1 // Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "sandbox/win/src/policy_target.h"
6
7 #include <stddef.h>
8
9 #include "sandbox/win/src/crosscall_client.h"
10 #include "sandbox/win/src/ipc_tags.h"
11 #include "sandbox/win/src/policy_engine_processor.h"
12 #include "sandbox/win/src/policy_low_level.h"
13 #include "sandbox/win/src/policy_params.h"
14 #include "sandbox/win/src/sandbox_factory.h"
15 #include "sandbox/win/src/sandbox_nt_util.h"
16 #include "sandbox/win/src/sharedmem_ipc_client.h"
17 #include "sandbox/win/src/target_services.h"
18
19 namespace sandbox {
20
21 // Handle for our private heap.
22 extern void* g_heap;
23
24 // This is the list of all imported symbols from ntdll.dll.
25 SANDBOX_INTERCEPT NtExports g_nt;
26
27 // Policy data.
28 extern void* volatile g_shared_policy_memory;
29 SANDBOX_INTERCEPT size_t g_shared_policy_size;
30
QueryBroker(IpcTag ipc_id,CountedParameterSetBase * params)31 bool QueryBroker(IpcTag ipc_id, CountedParameterSetBase* params) {
32 DCHECK_NT(static_cast<size_t>(ipc_id) < kMaxServiceCount);
33 DCHECK_NT(g_shared_policy_memory);
34 DCHECK_NT(g_shared_policy_size > 0);
35
36 if (static_cast<size_t>(ipc_id) >= kMaxServiceCount)
37 return false;
38
39 PolicyGlobal* global_policy =
40 reinterpret_cast<PolicyGlobal*>(g_shared_policy_memory);
41
42 if (!global_policy->entry[static_cast<size_t>(ipc_id)])
43 return false;
44
45 PolicyBuffer* policy = reinterpret_cast<PolicyBuffer*>(
46 reinterpret_cast<char*>(g_shared_policy_memory) +
47 reinterpret_cast<size_t>(
48 global_policy->entry[static_cast<size_t>(ipc_id)]));
49
50 if ((reinterpret_cast<size_t>(
51 global_policy->entry[static_cast<size_t>(ipc_id)]) >
52 global_policy->data_size) ||
53 (g_shared_policy_size < global_policy->data_size)) {
54 NOTREACHED_NT();
55 return false;
56 }
57
58 for (size_t i = 0; i < params->count; i++) {
59 if (!params->parameters[i].IsValid()) {
60 NOTREACHED_NT();
61 return false;
62 }
63 }
64
65 PolicyProcessor processor(policy);
66 PolicyResult result =
67 processor.Evaluate(kShortEval, params->parameters, params->count);
68 DCHECK_NT(POLICY_ERROR != result);
69
70 return POLICY_MATCH == result && ASK_BROKER == processor.GetAction();
71 }
72
73 // -----------------------------------------------------------------------
74
75 // Hooks NtSetInformationThread to block RevertToSelf from being
76 // called before the actual call to LowerToken.
TargetNtSetInformationThread(NtSetInformationThreadFunction orig_SetInformationThread,HANDLE thread,NT_THREAD_INFORMATION_CLASS thread_info_class,PVOID thread_information,ULONG thread_information_bytes)77 NTSTATUS WINAPI TargetNtSetInformationThread(
78 NtSetInformationThreadFunction orig_SetInformationThread,
79 HANDLE thread,
80 NT_THREAD_INFORMATION_CLASS thread_info_class,
81 PVOID thread_information,
82 ULONG thread_information_bytes) {
83 do {
84 if (SandboxFactory::GetTargetServices()->GetState()->RevertedToSelf())
85 break;
86 if (ThreadImpersonationToken != thread_info_class)
87 break;
88 // This is a revert to self.
89 return STATUS_SUCCESS;
90 } while (false);
91
92 return orig_SetInformationThread(
93 thread, thread_info_class, thread_information, thread_information_bytes);
94 }
95
96 // Hooks NtOpenThreadToken to force the open_as_self parameter to be set to
97 // false if we are still running with the impersonation token. open_as_self set
98 // to true means that the token will be open using the process token instead of
99 // the impersonation token. This is bad because the process token does not have
100 // access to open the thread token.
101 NTSTATUS WINAPI
TargetNtOpenThreadToken(NtOpenThreadTokenFunction orig_OpenThreadToken,HANDLE thread,ACCESS_MASK desired_access,BOOLEAN open_as_self,PHANDLE token)102 TargetNtOpenThreadToken(NtOpenThreadTokenFunction orig_OpenThreadToken,
103 HANDLE thread,
104 ACCESS_MASK desired_access,
105 BOOLEAN open_as_self,
106 PHANDLE token) {
107 if (!SandboxFactory::GetTargetServices()->GetState()->RevertedToSelf())
108 open_as_self = false;
109
110 return orig_OpenThreadToken(thread, desired_access, open_as_self, token);
111 }
112
113 // See comment for TargetNtOpenThreadToken
114 NTSTATUS WINAPI
TargetNtOpenThreadTokenEx(NtOpenThreadTokenExFunction orig_OpenThreadTokenEx,HANDLE thread,ACCESS_MASK desired_access,BOOLEAN open_as_self,ULONG handle_attributes,PHANDLE token)115 TargetNtOpenThreadTokenEx(NtOpenThreadTokenExFunction orig_OpenThreadTokenEx,
116 HANDLE thread,
117 ACCESS_MASK desired_access,
118 BOOLEAN open_as_self,
119 ULONG handle_attributes,
120 PHANDLE token) {
121 if (!SandboxFactory::GetTargetServices()->GetState()->RevertedToSelf())
122 open_as_self = false;
123
124 return orig_OpenThreadTokenEx(thread, desired_access, open_as_self,
125 handle_attributes, token);
126 }
127
128 } // namespace sandbox
129