udemy-go-web-2/internal/models/tokens.go
2024-08-19 22:35:40 +02:00

99 lines
2.1 KiB
Go

package models
import (
"context"
"crypto/rand"
"crypto/sha256"
"encoding/base32"
"time"
)
const (
ScopeAuthentication = "authentication"
)
// Token is the type for authentication tokens
type Token struct {
PlainText string `json:"token"`
UserID int64 `json:"-"`
Hash []byte `json:"-"`
Expiry time.Time `json:"expiry"`
Scope string `json:"-"`
}
// GenerateToken Generates a token that lasts for ttl, and returns it
func GenerateToken(userID int, ttl time.Duration, scope string) (*Token, error) {
token := &Token{
UserID: int64(userID),
Expiry: time.Now().Add(ttl),
Scope: scope,
}
randomBytes := make([]byte, 16)
_, err := rand.Read(randomBytes)
if err != nil {
return nil, err
}
token.PlainText = base32.StdEncoding.WithPadding((base32.NoPadding)).
EncodeToString((randomBytes))
hash := sha256.Sum256([]byte(token.PlainText))
token.Hash = hash[:]
return token, nil
}
func (m *DBModel) InsertToken(t *Token, u User) error {
ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
defer cancel()
// delete existing tokens
stmt := `DELETE FROM tokens WHERE user_id = ?`
_, err := m.DB.ExecContext(ctx, stmt, u.ID)
if err != nil {
return err
}
stmt = `INSERT INTO tokens
(user_id, name, email, token_hash, expiry_at, created_at, updated_at)
VALUES (?, ?, ?, ?, ?, ?, ?)`
_, err = m.DB.ExecContext(ctx, stmt,
u.ID,
u.LastName,
u.Email,
t.Hash,
t.Expiry,
time.Now(),
time.Now(),
)
if err != nil {
return err
}
return nil
}
func (m *DBModel) GetUserForToken(token string) (*User, error) {
ctx, cancel := context.WithTimeout(context.Background(), 3*time.Second)
defer cancel()
tokenHash := sha256.Sum256([]byte(token))
var user User
query := `SELECT u.id, u.first_name, u.last_name, u.email
FROM users u
INNER JOIN tokens t on (u.id = t.user_id)
WHERE t.token_hash = ? AND t.expiry_at > ?`
err := m.DB.QueryRowContext(ctx, query, tokenHash[:], time.Now()).Scan(
&user.ID,
&user.FirstName,
&user.LastName,
&user.Email,
)
if err != nil {
return nil, err
}
return &user, nil
}