| // Copyright (c) 2011 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "sandbox/win/src/filesystem_policy.h" |
| |
| #include <stdint.h> |
| |
| #include <string> |
| |
| #include "base/logging.h" |
| #include "base/stl_util.h" |
| #include "base/win/scoped_handle.h" |
| #include "base/win/windows_version.h" |
| #include "sandbox/win/src/ipc_tags.h" |
| #include "sandbox/win/src/policy_engine_opcodes.h" |
| #include "sandbox/win/src/policy_params.h" |
| #include "sandbox/win/src/sandbox_types.h" |
| #include "sandbox/win/src/sandbox_utils.h" |
| #include "sandbox/win/src/win_utils.h" |
| |
| namespace { |
| |
| NTSTATUS NtCreateFileInTarget(HANDLE* target_file_handle, |
| ACCESS_MASK desired_access, |
| OBJECT_ATTRIBUTES* obj_attributes, |
| IO_STATUS_BLOCK* io_status_block, |
| ULONG file_attributes, |
| ULONG share_access, |
| ULONG create_disposition, |
| ULONG create_options, |
| PVOID ea_buffer, |
| ULONG ea_length, |
| HANDLE target_process) { |
| NtCreateFileFunction NtCreateFile = nullptr; |
| ResolveNTFunctionPtr("NtCreateFile", &NtCreateFile); |
| |
| HANDLE local_handle = INVALID_HANDLE_VALUE; |
| NTSTATUS status = |
| NtCreateFile(&local_handle, desired_access, obj_attributes, |
| io_status_block, nullptr, file_attributes, share_access, |
| create_disposition, create_options, ea_buffer, ea_length); |
| if (!NT_SUCCESS(status)) { |
| return status; |
| } |
| |
| if (!sandbox::SameObject(local_handle, obj_attributes->ObjectName->Buffer)) { |
| // The handle points somewhere else. Fail the operation. |
| ::CloseHandle(local_handle); |
| return STATUS_ACCESS_DENIED; |
| } |
| |
| if (!::DuplicateHandle(::GetCurrentProcess(), local_handle, target_process, |
| target_file_handle, 0, false, |
| DUPLICATE_CLOSE_SOURCE | DUPLICATE_SAME_ACCESS)) { |
| return STATUS_ACCESS_DENIED; |
| } |
| return STATUS_SUCCESS; |
| } |
| |
| // Get an initialized anonymous level Security QOS. |
| SECURITY_QUALITY_OF_SERVICE GetAnonymousQOS() { |
| SECURITY_QUALITY_OF_SERVICE security_qos = {0}; |
| security_qos.Length = sizeof(security_qos); |
| security_qos.ImpersonationLevel = SecurityAnonymous; |
| // Set dynamic tracking so that a pipe doesn't capture the broker's token |
| security_qos.ContextTrackingMode = SECURITY_DYNAMIC_TRACKING; |
| security_qos.EffectiveOnly = true; |
| |
| return security_qos; |
| } |
| |
| } // namespace. |
| |
| namespace sandbox { |
| |
| bool FileSystemPolicy::GenerateRules(const wchar_t* name, |
| TargetPolicy::Semantics semantics, |
| LowLevelPolicy* policy) { |
| base::string16 mod_name(name); |
| if (mod_name.empty()) { |
| return false; |
| } |
| |
| if (!PreProcessName(&mod_name)) { |
| // The path to be added might contain a reparse point. |
| NOTREACHED(); |
| return false; |
| } |
| |
| // TODO(cpu) bug 32224: This prefix add is a hack because we don't have the |
| // infrastructure to normalize names. In any case we need to escape the |
| // question marks. |
| if (_wcsnicmp(mod_name.c_str(), kNTDevicePrefix, kNTDevicePrefixLen)) { |
| mod_name = FixNTPrefixForMatch(mod_name); |
| name = mod_name.c_str(); |
| } |
| |
| EvalResult result = ASK_BROKER; |
| |
| // List of supported calls for the filesystem. |
| const unsigned kCallNtCreateFile = 0x1; |
| const unsigned kCallNtOpenFile = 0x2; |
| const unsigned kCallNtQueryAttributesFile = 0x4; |
| const unsigned kCallNtQueryFullAttributesFile = 0x8; |
| const unsigned kCallNtSetInfoRename = 0x10; |
| |
| DWORD rule_to_add = kCallNtOpenFile | kCallNtCreateFile | |
| kCallNtQueryAttributesFile | |
| kCallNtQueryFullAttributesFile | kCallNtSetInfoRename; |
| |
| PolicyRule create(result); |
| PolicyRule open(result); |
| PolicyRule query(result); |
| PolicyRule query_full(result); |
| PolicyRule rename(result); |
| |
| switch (semantics) { |
| case TargetPolicy::FILES_ALLOW_DIR_ANY: { |
| open.AddNumberMatch(IF, OpenFile::OPTIONS, FILE_DIRECTORY_FILE, AND); |
| create.AddNumberMatch(IF, OpenFile::OPTIONS, FILE_DIRECTORY_FILE, AND); |
| break; |
| } |
| case TargetPolicy::FILES_ALLOW_READONLY: { |
| // We consider all flags that are not known to be readonly as potentially |
| // used for write. |
| DWORD allowed_flags = FILE_READ_DATA | FILE_READ_ATTRIBUTES | |
| FILE_READ_EA | SYNCHRONIZE | FILE_EXECUTE | |
| GENERIC_READ | GENERIC_EXECUTE | READ_CONTROL; |
| DWORD restricted_flags = ~allowed_flags; |
| open.AddNumberMatch(IF_NOT, OpenFile::ACCESS, restricted_flags, AND); |
| open.AddNumberMatch(IF, OpenFile::DISPOSITION, FILE_OPEN, EQUAL); |
| create.AddNumberMatch(IF_NOT, OpenFile::ACCESS, restricted_flags, AND); |
| create.AddNumberMatch(IF, OpenFile::DISPOSITION, FILE_OPEN, EQUAL); |
| |
| // Read only access don't work for rename. |
| rule_to_add &= ~kCallNtSetInfoRename; |
| break; |
| } |
| case TargetPolicy::FILES_ALLOW_QUERY: { |
| // Here we don't want to add policy for the open or the create. |
| rule_to_add &= |
| ~(kCallNtOpenFile | kCallNtCreateFile | kCallNtSetInfoRename); |
| break; |
| } |
| case TargetPolicy::FILES_ALLOW_ANY: { |
| break; |
| } |
| default: { |
| NOTREACHED(); |
| return false; |
| } |
| } |
| |
| if ((rule_to_add & kCallNtCreateFile) && |
| (!create.AddStringMatch(IF, OpenFile::NAME, name, CASE_INSENSITIVE) || |
| !policy->AddRule(IPC_NTCREATEFILE_TAG, &create))) { |
| return false; |
| } |
| |
| if ((rule_to_add & kCallNtOpenFile) && |
| (!open.AddStringMatch(IF, OpenFile::NAME, name, CASE_INSENSITIVE) || |
| !policy->AddRule(IPC_NTOPENFILE_TAG, &open))) { |
| return false; |
| } |
| |
| if ((rule_to_add & kCallNtQueryAttributesFile) && |
| (!query.AddStringMatch(IF, FileName::NAME, name, CASE_INSENSITIVE) || |
| !policy->AddRule(IPC_NTQUERYATTRIBUTESFILE_TAG, &query))) { |
| return false; |
| } |
| |
| if ((rule_to_add & kCallNtQueryFullAttributesFile) && |
| (!query_full.AddStringMatch(IF, FileName::NAME, name, CASE_INSENSITIVE) || |
| !policy->AddRule(IPC_NTQUERYFULLATTRIBUTESFILE_TAG, &query_full))) { |
| return false; |
| } |
| |
| if ((rule_to_add & kCallNtSetInfoRename) && |
| (!rename.AddStringMatch(IF, FileName::NAME, name, CASE_INSENSITIVE) || |
| !policy->AddRule(IPC_NTSETINFO_RENAME_TAG, &rename))) { |
| return false; |
| } |
| |
| return true; |
| } |
| |
| // Right now we insert two rules, to be evaluated before any user supplied rule: |
| // - go to the broker if the path doesn't look like the paths that we push on |
| // the policy (namely \??\something). |
| // - go to the broker if it looks like this is a short-name path. |
| // |
| // It is possible to add a rule to go to the broker in any case; it would look |
| // something like: |
| // rule = new PolicyRule(ASK_BROKER); |
| // rule->AddNumberMatch(IF_NOT, FileName::BROKER, true, AND); |
| // policy->AddRule(service, rule); |
| bool FileSystemPolicy::SetInitialRules(LowLevelPolicy* policy) { |
| PolicyRule format(ASK_BROKER); |
| PolicyRule short_name(ASK_BROKER); |
| |
| bool rv = format.AddNumberMatch(IF_NOT, FileName::BROKER, BROKER_TRUE, AND); |
| rv &= format.AddStringMatch(IF_NOT, FileName::NAME, L"\\/?/?\\*", |
| CASE_SENSITIVE); |
| |
| rv &= short_name.AddNumberMatch(IF_NOT, FileName::BROKER, BROKER_TRUE, AND); |
| rv &= short_name.AddStringMatch(IF, FileName::NAME, L"*~*", CASE_SENSITIVE); |
| |
| if (!rv || !policy->AddRule(IPC_NTCREATEFILE_TAG, &format)) |
| return false; |
| |
| if (!policy->AddRule(IPC_NTCREATEFILE_TAG, &short_name)) |
| return false; |
| |
| if (!policy->AddRule(IPC_NTOPENFILE_TAG, &format)) |
| return false; |
| |
| if (!policy->AddRule(IPC_NTOPENFILE_TAG, &short_name)) |
| return false; |
| |
| if (!policy->AddRule(IPC_NTQUERYATTRIBUTESFILE_TAG, &format)) |
| return false; |
| |
| if (!policy->AddRule(IPC_NTQUERYATTRIBUTESFILE_TAG, &short_name)) |
| return false; |
| |
| if (!policy->AddRule(IPC_NTQUERYFULLATTRIBUTESFILE_TAG, &format)) |
| return false; |
| |
| if (!policy->AddRule(IPC_NTQUERYFULLATTRIBUTESFILE_TAG, &short_name)) |
| return false; |
| |
| if (!policy->AddRule(IPC_NTSETINFO_RENAME_TAG, &format)) |
| return false; |
| |
| if (!policy->AddRule(IPC_NTSETINFO_RENAME_TAG, &short_name)) |
| return false; |
| |
| return true; |
| } |
| |
| bool FileSystemPolicy::CreateFileAction(EvalResult eval_result, |
| const ClientInfo& client_info, |
| const base::string16& file, |
| uint32_t attributes, |
| uint32_t desired_access, |
| uint32_t file_attributes, |
| uint32_t share_access, |
| uint32_t create_disposition, |
| uint32_t create_options, |
| HANDLE* handle, |
| NTSTATUS* nt_status, |
| ULONG_PTR* io_information) { |
| *handle = nullptr; |
| // The only action supported is ASK_BROKER which means create the requested |
| // file as specified. |
| if (ASK_BROKER != eval_result) { |
| *nt_status = STATUS_ACCESS_DENIED; |
| return false; |
| } |
| IO_STATUS_BLOCK io_block = {}; |
| UNICODE_STRING uni_name = {}; |
| OBJECT_ATTRIBUTES obj_attributes = {}; |
| SECURITY_QUALITY_OF_SERVICE security_qos = GetAnonymousQOS(); |
| |
| InitObjectAttribs(file, attributes, nullptr, &obj_attributes, &uni_name, |
| IsPipe(file) ? &security_qos : nullptr); |
| *nt_status = |
| NtCreateFileInTarget(handle, desired_access, &obj_attributes, &io_block, |
| file_attributes, share_access, create_disposition, |
| create_options, nullptr, 0, client_info.process); |
| |
| *io_information = io_block.Information; |
| return true; |
| } |
| |
| bool FileSystemPolicy::OpenFileAction(EvalResult eval_result, |
| const ClientInfo& client_info, |
| const base::string16& file, |
| uint32_t attributes, |
| uint32_t desired_access, |
| uint32_t share_access, |
| uint32_t open_options, |
| HANDLE* handle, |
| NTSTATUS* nt_status, |
| ULONG_PTR* io_information) { |
| *handle = nullptr; |
| // The only action supported is ASK_BROKER which means open the requested |
| // file as specified. |
| if (ASK_BROKER != eval_result) { |
| *nt_status = STATUS_ACCESS_DENIED; |
| return false; |
| } |
| // An NtOpen is equivalent to an NtCreate with FileAttributes = 0 and |
| // CreateDisposition = FILE_OPEN. |
| IO_STATUS_BLOCK io_block = {}; |
| UNICODE_STRING uni_name = {}; |
| OBJECT_ATTRIBUTES obj_attributes = {}; |
| SECURITY_QUALITY_OF_SERVICE security_qos = GetAnonymousQOS(); |
| |
| InitObjectAttribs(file, attributes, nullptr, &obj_attributes, &uni_name, |
| IsPipe(file) ? &security_qos : nullptr); |
| *nt_status = NtCreateFileInTarget( |
| handle, desired_access, &obj_attributes, &io_block, 0, share_access, |
| FILE_OPEN, open_options, nullptr, 0, client_info.process); |
| |
| *io_information = io_block.Information; |
| return true; |
| } |
| |
| bool FileSystemPolicy::QueryAttributesFileAction( |
| EvalResult eval_result, |
| const ClientInfo& client_info, |
| const base::string16& file, |
| uint32_t attributes, |
| FILE_BASIC_INFORMATION* file_info, |
| NTSTATUS* nt_status) { |
| // The only action supported is ASK_BROKER which means query the requested |
| // file as specified. |
| if (ASK_BROKER != eval_result) { |
| *nt_status = STATUS_ACCESS_DENIED; |
| return false; |
| } |
| |
| NtQueryAttributesFileFunction NtQueryAttributesFile = nullptr; |
| ResolveNTFunctionPtr("NtQueryAttributesFile", &NtQueryAttributesFile); |
| |
| UNICODE_STRING uni_name = {0}; |
| OBJECT_ATTRIBUTES obj_attributes = {0}; |
| SECURITY_QUALITY_OF_SERVICE security_qos = GetAnonymousQOS(); |
| |
| InitObjectAttribs(file, attributes, nullptr, &obj_attributes, &uni_name, |
| IsPipe(file) ? &security_qos : nullptr); |
| *nt_status = NtQueryAttributesFile(&obj_attributes, file_info); |
| |
| return true; |
| } |
| |
| bool FileSystemPolicy::QueryFullAttributesFileAction( |
| EvalResult eval_result, |
| const ClientInfo& client_info, |
| const base::string16& file, |
| uint32_t attributes, |
| FILE_NETWORK_OPEN_INFORMATION* file_info, |
| NTSTATUS* nt_status) { |
| // The only action supported is ASK_BROKER which means query the requested |
| // file as specified. |
| if (ASK_BROKER != eval_result) { |
| *nt_status = STATUS_ACCESS_DENIED; |
| return false; |
| } |
| |
| NtQueryFullAttributesFileFunction NtQueryFullAttributesFile = nullptr; |
| ResolveNTFunctionPtr("NtQueryFullAttributesFile", &NtQueryFullAttributesFile); |
| |
| UNICODE_STRING uni_name = {0}; |
| OBJECT_ATTRIBUTES obj_attributes = {0}; |
| SECURITY_QUALITY_OF_SERVICE security_qos = GetAnonymousQOS(); |
| |
| InitObjectAttribs(file, attributes, nullptr, &obj_attributes, &uni_name, |
| IsPipe(file) ? &security_qos : nullptr); |
| *nt_status = NtQueryFullAttributesFile(&obj_attributes, file_info); |
| |
| return true; |
| } |
| |
| bool FileSystemPolicy::SetInformationFileAction(EvalResult eval_result, |
| const ClientInfo& client_info, |
| HANDLE target_file_handle, |
| void* file_info, |
| uint32_t length, |
| uint32_t info_class, |
| IO_STATUS_BLOCK* io_block, |
| NTSTATUS* nt_status) { |
| // The only action supported is ASK_BROKER which means open the requested |
| // file as specified. |
| if (ASK_BROKER != eval_result) { |
| *nt_status = STATUS_ACCESS_DENIED; |
| return false; |
| } |
| |
| NtSetInformationFileFunction NtSetInformationFile = nullptr; |
| ResolveNTFunctionPtr("NtSetInformationFile", &NtSetInformationFile); |
| |
| HANDLE local_handle = nullptr; |
| if (!::DuplicateHandle(client_info.process, target_file_handle, |
| ::GetCurrentProcess(), &local_handle, 0, false, |
| DUPLICATE_SAME_ACCESS)) { |
| *nt_status = STATUS_ACCESS_DENIED; |
| return false; |
| } |
| |
| base::win::ScopedHandle handle(local_handle); |
| |
| FILE_INFORMATION_CLASS file_info_class = |
| static_cast<FILE_INFORMATION_CLASS>(info_class); |
| *nt_status = NtSetInformationFile(local_handle, io_block, file_info, length, |
| file_info_class); |
| |
| return true; |
| } |
| |
| bool PreProcessName(base::string16* path) { |
| ConvertToLongPath(path); |
| |
| if (ERROR_NOT_A_REPARSE_POINT == IsReparsePoint(*path)) |
| return true; |
| |
| // We can't process a reparsed file. |
| return false; |
| } |
| |
| base::string16 FixNTPrefixForMatch(const base::string16& name) { |
| base::string16 mod_name = name; |
| |
| // NT prefix escaped for rule matcher |
| const wchar_t kNTPrefixEscaped[] = L"\\/?/?\\"; |
| const int kNTPrefixEscapedLen = base::size(kNTPrefixEscaped) - 1; |
| |
| if (0 != mod_name.compare(0, kNTPrefixLen, kNTPrefix)) { |
| if (0 != mod_name.compare(0, kNTPrefixEscapedLen, kNTPrefixEscaped)) { |
| // TODO(nsylvain): Find a better way to do name resolution. Right now we |
| // take the name and we expand it. |
| mod_name.insert(0, kNTPrefixEscaped); |
| } |
| } else { |
| // Start of name matches NT prefix, replace with escaped format |
| // Fixes bug: 334882 |
| mod_name.replace(0, kNTPrefixLen, kNTPrefixEscaped); |
| } |
| |
| return mod_name; |
| } |
| |
| } // namespace sandbox |
