Phase 3+4

user/magic_link_test.go

@@ -239,6 +239,71 @@ func TestUser_MagicLink_Reaper(t *testing.T) {
 	})
 }
 
+func TestUser_MagicLink_ResetPassword(t *testing.T) {
+	forEachBackend(t, func(t *testing.T, newManager newManagerFunc) {
+		a := newTestManager(t, newManager, PermissionDenyAll)
+		require.Nil(t, a.AddUser("phil", "oldpass", RoleUser, false))
+		phil, err := a.User("phil")
+		require.Nil(t, err)
+
+		raw, err := a.CreateMagicLink(MagicLinkKindPasswordReset, phil.ID, "", time.Hour)
+		require.Nil(t, err)
+
+		// Old password works before reset
+		_, err = a.Authenticate("phil", "oldpass")
+		require.Nil(t, err)
+
+		require.Nil(t, a.ResetPassword(raw, "newpass"))
+
+		// New password works, old does not
+		_, err = a.Authenticate("phil", "newpass")
+		require.Nil(t, err)
+		_, err = a.Authenticate("phil", "oldpass")
+		require.ErrorIs(t, err, ErrUnauthenticated)
+
+		// Token is single-use
+		require.ErrorIs(t, a.ResetPassword(raw, "againpass"), ErrMagicLinkNotFound)
+	})
+}
+
+func TestUser_MagicLink_ResetPassword_WrongKindRejected(t *testing.T) {
+	forEachBackend(t, func(t *testing.T, newManager newManagerFunc) {
+		a := newTestManager(t, newManager, PermissionDenyAll)
+		require.Nil(t, a.AddUser("phil", "oldpass", RoleUser, false))
+		phil, err := a.User("phil")
+		require.Nil(t, err)
+
+		// An email-verification token must not be usable for password reset...
+		verifyToken := addVerifyLink(t, a, phil.ID, "phil@example.com", time.Hour)
+		require.ErrorIs(t, a.ResetPassword(verifyToken, "newpass"), ErrMagicLinkNotFound)
+
+		// ...and a reset token must not be usable for email verification
+		resetToken, err := a.CreateMagicLink(MagicLinkKindPasswordReset, phil.ID, "", time.Hour)
+		require.Nil(t, err)
+		_, err = a.VerifyEmail(resetToken)
+		require.ErrorIs(t, err, ErrMagicLinkNotFound)
+
+		// Old password unchanged
+		_, err = a.Authenticate("phil", "oldpass")
+		require.Nil(t, err)
+	})
+}
+
+func TestUser_MagicLink_ResetPassword_Expired(t *testing.T) {
+	forEachBackend(t, func(t *testing.T, newManager newManagerFunc) {
+		a := newTestManager(t, newManager, PermissionDenyAll)
+		require.Nil(t, a.AddUser("phil", "oldpass", RoleUser, false))
+		phil, err := a.User("phil")
+		require.Nil(t, err)
+
+		raw, err := a.CreateMagicLink(MagicLinkKindPasswordReset, phil.ID, "", -time.Minute)
+		require.Nil(t, err)
+		require.ErrorIs(t, a.ResetPassword(raw, "newpass"), ErrMagicLinkNotFound)
+		_, err = a.Authenticate("phil", "oldpass")
+		require.Nil(t, err)
+	})
+}
+
 func TestUser_MagicLink_UserIDByPrimaryEmail_NotFound(t *testing.T) {
 	forEachBackend(t, func(t *testing.T, newManager newManagerFunc) {
 		a := newTestManager(t, newManager, PermissionDenyAll)

user/manager.go

@@ -1696,6 +1696,37 @@ func (a *Manager) VerifyEmail(rawToken string) (*MagicLink, error) {
 	return m, nil
 }
 
+// ResetPassword consumes a password-reset magic link, identified by its raw token: after
+// validating the token (kind + expiry), it sets the user's password and deletes the link in one
+// transaction. Existing access tokens are intentionally left valid (only the password changes).
+// Returns ErrMagicLinkNotFound if the token is invalid, expired, or not a reset token.
+func (a *Manager) ResetPassword(rawToken, password string) error {
+	m, err := a.MagicLinkByHash(hashToken(rawToken))
+	if err != nil {
+		return err
+	}
+	if m.Kind != MagicLinkKindPasswordReset || time.Now().Unix() > m.Expires {
+		return ErrMagicLinkNotFound
+	}
+	u, err := a.UserByID(m.UserID)
+	if err != nil {
+		return err
+	}
+	hash, err := a.maybeHashPassword(password, false)
+	if err != nil {
+		return err
+	}
+	return db.ExecTx(a.db, func(tx *sql.Tx) error {
+		if err := a.changePasswordHashTx(tx, u.Name, hash); err != nil {
+			return err
+		}
+		if _, err := tx.Exec(a.queries.deleteMagicLinkByHash, m.TokenHash); err != nil {
+			return err
+		}
+		return nil
+	})
+}
+
 // deleteExpiredMagicLinks removes magic links whose expiry has passed. Expiry is also enforced
 // on read, so this is purely housekeeping to bound table growth; it runs from the reaper loop.
 func (a *Manager) deleteExpiredMagicLinks() error {