go.mod github.com/Microsoft/hcsshim v0.8.16

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

vendor/github.com/Microsoft/go-winio/pkg/security/grantvmgroupaccess.go

@@ -0,0 +1,161 @@
+// +build windows
+
+package security
+
+import (
+	"os"
+	"syscall"
+	"unsafe"
+
+	"github.com/pkg/errors"
+)
+
+type (
+	accessMask          uint32
+	accessMode          uint32
+	desiredAccess       uint32
+	inheritMode         uint32
+	objectType          uint32
+	shareMode           uint32
+	securityInformation uint32
+	trusteeForm         uint32
+	trusteeType         uint32
+
+	explicitAccess struct {
+		accessPermissions accessMask
+		accessMode        accessMode
+		inheritance       inheritMode
+		trustee           trustee
+	}
+
+	trustee struct {
+		multipleTrustee          *trustee
+		multipleTrusteeOperation int32
+		trusteeForm              trusteeForm
+		trusteeType              trusteeType
+		name                     uintptr
+	}
+)
+
+const (
+	accessMaskDesiredPermission accessMask = 1 << 31 // GENERIC_READ
+
+	accessModeGrant accessMode = 1
+
+	desiredAccessReadControl desiredAccess = 0x20000
+	desiredAccessWriteDac    desiredAccess = 0x40000
+
+	gvmga = "GrantVmGroupAccess:"
+
+	inheritModeNoInheritance                  inheritMode = 0x0
+	inheritModeSubContainersAndObjectsInherit inheritMode = 0x3
+
+	objectTypeFileObject objectType = 0x1
+
+	securityInformationDACL securityInformation = 0x4
+
+	shareModeRead  shareMode = 0x1
+	shareModeWrite shareMode = 0x2
+
+	sidVmGroup = "S-1-5-83-0"
+
+	trusteeFormIsSid trusteeForm = 0
+
+	trusteeTypeWellKnownGroup trusteeType = 5
+)
+
+// GrantVMGroupAccess sets the DACL for a specified file or directory to
+// include Grant ACE entries for the VM Group SID. This is a golang re-
+// implementation of the same function in vmcompute, just not exported in
+// RS5. Which kind of sucks. Sucks a lot :/
+func GrantVmGroupAccess(name string) error {
+	// Stat (to determine if `name` is a directory).
+	s, err := os.Stat(name)
+	if err != nil {
+		return errors.Wrapf(err, "%s os.Stat %s", gvmga, name)
+	}
+
+	// Get a handle to the file/directory. Must defer Close on success.
+	fd, err := createFile(name, s.IsDir())
+	if err != nil {
+		return err // Already wrapped
+	}
+	defer syscall.CloseHandle(fd)
+
+	// Get the current DACL and Security Descriptor. Must defer LocalFree on success.
+	ot := objectTypeFileObject
+	si := securityInformationDACL
+	sd := uintptr(0)
+	origDACL := uintptr(0)
+	if err := getSecurityInfo(fd, uint32(ot), uint32(si), nil, nil, &origDACL, nil, &sd); err != nil {
+		return errors.Wrapf(err, "%s GetSecurityInfo %s", gvmga, name)
+	}
+	defer syscall.LocalFree((syscall.Handle)(unsafe.Pointer(sd)))
+
+	// Generate a new DACL which is the current DACL with the required ACEs added.
+	// Must defer LocalFree on success.
+	newDACL, err := generateDACLWithAcesAdded(name, s.IsDir(), origDACL)
+	if err != nil {
+		return err // Already wrapped
+	}
+	defer syscall.LocalFree((syscall.Handle)(unsafe.Pointer(newDACL)))
+
+	// And finally use SetSecurityInfo to apply the updated DACL.
+	if err := setSecurityInfo(fd, uint32(ot), uint32(si), uintptr(0), uintptr(0), newDACL, uintptr(0)); err != nil {
+		return errors.Wrapf(err, "%s SetSecurityInfo %s", gvmga, name)
+	}
+
+	return nil
+}
+
+// createFile is a helper function to call [Nt]CreateFile to get a handle to
+// the file or directory.
+func createFile(name string, isDir bool) (syscall.Handle, error) {
+	namep := syscall.StringToUTF16(name)
+	da := uint32(desiredAccessReadControl | desiredAccessWriteDac)
+	sm := uint32(shareModeRead | shareModeWrite)
+	fa := uint32(syscall.FILE_ATTRIBUTE_NORMAL)
+	if isDir {
+		fa = uint32(fa | syscall.FILE_FLAG_BACKUP_SEMANTICS)
+	}
+	fd, err := syscall.CreateFile(&namep[0], da, sm, nil, syscall.OPEN_EXISTING, fa, 0)
+	if err != nil {
+		return 0, errors.Wrapf(err, "%s syscall.CreateFile %s", gvmga, name)
+	}
+	return fd, nil
+}
+
+// generateDACLWithAcesAdded generates a new DACL with the two needed ACEs added.
+// The caller is responsible for LocalFree of the returned DACL on success.
+func generateDACLWithAcesAdded(name string, isDir bool, origDACL uintptr) (uintptr, error) {
+	// Generate pointers to the SIDs based on the string SIDs
+	sid, err := syscall.StringToSid(sidVmGroup)
+	if err != nil {
+		return 0, errors.Wrapf(err, "%s syscall.StringToSid %s %s", gvmga, name, sidVmGroup)
+	}
+
+	inheritance := inheritModeNoInheritance
+	if isDir {
+		inheritance = inheritModeSubContainersAndObjectsInherit
+	}
+
+	eaArray := []explicitAccess{
+		explicitAccess{
+			accessPermissions: accessMaskDesiredPermission,
+			accessMode:        accessModeGrant,
+			inheritance:       inheritance,
+			trustee: trustee{
+				trusteeForm: trusteeFormIsSid,
+				trusteeType: trusteeTypeWellKnownGroup,
+				name:        uintptr(unsafe.Pointer(sid)),
+			},
+		},
+	}
+
+	modifiedDACL := uintptr(0)
+	if err := setEntriesInAcl(uintptr(uint32(1)), uintptr(unsafe.Pointer(&eaArray[0])), origDACL, &modifiedDACL); err != nil {
+		return 0, errors.Wrapf(err, "%s SetEntriesInAcl %s", gvmga, name)
+	}
+
+	return modifiedDACL, nil
+}