/*
* security-core-clr.c: CoreCLR security
*
- * Author:
+ * Authors:
* Mark Probst <mark.probst@gmail.com>
+ * Sebastien Pouliot <sebastien@ximian.com>
*
* Copyright 2007-2009 Novell, Inc (http://www.novell.com)
*/
return class;
}
+/*
+ * mono_security_core_clr_check_inheritance:
+ *
+ * Determine if the specified class can inherit from its parent using
+ * the CoreCLR inheritance rules.
+ *
+ * Base Type Allow Derived Type
+ * ------------ ------------------
+ * Transparent Transparent, SafeCritical, Critical
+ * SafeCritical SafeCritical, Critical
+ * Critical Critical
+ *
+ * Reference: http://msdn.microsoft.com/en-us/magazine/cc765416.aspx#id0190030
+ */
+void
+mono_security_core_clr_check_inheritance (MonoClass *class)
+{
+ MonoSecurityCoreCLRLevel class_level, parent_level;
+ MonoClass *parent = class->parent;
+
+ if (!parent)
+ return;
+
+ class_level = mono_security_core_clr_class_level (class);
+ parent_level = mono_security_core_clr_class_level (parent);
+
+ if (class_level < parent_level)
+ mono_class_set_failure (class, MONO_EXCEPTION_TYPE_LOAD, NULL);
+}
+
+/*
+ * mono_security_core_clr_check_override:
+ *
+ * Determine if the specified override can "legally" override the
+ * specified base method using the CoreCLR inheritance rules.
+ *
+ * Base (virtual/interface) Allowed override
+ * ------------------------ -------------------------
+ * Transparent Transparent, SafeCritical
+ * SafeCritical Transparent, SafeCritical
+ * Critical Critical
+ *
+ * Reference: http://msdn.microsoft.com/en-us/magazine/cc765416.aspx#id0190030
+ */
+void
+mono_security_core_clr_check_override (MonoClass *class, MonoMethod *override, MonoMethod *base)
+{
+ MonoSecurityCoreCLRLevel base_level = mono_security_core_clr_method_level (base, FALSE);
+ MonoSecurityCoreCLRLevel override_level = mono_security_core_clr_method_level (override, FALSE);
+ /* if the base method is decorated with [SecurityCritical] then the overrided method MUST be too */
+ if (base_level == MONO_SECURITY_CORE_CLR_CRITICAL) {
+ if (override_level != MONO_SECURITY_CORE_CLR_CRITICAL)
+ mono_class_set_failure (class, MONO_EXCEPTION_TYPE_LOAD, NULL);
+ } else {
+ /* base is [SecuritySafeCritical] or [SecurityTransparent], override MUST NOT be [SecurityCritical] */
+ if (override_level == MONO_SECURITY_CORE_CLR_CRITICAL)
+ mono_class_set_failure (class, MONO_EXCEPTION_TYPE_LOAD, NULL);
+ }
+}
+
/*
* get_caller_no_reflection_related:
*
/* calls from System.Delegate are also possible and allowed */
if (strcmp (ns, "System") == 0) {
const char *kname = m->klass->name;
- if ((*kname == 'D') && (strcmp (kname, "Delegate") == 0))
- return FALSE;
- if ((*kname == 'M') && (strcmp (kname, "MulticastDelegate")) == 0)
- return FALSE;
if ((*kname == 'A') && (strcmp (kname, "Activator") == 0))
return FALSE;
+
+ /* unlike most Invoke* cases InvokeMember is not inside System.Reflection[.Emit] but is SecuritySafeCritical */
+ if (((*kname == 'T') && (strcmp (kname, "Type") == 0)) ||
+ ((*kname == 'M') && (strcmp (kname, "MonoType")) == 0)) {
+
+ /* if calling InvokeMember then we can't stop the stackwalk here and need to look at the caller */
+ if (strcmp (m->name, "InvokeMember") == 0)
+ return FALSE;
+ }
+
+ /* the security check on the delegate is made at creation time, not at invoke time */
+ if (((*kname == 'D') && (strcmp (kname, "Delegate") == 0)) ||
+ ((*kname == 'M') && (strcmp (kname, "MulticastDelegate")) == 0)) {
+
+ /* if we're invoking then we can stop our stack walk */
+ if (strcmp (m->name, "DynamicInvoke") != 0)
+ return FALSE;
+ }
}
if (m == *dest) {
static MonoMethod*
get_reflection_caller (void)
{
- MonoMethod *m = mono_method_get_last_managed ();
+ MonoMethod *m = NULL;
mono_stack_walk_no_il (get_caller_no_reflection_related, &m);
+ if (!m)
+ g_warning ("could not find a caller outside reflection");
return m;
}
static gboolean
check_field_access (MonoMethod *caller, MonoClassField *field)
{
- MonoClass *klass = (mono_field_get_flags (field) & FIELD_ATTRIBUTE_STATIC) ? NULL : mono_field_get_parent (field);
- return mono_method_can_access_field_full (caller, field, klass);
+ /* if get_reflection_caller returns NULL then we assume the caller has NO privilege */
+ if (caller) {
+ MonoClass *klass = (mono_field_get_flags (field) & FIELD_ATTRIBUTE_STATIC) ? NULL : mono_field_get_parent (field);
+ return mono_method_can_access_field_full (caller, field, klass);
+ }
+ return FALSE;
}
/*
static gboolean
check_method_access (MonoMethod *caller, MonoMethod *callee)
{
- MonoClass *klass = (callee->flags & METHOD_ATTRIBUTE_STATIC) ? NULL : callee->klass;
- return mono_method_can_access_method_full (caller, callee, klass);
+ /* if get_reflection_caller returns NULL then we assume the caller has NO privilege */
+ if (caller) {
+ MonoClass *klass = (callee->flags & METHOD_ATTRIBUTE_STATIC) ? NULL : callee->klass;
+ return mono_method_can_access_method_full (caller, callee, klass);
+ }
+ return FALSE;
}
/*
void
mono_security_core_clr_ensure_reflection_access_field (MonoClassField *field)
{
- MonoClass *klass = mono_field_get_parent (field);
-
- /* under CoreCLR you cannot use the value (get/set) of the reflected field: */
MonoMethod *caller = get_reflection_caller ();
+ /* CoreCLR restrictions applies to Transparent code/caller */
+ if (mono_security_core_clr_method_level (caller, TRUE) != MONO_SECURITY_CORE_CLR_TRANSPARENT)
+ return;
- /* (a) of a Critical type when called from a Transparent caller */
- if (mono_security_core_clr_class_level (klass) == MONO_SECURITY_CORE_CLR_CRITICAL) {
- if (mono_security_core_clr_method_level (caller, TRUE) == MONO_SECURITY_CORE_CLR_TRANSPARENT)
- mono_raise_exception (mono_get_exception_field_access ());
- }
- /* (b) that are not accessible from the caller pov */
- if (!mono_method_can_access_field_full (caller, field, klass))
+ /* Transparent code cannot [get|set]value on Critical fields */
+ if (mono_security_core_clr_class_level (mono_field_get_parent (field)) == MONO_SECURITY_CORE_CLR_CRITICAL)
+ mono_raise_exception (mono_get_exception_field_access ());
+
+ /* also it cannot access a fields that is not visible from it's (caller) point of view */
+ if (!check_field_access (caller, field))
mono_raise_exception (mono_get_exception_field_access ());
}
mono_raise_exception (mono_get_exception_method_access ());
/* also it cannot invoke a method that is not visible from it's (caller) point of view */
- if (!mono_method_can_access_method_full (caller, method, (method->flags & METHOD_ATTRIBUTE_STATIC) ? NULL : method->klass))
+ if (!check_method_access (caller, method))
mono_raise_exception (mono_get_exception_method_access ());
}
+/*
+ * can_avoid_corlib_reflection_delegate_optimization:
+ *
+ * Mono's mscorlib use delegates to optimize PropertyInfo and EventInfo
+ * reflection calls. This requires either a bunch of additional, and not
+ * really required, [SecuritySafeCritical] in the class libraries or
+ * (like this) a way to skip them. As a bonus we also avoid the stack
+ * walk to find the caller.
+ *
+ * Return TRUE if we can skip this "internal" delegate creation, FALSE
+ * otherwise.
+ */
+static gboolean
+can_avoid_corlib_reflection_delegate_optimization (MonoMethod *method)
+{
+ if (!mono_security_core_clr_is_platform_image (method->klass->image))
+ return FALSE;
+
+ if (strcmp (method->klass->name_space, "System.Reflection") != 0)
+ return FALSE;
+
+ if (strcmp (method->klass->name, "MonoProperty") == 0) {
+ if ((strcmp (method->name, "GetterAdapterFrame") == 0) || strcmp (method->name, "StaticGetterAdapterFrame") == 0)
+ return TRUE;
+ } else if (strcmp (method->klass->name, "EventInfo") == 0) {
+ if ((strcmp (method->name, "AddEventFrame") == 0) || strcmp (method->name, "StaticAddEventAdapterFrame") == 0)
+ return TRUE;
+ }
+
+ return FALSE;
+}
+
/*
* mono_security_core_clr_ensure_delegate_creation:
*
* Return TRUE if a delegate can be created on the specified method.
* CoreCLR also affect the binding, so throwOnBindFailure must be
* FALSE to let this function return (FALSE) normally, otherwise (if
- * throwOnBindFailure is TRUE) itwill throw an ArgumentException.
+ * throwOnBindFailure is TRUE) it will throw an ArgumentException.
*
* A MethodAccessException is thrown if the specified method is not
* visible from the caller point of view.
gboolean
mono_security_core_clr_ensure_delegate_creation (MonoMethod *method, gboolean throwOnBindFailure)
{
+ MonoMethod *caller;
+
/* note: mscorlib creates delegates to avoid reflection (optimization), we ignore those cases */
- MonoMethod *caller = get_reflection_caller ();
+ if (can_avoid_corlib_reflection_delegate_optimization (method))
+ return TRUE;
+
+ caller = get_reflection_caller ();
/* if the "real" caller is not Transparent then it do can anything */
if (mono_security_core_clr_method_level (caller, TRUE) != MONO_SECURITY_CORE_CLR_TRANSPARENT)
return TRUE;
return NULL;
}
+/*
+ * mono_security_core_clr_can_access_internals
+ *
+ * Check if we allow [InternalsVisibleTo] to work between two images.
+ */
+gboolean
+mono_security_core_clr_can_access_internals (MonoImage *accessing, MonoImage* accessed)
+{
+ /* are we trying to access internals of a platform assembly ? if not this is acceptable */
+ if (!mono_security_core_clr_is_platform_image (accessed))
+ return TRUE;
+
+ /* we can't let everyone with the right name and public key token access the internals of platform code.
+ * (Silverlight can rely on the strongname signature of the assemblies, but Mono does not verify them)
+ * However platform code is fully trusted so it can access the internals of other platform code assemblies */
+ if (mono_security_core_clr_is_platform_image (accessing))
+ return TRUE;
+
+ /* catch-22: System.Xml needs access to mscorlib's internals (e.g. ArrayList) but is not considered platform code.
+ * Promoting it to platform code would create another issue since (both Mono/Moonlight or MS version of)
+ * System.Xml.Linq.dll (an SDK, not platform, assembly) needs access to System.Xml.dll internals (either ).
+ * The solution is to trust, even transparent code, in the plugin directory to access platform code internals */
+ return (strcmp (accessed->assembly->basedir, accessing->assembly->basedir) == 0);
+}
+
/*
* mono_security_core_clr_level_from_cinfo:
*
}
/*
- * mono_security_core_clr_class_level:
+ * mono_security_core_clr_class_level_no_platform_check:
*
- * Return the MonoSecurityCoreCLRLevel for the specified class.
+ * Return the MonoSecurityCoreCLRLevel for the specified class, without
+ * checking for platform code. This help us avoid multiple redundant
+ * checks, e.g.
+ * - a check for the method and one for the class;
+ * - a check for the class and outer class(es) ...
*/
-MonoSecurityCoreCLRLevel
-mono_security_core_clr_class_level (MonoClass *class)
+static MonoSecurityCoreCLRLevel
+mono_security_core_clr_class_level_no_platform_check (MonoClass *class)
{
- MonoCustomAttrInfo *cinfo;
MonoSecurityCoreCLRLevel level = MONO_SECURITY_CORE_CLR_TRANSPARENT;
-
- /* non-platform code is always Transparent - whatever the attributes says */
- if (!mono_security_core_clr_test && !mono_security_core_clr_is_platform_image (class->image))
- return level;
-
- cinfo = mono_custom_attrs_from_class (class);
+ MonoCustomAttrInfo *cinfo = mono_custom_attrs_from_class (class);
if (cinfo) {
level = mono_security_core_clr_level_from_cinfo (cinfo, class->image);
mono_custom_attrs_free (cinfo);
}
if (level == MONO_SECURITY_CORE_CLR_TRANSPARENT && class->nested_in)
- level = mono_security_core_clr_class_level (class->nested_in);
+ level = mono_security_core_clr_class_level_no_platform_check (class->nested_in);
return level;
}
+/*
+ * mono_security_core_clr_class_level:
+ *
+ * Return the MonoSecurityCoreCLRLevel for the specified class.
+ */
+MonoSecurityCoreCLRLevel
+mono_security_core_clr_class_level (MonoClass *class)
+{
+ /* non-platform code is always Transparent - whatever the attributes says */
+ if (!mono_security_core_clr_test && !mono_security_core_clr_is_platform_image (class->image))
+ return MONO_SECURITY_CORE_CLR_TRANSPARENT;
+
+ return mono_security_core_clr_class_level_no_platform_check (class);
+}
+
/*
* mono_security_core_clr_method_level:
*
MonoCustomAttrInfo *cinfo;
MonoSecurityCoreCLRLevel level = MONO_SECURITY_CORE_CLR_TRANSPARENT;
+ /* if get_reflection_caller returns NULL then we assume the caller has NO privilege */
+ if (!method)
+ return level;
+
/* non-platform code is always Transparent - whatever the attributes says */
if (!mono_security_core_clr_test && !mono_security_core_clr_is_platform_image (method->klass->image))
return level;
/*
* default_platform_check:
*
- * Default platform check. Always return FALSE.
+ * Default platform check. Always TRUE for current corlib (minimum
+ * trust-able subset) otherwise return FALSE. Any real CoreCLR host
+ * should provide its own callback to define platform code (i.e.
+ * this default is meant for test only).
*/
static gboolean
default_platform_check (const char *image_name)
{
- return FALSE;
+ if (mono_defaults.corlib) {
+ return (strcmp (mono_defaults.corlib->name, image_name) == 0);
+ } else {
+ /* this can get called even before we load corlib (e.g. the EXE itself) */
+ const char *corlib = "mscorlib.dll";
+ int ilen = strlen (image_name);
+ int clen = strlen (corlib);
+ return ((ilen >= clen) && (strcmp ("mscorlib.dll", image_name + ilen - clen) == 0));
+ }
}
static MonoCoreClrPlatformCB platform_callback = default_platform_check;
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