1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Copyright (c) 2009-2020 The Bitcoin Core developers
3 // Distributed under the MIT software license, see the accompanying
4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
5
6 #include <chainparams.h>
7 #include <fs.h>
8 #include <logging.h>
9 #include <wallet/db.h>
10
11 #include <string>
12
ListDatabases(const fs::path & wallet_dir)13 std::vector<fs::path> ListDatabases(const fs::path& wallet_dir)
14 {
15 const size_t offset = wallet_dir.string().size() + (wallet_dir == wallet_dir.root_name() ? 0 : 1);
16 std::vector<fs::path> paths;
17 boost::system::error_code ec;
18
19 for (auto it = fs::recursive_directory_iterator(wallet_dir, ec); it != fs::recursive_directory_iterator(); it.increment(ec)) {
20 if (ec) {
21 if (fs::is_directory(*it)) {
22 it.no_push();
23 LogPrintf("%s: %s %s -- skipping.\n", __func__, ec.message(), it->path().string());
24 } else {
25 LogPrintf("%s: %s %s\n", __func__, ec.message(), it->path().string());
26 }
27 continue;
28 }
29
30 try {
31 // Get wallet path relative to walletdir by removing walletdir from the wallet path.
32 // This can be replaced by boost::filesystem::lexically_relative once boost is bumped to 1.60.
33 const fs::path path = it->path().string().substr(offset);
34
35 if (it->status().type() == fs::directory_file &&
36 (IsBDBFile(BDBDataFile(it->path())) || IsSQLiteFile(SQLiteDataFile(it->path())))) {
37 // Found a directory which contains wallet.dat btree file, add it as a wallet.
38 paths.emplace_back(path);
39 } else if (it.level() == 0 && it->symlink_status().type() == fs::regular_file && IsBDBFile(it->path())) {
40 if (it->path().filename() == "wallet.dat") {
41 // Found top-level wallet.dat btree file, add top level directory ""
42 // as a wallet.
43 paths.emplace_back();
44 } else {
45 // Found top-level btree file not called wallet.dat. Current bitcoin
46 // software will never create these files but will allow them to be
47 // opened in a shared database environment for backwards compatibility.
48 // Add it to the list of available wallets.
49 paths.emplace_back(path);
50 }
51 }
52 } catch (const std::exception& e) {
53 LogPrintf("%s: Error scanning %s: %s\n", __func__, it->path().string(), e.what());
54 it.no_push();
55 }
56 }
57
58 return paths;
59 }
60
BDBDataFile(const fs::path & wallet_path)61 fs::path BDBDataFile(const fs::path& wallet_path)
62 {
63 if (fs::is_regular_file(wallet_path)) {
64 // Special case for backwards compatibility: if wallet path points to an
65 // existing file, treat it as the path to a BDB data file in a parent
66 // directory that also contains BDB log files.
67 return wallet_path;
68 } else {
69 // Normal case: Interpret wallet path as a directory path containing
70 // data and log files.
71 return wallet_path / "wallet.dat";
72 }
73 }
74
SQLiteDataFile(const fs::path & path)75 fs::path SQLiteDataFile(const fs::path& path)
76 {
77 return path / "wallet.dat";
78 }
79
IsBDBFile(const fs::path & path)80 bool IsBDBFile(const fs::path& path)
81 {
82 if (!fs::exists(path)) return false;
83
84 // A Berkeley DB Btree file has at least 4K.
85 // This check also prevents opening lock files.
86 boost::system::error_code ec;
87 auto size = fs::file_size(path, ec);
88 if (ec) LogPrintf("%s: %s %s\n", __func__, ec.message(), path.string());
89 if (size < 4096) return false;
90
91 fsbridge::ifstream file(path, std::ios::binary);
92 if (!file.is_open()) return false;
93
94 file.seekg(12, std::ios::beg); // Magic bytes start at offset 12
95 uint32_t data = 0;
96 file.read((char*) &data, sizeof(data)); // Read 4 bytes of file to compare against magic
97
98 // Berkeley DB Btree magic bytes, from:
99 // https://github.com/file/file/blob/5824af38469ec1ca9ac3ffd251e7afe9dc11e227/magic/Magdir/database#L74-L75
100 // - big endian systems - 00 05 31 62
101 // - little endian systems - 62 31 05 00
102 return data == 0x00053162 || data == 0x62310500;
103 }
104
IsSQLiteFile(const fs::path & path)105 bool IsSQLiteFile(const fs::path& path)
106 {
107 if (!fs::exists(path)) return false;
108
109 // A SQLite Database file is at least 512 bytes.
110 boost::system::error_code ec;
111 auto size = fs::file_size(path, ec);
112 if (ec) LogPrintf("%s: %s %s\n", __func__, ec.message(), path.string());
113 if (size < 512) return false;
114
115 fsbridge::ifstream file(path, std::ios::binary);
116 if (!file.is_open()) return false;
117
118 // Magic is at beginning and is 16 bytes long
119 char magic[16];
120 file.read(magic, 16);
121
122 // Application id is at offset 68 and 4 bytes long
123 file.seekg(68, std::ios::beg);
124 char app_id[4];
125 file.read(app_id, 4);
126
127 file.close();
128
129 // Check the magic, see https://sqlite.org/fileformat2.html
130 std::string magic_str(magic, 16);
131 if (magic_str != std::string("SQLite format 3", 16)) {
132 return false;
133 }
134
135 // Check the application id matches our network magic
136 return memcmp(Params().MessageStart(), app_id, 4) == 0;
137 }
138