1 // Copyright (c) 2012 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 "webkit/browser/database/database_util.h" 6 7 #include "base/basictypes.h" 8 #include "base/strings/utf_string_conversions.h" 9 #include "webkit/browser/database/database_tracker.h" 10 #include "webkit/browser/database/vfs_backend.h" 11 #include "webkit/common/database/database_identifier.h" 12 13 namespace webkit_database { 14 15 namespace { 16 17 bool IsSafeSuffix(const base::string16& suffix) { 18 base::char16 prev_c = 0; 19 for (base::string16::const_iterator it = suffix.begin(); 20 it < suffix.end(); ++it) { 21 base::char16 c = *it; 22 if (!(IsAsciiAlpha(c) || IsAsciiDigit(c) || 23 c == '-' || c == '.' || c == '_')) { 24 return false; 25 } 26 if (c == '.' && prev_c == '.') 27 return false; 28 prev_c = c; 29 } 30 return true; 31 } 32 33 } 34 35 const char DatabaseUtil::kJournalFileSuffix[] = "-journal"; 36 37 bool DatabaseUtil::CrackVfsFileName(const base::string16& vfs_file_name, 38 std::string* origin_identifier, 39 base::string16* database_name, 40 base::string16* sqlite_suffix) { 41 // 'vfs_file_name' is of the form <origin_identifier>/<db_name>#<suffix>. 42 // <suffix> is optional. 43 DCHECK(!vfs_file_name.empty()); 44 size_t first_slash_index = vfs_file_name.find('/'); 45 size_t last_pound_index = vfs_file_name.rfind('#'); 46 // '/' and '#' must be present in the string. Also, the string cannot start 47 // with a '/' (origin_identifier cannot be empty) and '/' must come before '#' 48 if ((first_slash_index == base::string16::npos) || 49 (last_pound_index == base::string16::npos) || 50 (first_slash_index == 0) || 51 (first_slash_index > last_pound_index)) { 52 return false; 53 } 54 55 std::string origin_id = base::UTF16ToASCII( 56 vfs_file_name.substr(0, first_slash_index)); 57 if (!IsValidOriginIdentifier(origin_id)) 58 return false; 59 60 base::string16 suffix = vfs_file_name.substr( 61 last_pound_index + 1, vfs_file_name.length() - last_pound_index - 1); 62 if (!IsSafeSuffix(suffix)) 63 return false; 64 65 if (origin_identifier) 66 *origin_identifier = origin_id; 67 68 if (database_name) { 69 *database_name = vfs_file_name.substr( 70 first_slash_index + 1, last_pound_index - first_slash_index - 1); 71 } 72 73 if (sqlite_suffix) 74 *sqlite_suffix = suffix; 75 76 return true; 77 } 78 79 base::FilePath DatabaseUtil::GetFullFilePathForVfsFile( 80 DatabaseTracker* db_tracker, const base::string16& vfs_file_name) { 81 std::string origin_identifier; 82 base::string16 database_name; 83 base::string16 sqlite_suffix; 84 if (!CrackVfsFileName(vfs_file_name, &origin_identifier, 85 &database_name, &sqlite_suffix)) { 86 return base::FilePath(); // invalid vfs_file_name 87 } 88 89 base::FilePath full_path = db_tracker->GetFullDBFilePath( 90 origin_identifier, database_name); 91 if (!full_path.empty() && !sqlite_suffix.empty()) { 92 DCHECK(full_path.Extension().empty()); 93 full_path = full_path.InsertBeforeExtensionASCII( 94 base::UTF16ToASCII(sqlite_suffix)); 95 } 96 // Watch out for directory traversal attempts from a compromised renderer. 97 if (full_path.value().find(FILE_PATH_LITERAL("..")) != 98 base::FilePath::StringType::npos) 99 return base::FilePath(); 100 return full_path; 101 } 102 103 bool DatabaseUtil::IsValidOriginIdentifier( 104 const std::string& origin_identifier) { 105 return GetOriginFromIdentifier(origin_identifier).is_valid(); 106 } 107 108 } // namespace webkit_database 109
