1 package mailmux
2 
3 import (
4 	"database/sql"
5 	"errors"
6 	"fmt"
7 
8 	_ "github.com/mattn/go-sqlite3"
9 )
10 
11 // UserDB is an implementation of UserStore backed by a SQLite3 database.
12 // Users are fully authenticated after confirming ownership of their
13 // email address by supplying a matching ticket to a generated ticket file.
14 type UserDB struct {
15 	*sql.DB
16 	TicketDir string
17 }
18 
19 // OpenUserDB opens the named user database file and ticket directory.
20 func OpenUserDB(name, dir string) (*UserDB, error) {
21 	db, err := sql.Open("sqlite3", name)
22 	if err != nil {
23 		return nil, err
24 	}
25 	return &UserDB{db, dir}, db.Ping()
26 }
27 
28 func (db *UserDB) Lookup(name string) (User, error) {
29 	var u User
30 	row := db.QueryRow("SELECT username, password FROM users WHERE username = ?", name)
31 	if err := row.Scan(&u.name, &u.password); err != nil {
32 		if errors.Is(err, sql.ErrNoRows) {
33 			return User{}, fmt.Errorf("lookup %s: %w", name, ErrUnknownUser)
34 		}
35 		return User{}, fmt.Errorf("lookup %s: %w", name, err)
36 	}
37 	return u, nil
38 }
39 
40 func (db *UserDB) add(username string, pw Password) error {
41 	_, err := db.Exec("INSERT INTO users (username, password) VALUES (?, ?)", username, pw)
42 	if err != nil {
43 		return fmt.Errorf("add %s: %w", username, err)
44 	}
45 	if err := createTicket(db.TicketDir, username, pw); err != nil {
46 		return fmt.Errorf("add %s: create ticket: %w", username, err)
47 	}
48 	return nil
49 }
50 
51 func (db *UserDB) Change(name string, new Password) error {
52 	_, err := db.Lookup(name)
53 	if errors.Is(err, ErrUnknownUser) {
54 		return db.add(name, new)
55 	}
56 	if err != nil {
57 		return fmt.Errorf("change %s: %w", name, err)
58 	}
59 
60 	_, err = db.Exec("UPDATE users SET password = ? WHERE username = ?", new, name)
61 	if err != nil {
62 		return fmt.Errorf("change %s: %w", name, err)
63 	}
64 	return nil
65 }
66 
67 func (db *UserDB) Delete(name string) error {
68 	_, err := db.Lookup(name)
69 	if err != nil {
70 		return fmt.Errorf("delete %s: %w", name, err)
71 	}
72 	_, err = db.Exec("DELETE FROM users WHERE username = ?", name)
73 	if err != nil {
74 		return fmt.Errorf("delete %s: %w", name, err)
75 	}
76 	return nil
77 }