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auth.go
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| 1 | package auth |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "crypto/rand" |
| 6 | "crypto/sha256" |
| 7 | "crypto/subtle" |
| 8 | "database/sql" |
| 9 | "encoding/base64" |
| 10 | "encoding/hex" |
| 11 | "errors" |
| 12 | "fmt" |
| 13 | "strings" |
| 14 | "time" |
| 15 | |
| 16 | "polar/internal/db" |
| 17 | |
| 18 | "golang.org/x/crypto/argon2" |
| 19 | ) |
| 20 | |
| 21 | var ( |
| 22 | ErrInvalidCredentials = errors.New("invalid credentials") |
| 23 | ErrSessionExpired = errors.New("session expired or not found") |
| 24 | ErrInvalidToken = errors.New("invalid access token") |
| 25 | ) |
| 26 | |
| 27 | const ( |
| 28 | argonTime uint32 = 1 |
| 29 | argonMemory uint32 = 64 * 1024 |
| 30 | argonThreads uint8 = 4 |
| 31 | argonKeyLen uint32 = 32 |
| 32 | saltLen = 16 |
| 33 | SessionTTL = 30 * 24 * time.Hour |
| 34 | ) |
| 35 | |
| 36 | type Session struct { |
| 37 | ID string |
| 38 | UserID int64 |
| 39 | CSRFToken string |
| 40 | ExpiresAt time.Time |
| 41 | CreatedAt time.Time |
| 42 | } |
| 43 | |
| 44 | type AccessToken struct { |
| 45 | ID int64 |
| 46 | UserID int64 |
| 47 | Name string |
| 48 | TokenPrefix string |
| 49 | LastUsedAt *time.Time |
| 50 | CreatedAt time.Time |
| 51 | } |
| 52 | |
| 53 | type Service struct { |
| 54 | db *db.DB |
| 55 | } |
| 56 | |
| 57 | func NewService(database *db.DB) *Service { |
| 58 | return &Service{db: database} |
| 59 | } |
| 60 | |
| 61 | func HashPassword(password string) (string, error) { |
| 62 | if len(password) < 8 { |
| 63 | return "", errors.New("password must be at least 8 characters") |
| 64 | } |
| 65 | salt := make([]byte, saltLen) |
| 66 | if _, err := rand.Read(salt); err != nil { |
| 67 | return "", fmt.Errorf("generate salt: %w", err) |
| 68 | } |
| 69 | hash := argon2.IDKey([]byte(password), salt, argonTime, argonMemory, argonThreads, argonKeyLen) |
| 70 | b64Salt := base64.RawStdEncoding.EncodeToString(salt) |
| 71 | b64Hash := base64.RawStdEncoding.EncodeToString(hash) |
| 72 | encoded := fmt.Sprintf("$argon2id$v=%d$m=%d,t=%d,p=%d$%s$%s", |
| 73 | argon2.Version, argonMemory, argonTime, argonThreads, b64Salt, b64Hash) |
| 74 | return encoded, nil |
| 75 | } |
| 76 | |
| 77 | func VerifyPassword(password, encodedHash string) (bool, error) { |
| 78 | parts := strings.Split(encodedHash, "$") |
| 79 | if len(parts) != 6 || parts[1] != "argon2id" { |
| 80 | return false, errors.New("invalid argon2id hash format") |
| 81 | } |
| 82 | var memory, timeCost uint32 |
| 83 | var threads uint8 |
| 84 | _, err := fmt.Sscanf(parts[3], "m=%d,t=%d,p=%d", &memory, &timeCost, &threads) |
| 85 | if err != nil { |
| 86 | return false, fmt.Errorf("parse argon2 params: %w", err) |
| 87 | } |
| 88 | salt, err := base64.RawStdEncoding.DecodeString(parts[4]) |
| 89 | if err != nil { |
| 90 | return false, fmt.Errorf("decode salt: %w", err) |
| 91 | } |
| 92 | expectedHash, err := base64.RawStdEncoding.DecodeString(parts[5]) |
| 93 | if err != nil { |
| 94 | return false, fmt.Errorf("decode hash: %w", err) |
| 95 | } |
| 96 | computed := argon2.IDKey([]byte(password), salt, timeCost, memory, threads, uint32(len(expectedHash))) |
| 97 | return subtle.ConstantTimeCompare(computed, expectedHash) == 1, nil |
| 98 | } |
| 99 | |
| 100 | func randomHex(bytesLen int) (string, error) { |
| 101 | b := make([]byte, bytesLen) |
| 102 | if _, err := rand.Read(b); err != nil { |
| 103 | return "", err |
| 104 | } |
| 105 | return hex.EncodeToString(b), nil |
| 106 | } |
| 107 | |
| 108 | func (s *Service) CreateSession(ctx context.Context, userID int64) (*Session, error) { |
| 109 | cctx, cancel := context.WithTimeout(ctx, 5*time.Second) |
| 110 | defer cancel() |
| 111 | |
| 112 | id, err := randomHex(32) |
| 113 | if err != nil { |
| 114 | return nil, fmt.Errorf("generate session id: %w", err) |
| 115 | } |
| 116 | csrf, err := randomHex(24) |
| 117 | if err != nil { |
| 118 | return nil, fmt.Errorf("generate csrf token: %w", err) |
| 119 | } |
| 120 | now := time.Now().UTC() |
| 121 | expires := now.Add(SessionTTL) |
| 122 | |
| 123 | _, err = s.db.ExecContext(cctx, ` |
| 124 | INSERT INTO sessions (id, user_id, csrf_token, expires_at, created_at) |
| 125 | VALUES (?, ?, ?, ?, ?) |
| 126 | `, id, userID, csrf, expires, now) |
| 127 | if err != nil { |
| 128 | return nil, fmt.Errorf("insert session: %w", err) |
| 129 | } |
| 130 | |
| 131 | return &Session{ |
| 132 | ID: id, |
| 133 | UserID: userID, |
| 134 | CSRFToken: csrf, |
| 135 | ExpiresAt: expires, |
| 136 | CreatedAt: now, |
| 137 | }, nil |
| 138 | } |
| 139 | |
| 140 | func (s *Service) GetSession(ctx context.Context, sessionID string) (*Session, error) { |
| 141 | if sessionID == "" { |
| 142 | return nil, ErrSessionExpired |
| 143 | } |
| 144 | cctx, cancel := context.WithTimeout(ctx, 3*time.Second) |
| 145 | defer cancel() |
| 146 | |
| 147 | var sess Session |
| 148 | err := s.db.QueryRowContext(cctx, ` |
| 149 | SELECT id, user_id, csrf_token, expires_at, created_at |
| 150 | FROM sessions WHERE id = ? |
| 151 | `, sessionID).Scan(&sess.ID, &sess.UserID, &sess.CSRFToken, &sess.ExpiresAt, &sess.CreatedAt) |
| 152 | if err != nil { |
| 153 | if errors.Is(err, sql.ErrNoRows) { |
| 154 | return nil, ErrSessionExpired |
| 155 | } |
| 156 | return nil, fmt.Errorf("query session: %w", err) |
| 157 | } |
| 158 | |
| 159 | if time.Now().UTC().After(sess.ExpiresAt) { |
| 160 | _ = s.DeleteSession(ctx, sessionID) |
| 161 | return nil, ErrSessionExpired |
| 162 | } |
| 163 | return &sess, nil |
| 164 | } |
| 165 | |
| 166 | func (s *Service) DeleteSession(ctx context.Context, sessionID string) error { |
| 167 | cctx, cancel := context.WithTimeout(ctx, 3*time.Second) |
| 168 | defer cancel() |
| 169 | _, err := s.db.ExecContext(cctx, `DELETE FROM sessions WHERE id = ?`, sessionID) |
| 170 | return err |
| 171 | } |
| 172 | |
| 173 | func HashToken(rawToken string) string { |
| 174 | sum := sha256.Sum256([]byte(rawToken)) |
| 175 | return hex.EncodeToString(sum[:]) |
| 176 | } |
| 177 | |
| 178 | func (s *Service) CreateToken(ctx context.Context, userID int64, name string) (string, *AccessToken, error) { |
| 179 | name = strings.TrimSpace(name) |
| 180 | if name == "" || len(name) > 64 { |
| 181 | return "", nil, errors.New("token name must be between 1 and 64 characters") |
| 182 | } |
| 183 | |
| 184 | secret, err := randomHex(20) |
| 185 | if err != nil { |
| 186 | return "", nil, fmt.Errorf("generate token secret: %w", err) |
| 187 | } |
| 188 | rawToken := "polar_" + secret |
| 189 | tokenHash := HashToken(rawToken) |
| 190 | prefix := rawToken[:10] |
| 191 | now := time.Now().UTC() |
| 192 | |
| 193 | cctx, cancel := context.WithTimeout(ctx, 5*time.Second) |
| 194 | defer cancel() |
| 195 | |
| 196 | res, err := s.db.ExecContext(cctx, ` |
| 197 | INSERT INTO access_tokens (user_id, name, token_prefix, token_hash, created_at) |
| 198 | VALUES (?, ?, ?, ?, ?) |
| 199 | `, userID, name, prefix, tokenHash, now) |
| 200 | if err != nil { |
| 201 | return "", nil, fmt.Errorf("insert access token: %w", err) |
| 202 | } |
| 203 | id, _ := res.LastInsertId() |
| 204 | |
| 205 | return rawToken, &AccessToken{ |
| 206 | ID: id, |
| 207 | UserID: userID, |
| 208 | Name: name, |
| 209 | TokenPrefix: prefix, |
| 210 | CreatedAt: now, |
| 211 | }, nil |
| 212 | } |
| 213 | |
| 214 | func (s *Service) VerifyToken(ctx context.Context, rawToken string) (int64, error) { |
| 215 | rawToken = strings.TrimSpace(rawToken) |
| 216 | if !strings.HasPrefix(rawToken, "polar_") { |
| 217 | return 0, ErrInvalidToken |
| 218 | } |
| 219 | tokenHash := HashToken(rawToken) |
| 220 | |
| 221 | cctx, cancel := context.WithTimeout(ctx, 5*time.Second) |
| 222 | defer cancel() |
| 223 | |
| 224 | var tokenID, userID int64 |
| 225 | err := s.db.QueryRowContext(cctx, ` |
| 226 | SELECT id, user_id FROM access_tokens WHERE token_hash = ? |
| 227 | `, tokenHash).Scan(&tokenID, &userID) |
| 228 | if err != nil { |
| 229 | if errors.Is(err, sql.ErrNoRows) { |
| 230 | return 0, ErrInvalidToken |
| 231 | } |
| 232 | return 0, fmt.Errorf("lookup token: %w", err) |
| 233 | } |
| 234 | |
| 235 | now := time.Now().UTC() |
| 236 | _, _ = s.db.ExecContext(cctx, `UPDATE access_tokens SET last_used_at = ? WHERE id = ?`, now, tokenID) |
| 237 | return userID, nil |
| 238 | } |
| 239 | |
| 240 | func (s *Service) ListTokens(ctx context.Context, userID int64) ([]AccessToken, error) { |
| 241 | cctx, cancel := context.WithTimeout(ctx, 5*time.Second) |
| 242 | defer cancel() |
| 243 | |
| 244 | rows, err := s.db.QueryContext(cctx, ` |
| 245 | SELECT id, user_id, name, token_prefix, last_used_at, created_at |
| 246 | FROM access_tokens |
| 247 | WHERE user_id = ? |
| 248 | ORDER BY created_at DESC |
| 249 | `, userID) |
| 250 | if err != nil { |
| 251 | return nil, fmt.Errorf("list access tokens: %w", err) |
| 252 | } |
| 253 | defer rows.Close() |
| 254 | |
| 255 | var list []AccessToken |
| 256 | for rows.Next() { |
| 257 | var t AccessToken |
| 258 | var lastUsed sql.NullTime |
| 259 | if err := rows.Scan(&t.ID, &t.UserID, &t.Name, &t.TokenPrefix, &lastUsed, &t.CreatedAt); err != nil { |
| 260 | return nil, fmt.Errorf("scan access token: %w", err) |
| 261 | } |
| 262 | if lastUsed.Valid { |
| 263 | tm := lastUsed.Time |
| 264 | t.LastUsedAt = &tm |
| 265 | } |
| 266 | list = append(list, t) |
| 267 | } |
| 268 | return list, rows.Err() |
| 269 | } |
| 270 | |
| 271 | func (s *Service) RevokeToken(ctx context.Context, userID, tokenID int64) error { |
| 272 | cctx, cancel := context.WithTimeout(ctx, 5*time.Second) |
| 273 | defer cancel() |
| 274 | |
| 275 | _, err := s.db.ExecContext(cctx, `DELETE FROM access_tokens WHERE id = ? AND user_id = ?`, tokenID, userID) |
| 276 | if err != nil { |
| 277 | return fmt.Errorf("revoke token: %w", err) |
| 278 | } |
| 279 | return nil |
| 280 | } |
| 281 |