/charmbracelet/ssh v0.0.0-20250213143314-8712ec3ff3ef
 	github.com/charmbracelet/wish v1.4.7
+	github.com/mattn/go-sqlite3 v1.14.27
 )
 
 require (

go.sum

@@ -52,6 +52,8 @@ github.com/mattn/go-localereader v0.0.1 h1:ygSAOl7ZXTx4RdPYinUpg6W99U8jWvWi9Ye2J
 github.com/mattn/go-localereader v0.0.1/go.mod h1:8fBrzywKY7BI3czFoHkuzRoWE9C+EiG4R1k4Cjx5p88=
 github.com/mattn/go-runewidth v0.0.16 h1:E5ScNMtiwvlvB5paMFdw9p4kSQzbXFikJ5SQO6TULQc=
 github.com/mattn/go-runewidth v0.0.16/go.mod h1:Jdepj2loyihRzMpdS35Xk/zdY8IAYHsh153qUoGf23w=
+github.com/mattn/go-sqlite3 v1.14.27 h1:drZCnuvf37yPfs95E5jd9s3XhdVWLal+6BOK6qrv6IU=
+github.com/mattn/go-sqlite3 v1.14.27/go.mod h1:Uh1q+B4BYcTPb+yiD3kU8Ct7aC0hY9fxUwlHK0RXw+Y=
 github.com/muesli/ansi v0.0.0-20230316100256-276c6243b2f6 h1:ZK8zHtRHOkbHy6Mmr5D264iyp3TiX5OmNcI5cIARiQI=
 github.com/muesli/ansi v0.0.0-20230316100256-276c6243b2f6/go.mod h1:CJlz5H+gyd6CUWT45Oy4q24RdLyn7Md9Vj2/ldJBSIo=
 github.com/muesli/cancelreader v0.2.2 h1:3I4Kt4BQjOR54NavqnDogx/MIoWBFa0StPA8ELUXHmA=

main.go

@@ -3,6 +3,7 @@ package main
 import (
 	"context"
 	"crypto/md5"
+	"database/sql"
 	"encoding/hex"
 	"errors"
 	"fmt"
@@ -21,22 +22,45 @@ import (
 	"github.com/charmbracelet/wish"
 	"github.com/charmbracelet/wish/bubbletea"
 	"github.com/charmbracelet/wish/logging"
+	_ "github.com/mattn/go-sqlite3"
 )
 
 const (
-	host = "localhost"
+	host   = "localhost"
-	port = "23234"
+	port   = "23234"
+	dbFile = "users.db"
 )
 
 var (
-	// knownUsers maps public key fingerprints to nicknames
-	knownUsers   = make(map[string]string)
-	usersMutex   sync.Mutex
 	errorStyle   = lipgloss.NewStyle().Foreground(lipgloss.Color("9"))
 	successStyle = lipgloss.NewStyle().Foreground(lipgloss.Color("10"))
+	db           *sql.DB
+	dbMutex      sync.Mutex
 )
 
 func main() {
+	// Initialize database
+	var err error
+	db, err = sql.Open("sqlite3", dbFile)
+	if err != nil {
+		log.Fatal("Could not open database", "error", err)
+	}
+	defer db.Close()
+
+	// Create users table if it doesn't exist
+	_, err = db.Exec(`
+		CREATE TABLE IF NOT EXISTS users (
+			fingerprint TEXT PRIMARY KEY,
+			public_key BLOB NOT NULL,
+			nickname TEXT NOT NULL,
+			created_at DATETIME NOT NULL,
+			CHECK(length(nickname) >= 3 AND length(nickname) <= 12)
+		)
+	`)
+	if err != nil {
+		log.Fatal("Could not create users table", "error", err)
+	}
+
 	s, err := wish.NewServer(
 		wish.WithAddress(net.JoinHostPort(host, port)),
 		wish.WithHostKeyPath(".ssh/id_ed25519"),
@@ -78,6 +102,37 @@ func getFingerprint(pubKey ssh.PublicKey) string {
 	return hex.EncodeToString(hash[:])
 }
 
+// getUserNickname retrieves a user's nickname from the database
+func getUserNickname(fingerprint string) (string, error) {
+	dbMutex.Lock()
+	defer dbMutex.Unlock()
+
+	var nickname string
+	err := db.QueryRow("SELECT nickname FROM users WHERE fingerprint = ?", fingerprint).Scan(&nickname)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return "", nil
+		}
+		return "", err
+	}
+	return nickname, nil
+}
+
+// addUser adds a new user to the database
+func addUser(fingerprint string, pubKey ssh.PublicKey, nickname string) error {
+	dbMutex.Lock()
+	defer dbMutex.Unlock()
+
+	_, err := db.Exec(
+		"INSERT INTO users (fingerprint, public_key, nickname, created_at) VALUES (?, ?, ?, ?)",
+		fingerprint,
+		pubKey.Marshal(),
+		nickname,
+		time.Now().UTC(),
+	)
+	return err
+}
+
 // teaHandler creates a Bubble Tea program for each SSH session
 func teaHandler(s ssh.Session) (tea.Model, []tea.ProgramOption) {
 	_, _, active := s.Pty()
@@ -95,11 +150,13 @@ func teaHandler(s ssh.Session) (tea.Model, []tea.ProgramOption) {
 	fingerprint := getFingerprint(pubKey)
 
 	// Check if we know this user
-	usersMutex.Lock()
+	nickname, err := getUserNickname(fingerprint)
-	nickname, known := knownUsers[fingerprint]
+	if err != nil {
-	usersMutex.Unlock()
+		wish.Fatalln(s, fmt.Sprintf("database error: %v", err))
+		return nil, nil
+	}
 
-	if known {
+	if nickname != "" {
 		// Known user - send greeting and close connection
 		wish.Println(s, fmt.Sprintf("Hello, %s!", nickname))
 		return nil, nil
@@ -115,6 +172,7 @@ func teaHandler(s ssh.Session) (tea.Model, []tea.ProgramOption) {
 	m := model{
 		textInput:   ti,
 		fingerprint: fingerprint,
+		pubKey:      pubKey,
 		session:     s,
 	}
 	return m, []tea.ProgramOption{tea.WithAltScreen()}
@@ -124,6 +182,7 @@ func teaHandler(s ssh.Session) (tea.Model, []tea.ProgramOption) {
 type model struct {
 	textInput   textinput.Model
 	fingerprint string
+	pubKey      ssh.PublicKey
 	nickname    string
 	known       bool
 	err         string
@@ -159,13 +218,15 @@ func (m model) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 				return m, nil
 			}
 
-			// Store the nickname
+			// Store the user in the database
-			usersMutex.Lock()
+			err := addUser(m.fingerprint, m.pubKey, nick)
-			knownUsers[m.fingerprint] = nick
+			if err != nil {
-			usersMutex.Unlock()
+				m.err = fmt.Sprintf("Could not save nickname: %v", err)
+				return m, nil
+			}
 
 			// Send greeting and close connection
-			wish.Println(m.session, fmt.Sprintf("Hello, %s!", nick))
+			wish.Println(m.session, fmt.Sprintf("Hello, %s! Your account has been created.", nick))
 			return m, tea.Quit
 
 		case tea.KeyCtrlC, tea.KeyEsc: