Merge bitcoin/bitcoin#22937: refactor: Forbid calling unsafe fs::path(std::string) constructor and fs::path::string() method

6544ea5035268025207d2402db2f7d90fde947a6 refactor: Block unsafe fs::path std::string conversion calls (Russell Yanofsky)
b39a477ec69a51b2016d3a8c70c0c77670f87f2b refactor: Add fs::PathToString, fs::PathFromString, u8string, u8path functions (Russell Yanofsky)

Pull request description:

  The `fs::path` class has a `std::string` constructor which will implicitly convert from strings. Implicit conversions like this are not great in general because they can hide complexity and inefficiencies in the code, but this case is especially bad, because after the transition from `boost::filesystem` to `std::filesystem` in #20744 the behavior of this constructor on windows will be more complicated and can mangle path strings. The `fs::path` class also has a `.string()` method which is inverse of the constructor and has the same problems.

  Fix this by replacing the unsafe method calls with `PathToString` and `PathFromString` function calls, and by forbidding unsafe method calls in the future.

ACKs for top commit:
  kiminuo:
    ACK 6544ea5035268025207d2402db2f7d90fde947a6
  laanwj:
    Code review ACK 6544ea5035268025207d2402db2f7d90fde947a6
  hebasto:
    re-ACK 6544ea5035268025207d2402db2f7d90fde947a6, only added `fsbridge_stem` test case, updated comment, and rebased since my [previous](https://github.com/bitcoin/bitcoin/pull/22937#pullrequestreview-765503126) review. Verified with the following command:

Tree-SHA512: c36324740eb4ee55151146626166c00d5ccc4b6f3df777e75c112bcb4d1db436c1d9cc8c29a1e7fb96051457d317961ab42e6c380c3be2771d135771b2b49fa0

44 files changed, 346 insertions, 195 deletions

diff --git a/src/addrdb.cpp b/src/addrdb.cpp
index 50fd09101e..bdb1fc6b2b 100644
--- a/src/addrdb.cpp
+++ b/src/addrdb.cpp
@@ -58,7 +58,7 @@ bool SerializeFileDB(const std::string& prefix, const fs::path& path, const Data
     if (fileout.IsNull()) {
         fileout.fclose();
         remove(pathTmp);
-        return error("%s: Failed to open file %s", __func__, pathTmp.string());
+        return error("%s: Failed to open file %s", __func__, fs::PathToString(pathTmp));
     }
 
     // Serialize
@@ -70,7 +70,7 @@ bool SerializeFileDB(const std::string& prefix, const fs::path& path, const Data
     if (!FileCommit(fileout.Get())) {
         fileout.fclose();
         remove(pathTmp);
-        return error("%s: Failed to flush file %s", __func__, pathTmp.string());
+        return error("%s: Failed to flush file %s", __func__, fs::PathToString(pathTmp));
     }
     fileout.fclose();
 
@@ -122,8 +122,8 @@ void DeserializeFileDB(const fs::path& path, Data& data, int version)
 } // namespace
 
 CBanDB::CBanDB(fs::path ban_list_path)
-    : m_banlist_dat(ban_list_path.string() + ".dat"),
-      m_banlist_json(ban_list_path.string() + ".json")
+    : m_banlist_dat(ban_list_path + ".dat"),
+      m_banlist_json(ban_list_path + ".json")
 {
 }
 
@@ -143,7 +143,7 @@ bool CBanDB::Write(const banmap_t& banSet)
 bool CBanDB::Read(banmap_t& banSet)
 {
     if (fs::exists(m_banlist_dat)) {
-        LogPrintf("banlist.dat ignored because it can only be read by " PACKAGE_NAME " version 22.x. Remove %s to silence this warning.\n", m_banlist_dat);
+        LogPrintf("banlist.dat ignored because it can only be read by " PACKAGE_NAME " version 22.x. Remove %s to silence this warning.\n", fs::quoted(fs::PathToString(m_banlist_dat)));
     }
     // If the JSON banlist does not exist, then recreate it
     if (!fs::exists(m_banlist_json)) {
@@ -155,7 +155,7 @@ bool CBanDB::Read(banmap_t& banSet)
 
     if (!util::ReadSettings(m_banlist_json, settings, errors)) {
         for (const auto& err : errors) {
-            LogPrintf("Cannot load banlist %s: %s\n", m_banlist_json.string(), err);
+            LogPrintf("Cannot load banlist %s: %s\n", fs::PathToString(m_banlist_json), err);
         }
         return false;
     }
@@ -163,7 +163,7 @@ bool CBanDB::Read(banmap_t& banSet)
     try {
         BanMapFromJson(settings[JSON_KEY], banSet);
     } catch (const std::runtime_error& e) {
-        LogPrintf("Cannot parse banlist %s: %s\n", m_banlist_json.string(), e.what());
+        LogPrintf("Cannot parse banlist %s: %s\n", fs::PathToString(m_banlist_json), e.what());
         return false;
     }
 
@@ -194,12 +194,12 @@ std::optional<bilingual_str> LoadAddrman(const std::vector<bool>& asmap, const A
     } catch (const DbNotFoundError&) {
         // Addrman can be in an inconsistent state after failure, reset it
         addrman = std::make_unique<AddrMan>(asmap, /* deterministic */ false, /* consistency_check_ratio */ check_addrman);
-        LogPrintf("Creating peers.dat because the file was not found (%s)\n", path_addr);
+        LogPrintf("Creating peers.dat because the file was not found (%s)\n", fs::quoted(fs::PathToString(path_addr)));
         DumpPeerAddresses(args, *addrman);
     } catch (const std::exception& e) {
         addrman = nullptr;
         return strprintf(_("Invalid or corrupt peers.dat (%s). If you believe this is a bug, please report it to %s. As a workaround, you can move the file (%s) out of the way (rename, move, or delete) to have a new one created on the next start."),
-                         e.what(), PACKAGE_BUGREPORT, path_addr);
+                         e.what(), PACKAGE_BUGREPORT, fs::quoted(fs::PathToString(path_addr)));
     }
     return std::nullopt;
 }
@@ -215,7 +215,7 @@ std::vector<CAddress> ReadAnchors(const fs::path& anchors_db_path)
     std::vector<CAddress> anchors;
     try {
         DeserializeFileDB(anchors_db_path, anchors, CLIENT_VERSION | ADDRV2_FORMAT);
-        LogPrintf("Loaded %i addresses from %s\n", anchors.size(), anchors_db_path.filename());
+        LogPrintf("Loaded %i addresses from %s\n", anchors.size(), fs::quoted(fs::PathToString(anchors_db_path.filename())));
     } catch (const std::exception&) {
         anchors.clear();
     }
diff --git a/src/bitcoin-cli.cpp b/src/bitcoin-cli.cpp
index 3c22ee0f67..43e986a765 100644
--- a/src/bitcoin-cli.cpp
+++ b/src/bitcoin-cli.cpp
@@ -786,7 +786,7 @@ static UniValue CallRPC(BaseRequestHandler* rh, const std::string& strMethod, co
         if (failedToGetAuthCookie) {
             throw std::runtime_error(strprintf(
                 "Could not locate RPC credentials. No authentication cookie could be found, and RPC password is not set.  See -rpcpassword and -stdinrpcpass.  Configuration file: (%s)",
-                GetConfigFile(gArgs.GetArg("-conf", BITCOIN_CONF_FILENAME)).string()));
+                fs::PathToString(GetConfigFile(gArgs.GetArg("-conf", BITCOIN_CONF_FILENAME)))));
         } else {
             throw std::runtime_error("Authorization failed: Incorrect rpcuser or rpcpassword");
         }
diff --git a/src/dbwrapper.cpp b/src/dbwrapper.cpp
index bcaf746167..2fdc54464a 100644
--- a/src/dbwrapper.cpp
+++ b/src/dbwrapper.cpp
@@ -115,7 +115,7 @@ static leveldb::Options GetOptions(size_t nCacheSize)
 }
 
 CDBWrapper::CDBWrapper(const fs::path& path, size_t nCacheSize, bool fMemory, bool fWipe, bool obfuscate)
-    : m_name{path.stem().string()}
+    : m_name{fs::PathToString(path.stem())}
 {
     penv = nullptr;
     readoptions.verify_checksums = true;
@@ -129,21 +129,21 @@ CDBWrapper::CDBWrapper(const fs::path& path, size_t nCacheSize, bool fMemory, bo
         options.env = penv;
     } else {
         if (fWipe) {
-            LogPrintf("Wiping LevelDB in %s\n", path.string());
-            leveldb::Status result = leveldb::DestroyDB(path.string(), options);
+            LogPrintf("Wiping LevelDB in %s\n", fs::PathToString(path));
+            leveldb::Status result = leveldb::DestroyDB(fs::PathToString(path), options);
             dbwrapper_private::HandleError(result);
         }
         TryCreateDirectories(path);
-        LogPrintf("Opening LevelDB in %s\n", path.string());
+        LogPrintf("Opening LevelDB in %s\n", fs::PathToString(path));
     }
-    leveldb::Status status = leveldb::DB::Open(options, path.string(), &pdb);
+    leveldb::Status status = leveldb::DB::Open(options, fs::PathToString(path), &pdb);
     dbwrapper_private::HandleError(status);
     LogPrintf("Opened LevelDB successfully\n");
 
     if (gArgs.GetBoolArg("-forcecompactdb", false)) {
-        LogPrintf("Starting database compaction of %s\n", path.string());
+        LogPrintf("Starting database compaction of %s\n", fs::PathToString(path));
         pdb->CompactRange(nullptr, nullptr);
-        LogPrintf("Finished database compaction of %s\n", path.string());
+        LogPrintf("Finished database compaction of %s\n", fs::PathToString(path));
     }
 
     // The base-case obfuscation key, which is a noop.
@@ -160,10 +160,10 @@ CDBWrapper::CDBWrapper(const fs::path& path, size_t nCacheSize, bool fMemory, bo
         Write(OBFUSCATE_KEY_KEY, new_key);
         obfuscate_key = new_key;
 
-        LogPrintf("Wrote new obfuscate key for %s: %s\n", path.string(), HexStr(obfuscate_key));
+        LogPrintf("Wrote new obfuscate key for %s: %s\n", fs::PathToString(path), HexStr(obfuscate_key));
     }
 
-    LogPrintf("Using obfuscation key for %s: %s\n", path.string(), HexStr(obfuscate_key));
+    LogPrintf("Using obfuscation key for %s: %s\n", fs::PathToString(path), HexStr(obfuscate_key));
 }
 
 CDBWrapper::~CDBWrapper()
diff --git a/src/flatfile.cpp b/src/flatfile.cpp
index 151f1a38f1..929808c7fa 100644
--- a/src/flatfile.cpp
+++ b/src/flatfile.cpp
@@ -41,11 +41,11 @@ FILE* FlatFileSeq::Open(const FlatFilePos& pos, bool read_only)
     if (!file && !read_only)
         file = fsbridge::fopen(path, "wb+");
     if (!file) {
-        LogPrintf("Unable to open file %s\n", path.string());
+        LogPrintf("Unable to open file %s\n", fs::PathToString(path));
         return nullptr;
     }
     if (pos.nPos && fseek(file, pos.nPos, SEEK_SET)) {
-        LogPrintf("Unable to seek to position %u of %s\n", pos.nPos, path.string());
+        LogPrintf("Unable to seek to position %u of %s\n", pos.nPos, fs::PathToString(path));
         fclose(file);
         return nullptr;
     }
diff --git a/src/fs.cpp b/src/fs.cpp
index b9b3c46d8d..8cae7f32c6 100644
--- a/src/fs.cpp
+++ b/src/fs.cpp
@@ -24,7 +24,7 @@ namespace fsbridge {
 FILE *fopen(const fs::path& p, const char *mode)
 {
 #ifndef WIN32
-    return ::fopen(p.string().c_str(), mode);
+    return ::fopen(p.c_str(), mode);
 #else
     std::wstring_convert<std::codecvt_utf8_utf16<wchar_t>,wchar_t> utf8_cvt;
     return ::_wfopen(p.wstring().c_str(), utf8_cvt.from_bytes(mode).c_str());
@@ -46,7 +46,7 @@ static std::string GetErrorReason()
 
 FileLock::FileLock(const fs::path& file)
 {
-    fd = open(file.string().c_str(), O_RDWR);
+    fd = open(file.c_str(), O_RDWR);
     if (fd == -1) {
         reason = GetErrorReason();
     }
@@ -249,9 +249,9 @@ void ofstream::close()
 #else // __GLIBCXX__
 
 #if BOOST_VERSION >= 107700
-static_assert(sizeof(*BOOST_FILESYSTEM_C_STR(fs::path())) == sizeof(wchar_t),
+static_assert(sizeof(*BOOST_FILESYSTEM_C_STR(boost::filesystem::path())) == sizeof(wchar_t),
 #else
-static_assert(sizeof(*fs::path().BOOST_FILESYSTEM_C_STR) == sizeof(wchar_t),
+static_assert(sizeof(*boost::filesystem::path().BOOST_FILESYSTEM_C_STR) == sizeof(wchar_t),
 #endif // BOOST_VERSION >= 107700
     "Warning: This build is using boost::filesystem ofstream and ifstream "
     "implementations which will fail to open paths containing multibyte "
diff --git a/src/fs.h b/src/fs.h
index d77b90be66..4a0bf39e95 100644
--- a/src/fs.h
+++ b/src/fs.h
@@ -13,9 +13,132 @@
 
 #include <boost/filesystem.hpp>
 #include <boost/filesystem/fstream.hpp>
+#include <tinyformat.h>
 
 /** Filesystem operations and types */
-namespace fs = boost::filesystem;
+namespace fs {
+
+using namespace boost::filesystem;
+
+/**
+ * Path class wrapper to prepare application code for transition from
+ * boost::filesystem library to std::filesystem implementation. The main
+ * purpose of the class is to define fs::path::u8string() and fs::u8path()
+ * functions not present in boost. It also blocks calls to the
+ * fs::path(std::string) implicit constructor and the fs::path::string()
+ * method, which worked well in the boost::filesystem implementation, but have
+ * unsafe and unpredictable behavior on Windows in the std::filesystem
+ * implementation (see implementation note in \ref PathToString for details).
+ */
+class path : public boost::filesystem::path
+{
+public:
+    using boost::filesystem::path::path;
+
+    // Allow path objects arguments for compatibility.
+    path(boost::filesystem::path path) : boost::filesystem::path::path(std::move(path)) {}
+    path& operator=(boost::filesystem::path path) { boost::filesystem::path::operator=(std::move(path)); return *this; }
+    path& operator/=(boost::filesystem::path path) { boost::filesystem::path::operator/=(std::move(path)); return *this; }
+
+    // Allow literal string arguments, which are safe as long as the literals are ASCII.
+    path(const char* c) : boost::filesystem::path(c) {}
+    path& operator=(const char* c) { boost::filesystem::path::operator=(c); return *this; }
+    path& operator/=(const char* c) { boost::filesystem::path::operator/=(c); return *this; }
+    path& append(const char* c) { boost::filesystem::path::append(c); return *this; }
+
+    // Disallow std::string arguments to avoid locale-dependent decoding on windows.
+    path(std::string) = delete;
+    path& operator=(std::string) = delete;
+    path& operator/=(std::string) = delete;
+    path& append(std::string) = delete;
+
+    // Disallow std::string conversion method to avoid locale-dependent encoding on windows.
+    std::string string() const = delete;
+
+    // Define UTF-8 string conversion method not present in boost::filesystem but present in std::filesystem.
+    std::string u8string() const { return boost::filesystem::path::string(); }
+};
+
+// Define UTF-8 string conversion function not present in boost::filesystem but present in std::filesystem.
+static inline path u8path(const std::string& string)
+{
+    return boost::filesystem::path(string);
+}
+
+// Disallow implicit std::string conversion for system_complete to avoid
+// locale-dependent encoding on windows.
+static inline path system_complete(const path& p)
+{
+    return boost::filesystem::system_complete(p);
+}
+
+// Disallow implicit std::string conversion for exists to avoid
+// locale-dependent encoding on windows.
+static inline bool exists(const path& p)
+{
+    return boost::filesystem::exists(p);
+}
+
+// Allow explicit quoted stream I/O.
+static inline auto quoted(const std::string& s)
+{
+    return boost::io::quoted(s, '&');
+}
+
+// Allow safe path append operations.
+static inline path operator+(path p1, path p2)
+{
+    p1 += std::move(p2);
+    return p1;
+}
+
+/**
+ * Convert path object to byte string. On POSIX, paths natively are byte
+ * strings so this is trivial. On Windows, paths natively are Unicode, so an
+ * encoding step is necessary.
+ *
+ * The inverse of \ref PathToString is \ref PathFromString. The strings
+ * returned and parsed by these functions can be used to call POSIX APIs, and
+ * for roundtrip conversion, logging, and debugging. But they are not
+ * guaranteed to be valid UTF-8, and are generally meant to be used internally,
+ * not externally. When communicating with external programs and libraries that
+ * require UTF-8, fs::path::u8string() and fs::u8path() methods can be used.
+ * For other applications, if support for non UTF-8 paths is required, or if
+ * higher-level JSON or XML or URI or C-style escapes are preferred, it may be
+ * also be appropriate to use different path encoding functions.
+ *
+ * Implementation note: On Windows, the std::filesystem::path(string)
+ * constructor and std::filesystem::path::string() method are not safe to use
+ * here, because these methods encode the path using C++'s narrow multibyte
+ * encoding, which on Windows corresponds to the current "code page", which is
+ * unpredictable and typically not able to represent all valid paths. So
+ * std::filesystem::path::u8string() and std::filesystem::u8path() functions
+ * are used instead on Windows. On POSIX, u8string/u8path functions are not
+ * safe to use because paths are not always valid UTF-8, so plain string
+ * methods which do not transform the path there are used.
+ */
+static inline std::string PathToString(const path& path)
+{
+#ifdef WIN32
+    return path.u8string();
+#else
+    static_assert(std::is_same<path::string_type, std::string>::value, "PathToString not implemented on this platform");
+    return path.boost::filesystem::path::string();
+#endif
+}
+
+/**
+ * Convert byte string to path object. Inverse of \ref PathToString.
+ */
+static inline path PathFromString(const std::string& string)
+{
+#ifdef WIN32
+    return u8path(string);
+#else
+    return boost::filesystem::path(string);
+#endif
+}
+} // namespace fs
 
 /** Bridge operations to C stdio */
 namespace fsbridge {
@@ -103,4 +226,11 @@ namespace fsbridge {
 #endif // WIN32 && __GLIBCXX__
 };
 
+// Disallow path operator<< formatting in tinyformat to avoid locale-dependent
+// encoding on windows.
+namespace tinyformat {
+template<> inline void formatValue(std::ostream&, const char*, const char*, int, const boost::filesystem::path&) = delete;
+template<> inline void formatValue(std::ostream&, const char*, const char*, int, const fs::path&) = delete;
+} // namespace tinyformat
+
 #endif // BITCOIN_FS_H
diff --git a/src/i2p.cpp b/src/i2p.cpp
index 5e7e42fb77..35ac8731f2 100644
--- a/src/i2p.cpp
+++ b/src/i2p.cpp
@@ -328,7 +328,7 @@ void Session::GenerateAndSavePrivateKey(const Sock& sock)
     if (!WriteBinaryFile(m_private_key_file,
                          std::string(m_private_key.begin(), m_private_key.end()))) {
         throw std::runtime_error(
-            strprintf("Cannot save I2P private key to %s", m_private_key_file));
+            strprintf("Cannot save I2P private key to %s", fs::quoted(fs::PathToString(m_private_key_file))));
     }
 }
 
diff --git a/src/init.cpp b/src/init.cpp
index 4495ded64d..164b7bb55d 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -113,7 +113,7 @@ static const char* BITCOIN_PID_FILENAME = "bitcoind.pid";
 
 static fs::path GetPidFile(const ArgsManager& args)
 {
-    return AbsPathForConfigVal(fs::path(args.GetArg("-pid", BITCOIN_PID_FILENAME)));
+    return AbsPathForConfigVal(fs::PathFromString(args.GetArg("-pid", BITCOIN_PID_FILENAME)));
 }
 
 [[nodiscard]] static bool CreatePidFile(const ArgsManager& args)
@@ -127,7 +127,7 @@ static fs::path GetPidFile(const ArgsManager& args)
 #endif
         return true;
     } else {
-        return InitError(strprintf(_("Unable to create the PID file '%s': %s"), GetPidFile(args).string(), std::strerror(errno)));
+        return InitError(strprintf(_("Unable to create the PID file '%s': %s"), fs::PathToString(GetPidFile(args)), std::strerror(errno)));
     }
 }
 
@@ -1062,10 +1062,10 @@ static bool LockDataDirectory(bool probeOnly)
     // Make sure only a single Bitcoin process is using the data directory.
     fs::path datadir = gArgs.GetDataDirNet();
     if (!DirIsWritable(datadir)) {
-        return InitError(strprintf(_("Cannot write to data directory '%s'; check permissions."), datadir.string()));
+        return InitError(strprintf(_("Cannot write to data directory '%s'; check permissions."), fs::PathToString(datadir)));
     }
     if (!LockDirectory(datadir, ".lock", probeOnly)) {
-        return InitError(strprintf(_("Cannot obtain a lock on data directory %s. %s is probably already running."), datadir.string(), PACKAGE_NAME));
+        return InitError(strprintf(_("Cannot obtain a lock on data directory %s. %s is probably already running."), fs::PathToString(datadir), PACKAGE_NAME));
     }
     return true;
 }
@@ -1126,12 +1126,12 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
     LogPrintf("Using at most %i automatic connections (%i file descriptors available)\n", nMaxConnections, nFD);
 
     // Warn about relative -datadir path.
-    if (args.IsArgSet("-datadir") && !fs::path(args.GetArg("-datadir", "")).is_absolute()) {
+    if (args.IsArgSet("-datadir") && !fs::PathFromString(args.GetArg("-datadir", "")).is_absolute()) {
         LogPrintf("Warning: relative datadir option '%s' specified, which will be interpreted relative to the " /* Continued */
                   "current working directory '%s'. This is fragile, because if bitcoin is started in the future "
                   "from a different location, it will be unable to locate the current data files. There could "
                   "also be data loss if bitcoin is started while in a temporary directory.\n",
-                  args.GetArg("-datadir", ""), fs::current_path().string());
+                  args.GetArg("-datadir", ""), fs::PathToString(fs::current_path()));
     }
 
     InitSignatureCache();
@@ -1215,20 +1215,20 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
         // Read asmap file if configured
         std::vector<bool> asmap;
         if (args.IsArgSet("-asmap")) {
-            fs::path asmap_path = fs::path(args.GetArg("-asmap", ""));
+            fs::path asmap_path = fs::PathFromString(args.GetArg("-asmap", ""));
             if (asmap_path.empty()) {
-                asmap_path = DEFAULT_ASMAP_FILENAME;
+                asmap_path = fs::PathFromString(DEFAULT_ASMAP_FILENAME);
             }
             if (!asmap_path.is_absolute()) {
                 asmap_path = gArgs.GetDataDirNet() / asmap_path;
             }
             if (!fs::exists(asmap_path)) {
-                InitError(strprintf(_("Could not find asmap file %s"), asmap_path));
+                InitError(strprintf(_("Could not find asmap file %s"), fs::quoted(fs::PathToString(asmap_path))));
                 return false;
             }
             asmap = DecodeAsmap(asmap_path);
             if (asmap.size() == 0) {
-                InitError(strprintf(_("Could not parse asmap file %s"), asmap_path));
+                InitError(strprintf(_("Could not parse asmap file %s"), fs::quoted(fs::PathToString(asmap_path))));
                 return false;
             }
             const uint256 asmap_version = SerializeHash(asmap);
@@ -1653,11 +1653,11 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
     // ********************************************************* Step 11: import blocks
 
     if (!CheckDiskSpace(gArgs.GetDataDirNet())) {
-        InitError(strprintf(_("Error: Disk space is low for %s"), gArgs.GetDataDirNet()));
+        InitError(strprintf(_("Error: Disk space is low for %s"), fs::quoted(fs::PathToString(gArgs.GetDataDirNet()))));
         return false;
     }
     if (!CheckDiskSpace(gArgs.GetBlocksDirPath())) {
-        InitError(strprintf(_("Error: Disk space is low for %s"), gArgs.GetBlocksDirPath()));
+        InitError(strprintf(_("Error: Disk space is low for %s"), fs::quoted(fs::PathToString(gArgs.GetBlocksDirPath()))));
         return false;
     }
 
@@ -1685,7 +1685,7 @@ bool AppInitMain(NodeContext& node, interfaces::BlockAndHeaderTipInfo* tip_info)
 
     std::vector<fs::path> vImportFiles;
     for (const std::string& strFile : args.GetArgs("-loadblock")) {
-        vImportFiles.push_back(strFile);
+        vImportFiles.push_back(fs::PathFromString(strFile));
     }
 
     chainman.m_load_block = std::thread(&util::TraceThread, "loadblk", [=, &chainman, &args] {
diff --git a/src/init/common.cpp b/src/init/common.cpp
index 5c1f469081..8f9e0ebc87 100644
--- a/src/init/common.cpp
+++ b/src/init/common.cpp
@@ -81,7 +81,7 @@ void AddLoggingArgs(ArgsManager& argsman)
 void SetLoggingOptions(const ArgsManager& args)
 {
     LogInstance().m_print_to_file = !args.IsArgNegated("-debuglogfile");
-    LogInstance().m_file_path = AbsPathForConfigVal(args.GetArg("-debuglogfile", DEFAULT_DEBUGLOGFILE));
+    LogInstance().m_file_path = AbsPathForConfigVal(fs::PathFromString(args.GetArg("-debuglogfile", DEFAULT_DEBUGLOGFILE)));
     LogInstance().m_print_to_console = args.GetBoolArg("-printtoconsole", !args.GetBoolArg("-daemon", false));
     LogInstance().m_log_timestamps = args.GetBoolArg("-logtimestamps", DEFAULT_LOGTIMESTAMPS);
     LogInstance().m_log_time_micros = args.GetBoolArg("-logtimemicros", DEFAULT_LOGTIMEMICROS);
@@ -128,24 +128,24 @@ bool StartLogging(const ArgsManager& args)
     }
     if (!LogInstance().StartLogging()) {
             return InitError(strprintf(Untranslated("Could not open debug log file %s"),
-                LogInstance().m_file_path.string()));
+                fs::PathToString(LogInstance().m_file_path)));
     }
 
     if (!LogInstance().m_log_timestamps)
         LogPrintf("Startup time: %s\n", FormatISO8601DateTime(GetTime()));
-    LogPrintf("Default data directory %s\n", GetDefaultDataDir().string());
-    LogPrintf("Using data directory %s\n", gArgs.GetDataDirNet().string());
+    LogPrintf("Default data directory %s\n", fs::PathToString(GetDefaultDataDir()));
+    LogPrintf("Using data directory %s\n", fs::PathToString(gArgs.GetDataDirNet()));
 
     // Only log conf file usage message if conf file actually exists.
     fs::path config_file_path = GetConfigFile(args.GetArg("-conf", BITCOIN_CONF_FILENAME));
     if (fs::exists(config_file_path)) {
-        LogPrintf("Config file: %s\n", config_file_path.string());
+        LogPrintf("Config file: %s\n", fs::PathToString(config_file_path));
     } else if (args.IsArgSet("-conf")) {
         // Warn if no conf file exists at path provided by user
-        InitWarning(strprintf(_("The specified config file %s does not exist"), config_file_path.string()));
+        InitWarning(strprintf(_("The specified config file %s does not exist"), fs::PathToString(config_file_path)));
     } else {
         // Not categorizing as "Warning" because it's the default behavior
-        LogPrintf("Config file: %s (not found, skipping)\n", config_file_path.string());
+        LogPrintf("Config file: %s (not found, skipping)\n", fs::PathToString(config_file_path));
     }
 
     // Log the config arguments to debug.log
diff --git a/src/ipc/process.cpp b/src/ipc/process.cpp
index 43ed1f1bae..9036b80c45 100644
--- a/src/ipc/process.cpp
+++ b/src/ipc/process.cpp
@@ -30,8 +30,8 @@ public:
         return mp::SpawnProcess(pid, [&](int fd) {
             fs::path path = argv0_path;
             path.remove_filename();
-            path.append(new_exe_name);
-            return std::vector<std::string>{path.string(), "-ipcfd", strprintf("%i", fd)};
+            path /= fs::PathFromString(new_exe_name);
+            return std::vector<std::string>{fs::PathToString(path), "-ipcfd", strprintf("%i", fd)};
         });
     }
     int waitSpawned(int pid) override { return mp::WaitProcess(pid); }
diff --git a/src/node/blockstorage.cpp b/src/node/blockstorage.cpp
index bb2acfafe0..53bc2b5069 100644
--- a/src/node/blockstorage.cpp
+++ b/src/node/blockstorage.cpp
@@ -68,13 +68,14 @@ void CleanupBlockRevFiles()
     LogPrintf("Removing unusable blk?????.dat and rev?????.dat files for -reindex with -prune\n");
     fs::path blocksdir = gArgs.GetBlocksDirPath();
     for (fs::directory_iterator it(blocksdir); it != fs::directory_iterator(); it++) {
+        const std::string path = fs::PathToString(it->path().filename());
         if (fs::is_regular_file(*it) &&
-            it->path().filename().string().length() == 12 &&
-            it->path().filename().string().substr(8,4) == ".dat")
+            path.length() == 12 &&
+            path.substr(8,4) == ".dat")
         {
-            if (it->path().filename().string().substr(0, 3) == "blk") {
-                mapBlockFiles[it->path().filename().string().substr(3, 5)] = it->path();
-            } else if (it->path().filename().string().substr(0, 3) == "rev") {
+            if (path.substr(0, 3) == "blk") {
+                mapBlockFiles[path.substr(3, 5)] = it->path();
+            } else if (path.substr(0, 3) == "rev") {
                 remove(it->path());
             }
         }
@@ -527,14 +528,14 @@ void ThreadImport(ChainstateManager& chainman, std::vector<fs::path> vImportFile
         for (const fs::path& path : vImportFiles) {
             FILE* file = fsbridge::fopen(path, "rb");
             if (file) {
-                LogPrintf("Importing blocks file %s...\n", path.string());
+                LogPrintf("Importing blocks file %s...\n", fs::PathToString(path));
                 chainman.ActiveChainstate().LoadExternalBlockFile(file);
                 if (ShutdownRequested()) {
                     LogPrintf("Shutdown requested. Exit %s\n", __func__);
                     return;
                 }
             } else {
-                LogPrintf("Warning: Could not open blocks file %s\n", path.string());
+                LogPrintf("Warning: Could not open blocks file %s\n", fs::PathToString(path));
             }
         }
 
diff --git a/src/policy/fees.cpp b/src/policy/fees.cpp
index 2ae5798ebe..850b4f0439 100644
--- a/src/policy/fees.cpp
+++ b/src/policy/fees.cpp
@@ -527,7 +527,7 @@ CBlockPolicyEstimator::CBlockPolicyEstimator()
     fs::path est_filepath = gArgs.GetDataDirNet() / FEE_ESTIMATES_FILENAME;
     CAutoFile est_file(fsbridge::fopen(est_filepath, "rb"), SER_DISK, CLIENT_VERSION);
     if (est_file.IsNull() || !Read(est_file)) {
-        LogPrintf("Failed to read fee estimates from %s. Continue anyway.\n", est_filepath.string());
+        LogPrintf("Failed to read fee estimates from %s. Continue anyway.\n", fs::PathToString(est_filepath));
     }
 }
 
@@ -887,7 +887,7 @@ void CBlockPolicyEstimator::Flush() {
     fs::path est_filepath = gArgs.GetDataDirNet() / FEE_ESTIMATES_FILENAME;
     CAutoFile est_file(fsbridge::fopen(est_filepath, "wb"), SER_DISK, CLIENT_VERSION);
     if (est_file.IsNull() || !Write(est_file)) {
-        LogPrintf("Failed to write fee estimates to %s. Continue anyway.\n", est_filepath.string());
+        LogPrintf("Failed to write fee estimates to %s. Continue anyway.\n", fs::PathToString(est_filepath));
     }
 }
 
diff --git a/src/qt/guiutil.cpp b/src/qt/guiutil.cpp
index 12d3a48d01..4262866f32 100644
--- a/src/qt/guiutil.cpp
+++ b/src/qt/guiutil.cpp
@@ -653,12 +653,12 @@ void setClipboard(const QString& str)
 
 fs::path qstringToBoostPath(const QString &path)
 {
-    return fs::path(path.toStdString());
+    return fs::u8path(path.toStdString());
 }
 
 QString boostPathToQString(const fs::path &path)
 {
-    return QString::fromStdString(path.string());
+    return QString::fromStdString(path.u8string());
 }
 
 QString NetworkToQString(Network net)
diff --git a/src/qt/intro.cpp b/src/qt/intro.cpp
index 4c78fba752..2ca4b6a21e 100644
--- a/src/qt/intro.cpp
+++ b/src/qt/intro.cpp
@@ -263,7 +263,7 @@ bool Intro::showIfNeeded(bool& did_show_intro, int64_t& prune_MiB)
      * (to be consistent with bitcoind behavior)
      */
     if(dataDir != GUIUtil::getDefaultDataDirectory()) {
-        gArgs.SoftSetArg("-datadir", GUIUtil::qstringToBoostPath(dataDir).string()); // use OS locale for path setting
+        gArgs.SoftSetArg("-datadir", fs::PathToString(GUIUtil::qstringToBoostPath(dataDir))); // use OS locale for path setting
     }
     return true;
 }
diff --git a/src/rpc/blockchain.cpp b/src/rpc/blockchain.cpp
index ac746de32f..fc99c8eed9 100644
--- a/src/rpc/blockchain.cpp
+++ b/src/rpc/blockchain.cpp
@@ -2537,15 +2537,15 @@ static RPCHelpMan dumptxoutset()
         },
         [&](const RPCHelpMan& self, const JSONRPCRequest& request) -> UniValue
 {
-    const fs::path path = fsbridge::AbsPathJoin(gArgs.GetDataDirNet(), request.params[0].get_str());
+    const fs::path path = fsbridge::AbsPathJoin(gArgs.GetDataDirNet(), fs::u8path(request.params[0].get_str()));
     // Write to a temporary path and then move into `path` on completion
     // to avoid confusion due to an interruption.
-    const fs::path temppath = fsbridge::AbsPathJoin(gArgs.GetDataDirNet(), request.params[0].get_str() + ".incomplete");
+    const fs::path temppath = fsbridge::AbsPathJoin(gArgs.GetDataDirNet(), fs::u8path(request.params[0].get_str() + ".incomplete"));
 
     if (fs::exists(path)) {
         throw JSONRPCError(
             RPC_INVALID_PARAMETER,
-            path.string() + " already exists. If you are sure this is what you want, "
+            path.u8string() + " already exists. If you are sure this is what you want, "
             "move it out of the way first");
     }
 
@@ -2555,7 +2555,7 @@ static RPCHelpMan dumptxoutset()
     UniValue result = CreateUTXOSnapshot(node, node.chainman->ActiveChainstate(), afile);
     fs::rename(temppath, path);
 
-    result.pushKV("path", path.string());
+    result.pushKV("path", path.u8string());
     return result;
 },
     };
diff --git a/src/rpc/request.cpp b/src/rpc/request.cpp
index a7866474e1..3245e04cdf 100644
--- a/src/rpc/request.cpp
+++ b/src/rpc/request.cpp
@@ -70,7 +70,7 @@ static fs::path GetAuthCookieFile(bool temp=false)
     if (temp) {
         arg += ".tmp";
     }
-    return AbsPathForConfigVal(fs::path(arg));
+    return AbsPathForConfigVal(fs::PathFromString(arg));
 }
 
 bool GenerateAuthCookie(std::string *cookie_out)
@@ -87,7 +87,7 @@ bool GenerateAuthCookie(std::string *cookie_out)
     fs::path filepath_tmp = GetAuthCookieFile(true);
     file.open(filepath_tmp);
     if (!file.is_open()) {
-        LogPrintf("Unable to open cookie authentication file %s for writing\n", filepath_tmp.string());
+        LogPrintf("Unable to open cookie authentication file %s for writing\n", fs::PathToString(filepath_tmp));
         return false;
     }
     file << cookie;
@@ -95,10 +95,10 @@ bool GenerateAuthCookie(std::string *cookie_out)
 
     fs::path filepath = GetAuthCookieFile(false);
     if (!RenameOver(filepath_tmp, filepath)) {
-        LogPrintf("Unable to rename cookie authentication file %s to %s\n", filepath_tmp.string(), filepath.string());
+        LogPrintf("Unable to rename cookie authentication file %s to %s\n", fs::PathToString(filepath_tmp), fs::PathToString(filepath));
         return false;
     }
-    LogPrintf("Generated RPC authentication cookie %s\n", filepath.string());
+    LogPrintf("Generated RPC authentication cookie %s\n", fs::PathToString(filepath));
 
     if (cookie_out)
         *cookie_out = cookie;
diff --git a/src/rpc/server.cpp b/src/rpc/server.cpp
index 0d02ec5c47..9bcfba3507 100644
--- a/src/rpc/server.cpp
+++ b/src/rpc/server.cpp
@@ -239,7 +239,7 @@ static RPCHelpMan getrpcinfo()
     UniValue result(UniValue::VOBJ);
     result.pushKV("active_commands", active_commands);
 
-    const std::string path = LogInstance().m_file_path.string();
+    const std::string path = LogInstance().m_file_path.u8string();
     UniValue log_path(UniValue::VSTR, path);
     result.pushKV("logpath", log_path);
 
diff --git a/src/test/fs_tests.cpp b/src/test/fs_tests.cpp
index 526a3c27be..ecb838a7dd 100644
--- a/src/test/fs_tests.cpp
+++ b/src/test/fs_tests.cpp
@@ -11,6 +11,33 @@
 
 BOOST_FIXTURE_TEST_SUITE(fs_tests, BasicTestingSetup)
 
+BOOST_AUTO_TEST_CASE(fsbridge_pathtostring)
+{
+    std::string u8_str = "fs_tests_₿_🏃";
+    BOOST_CHECK_EQUAL(fs::PathToString(fs::PathFromString(u8_str)), u8_str);
+    BOOST_CHECK_EQUAL(fs::u8path(u8_str).u8string(), u8_str);
+    BOOST_CHECK_EQUAL(fs::PathFromString(u8_str).u8string(), u8_str);
+    BOOST_CHECK_EQUAL(fs::PathToString(fs::u8path(u8_str)), u8_str);
+#ifndef WIN32
+    // On non-windows systems, verify that arbitrary byte strings containing
+    // invalid UTF-8 can be round tripped successfully with PathToString and
+    // PathFromString. On non-windows systems, paths are just byte strings so
+    // these functions do not do any encoding. On windows, paths are Unicode,
+    // and these functions do encoding and decoding, so the behavior of this
+    // test would be undefined.
+    std::string invalid_u8_str = "\xf0";
+    BOOST_CHECK_EQUAL(invalid_u8_str.size(), 1);
+    BOOST_CHECK_EQUAL(fs::PathToString(fs::PathFromString(invalid_u8_str)), invalid_u8_str);
+#endif
+}
+
+BOOST_AUTO_TEST_CASE(fsbridge_stem)
+{
+    std::string test_filename = "fs_tests_₿_🏃.dat";
+    std::string expected_stem = "fs_tests_₿_🏃";
+    BOOST_CHECK_EQUAL(fs::PathToString(fs::PathFromString(test_filename).stem()), expected_stem);
+}
+
 BOOST_AUTO_TEST_CASE(fsbridge_fstream)
 {
     fs::path tmpfolder = m_args.GetDataDirBase();
diff --git a/src/test/fuzz/banman.cpp b/src/test/fuzz/banman.cpp
index 561cc83c72..fbba25c404 100644
--- a/src/test/fuzz/banman.cpp
+++ b/src/test/fuzz/banman.cpp
@@ -48,7 +48,7 @@ FUZZ_TARGET_INIT(banman, initialize_banman)
     const bool start_with_corrupted_banlist{fuzzed_data_provider.ConsumeBool()};
     bool force_read_and_write_to_err{false};
     if (start_with_corrupted_banlist) {
-        assert(WriteBinaryFile(banlist_file.string() + ".json",
+        assert(WriteBinaryFile(banlist_file + ".json",
                                fuzzed_data_provider.ConsumeRandomLengthString()));
     } else {
         force_read_and_write_to_err = fuzzed_data_provider.ConsumeBool();
@@ -111,5 +111,5 @@ FUZZ_TARGET_INIT(banman, initialize_banman)
             assert(banmap == banmap_read);
         }
     }
-    fs::remove(banlist_file.string() + ".json");
+    fs::remove(fs::PathToString(banlist_file + ".json"));
 }
diff --git a/src/test/settings_tests.cpp b/src/test/settings_tests.cpp
index 340ce33d91..15cba9e3e5 100644
--- a/src/test/settings_tests.cpp
+++ b/src/test/settings_tests.cpp
@@ -80,19 +80,19 @@ BOOST_AUTO_TEST_CASE(ReadWrite)
         "dupe": "dupe"
     })");
     BOOST_CHECK(!util::ReadSettings(path, values, errors));
-    std::vector<std::string> dup_keys = {strprintf("Found duplicate key dupe in settings file %s", path.string())};
+    std::vector<std::string> dup_keys = {strprintf("Found duplicate key dupe in settings file %s", fs::PathToString(path))};
     BOOST_CHECK_EQUAL_COLLECTIONS(errors.begin(), errors.end(), dup_keys.begin(), dup_keys.end());
 
     // Check non-kv json files not allowed
     WriteText(path, R"("non-kv")");
     BOOST_CHECK(!util::ReadSettings(path, values, errors));
-    std::vector<std::string> non_kv = {strprintf("Found non-object value \"non-kv\" in settings file %s", path.string())};
+    std::vector<std::string> non_kv = {strprintf("Found non-object value \"non-kv\" in settings file %s", fs::PathToString(path))};
     BOOST_CHECK_EQUAL_COLLECTIONS(errors.begin(), errors.end(), non_kv.begin(), non_kv.end());
 
     // Check invalid json not allowed
     WriteText(path, R"(invalid json)");
     BOOST_CHECK(!util::ReadSettings(path, values, errors));
-    std::vector<std::string> fail_parse = {strprintf("Unable to parse settings file %s", path.string())};
+    std::vector<std::string> fail_parse = {strprintf("Unable to parse settings file %s", fs::PathToString(path))};
     BOOST_CHECK_EQUAL_COLLECTIONS(errors.begin(), errors.end(), fail_parse.begin(), fail_parse.end());
 }
 
diff --git a/src/test/util/chainstate.h b/src/test/util/chainstate.h
index 81ea4c38f5..e95573022c 100644
--- a/src/test/util/chainstate.h
+++ b/src/test/util/chainstate.h
@@ -36,7 +36,7 @@ CreateAndActivateUTXOSnapshot(NodeContext& node, const fs::path root, F malleati
 
     UniValue result = CreateUTXOSnapshot(node, node.chainman->ActiveChainstate(), auto_outfile);
     BOOST_TEST_MESSAGE(
-        "Wrote UTXO snapshot to " << snapshot_path.make_preferred().string() << ": " << result.write());
+        "Wrote UTXO snapshot to " << fs::PathToString(snapshot_path.make_preferred()) << ": " << result.write());
 
     // Read the written snapshot in and then activate it.
     //
diff --git a/src/test/util/setup_common.cpp b/src/test/util/setup_common.cpp
index ebefa9974e..a3c7564d76 100644
--- a/src/test/util/setup_common.cpp
+++ b/src/test/util/setup_common.cpp
@@ -91,8 +91,8 @@ BasicTestingSetup::BasicTestingSetup(const std::string& chainName, const std::ve
         extra_args);
     util::ThreadRename("test");
     fs::create_directories(m_path_root);
-    m_args.ForceSetArg("-datadir", m_path_root.string());
-    gArgs.ForceSetArg("-datadir", m_path_root.string());
+    m_args.ForceSetArg("-datadir", fs::PathToString(m_path_root));
+    gArgs.ForceSetArg("-datadir", fs::PathToString(m_path_root));
     gArgs.ClearPathCache();
     {
         SetupServerArgs(*m_node.args);
diff --git a/src/test/util_tests.cpp b/src/test/util_tests.cpp
index b5088d3c33..b1300d06ba 100644
--- a/src/test/util_tests.cpp
+++ b/src/test/util_tests.cpp
@@ -51,23 +51,23 @@ BOOST_AUTO_TEST_CASE(util_datadir)
 {
     // Use local args variable instead of m_args to avoid making assumptions about test setup
     ArgsManager args;
-    args.ForceSetArg("-datadir", m_path_root.string());
+    args.ForceSetArg("-datadir", fs::PathToString(m_path_root));
 
     const fs::path dd_norm = args.GetDataDirBase();
 
-    args.ForceSetArg("-datadir", dd_norm.string() + "/");
+    args.ForceSetArg("-datadir", fs::PathToString(dd_norm) + "/");
     args.ClearPathCache();
     BOOST_CHECK_EQUAL(dd_norm, args.GetDataDirBase());
 
-    args.ForceSetArg("-datadir", dd_norm.string() + "/.");
+    args.ForceSetArg("-datadir", fs::PathToString(dd_norm) + "/.");
     args.ClearPathCache();
     BOOST_CHECK_EQUAL(dd_norm, args.GetDataDirBase());
 
-    args.ForceSetArg("-datadir", dd_norm.string() + "/./");
+    args.ForceSetArg("-datadir", fs::PathToString(dd_norm) + "/./");
     args.ClearPathCache();
     BOOST_CHECK_EQUAL(dd_norm, args.GetDataDirBase());
 
-    args.ForceSetArg("-datadir", dd_norm.string() + "/.//");
+    args.ForceSetArg("-datadir", fs::PathToString(dd_norm) + "/.//");
     args.ClearPathCache();
     BOOST_CHECK_EQUAL(dd_norm, args.GetDataDirBase());
 }
@@ -1181,13 +1181,13 @@ BOOST_AUTO_TEST_CASE(util_ReadWriteSettings)
 {
     // Test writing setting.
     TestArgsManager args1;
-    args1.ForceSetArg("-datadir", m_path_root.string());
+    args1.ForceSetArg("-datadir", fs::PathToString(m_path_root));
     args1.LockSettings([&](util::Settings& settings) { settings.rw_settings["name"] = "value"; });
     args1.WriteSettingsFile();
 
     // Test reading setting.
     TestArgsManager args2;
-    args2.ForceSetArg("-datadir", m_path_root.string());
+    args2.ForceSetArg("-datadir", fs::PathToString(m_path_root));
     args2.ReadSettingsFile();
     args2.LockSettings([&](util::Settings& settings) { BOOST_CHECK_EQUAL(settings.rw_settings["name"].get_str(), "value"); });
 
diff --git a/src/torcontrol.cpp b/src/torcontrol.cpp
index f9caf48df8..55618a5c57 100644
--- a/src/torcontrol.cpp
+++ b/src/torcontrol.cpp
@@ -318,7 +318,7 @@ TorController::TorController(struct event_base* _base, const std::string& tor_co
     // Read service private key if cached
     std::pair<bool,std::string> pkf = ReadBinaryFile(GetPrivateKeyFile());
     if (pkf.first) {
-        LogPrint(BCLog::TOR, "tor: Reading cached private key from %s\n", GetPrivateKeyFile().string());
+        LogPrint(BCLog::TOR, "tor: Reading cached private key from %s\n", fs::PathToString(GetPrivateKeyFile()));
         private_key = pkf.second;
     }
 }
@@ -356,9 +356,9 @@ void TorController::add_onion_cb(TorControlConnection& _conn, const TorControlRe
         service = LookupNumeric(std::string(service_id+".onion"), Params().GetDefaultPort());
         LogPrintf("tor: Got service ID %s, advertising service %s\n", service_id, service.ToString());
         if (WriteBinaryFile(GetPrivateKeyFile(), private_key)) {
-            LogPrint(BCLog::TOR, "tor: Cached service private key to %s\n", GetPrivateKeyFile().string());
+            LogPrint(BCLog::TOR, "tor: Cached service private key to %s\n", fs::PathToString(GetPrivateKeyFile()));
         } else {
-            LogPrintf("tor: Error writing service private key to %s\n", GetPrivateKeyFile().string());
+            LogPrintf("tor: Error writing service private key to %s\n", fs::PathToString(GetPrivateKeyFile()));
         }
         AddLocal(service, LOCAL_MANUAL);
         // ... onion requested - keep connection open
@@ -508,7 +508,7 @@ void TorController::protocolinfo_cb(TorControlConnection& _conn, const TorContro
         } else if (methods.count("SAFECOOKIE")) {
             // Cookie: hexdump -e '32/1 "%02x""\n"'  ~/.tor/control_auth_cookie
             LogPrint(BCLog::TOR, "tor: Using SAFECOOKIE authentication, reading cookie authentication from %s\n", cookiefile);
-            std::pair<bool,std::string> status_cookie = ReadBinaryFile(cookiefile, TOR_COOKIE_SIZE);
+            std::pair<bool,std::string> status_cookie = ReadBinaryFile(fs::PathFromString(cookiefile), TOR_COOKIE_SIZE);
             if (status_cookie.first && status_cookie.second.size() == TOR_COOKIE_SIZE) {
                 // _conn.Command("AUTHENTICATE " + HexStr(status_cookie.second), std::bind(&TorController::auth_cb, this, std::placeholders::_1, std::placeholders::_2));
                 cookie = std::vector<uint8_t>(status_cookie.second.begin(), status_cookie.second.end());
diff --git a/src/util/asmap.cpp b/src/util/asmap.cpp
index 5695c62012..b696c65e9d 100644
--- a/src/util/asmap.cpp
+++ b/src/util/asmap.cpp
@@ -201,7 +201,7 @@ std::vector<bool> DecodeAsmap(fs::path path)
     }
     fseek(filestr, 0, SEEK_END);
     int length = ftell(filestr);
-    LogPrintf("Opened asmap file %s (%d bytes) from disk\n", path, length);
+    LogPrintf("Opened asmap file %s (%d bytes) from disk\n", fs::quoted(fs::PathToString(path)), length);
     fseek(filestr, 0, SEEK_SET);
     uint8_t cur_byte;
     for (int i = 0; i < length; ++i) {
@@ -211,7 +211,7 @@ std::vector<bool> DecodeAsmap(fs::path path)
         }
     }
     if (!SanityCheckASMap(bits, 128)) {
-        LogPrintf("Sanity check of asmap file %s failed\n", path);
+        LogPrintf("Sanity check of asmap file %s failed\n", fs::quoted(fs::PathToString(path)));
         return {};
     }
     return bits;
diff --git a/src/util/settings.cpp b/src/util/settings.cpp
index 846b34089d..7fb35c073e 100644
--- a/src/util/settings.cpp
+++ b/src/util/settings.cpp
@@ -66,24 +66,24 @@ bool ReadSettings(const fs::path& path, std::map<std::string, SettingsValue>& va
     fsbridge::ifstream file;
     file.open(path);
     if (!file.is_open()) {
-      errors.emplace_back(strprintf("%s. Please check permissions.", path.string()));
+      errors.emplace_back(strprintf("%s. Please check permissions.", fs::PathToString(path)));
       return false;
     }
 
     SettingsValue in;
     if (!in.read(std::string{std::istreambuf_iterator<char>(file), std::istreambuf_iterator<char>()})) {
-        errors.emplace_back(strprintf("Unable to parse settings file %s", path.string()));
+        errors.emplace_back(strprintf("Unable to parse settings file %s", fs::PathToString(path)));
         return false;
     }
 
     if (file.fail()) {
-        errors.emplace_back(strprintf("Failed reading settings file %s", path.string()));
+        errors.emplace_back(strprintf("Failed reading settings file %s", fs::PathToString(path)));
         return false;
     }
     file.close(); // Done with file descriptor. Release while copying data.
 
     if (!in.isObject()) {
-        errors.emplace_back(strprintf("Found non-object value %s in settings file %s", in.write(), path.string()));
+        errors.emplace_back(strprintf("Found non-object value %s in settings file %s", in.write(), fs::PathToString(path)));
         return false;
     }
 
@@ -92,7 +92,7 @@ bool ReadSettings(const fs::path& path, std::map<std::string, SettingsValue>& va
     for (size_t i = 0; i < in_keys.size(); ++i) {
         auto inserted = values.emplace(in_keys[i], in_values[i]);
         if (!inserted.second) {
-            errors.emplace_back(strprintf("Found duplicate key %s in settings file %s", in_keys[i], path.string()));
+            errors.emplace_back(strprintf("Found duplicate key %s in settings file %s", in_keys[i], fs::PathToString(path)));
         }
     }
     return errors.empty();
@@ -109,7 +109,7 @@ bool WriteSettings(const fs::path& path,
     fsbridge::ofstream file;
     file.open(path);
     if (file.fail()) {
-        errors.emplace_back(strprintf("Error: Unable to open settings file %s for writing", path.string()));
+        errors.emplace_back(strprintf("Error: Unable to open settings file %s for writing", fs::PathToString(path)));
         return false;
     }
     file << out.write(/* prettyIndent= */ 1, /* indentLevel= */ 4) << std::endl;
diff --git a/src/util/system.cpp b/src/util/system.cpp
index 79c08816fa..12d7dc49b2 100644
--- a/src/util/system.cpp
+++ b/src/util/system.cpp
@@ -98,7 +98,7 @@ bool LockDirectory(const fs::path& directory, const std::string lockfile_name, b
     fs::path pathLockFile = directory / lockfile_name;
 
     // If a lock for this directory already exists in the map, don't try to re-lock it
-    if (dir_locks.count(pathLockFile.string())) {
+    if (dir_locks.count(fs::PathToString(pathLockFile))) {
         return true;
     }
 
@@ -107,11 +107,11 @@ bool LockDirectory(const fs::path& directory, const std::string lockfile_name, b
     if (file) fclose(file);
     auto lock = std::make_unique<fsbridge::FileLock>(pathLockFile);
     if (!lock->TryLock()) {
-        return error("Error while attempting to lock directory %s: %s", directory.string(), lock->GetReason());
+        return error("Error while attempting to lock directory %s: %s", fs::PathToString(directory), lock->GetReason());
     }
     if (!probe_only) {
         // Lock successful and we're not just probing, put it into the map
-        dir_locks.emplace(pathLockFile.string(), std::move(lock));
+        dir_locks.emplace(fs::PathToString(pathLockFile), std::move(lock));
     }
     return true;
 }
@@ -119,7 +119,7 @@ bool LockDirectory(const fs::path& directory, const std::string lockfile_name, b
 void UnlockDirectory(const fs::path& directory, const std::string& lockfile_name)
 {
     LOCK(cs_dir_locks);
-    dir_locks.erase((directory / lockfile_name).string());
+    dir_locks.erase(fs::PathToString(directory / lockfile_name));
 }
 
 void ReleaseDirectoryLocks()
@@ -242,7 +242,7 @@ namespace {
 fs::path StripRedundantLastElementsOfPath(const fs::path& path)
 {
     auto result = path;
-    while (result.filename().string() == ".") {
+    while (fs::PathToString(result.filename()) == ".") {
         result = result.parent_path();
     }
 
@@ -402,7 +402,7 @@ const fs::path& ArgsManager::GetBlocksDirPath() const
     if (!path.empty()) return path;
 
     if (IsArgSet("-blocksdir")) {
-        path = fs::system_complete(GetArg("-blocksdir", ""));
+        path = fs::system_complete(fs::PathFromString(GetArg("-blocksdir", "")));
         if (!fs::is_directory(path)) {
             path = "";
             return path;
@@ -411,7 +411,7 @@ const fs::path& ArgsManager::GetBlocksDirPath() const
         path = GetDataDirBase();
     }
 
-    path /= BaseParams().DataDir();
+    path /= fs::PathFromString(BaseParams().DataDir());
     path /= "blocks";
     fs::create_directories(path);
     path = StripRedundantLastElementsOfPath(path);
@@ -429,7 +429,7 @@ const fs::path& ArgsManager::GetDataDir(bool net_specific) const
 
     std::string datadir = GetArg("-datadir", "");
     if (!datadir.empty()) {
-        path = fs::system_complete(datadir);
+        path = fs::system_complete(fs::PathFromString(datadir));
         if (!fs::is_directory(path)) {
             path = "";
             return path;
@@ -438,7 +438,7 @@ const fs::path& ArgsManager::GetDataDir(bool net_specific) const
         path = GetDefaultDataDir();
     }
     if (net_specific)
-        path /= BaseParams().DataDir();
+        path /= fs::PathFromString(BaseParams().DataDir());
 
     if (fs::create_directories(path)) {
         // This is the first run, create wallets subdirectory too
@@ -517,7 +517,7 @@ bool ArgsManager::GetSettingsPath(fs::path* filepath, bool temp) const
     }
     if (filepath) {
         std::string settings = GetArg("-settings", BITCOIN_SETTINGS_FILENAME);
-        *filepath = fsbridge::AbsPathJoin(GetDataDirNet(), temp ? settings + ".tmp" : settings);
+        *filepath = fsbridge::AbsPathJoin(GetDataDirNet(), fs::PathFromString(temp ? settings + ".tmp" : settings));
     }
     return true;
 }
@@ -572,7 +572,7 @@ bool ArgsManager::WriteSettingsFile(std::vector<std::string>* errors) const
         return false;
     }
     if (!RenameOver(path_tmp, path)) {
-        SaveErrors({strprintf("Failed renaming settings file %s to %s\n", path_tmp.string(), path.string())}, errors);
+        SaveErrors({strprintf("Failed renaming settings file %s to %s\n", fs::PathToString(path_tmp), fs::PathToString(path))}, errors);
         return false;
     }
     return true;
@@ -809,12 +809,12 @@ fs::path GetDefaultDataDir()
 bool CheckDataDirOption()
 {
     std::string datadir = gArgs.GetArg("-datadir", "");
-    return datadir.empty() || fs::is_directory(fs::system_complete(datadir));
+    return datadir.empty() || fs::is_directory(fs::system_complete(fs::PathFromString(datadir)));
 }
 
 fs::path GetConfigFile(const std::string& confPath)
 {
-    return AbsPathForConfigVal(fs::path(confPath), false);
+    return AbsPathForConfigVal(fs::PathFromString(confPath), false);
 }
 
 static bool GetConfigOptions(std::istream& stream, const std::string& filepath, std::string& error, std::vector<std::pair<std::string, std::string>>& options, std::list<SectionInfo>& sections)
@@ -1065,7 +1065,7 @@ bool RenameOver(fs::path src, fs::path dest)
     return MoveFileExW(src.wstring().c_str(), dest.wstring().c_str(),
                        MOVEFILE_REPLACE_EXISTING) != 0;
 #else
-    int rc = std::rename(src.string().c_str(), dest.string().c_str());
+    int rc = std::rename(src.c_str(), dest.c_str());
     return (rc == 0);
 #endif /* WIN32 */
 }
diff --git a/src/wallet/bdb.cpp b/src/wallet/bdb.cpp
index 2eb4d3106c..2290e119fd 100644
--- a/src/wallet/bdb.cpp
+++ b/src/wallet/bdb.cpp
@@ -61,9 +61,9 @@ bool WalletDatabaseFileId::operator==(const WalletDatabaseFileId& rhs) const
 std::shared_ptr<BerkeleyEnvironment> GetBerkeleyEnv(const fs::path& env_directory)
 {
     LOCK(cs_db);
-    auto inserted = g_dbenvs.emplace(env_directory.string(), std::weak_ptr<BerkeleyEnvironment>());
+    auto inserted = g_dbenvs.emplace(fs::PathToString(env_directory), std::weak_ptr<BerkeleyEnvironment>());
     if (inserted.second) {
-        auto env = std::make_shared<BerkeleyEnvironment>(env_directory.string());
+        auto env = std::make_shared<BerkeleyEnvironment>(env_directory);
         inserted.first->second = env;
         return env;
     }
@@ -101,7 +101,7 @@ void BerkeleyEnvironment::Close()
 
     if (error_file) fclose(error_file);
 
-    UnlockDirectory(strPath, ".walletlock");
+    UnlockDirectory(fs::PathFromString(strPath), ".walletlock");
 }
 
 void BerkeleyEnvironment::Reset()
@@ -111,7 +111,7 @@ void BerkeleyEnvironment::Reset()
     fMockDb = false;
 }
 
-BerkeleyEnvironment::BerkeleyEnvironment(const fs::path& dir_path) : strPath(dir_path.string())
+BerkeleyEnvironment::BerkeleyEnvironment(const fs::path& dir_path) : strPath(fs::PathToString(dir_path))
 {
     Reset();
 }
@@ -129,24 +129,24 @@ bool BerkeleyEnvironment::Open(bilingual_str& err)
         return true;
     }
 
-    fs::path pathIn = strPath;
+    fs::path pathIn = fs::PathFromString(strPath);
     TryCreateDirectories(pathIn);
     if (!LockDirectory(pathIn, ".walletlock")) {
         LogPrintf("Cannot obtain a lock on wallet directory %s. Another instance of bitcoin may be using it.\n", strPath);
-        err = strprintf(_("Error initializing wallet database environment %s!"), Directory());
+        err = strprintf(_("Error initializing wallet database environment %s!"), fs::quoted(fs::PathToString(Directory())));
         return false;
     }
 
     fs::path pathLogDir = pathIn / "database";
     TryCreateDirectories(pathLogDir);
     fs::path pathErrorFile = pathIn / "db.log";
-    LogPrintf("BerkeleyEnvironment::Open: LogDir=%s ErrorFile=%s\n", pathLogDir.string(), pathErrorFile.string());
+    LogPrintf("BerkeleyEnvironment::Open: LogDir=%s ErrorFile=%s\n", fs::PathToString(pathLogDir), fs::PathToString(pathErrorFile));
 
     unsigned int nEnvFlags = 0;
     if (gArgs.GetBoolArg("-privdb", DEFAULT_WALLET_PRIVDB))
         nEnvFlags |= DB_PRIVATE;
 
-    dbenv->set_lg_dir(pathLogDir.string().c_str());
+    dbenv->set_lg_dir(fs::PathToString(pathLogDir).c_str());
     dbenv->set_cachesize(0, 0x100000, 1); // 1 MiB should be enough for just the wallet
     dbenv->set_lg_bsize(0x10000);
     dbenv->set_lg_max(1048576);
@@ -173,7 +173,7 @@ bool BerkeleyEnvironment::Open(bilingual_str& err)
             LogPrintf("BerkeleyEnvironment::Open: Error %d closing failed database environment: %s\n", ret2, DbEnv::strerror(ret2));
         }
         Reset();
-        err = strprintf(_("Error initializing wallet database environment %s!"), Directory());
+        err = strprintf(_("Error initializing wallet database environment %s!"), fs::quoted(fs::PathToString(Directory())));
         if (ret == DB_RUNRECOVERY) {
             err += Untranslated(" ") + _("This error could occur if this wallet was not shutdown cleanly and was last loaded using a build with a newer version of Berkeley DB. If so, please use the software that last loaded this wallet");
         }
@@ -261,7 +261,7 @@ bool BerkeleyDatabase::Verify(bilingual_str& errorStr)
     fs::path file_path = walletDir / strFile;
 
     LogPrintf("Using BerkeleyDB version %s\n", BerkeleyDatabaseVersion());
-    LogPrintf("Using wallet %s\n", file_path.string());
+    LogPrintf("Using wallet %s\n", fs::PathToString(file_path));
 
     if (!env->Open(errorStr)) {
         return false;
@@ -274,7 +274,7 @@ bool BerkeleyDatabase::Verify(bilingual_str& errorStr)
         Db db(env->dbenv.get(), 0);
         int result = db.verify(strFile.c_str(), nullptr, nullptr, 0);
         if (result != 0) {
-            errorStr = strprintf(_("%s corrupt. Try using the wallet tool bitcoin-wallet to salvage or restoring a backup."), file_path);
+            errorStr = strprintf(_("%s corrupt. Try using the wallet tool bitcoin-wallet to salvage or restoring a backup."), fs::quoted(fs::PathToString(file_path)));
             return false;
         }
     }
@@ -566,7 +566,7 @@ void BerkeleyEnvironment::Flush(bool fShutdown)
                 dbenv->log_archive(&listp, DB_ARCH_REMOVE);
                 Close();
                 if (!fMockDb) {
-                    fs::remove_all(fs::path(strPath) / "database");
+                    fs::remove_all(fs::PathFromString(strPath) / "database");
                 }
             }
         }
@@ -614,21 +614,21 @@ bool BerkeleyDatabase::Backup(const std::string& strDest) const
 
                 // Copy wallet file
                 fs::path pathSrc = env->Directory() / strFile;
-                fs::path pathDest(strDest);
+                fs::path pathDest(fs::PathFromString(strDest));
                 if (fs::is_directory(pathDest))
-                    pathDest /= strFile;
+                    pathDest /= fs::PathFromString(strFile);
 
                 try {
                     if (fs::equivalent(pathSrc, pathDest)) {
-                        LogPrintf("cannot backup to wallet source file %s\n", pathDest.string());
+                        LogPrintf("cannot backup to wallet source file %s\n", fs::PathToString(pathDest));
                         return false;
                     }
 
                     fs::copy_file(pathSrc, pathDest, fs::copy_option::overwrite_if_exists);
-                    LogPrintf("copied %s to %s\n", strFile, pathDest.string());
+                    LogPrintf("copied %s to %s\n", strFile, fs::PathToString(pathDest));
                     return true;
                 } catch (const fs::filesystem_error& e) {
-                    LogPrintf("error copying %s to %s - %s\n", strFile, pathDest.string(), fsbridge::get_filesystem_error_message(e));
+                    LogPrintf("error copying %s to %s - %s\n", strFile, fs::PathToString(pathDest), fsbridge::get_filesystem_error_message(e));
                     return false;
                 }
             }
@@ -828,10 +828,10 @@ std::unique_ptr<BerkeleyDatabase> MakeBerkeleyDatabase(const fs::path& path, con
     std::unique_ptr<BerkeleyDatabase> db;
     {
         LOCK(cs_db); // Lock env.m_databases until insert in BerkeleyDatabase constructor
-        std::string data_filename = data_file.filename().string();
+        std::string data_filename = fs::PathToString(data_file.filename());
         std::shared_ptr<BerkeleyEnvironment> env = GetBerkeleyEnv(data_file.parent_path());
         if (env->m_databases.count(data_filename)) {
-            error = Untranslated(strprintf("Refusing to load database. Data file '%s' is already loaded.", (env->Directory() / data_filename).string()));
+            error = Untranslated(strprintf("Refusing to load database. Data file '%s' is already loaded.", fs::PathToString(env->Directory() / data_filename)));
             status = DatabaseStatus::FAILED_ALREADY_LOADED;
             return nullptr;
         }
diff --git a/src/wallet/bdb.h b/src/wallet/bdb.h
index a8209587d7..b666a8e73a 100644
--- a/src/wallet/bdb.h
+++ b/src/wallet/bdb.h
@@ -63,7 +63,7 @@ public:
 
     bool IsMock() const { return fMockDb; }
     bool IsInitialized() const { return fDbEnvInit; }
-    fs::path Directory() const { return strPath; }
+    fs::path Directory() const { return fs::PathFromString(strPath); }
 
     bool Open(bilingual_str& error);
     void Close();
@@ -141,7 +141,7 @@ public:
     bool Verify(bilingual_str& error);
 
     /** Return path to main database filename */
-    std::string Filename() override { return (env->Directory() / strFile).string(); }
+    std::string Filename() override { return fs::PathToString(env->Directory() / strFile); }
 
     std::string Format() override { return "bdb"; }
     /**
diff --git a/src/wallet/db.cpp b/src/wallet/db.cpp
index 8d5316e0af..c74c69ed09 100644
--- a/src/wallet/db.cpp
+++ b/src/wallet/db.cpp
@@ -12,7 +12,7 @@
 
 std::vector<fs::path> ListDatabases(const fs::path& wallet_dir)
 {
-    const size_t offset = wallet_dir.string().size() + (wallet_dir == wallet_dir.root_name() ? 0 : 1);
+    const size_t offset = wallet_dir.native().size() + (wallet_dir == wallet_dir.root_name() ? 0 : 1);
     std::vector<fs::path> paths;
     boost::system::error_code ec;
 
@@ -20,9 +20,9 @@ std::vector<fs::path> ListDatabases(const fs::path& wallet_dir)
         if (ec) {
             if (fs::is_directory(*it)) {
                 it.no_push();
-                LogPrintf("%s: %s %s -- skipping.\n", __func__, ec.message(), it->path().string());
+                LogPrintf("%s: %s %s -- skipping.\n", __func__, ec.message(), fs::PathToString(it->path()));
             } else {
-                LogPrintf("%s: %s %s\n", __func__, ec.message(), it->path().string());
+                LogPrintf("%s: %s %s\n", __func__, ec.message(), fs::PathToString(it->path()));
             }
             continue;
         }
@@ -30,7 +30,8 @@ std::vector<fs::path> ListDatabases(const fs::path& wallet_dir)
         try {
             // Get wallet path relative to walletdir by removing walletdir from the wallet path.
             // This can be replaced by boost::filesystem::lexically_relative once boost is bumped to 1.60.
-            const fs::path path = it->path().string().substr(offset);
+            const auto path_str = it->path().native().substr(offset);
+            const fs::path path{path_str.begin(), path_str.end()};
 
             if (it->status().type() == fs::directory_file &&
                 (IsBDBFile(BDBDataFile(it->path())) || IsSQLiteFile(SQLiteDataFile(it->path())))) {
@@ -50,7 +51,7 @@ std::vector<fs::path> ListDatabases(const fs::path& wallet_dir)
                 }
             }
         } catch (const std::exception& e) {
-            LogPrintf("%s: Error scanning %s: %s\n", __func__, it->path().string(), e.what());
+            LogPrintf("%s: Error scanning %s: %s\n", __func__, fs::PathToString(it->path()), e.what());
             it.no_push();
         }
     }
@@ -85,7 +86,7 @@ bool IsBDBFile(const fs::path& path)
     // This check also prevents opening lock files.
     boost::system::error_code ec;
     auto size = fs::file_size(path, ec);
-    if (ec) LogPrintf("%s: %s %s\n", __func__, ec.message(), path.string());
+    if (ec) LogPrintf("%s: %s %s\n", __func__, ec.message(), fs::PathToString(path));
     if (size < 4096) return false;
 
     fsbridge::ifstream file(path, std::ios::binary);
@@ -109,7 +110,7 @@ bool IsSQLiteFile(const fs::path& path)
     // A SQLite Database file is at least 512 bytes.
     boost::system::error_code ec;
     auto size = fs::file_size(path, ec);
-    if (ec) LogPrintf("%s: %s %s\n", __func__, ec.message(), path.string());
+    if (ec) LogPrintf("%s: %s %s\n", __func__, ec.message(), fs::PathToString(path));
     if (size < 512) return false;
 
     fsbridge::ifstream file(path, std::ios::binary);
diff --git a/src/wallet/dump.cpp b/src/wallet/dump.cpp
index c39c0c7e73..08d94b76d9 100644
--- a/src/wallet/dump.cpp
+++ b/src/wallet/dump.cpp
@@ -19,16 +19,16 @@ bool DumpWallet(CWallet& wallet, bilingual_str& error)
         return false;
     }
 
-    fs::path path = dump_filename;
+    fs::path path = fs::PathFromString(dump_filename);
     path = fs::absolute(path);
     if (fs::exists(path)) {
-        error = strprintf(_("File %s already exists. If you are sure this is what you want, move it out of the way first."), path.string());
+        error = strprintf(_("File %s already exists. If you are sure this is what you want, move it out of the way first."), fs::PathToString(path));
         return false;
     }
     fsbridge::ofstream dump_file;
     dump_file.open(path);
     if (dump_file.fail()) {
-        error = strprintf(_("Unable to open %s for writing"), path.string());
+        error = strprintf(_("Unable to open %s for writing"), fs::PathToString(path));
         return false;
     }
 
@@ -114,10 +114,10 @@ bool CreateFromDump(const std::string& name, const fs::path& wallet_path, biling
         return false;
     }
 
-    fs::path dump_path = dump_filename;
+    fs::path dump_path = fs::PathFromString(dump_filename);
     dump_path = fs::absolute(dump_path);
     if (!fs::exists(dump_path)) {
-        error = strprintf(_("Dump file %s does not exist."), dump_path.string());
+        error = strprintf(_("Dump file %s does not exist."), fs::PathToString(dump_path));
         return false;
     }
     fsbridge::ifstream dump_file(dump_path);
diff --git a/src/wallet/interfaces.cpp b/src/wallet/interfaces.cpp
index 7d0cdb6934..57f1a6a67a 100644
--- a/src/wallet/interfaces.cpp
+++ b/src/wallet/interfaces.cpp
@@ -551,13 +551,13 @@ public:
     }
     std::string getWalletDir() override
     {
-        return GetWalletDir().string();
+        return fs::PathToString(GetWalletDir());
     }
     std::vector<std::string> listWalletDir() override
     {
         std::vector<std::string> paths;
         for (auto& path : ListDatabases(GetWalletDir())) {
-            paths.push_back(path.string());
+            paths.push_back(fs::PathToString(path));
         }
         return paths;
     }
diff --git a/src/wallet/load.cpp b/src/wallet/load.cpp
index 1b841026b8..7ef5a0cf55 100644
--- a/src/wallet/load.cpp
+++ b/src/wallet/load.cpp
@@ -25,25 +25,25 @@ bool VerifyWallets(WalletContext& context)
     ArgsManager& args = *Assert(context.args);
 
     if (args.IsArgSet("-walletdir")) {
-        fs::path wallet_dir = args.GetArg("-walletdir", "");
+        fs::path wallet_dir = fs::PathFromString(args.GetArg("-walletdir", ""));
         boost::system::error_code error;
         // The canonical path cleans the path, preventing >1 Berkeley environment instances for the same directory
         fs::path canonical_wallet_dir = fs::canonical(wallet_dir, error);
         if (error || !fs::exists(wallet_dir)) {
-            chain.initError(strprintf(_("Specified -walletdir \"%s\" does not exist"), wallet_dir.string()));
+            chain.initError(strprintf(_("Specified -walletdir \"%s\" does not exist"), fs::PathToString(wallet_dir)));
             return false;
         } else if (!fs::is_directory(wallet_dir)) {
-            chain.initError(strprintf(_("Specified -walletdir \"%s\" is not a directory"), wallet_dir.string()));
+            chain.initError(strprintf(_("Specified -walletdir \"%s\" is not a directory"), fs::PathToString(wallet_dir)));
             return false;
         // The canonical path transforms relative paths into absolute ones, so we check the non-canonical version
         } else if (!wallet_dir.is_absolute()) {
-            chain.initError(strprintf(_("Specified -walletdir \"%s\" is a relative path"), wallet_dir.string()));
+            chain.initError(strprintf(_("Specified -walletdir \"%s\" is a relative path"), fs::PathToString(wallet_dir)));
             return false;
         }
-        args.ForceSetArg("-walletdir", canonical_wallet_dir.string());
+        args.ForceSetArg("-walletdir", fs::PathToString(canonical_wallet_dir));
     }
 
-    LogPrintf("Using wallet directory %s\n", GetWalletDir().string());
+    LogPrintf("Using wallet directory %s\n", fs::PathToString(GetWalletDir()));
 
     chain.initMessage(_("Verifying wallet(s)…").translated);
 
@@ -70,7 +70,7 @@ bool VerifyWallets(WalletContext& context)
 
     for (const auto& wallet : chain.getSettingsList("wallet")) {
         const auto& wallet_file = wallet.get_str();
-        const fs::path path = fsbridge::AbsPathJoin(GetWalletDir(), wallet_file);
+        const fs::path path = fsbridge::AbsPathJoin(GetWalletDir(), fs::PathFromString(wallet_file));
 
         if (!wallet_paths.insert(path).second) {
             chain.initWarning(strprintf(_("Ignoring duplicate -wallet %s."), wallet_file));
@@ -102,7 +102,7 @@ bool LoadWallets(WalletContext& context)
         std::set<fs::path> wallet_paths;
         for (const auto& wallet : chain.getSettingsList("wallet")) {
             const auto& name = wallet.get_str();
-            if (!wallet_paths.insert(name).second) {
+            if (!wallet_paths.insert(fs::PathFromString(name)).second) {
                 continue;
             }
             DatabaseOptions options;
diff --git a/src/wallet/rpcdump.cpp b/src/wallet/rpcdump.cpp
index 4d7fb2d38c..9b09bc23d6 100644
--- a/src/wallet/rpcdump.cpp
+++ b/src/wallet/rpcdump.cpp
@@ -550,7 +550,7 @@ RPCHelpMan importwallet()
         EnsureWalletIsUnlocked(*pwallet);
 
         fsbridge::ifstream file;
-        file.open(request.params[0].get_str(), std::ios::in | std::ios::ate);
+        file.open(fs::u8path(request.params[0].get_str()), std::ios::in | std::ios::ate);
         if (!file.is_open()) {
             throw JSONRPCError(RPC_INVALID_PARAMETER, "Cannot open wallet dump file");
         }
@@ -745,7 +745,7 @@ RPCHelpMan dumpwallet()
 
     EnsureWalletIsUnlocked(wallet);
 
-    fs::path filepath = request.params[0].get_str();
+    fs::path filepath = fs::u8path(request.params[0].get_str());
     filepath = fs::absolute(filepath);
 
     /* Prevent arbitrary files from being overwritten. There have been reports
@@ -754,7 +754,7 @@ RPCHelpMan dumpwallet()
      * It may also avoid other security issues.
      */
     if (fs::exists(filepath)) {
-        throw JSONRPCError(RPC_INVALID_PARAMETER, filepath.string() + " already exists. If you are sure this is what you want, move it out of the way first");
+        throw JSONRPCError(RPC_INVALID_PARAMETER, filepath.u8string() + " already exists. If you are sure this is what you want, move it out of the way first");
     }
 
     fsbridge::ofstream file;
@@ -844,7 +844,7 @@ RPCHelpMan dumpwallet()
     file.close();
 
     UniValue reply(UniValue::VOBJ);
-    reply.pushKV("filename", filepath.string());
+    reply.pushKV("filename", filepath.u8string());
 
     return reply;
 },
diff --git a/src/wallet/rpcwallet.cpp b/src/wallet/rpcwallet.cpp
index 9d86ec4810..6959466d1d 100644
--- a/src/wallet/rpcwallet.cpp
+++ b/src/wallet/rpcwallet.cpp
@@ -2582,7 +2582,7 @@ static RPCHelpMan listwalletdir()
     UniValue wallets(UniValue::VARR);
     for (const auto& path : ListDatabases(GetWalletDir())) {
         UniValue wallet(UniValue::VOBJ);
-        wallet.pushKV("name", path.string());
+        wallet.pushKV("name", path.u8string());
         wallets.push_back(wallet);
     }
 
@@ -2883,7 +2883,7 @@ static RPCHelpMan restorewallet()
 
     WalletContext& context = EnsureWalletContext(request.context);
 
-    std::string backup_file = request.params[1].get_str();
+    auto backup_file = fs::u8path(request.params[1].get_str());
 
     if (!fs::exists(backup_file)) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Backup file does not exist");
@@ -2891,14 +2891,14 @@ static RPCHelpMan restorewallet()
 
     std::string wallet_name = request.params[0].get_str();
 
-    const fs::path wallet_path = fsbridge::AbsPathJoin(GetWalletDir(), wallet_name);
+    const fs::path wallet_path = fsbridge::AbsPathJoin(GetWalletDir(), fs::u8path(wallet_name));
 
     if (fs::exists(wallet_path)) {
         throw JSONRPCError(RPC_INVALID_PARAMETER, "Wallet name already exists.");
     }
 
     if (!TryCreateDirectories(wallet_path)) {
-        throw JSONRPCError(RPC_WALLET_ERROR, strprintf("Failed to create database path '%s'. Database already exists.", wallet_path.string()));
+        throw JSONRPCError(RPC_WALLET_ERROR, strprintf("Failed to create database path '%s'. Database already exists.", wallet_path.u8string()));
     }
 
     auto wallet_file = wallet_path / "wallet.dat";
diff --git a/src/wallet/sqlite.cpp b/src/wallet/sqlite.cpp
index 815d17967c..650e083e8e 100644
--- a/src/wallet/sqlite.cpp
+++ b/src/wallet/sqlite.cpp
@@ -67,7 +67,7 @@ static void SetPragma(sqlite3* db, const std::string& key, const std::string& va
 }
 
 SQLiteDatabase::SQLiteDatabase(const fs::path& dir_path, const fs::path& file_path, bool mock)
-    : WalletDatabase(), m_mock(mock), m_dir_path(dir_path.string()), m_file_path(file_path.string())
+    : WalletDatabase(), m_mock(mock), m_dir_path(fs::PathToString(dir_path)), m_file_path(fs::PathToString(file_path))
 {
     {
         LOCK(g_sqlite_mutex);
@@ -206,7 +206,7 @@ void SQLiteDatabase::Open()
 
     if (m_db == nullptr) {
         if (!m_mock) {
-            TryCreateDirectories(m_dir_path);
+            TryCreateDirectories(fs::PathFromString(m_dir_path));
         }
         int ret = sqlite3_open_v2(m_file_path.c_str(), &m_db, flags, nullptr);
         if (ret != SQLITE_OK) {
diff --git a/src/wallet/test/db_tests.cpp b/src/wallet/test/db_tests.cpp
index 16cb7e0baf..dba3f35025 100644
--- a/src/wallet/test/db_tests.cpp
+++ b/src/wallet/test/db_tests.cpp
@@ -16,7 +16,7 @@ BOOST_FIXTURE_TEST_SUITE(db_tests, BasicTestingSetup)
 static std::shared_ptr<BerkeleyEnvironment> GetWalletEnv(const fs::path& path, std::string& database_filename)
 {
     fs::path data_file = BDBDataFile(path);
-    database_filename = data_file.filename().string();
+    database_filename = fs::PathToString(data_file.filename());
     return GetBerkeleyEnv(data_file.parent_path());
 }
 
@@ -25,11 +25,7 @@ BOOST_AUTO_TEST_CASE(getwalletenv_file)
     std::string test_name = "test_name.dat";
     const fs::path datadir = gArgs.GetDataDirNet();
     fs::path file_path = datadir / test_name;
-#if BOOST_VERSION >= 107700
-    std::ofstream f(BOOST_FILESYSTEM_C_STR(file_path));
-#else
-    std::ofstream f(file_path.BOOST_FILESYSTEM_C_STR);
-#endif // BOOST_VERSION >= 107700
+    fs::ofstream f(file_path);
     f.close();
 
     std::string filename;
diff --git a/src/wallet/test/init_test_fixture.cpp b/src/wallet/test/init_test_fixture.cpp
index 53c972c46d..170675c035 100644
--- a/src/wallet/test/init_test_fixture.cpp
+++ b/src/wallet/test/init_test_fixture.cpp
@@ -32,11 +32,7 @@ InitWalletDirTestingSetup::InitWalletDirTestingSetup(const std::string& chainNam
     fs::create_directories(m_walletdir_path_cases["default"]);
     fs::create_directories(m_walletdir_path_cases["custom"]);
     fs::create_directories(m_walletdir_path_cases["relative"]);
-#if BOOST_VERSION >= 107700
-    std::ofstream f(BOOST_FILESYSTEM_C_STR(m_walletdir_path_cases["file"]));
-#else
-    std::ofstream f(m_walletdir_path_cases["file"].BOOST_FILESYSTEM_C_STR);
-#endif // BOOST_VERSION >= 107700
+    fs::ofstream f(m_walletdir_path_cases["file"]);
     f.close();
 }
 
@@ -50,5 +46,5 @@ InitWalletDirTestingSetup::~InitWalletDirTestingSetup()
 
 void InitWalletDirTestingSetup::SetWalletDir(const fs::path& walletdir_path)
 {
-    gArgs.ForceSetArg("-walletdir", walletdir_path.string());
+    gArgs.ForceSetArg("-walletdir", fs::PathToString(walletdir_path));
 }
diff --git a/src/wallet/test/init_tests.cpp b/src/wallet/test/init_tests.cpp
index 45e1b8c4b8..222c2bf4b7 100644
--- a/src/wallet/test/init_tests.cpp
+++ b/src/wallet/test/init_tests.cpp
@@ -17,7 +17,7 @@ BOOST_AUTO_TEST_CASE(walletinit_verify_walletdir_default)
     SetWalletDir(m_walletdir_path_cases["default"]);
     bool result = m_wallet_client->verify();
     BOOST_CHECK(result == true);
-    fs::path walletdir = gArgs.GetArg("-walletdir", "");
+    fs::path walletdir = fs::PathFromString(gArgs.GetArg("-walletdir", ""));
     fs::path expected_path = fs::canonical(m_walletdir_path_cases["default"]);
     BOOST_CHECK_EQUAL(walletdir, expected_path);
 }
@@ -27,7 +27,7 @@ BOOST_AUTO_TEST_CASE(walletinit_verify_walletdir_custom)
     SetWalletDir(m_walletdir_path_cases["custom"]);
     bool result = m_wallet_client->verify();
     BOOST_CHECK(result == true);
-    fs::path walletdir = gArgs.GetArg("-walletdir", "");
+    fs::path walletdir = fs::PathFromString(gArgs.GetArg("-walletdir", ""));
     fs::path expected_path = fs::canonical(m_walletdir_path_cases["custom"]);
     BOOST_CHECK_EQUAL(walletdir, expected_path);
 }
@@ -67,7 +67,7 @@ BOOST_AUTO_TEST_CASE(walletinit_verify_walletdir_no_trailing)
     SetWalletDir(m_walletdir_path_cases["trailing"]);
     bool result = m_wallet_client->verify();
     BOOST_CHECK(result == true);
-    fs::path walletdir = gArgs.GetArg("-walletdir", "");
+    fs::path walletdir = fs::PathFromString(gArgs.GetArg("-walletdir", ""));
     fs::path expected_path = fs::canonical(m_walletdir_path_cases["default"]);
     BOOST_CHECK_EQUAL(walletdir, expected_path);
 }
@@ -77,7 +77,7 @@ BOOST_AUTO_TEST_CASE(walletinit_verify_walletdir_no_trailing2)
     SetWalletDir(m_walletdir_path_cases["trailing2"]);
     bool result = m_wallet_client->verify();
     BOOST_CHECK(result == true);
-    fs::path walletdir = gArgs.GetArg("-walletdir", "");
+    fs::path walletdir = fs::PathFromString(gArgs.GetArg("-walletdir", ""));
     fs::path expected_path = fs::canonical(m_walletdir_path_cases["default"]);
     BOOST_CHECK_EQUAL(walletdir, expected_path);
 }
diff --git a/src/wallet/test/wallet_tests.cpp b/src/wallet/test/wallet_tests.cpp
index 9938380369..94b5abfba7 100644
--- a/src/wallet/test/wallet_tests.cpp
+++ b/src/wallet/test/wallet_tests.cpp
@@ -258,7 +258,7 @@ BOOST_FIXTURE_TEST_CASE(importwallet_rescan, TestChain100Setup)
     SetMockTime(KEY_TIME);
     m_coinbase_txns.emplace_back(CreateAndProcessBlock({}, GetScriptForRawPubKey(coinbaseKey.GetPubKey())).vtx[0]);
 
-    std::string backup_file = (gArgs.GetDataDirNet() / "wallet.backup").string();
+    std::string backup_file = fs::PathToString(gArgs.GetDataDirNet() / "wallet.backup");
 
     // Import key into wallet and call dumpwallet to create backup file.
     {
diff --git a/src/wallet/wallet.cpp b/src/wallet/wallet.cpp
index abfe9d7dba..598fce0112 100644
--- a/src/wallet/wallet.cpp
+++ b/src/wallet/wallet.cpp
@@ -2515,16 +2515,16 @@ std::unique_ptr<WalletDatabase> MakeWalletDatabase(const std::string& name, cons
     // 2. Path to an existing directory.
     // 3. Path to a symlink to a directory.
     // 4. For backwards compatibility, the name of a data file in -walletdir.
-    const fs::path wallet_path = fsbridge::AbsPathJoin(GetWalletDir(), name);
+    const fs::path wallet_path = fsbridge::AbsPathJoin(GetWalletDir(), fs::PathFromString(name));
     fs::file_type path_type = fs::symlink_status(wallet_path).type();
     if (!(path_type == fs::file_not_found || path_type == fs::directory_file ||
           (path_type == fs::symlink_file && fs::is_directory(wallet_path)) ||
-          (path_type == fs::regular_file && fs::path(name).filename() == name))) {
+          (path_type == fs::regular_file && fs::PathFromString(name).filename() == fs::PathFromString(name)))) {
         error_string = Untranslated(strprintf(
               "Invalid -wallet path '%s'. -wallet path should point to a directory where wallet.dat and "
               "database/log.?????????? files can be stored, a location where such a directory could be created, "
               "or (for backwards compatibility) the name of an existing data file in -walletdir (%s)",
-              name, GetWalletDir()));
+              name, fs::quoted(fs::PathToString(GetWalletDir()))));
         status = DatabaseStatus::FAILED_BAD_PATH;
         return nullptr;
     }
diff --git a/src/wallet/walletdb.cpp b/src/wallet/walletdb.cpp
index 8ff09a0878..a6839f1f78 100644
--- a/src/wallet/walletdb.cpp
+++ b/src/wallet/walletdb.cpp
@@ -1106,7 +1106,7 @@ std::unique_ptr<WalletDatabase> MakeDatabase(const fs::path& path, const Databas
     try {
         exists = fs::symlink_status(path).type() != fs::file_not_found;
     } catch (const fs::filesystem_error& e) {
-        error = Untranslated(strprintf("Failed to access database path '%s': %s", path.string(), fsbridge::get_filesystem_error_message(e)));
+        error = Untranslated(strprintf("Failed to access database path '%s': %s", fs::PathToString(path), fsbridge::get_filesystem_error_message(e)));
         status = DatabaseStatus::FAILED_BAD_PATH;
         return nullptr;
     }
@@ -1118,33 +1118,33 @@ std::unique_ptr<WalletDatabase> MakeDatabase(const fs::path& path, const Databas
         }
         if (IsSQLiteFile(SQLiteDataFile(path))) {
             if (format) {
-                error = Untranslated(strprintf("Failed to load database path '%s'. Data is in ambiguous format.", path.string()));
+                error = Untranslated(strprintf("Failed to load database path '%s'. Data is in ambiguous format.", fs::PathToString(path)));
                 status = DatabaseStatus::FAILED_BAD_FORMAT;
                 return nullptr;
             }
             format = DatabaseFormat::SQLITE;
         }
     } else if (options.require_existing) {
-        error = Untranslated(strprintf("Failed to load database path '%s'. Path does not exist.", path.string()));
+        error = Untranslated(strprintf("Failed to load database path '%s'. Path does not exist.", fs::PathToString(path)));
         status = DatabaseStatus::FAILED_NOT_FOUND;
         return nullptr;
     }
 
     if (!format && options.require_existing) {
-        error = Untranslated(strprintf("Failed to load database path '%s'. Data is not in recognized format.", path.string()));
+        error = Untranslated(strprintf("Failed to load database path '%s'. Data is not in recognized format.", fs::PathToString(path)));
         status = DatabaseStatus::FAILED_BAD_FORMAT;
         return nullptr;
     }
 
     if (format && options.require_create) {
-        error = Untranslated(strprintf("Failed to create database path '%s'. Database already exists.", path.string()));
+        error = Untranslated(strprintf("Failed to create database path '%s'. Database already exists.", fs::PathToString(path)));
         status = DatabaseStatus::FAILED_ALREADY_EXISTS;
         return nullptr;
     }
 
     // A db already exists so format is set, but options also specifies the format, so make sure they agree
     if (format && options.require_format && format != options.require_format) {
-        error = Untranslated(strprintf("Failed to load database path '%s'. Data is not in required format.", path.string()));
+        error = Untranslated(strprintf("Failed to load database path '%s'. Data is not in required format.", fs::PathToString(path)));
         status = DatabaseStatus::FAILED_BAD_FORMAT;
         return nullptr;
     }
@@ -1166,7 +1166,7 @@ std::unique_ptr<WalletDatabase> MakeDatabase(const fs::path& path, const Databas
 #ifdef USE_SQLITE
         return MakeSQLiteDatabase(path, options, status, error);
 #endif
-        error = Untranslated(strprintf("Failed to open database path '%s'. Build does not support SQLite database format.", path.string()));
+        error = Untranslated(strprintf("Failed to open database path '%s'. Build does not support SQLite database format.", fs::PathToString(path)));
         status = DatabaseStatus::FAILED_BAD_FORMAT;
         return nullptr;
     }
@@ -1174,7 +1174,7 @@ std::unique_ptr<WalletDatabase> MakeDatabase(const fs::path& path, const Databas
 #ifdef USE_BDB
     return MakeBerkeleyDatabase(path, options, status, error);
 #endif
-    error = Untranslated(strprintf("Failed to open database path '%s'. Build does not support Berkeley DB database format.", path.string()));
+    error = Untranslated(strprintf("Failed to open database path '%s'. Build does not support Berkeley DB database format.", fs::PathToString(path)));
     status = DatabaseStatus::FAILED_BAD_FORMAT;
     return nullptr;
 }
diff --git a/src/wallet/wallettool.cpp b/src/wallet/wallettool.cpp
index e3cb5cee5d..788679bbeb 100644
--- a/src/wallet/wallettool.cpp
+++ b/src/wallet/wallettool.cpp
@@ -125,7 +125,7 @@ bool ExecuteWalletToolFunc(const ArgsManager& args, const std::string& command)
         return false;
     }
     const std::string name = args.GetArg("-wallet", "");
-    const fs::path path = fsbridge::AbsPathJoin(GetWalletDir(), name);
+    const fs::path path = fsbridge::AbsPathJoin(GetWalletDir(), fs::PathFromString(name));
 
     if (command == "create") {
         DatabaseOptions options;
diff --git a/src/wallet/walletutil.cpp b/src/wallet/walletutil.cpp
index 1c518daba6..7f813432b3 100644
--- a/src/wallet/walletutil.cpp
+++ b/src/wallet/walletutil.cpp
@@ -12,7 +12,7 @@ fs::path GetWalletDir()
     fs::path path;
 
     if (gArgs.IsArgSet("-walletdir")) {
-        path = gArgs.GetArg("-walletdir", "");
+        path = fs::PathFromString(gArgs.GetArg("-walletdir", ""));
         if (!fs::is_directory(path)) {
             // If the path specified doesn't exist, we return the deliberately
             // invalid empty string.