Trusted updates
There is disclosed in one example a computing apparatus, including: a hardware platform including a processor and a memory; a whitelist; an updater, the updater being an executable object authorized to modify files within the whitelist and to launch one or more child processes; and instructions encoded within the memory to provide a system management agent to: maintain a chain of trust between the one or more child processes and the updater, wherein the one or more child processes inherit whitelist permissions associated with the updater; and track the chain of trust across a system reboot, including granting a child process the chain of trust after a reboot only if the child process has associated with it a valid certificate.
1. A computing apparatus, comprising:
a hardware platform comprising a processor and a memory;
a whitelist;
an updater, the updater being an executable object authorized to modify files within the whitelist and to launch one or more child processes; and
instructions encoded within the memory to provide a system management agent to:
maintain a chain of trust between the one or more child processes and the updater, wherein the one or more child processes inherit whitelist permissions associated with the updater; and
track the chain of trust across a system reboot, comprising granting a child process the chain of trust after a reboot only if the child process has associated with it a valid certificate.
2. The computing apparatus of claim 1 , wherein the certificate is valid only if it is signed by a trusted certificate authority.
3. The computing apparatus of claim 1 , wherein maintaining the chain of trust comprises tracking files created or imported by a trusted executable and sharing a common certificate.
4. The computing apparatus of claim 1 , wherein the system management agent is further to permit files within a common chain of trust to modify one another.
5. The computing apparatus of claim 1 , wherein the whitelist is specific to the updater.
6. The computing apparatus of claim 1 , wherein the instructions are further to allocate a trusted file set, the trusted file set being a subset of the whitelist belonging to a common workflow with the updater.
7. The computing apparatus of claim 1 , wherein the updater is a system management agent.
8. The computing apparatus of claim 1 , wherein the updater is to run with elevated privileges.
9. The computing apparatus of claim 1 , wherein the updater is a kernel module.
10. The computing apparatus of claim 1 , wherein the whitelist is a system-wide whitelist.
11. The computing apparatus of claim 1 , wherein the updater is further authorized to execute any binary executable object on the computing apparatus, including binary executable objects not on the whitelist.
12. One or more tangible, non-transitory computer-readable media having stored thereon executable instructions to:
associate a whitelist with an authorized updater process, the whitelist including a list of files that the authorized updater process and its descendant processes are authorized to modify;
assign the updater process inheritable authority to launch child processes in a chain of trust;
maintain the chain of trust when the authorized updater or a descendant of the authorized updater launches a process; and
upon an invalidating event that invalidates the chain of trust, re-establish the chain of trust after establishing that a process in the chain of trust attempting to re-establish activity has a valid certificate for the chain of trust.
13. The one or more tangible, non-transitory computer-readable media of claim 12 , wherein the invalidating event is a reboot.
14. The one or more tangible, non-transitory computer-readable media of claim 12 , wherein the certificate is valid only if it is signed by a trusted certificate authority.
15. The one or more tangible, non-transitory computer-readable media of claim 12 , wherein maintaining the chain of trust comprises tracking files created or imported by a trusted executable and sharing a common certificate.
16. The one or more tangible, non-transitory computer-readable media of claim 12 , wherein the instructions are further to permit files within a common chain of trust to modify one another.
17. The one or more tangible, non-transitory computer-readable media of claim 12 , wherein the whitelist is specific to the authorized updater.
18. The one or more tangible, non-transitory computer-readable media of claim 12 , wherein the instructions are further to allocate a trusted file set, the trusted file set being a subset of the whitelist belonging to a common workflow with the updater.
19. A computer-implemented method, comprising:
associating a whitelist with an updater process, wherein the updater process has inheritable permissions, including permission to modify files in the whitelist;
maintaining a chain of trust for the updater process, wherein direct or indirect child processes of the updater process inherit the permissions of the updater process;
detecting a reboot event that breaks the chain of trust; and
re-establishing the chain of trust after determining that a process attempting to resume execution is a direct or indirect child of the updater process, and has a valid certificate.
20. The method of claim 19 , wherein the certificate is valid only if it is signed by a trusted certificate authority.