The Tor Browser: security/sandbox/win/src/filesystem_policy.cc@6474c204b198 (annotated)

security/sandbox/win/src/filesystem_policy.cc@6474c204b198 (annotated)

security/sandbox/win/src/filesystem_policy.cc

Wed, 31 Dec 2014 06:09:35 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Wed, 31 Dec 2014 06:09:35 +0100
changeset 0: 6474c204b198
permissions: -rw-r--r--

Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.

 // 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 <string>
 #include "sandbox/win/src/filesystem_policy.h"
 #include "base/logging.h"
 #include "base/win/scoped_handle.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_utils.h"
 #include "sandbox/win/src/sandbox_types.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_lenght,
                               HANDLE target_process) {
   NtCreateFileFunction NtCreateFile = NULL;
   ResolveNTFunctionPtr("NtCreateFile", &NtCreateFile);
   HANDLE local_handle = INVALID_HANDLE_VALUE;
   NTSTATUS status = NtCreateFile(&local_handle, desired_access, obj_attributes,
                                  io_status_block, NULL, file_attributes,
                                  share_access, create_disposition,
                                  create_options, ea_buffer, ea_lenght);
   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;
 }
 }  // namespace.
 namespace sandbox {
 bool FileSystemPolicy::GenerateRules(const wchar_t* name,
                                      TargetPolicy::Semantics semantics,
                                      LowLevelPolicy* policy) {
   std::wstring mod_name(name);
   if (mod_name.empty()) {
     return false;
   }
   // Don't do any pre-processing if the name starts like the the native
   // object manager style.
   if (0 != _wcsnicmp(mod_name.c_str(), kNTObjManPrefix, kNTObjManPrefixLen)) {
     // 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 (!PreProcessName(mod_name, &mod_name)) {
       // The path to be added might contain a reparse point.
       NOTREACHED();
       return false;
     }
     if (0 != mod_name.compare(0, kNTPrefixLen, kNTPrefix)) {
       // TODO(nsylvain): Find a better way to do name resolution. Right now we
       // take the name and we expand it.
       mod_name.insert(0, L"\\/?/?\\");
       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);
       create.AddNumberMatch(IF_NOT, OpenFile::ACCESS, restricted_flags, AND);
       // 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, TRUE, AND);
   rv &= format.AddStringMatch(IF_NOT, FileName::NAME, L"\\/?/?\\*",
                               CASE_SENSITIVE);
   rv &= short_name.AddNumberMatch(IF_NOT, FileName::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 std::wstring &file,
                                         uint32 attributes,
                                         uint32 desired_access,
                                         uint32 file_attributes,
                                         uint32 share_access,
                                         uint32 create_disposition,
                                         uint32 create_options,
                                         HANDLE *handle,
                                         NTSTATUS* nt_status,
                                         ULONG_PTR *io_information) {
   // 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 = {0};
   UNICODE_STRING uni_name = {0};
   OBJECT_ATTRIBUTES obj_attributes = {0};
   InitObjectAttribs(file, attributes, NULL, &obj_attributes, &uni_name);
   *nt_status = NtCreateFileInTarget(handle, desired_access, &obj_attributes,
                                     &io_block, file_attributes, share_access,
                                     create_disposition, create_options, NULL,
 , client_info.process);
   *io_information = io_block.Information;
   return true;
 }
 bool FileSystemPolicy::OpenFileAction(EvalResult eval_result,
                                       const ClientInfo& client_info,
                                       const std::wstring &file,
                                       uint32 attributes,
                                       uint32 desired_access,
                                       uint32 share_access,
                                       uint32 open_options,
                                       HANDLE *handle,
                                       NTSTATUS* nt_status,
                                       ULONG_PTR *io_information) {
   // 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 true;
   }
   // An NtOpen is equivalent to an NtCreate with FileAttributes = 0 and
   // CreateDisposition = FILE_OPEN.
   IO_STATUS_BLOCK io_block = {0};
   UNICODE_STRING uni_name = {0};
   OBJECT_ATTRIBUTES obj_attributes = {0};
   InitObjectAttribs(file, attributes, NULL, &obj_attributes, &uni_name);
   *nt_status = NtCreateFileInTarget(handle, desired_access, &obj_attributes,
                                     &io_block, 0, share_access, FILE_OPEN,
                                     open_options, NULL, 0,
                                     client_info.process);
   *io_information = io_block.Information;
   return true;
 }
 bool FileSystemPolicy::QueryAttributesFileAction(
     EvalResult eval_result,
     const ClientInfo& client_info,
     const std::wstring &file,
     uint32 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 true;
   }
   NtQueryAttributesFileFunction NtQueryAttributesFile = NULL;
   ResolveNTFunctionPtr("NtQueryAttributesFile", &NtQueryAttributesFile);
   UNICODE_STRING uni_name = {0};
   OBJECT_ATTRIBUTES obj_attributes = {0};
   InitObjectAttribs(file, attributes, NULL, &obj_attributes, &uni_name);
   *nt_status = NtQueryAttributesFile(&obj_attributes, file_info);
   return true;
 }
 bool FileSystemPolicy::QueryFullAttributesFileAction(
     EvalResult eval_result,
     const ClientInfo& client_info,
     const std::wstring &file,
     uint32 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 true;
   }
   NtQueryFullAttributesFileFunction NtQueryFullAttributesFile = NULL;
   ResolveNTFunctionPtr("NtQueryFullAttributesFile", &NtQueryFullAttributesFile);
   UNICODE_STRING uni_name = {0};
   OBJECT_ATTRIBUTES obj_attributes = {0};
   InitObjectAttribs(file, attributes, NULL, &obj_attributes, &uni_name);
   *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 length,
     uint32 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 true;
   }
   NtSetInformationFileFunction NtSetInformationFile = NULL;
   ResolveNTFunctionPtr("NtSetInformationFile", &NtSetInformationFile);
   HANDLE local_handle = NULL;
   if (!::DuplicateHandle(client_info.process, target_file_handle,
                          ::GetCurrentProcess(), &local_handle, 0, FALSE,
                          DUPLICATE_SAME_ACCESS)) {
     *nt_status = STATUS_ACCESS_DENIED;
     return true;
   }
   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(const std::wstring& path, std::wstring* new_path) {
   ConvertToLongPath(path, new_path);
   bool reparsed = false;
   if (ERROR_SUCCESS != IsReparsePoint(*new_path, &reparsed))
     return false;
   // We can't process reparsed file.
   return !reparsed;
 }
 }  // namespace sandbox

The Tor Browser / annotate

security/sandbox/win/src/filesystem_policy.cc@6474c204b198 (annotated)

security/sandbox/win/src/filesystem_policy.cc