* Fix: Correctly restore ACL inheritance state
When restoring a file or directory on Windows, the `IsInherited` property of its Access Control Entries (ACEs) was always being set to `False`, even if the ACEs were inherited in the original backup.
This was caused by the restore process calling the `SetNamedSecurityInfo` API without providing context about the object's inheritance policy. By default, this API applies the provided Discretionary Access Control List (DACL) as an explicit set of permissions, thereby losing the original inheritance state.
This commit fixes the issue by inspecting the `Control` flags of the saved Security Descriptor during restore. Based on whether the `SE_DACL_PROTECTED` flag is present, the code now adds the appropriate `PROTECTED_DACL_SECURITY_INFORMATION` or `UNPROTECTED_DACL_SECURITY_INFORMATION` flag to the `SetNamedSecurityInfo` API call.
By providing this crucial inheritance context, the Windows API can now correctly reconstruct the ACL, ensuring the `IsInherited` status of each ACE is preserved as it was at the time of backup.
* Fix: Correctly restore ACL inheritance flags
This commit resolves an issue where the ACL inheritance state (`IsInherited` property) was not being correctly restored for files and directories on Windows.
The root cause was that the `SECURITY_INFORMATION` flags used in the `SetNamedSecurityInfo` API call contained both the `PROTECTED_DACL_SECURITY_INFORMATION` and `UNPROTECTED_DACL_SECURITY_INFORMATION` flags simultaneously. When faced with this conflicting information, the Windows API defaulted to the more restrictive `PROTECTED` behavior, incorrectly disabling inheritance on restored items.
The fix modifies the `setNamedSecurityInfoHigh` function to first clear all existing inheritance-related flags from the `securityInfo` bitmask. It then adds the single, correct flag (`PROTECTED` or `UNPROTECTED`) based on the `SE_DACL_PROTECTED` control bit from the original, saved Security Descriptor.
This ensures that the API receives unambiguous instructions, allowing it to correctly preserve the inheritance state as it was at the time of backup. The accompanying test case for ACL inheritance now passes with this change.
* Fix inheritance flag handling in low-privilege security descriptor restore
When restoring files without admin privileges, the IsInherited property
of Access Control Entries (ACEs) was not being preserved correctly.
The low-privilege restore path (setNamedSecurityInfoLow) was using a
static PROTECTED_DACL_SECURITY_INFORMATION flag, which always marked
the restored DACL as explicitly set rather than inherited.
This commit updates setNamedSecurityInfoLow to dynamically determine
the correct inheritance flag based on the SE_DACL_PROTECTED control
flag from the original security descriptor, matching the behavior of
the high-privilege path (setNamedSecurityInfoHigh).
Changes:
- Update setNamedSecurityInfoLow to accept control flags parameter
- Add logic to set either PROTECTED_DACL_SECURITY_INFORMATION or
UNPROTECTED_DACL_SECURITY_INFORMATION based on the original SD
- Add TestRestoreSecurityDescriptorInheritanceLowPrivilege to verify
inheritance is correctly restored in low-privilege scenarios
This ensures that both admin and non-admin restore operations correctly
preserve the inheritance state of ACLs, maintaining the original
permissions flow on child objects.
Addresses review feedback on PR for issue #5427
* Refactor security flags into separate backup/restore variants
Split highSecurityFlags into highBackupSecurityFlags and
highRestoreSecurityFlags to avoid runtime bitwise operations.
This makes the code cleaner and more maintainable by using
appropriate flags for GET vs SET operations.
Addresses review feedback on PR for issue #5427
---------
Co-authored-by: Aneesh Nireshwalia <anireshw@akamai.com>
This adds proper support for filenames that include directories. For
example, `/foo/bar` would result in an error when trying to open `/foo`.
The directory tree is now build upfront. This ensures let's the
directory tree construction be handled only once. All accessors then
only have to look up the constructed directory entries.
* Refactor ea and sd helpers to use go-winio
Import go-winio and instead of copying the functions to encode/decode extended attributes and enable process privileges for security descriptors, call the functions defined in go-winio.
Only the `Sys()` value from os.FileInfo is kept as field `sys` to
support Windows. The os.FileInfo removal ensures that for values like
`ModTime` that existed in both data structures there's no more confusion
which value is actually used.
Depending on the change packages, the VSS tests from ./cmd/restic and
the fs package may overlap in time. This causes the snapshot creation to
fail. Add retries in that case.
The actual implementation still relies on file paths, but with the
abstraction layer in place, an FS implementation can ensure atomic file
accesses in the future.
