Add initial security subsystem

xtoskrnl/se/descript.cc

@@ -0,0 +1,127 @@
+/**
+ * PROJECT:         ExectOS
+ * COPYRIGHT:       See COPYING.md in the top level directory
+ * FILE:            xtoskrnl/se/descript.cc
+ * DESCRIPTION:     Security Descriptors
+ * DEVELOPERS:      Aiken Harris <harraiken91@gmail.com>
+ */
+
+#include <xtos.hh>
+
+
+/**
+* Creates a safe kernel-space copy of a security descriptor to prevent TOC/TOU vulnerabilities.
+*
+* @param InputDescriptor
+*        Supplies a pointer to the original security descriptor to be captured.
+*
+* @param ProcessorMode
+*        Supplies the processor mode from which the request originated.
+*
+* @param PoolType
+*        Supplies the type of memory pool to allocate the captured copy from.
+*
+* @param ForceCapture
+*        Supplies a boolean value indicating whether to force the capture in kernel mode.
+*
+* @param OutputDescriptor
+*        Supplies a pointer to a variable that receives the safely captured security descriptor.
+*
+* @return This routine returns a status code indicating the success or failure of the operation.
+*
+* @since XT 1.0
+*/
+XTAPI
+XTSTATUS
+SE::Descriptor::CaptureSecurityDescriptor(IN PSECURITY_DESCRIPTOR InputDescriptor,
+                                          IN KPROCESSOR_MODE ProcessorMode,
+                                          IN MMPOOL_TYPE PoolType,
+                                          IN BOOLEAN ForceCapture,
+                                          OUT PSECURITY_DESCRIPTOR *OutputDescriptor)
+{
+    UNIMPLEMENTED;
+
+    /* Return success */
+    return STATUS_SUCCESS;
+}
+
+/**
+ * Computes the memory quota required for a security descriptor.
+ *
+ * @param Size
+ *        Supplies the base size of the security information in bytes.
+ *
+ * @return This routine returns the computed security quota in bytes.
+ *
+ * @since XT 1.0
+ */
+XTFASTCALL
+ULONG
+SE::Descriptor::ComputeSecurityQuota(IN ULONG Size)
+{
+    ULONG ComputedSize;
+
+    /* Calculate double the base size */
+    ComputedSize = Size * 2;
+
+    /* Ensure the allocated quota meets the minimum default system threshold */
+    return (ComputedSize > SE_DEFAULT_SECURITY_QUOTA) ? ComputedSize : SE_DEFAULT_SECURITY_QUOTA;
+}
+
+/**
+* Calculates the exact memory footprint of a security descriptor for quota accounting.
+*
+* @param SecurityDescriptor
+*        Supplies a pointer to a valid, captured security descriptor.
+*
+* @param QuotaSize
+*        Supplies a pointer to a variable that receives the calculated quota size in bytes.
+*
+* @return This routine returns a status code indicating the success or failure of the operation.
+*
+* @since XT 1.0
+*/
+XTAPI
+XTSTATUS
+SE::Descriptor::ComputeQuotaInformationSize(IN PSECURITY_DESCRIPTOR SecurityDescriptor,
+                                            OUT PULONG QuotaSize)
+{
+    UNIMPLEMENTED;
+
+    /* Return success */
+    return STATUS_SUCCESS;
+}
+
+/**
+* Frees the memory of a captured security descriptor.
+*
+* @param Descriptor
+*        Supplies a pointer to the captured security descriptor to be released.
+*
+* @param ProcessorMode
+*        Supplies the processor mode that was originally used to capture the descriptor.
+*
+* @param ForceRelease
+*        Supplies a boolean value indicating whether to force the deallocation.
+*
+* @return This routine does not return any value.
+*
+* @since XT 1.0
+*/
+XTAPI
+VOID
+SE::Descriptor::ReleaseSecurityDescriptor(IN PSECURITY_DESCRIPTOR Descriptor,
+                                          IN KPROCESSOR_MODE ProcessorMode,
+                                          IN BOOLEAN ForceRelease)
+{
+    /* Check if the descriptor should be released */
+    if(((ProcessorMode == KernelMode) && (ForceRelease == TRUE)) || (ProcessorMode == UserMode))
+    {
+        /* Ensure the descriptor is valid */
+        if(Descriptor)
+        {
+            /* Free the descriptor */
+            MM::Allocator::FreePool(Descriptor, TAG_SE_DESCRIPTOR);
+        }
+    }
+}