teleport/lib/auth/access.go

/*
 * Teleport
 * Copyright (C) 2023  Gravitational, Inc.
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package auth

import (
	"context"
	"errors"
	"slices"
	"time"

	"github.com/gravitational/trace"

	"github.com/gravitational/teleport/api/types"
	"github.com/gravitational/teleport/api/types/accesslist"
	apievents "github.com/gravitational/teleport/api/types/events"
	"github.com/gravitational/teleport/lib/authz"
	"github.com/gravitational/teleport/lib/events"
)

// CreateRole creates a role and emits a related audit event.
func (a *Server) CreateRole(ctx context.Context, role types.Role) (types.Role, error) {
	created, err := a.Services.CreateRole(ctx, role)
	if err != nil {
		return nil, trace.Wrap(err)
	}

	if err := a.emitter.EmitAuditEvent(a.closeCtx, &apievents.RoleCreate{
		Metadata: apievents.Metadata{
			Type: events.RoleCreatedEvent,
			Code: events.RoleCreatedCode,
		},
		UserMetadata: authz.ClientUserMetadata(ctx),
		ResourceMetadata: apievents.ResourceMetadata{
			Name: role.GetName(),
		},
		ConnectionMetadata: authz.ConnectionMetadata(ctx),
	}); err != nil {
		log.WithError(err).Warnf("Failed to emit role create event.")
	}
	return created, nil
}

// UpdateRole updates a role and emits a related audit event.
func (a *Server) UpdateRole(ctx context.Context, role types.Role) (types.Role, error) {
	created, err := a.Services.UpdateRole(ctx, role)
	if err != nil {
		return nil, trace.Wrap(err)
	}

	if err := a.emitter.EmitAuditEvent(a.closeCtx, &apievents.RoleUpdate{
		Metadata: apievents.Metadata{
			Type: events.RoleUpdatedEvent,
			Code: events.RoleUpdatedCode,
		},
		UserMetadata: authz.ClientUserMetadata(ctx),
		ResourceMetadata: apievents.ResourceMetadata{
			Name: role.GetName(),
		},
		ConnectionMetadata: authz.ConnectionMetadata(ctx),
	}); err != nil {
		log.WithError(err).Warnf("Failed to emit role create event.")
	}
	return created, nil
}

// UpsertRole creates or updates a role and emits a related audit event.
func (a *Server) UpsertRole(ctx context.Context, role types.Role) (types.Role, error) {
	upserted, err := a.Services.UpsertRole(ctx, role)
	if err != nil {
		return nil, trace.Wrap(err)
	}

	if err := a.emitter.EmitAuditEvent(a.closeCtx, &apievents.RoleCreate{
		Metadata: apievents.Metadata{
			Type: events.RoleCreatedEvent,
			Code: events.RoleCreatedCode,
		},
		UserMetadata: authz.ClientUserMetadata(ctx),
		ResourceMetadata: apievents.ResourceMetadata{
			Name: role.GetName(),
		},
		ConnectionMetadata: authz.ConnectionMetadata(ctx),
	}); err != nil {
		log.WithError(err).Warnf("Failed to emit role create event.")
	}
	return upserted, nil
}

var (
	errDeleteRoleUser       = errors.New("failed to delete a role that is still in use by a user, check the system server logs for more details")
	errDeleteRoleCA         = errors.New("failed to delete a role that is still in use by a certificate authority, check the system server logs for more details")
	errDeleteRoleAccessList = errors.New("failed to delete a role that is still in use by an access list, check the system server logs for more details")
)

// DeleteRole deletes a role and emits a related audit event.
func (a *Server) DeleteRole(ctx context.Context, name string) error {
	// check if this role is used by CA or Users
	users, err := a.Services.GetUsers(ctx, false)
	if err != nil {
		return trace.Wrap(err)
	}
	for _, u := range users {
		if slices.Contains(u.GetRoles(), name) {
			// Mask the actual error here as it could be used to enumerate users
			// within the system.
			log.Warnf("Failed to delete role: role %v is used by user %v.", name, u.GetName())
			return trace.Wrap(errDeleteRoleUser)
		}
	}
	// check if it's used by some external cert authorities, e.g.
	// cert authorities related to external cluster
	cas, err := a.Services.GetCertAuthorities(ctx, types.UserCA, false)
	if err != nil {
		return trace.Wrap(err)
	}
	for _, a := range cas {
		if slices.Contains(a.GetRoles(), name) {
			// Mask the actual error here as it could be used to enumerate users
			// within the system.
			log.Warnf("Failed to delete role: role %v is used by user cert authority %v", name, a.GetClusterName())
			return trace.Wrap(errDeleteRoleCA)
		}
	}

	var nextToken string
	for {
		var accessLists []*accesslist.AccessList
		var err error
		accessLists, nextToken, err = a.Services.AccessListClient().ListAccessLists(ctx, 0 /* default page size */, nextToken)
		if err != nil {
			return trace.Wrap(err)
		}

		for _, accessList := range accessLists {
			if slices.Contains(accessList.Spec.Grants.Roles, name) {
				log.Warnf("Failed to delete role: role %v is granted by access list %s", name, accessList.GetName())
				return trace.Wrap(errDeleteRoleAccessList)
			}

			if slices.Contains(accessList.Spec.MembershipRequires.Roles, name) {
				log.Warnf("Failed to delete role: role %v is required by members of access list %s", name, accessList.GetName())
				return trace.Wrap(errDeleteRoleAccessList)
			}

			if slices.Contains(accessList.Spec.OwnershipRequires.Roles, name) {
				log.Warnf("Failed to delete role: role %v is required by owners of access list %s", name, accessList.GetName())
				return trace.Wrap(errDeleteRoleAccessList)
			}
		}

		if nextToken == "" {
			break
		}
	}

	if err := a.Services.DeleteRole(ctx, name); err != nil {
		return trace.Wrap(err)
	}

	if err := a.emitter.EmitAuditEvent(a.closeCtx, &apievents.RoleDelete{
		Metadata: apievents.Metadata{
			Type: events.RoleDeletedEvent,
			Code: events.RoleDeletedCode,
		},
		UserMetadata: authz.ClientUserMetadata(ctx),
		ResourceMetadata: apievents.ResourceMetadata{
			Name: name,
		},
		ConnectionMetadata: authz.ConnectionMetadata(ctx),
	}); err != nil {
		log.WithError(err).Warnf("Failed to emit role delete event.")
	}
	return nil
}

// UpsertLock upserts a lock and emits a related audit event.
func (a *Server) UpsertLock(ctx context.Context, lock types.Lock) error {
	if err := a.Services.UpsertLock(ctx, lock); err != nil {
		return trace.Wrap(err)
	}

	var expiresTime time.Time
	// leave as 0 if no lock expiration was set
	if le := lock.LockExpiry(); le != nil {
		expiresTime = le.UTC()
	}
	um := authz.ClientUserMetadata(ctx)
	if err := a.emitter.EmitAuditEvent(a.closeCtx, &apievents.LockCreate{
		Metadata: apievents.Metadata{
			Type: events.LockCreatedEvent,
			Code: events.LockCreatedCode,
		},
		UserMetadata: um,
		ResourceMetadata: apievents.ResourceMetadata{
			Name:      lock.GetName(),
			Expires:   expiresTime,
			UpdatedBy: um.User,
		},
		Target: lock.Target(),
		Lock: apievents.LockMetadata{
			Target: lock.Target(),
		},
	}); err != nil {
		log.WithError(err).Warning("Failed to emit lock create event.")
	}
	return nil
}

// DeleteLock deletes a lock and emits a related audit event.
func (a *Server) DeleteLock(ctx context.Context, lockName string) error {
	lock, err := a.Services.GetLock(ctx, lockName)
	if err != nil {
		return trace.Wrap(err)
	}
	if err := a.Services.DeleteLock(ctx, lockName); err != nil {
		return trace.Wrap(err)
	}

	if err := a.emitter.EmitAuditEvent(a.closeCtx, &apievents.LockDelete{
		Metadata: apievents.Metadata{
			Type: events.LockDeletedEvent,
			Code: events.LockDeletedCode,
		},
		UserMetadata: authz.ClientUserMetadata(ctx),
		ResourceMetadata: apievents.ResourceMetadata{
			Name: lockName,
		},
		Lock: apievents.LockMetadata{
			Target: lock.Target(),
		},
	}); err != nil {
		log.WithError(err).Warning("Failed to emit lock delete event.")
	}
	return nil
}