diff --git a/cdoc/CDoc2Reader.cpp b/cdoc/CDoc2Reader.cpp
index 114baaf0..98db9ad8 100644
--- a/cdoc/CDoc2Reader.cpp
+++ b/cdoc/CDoc2Reader.cpp
@@ -37,8 +37,6 @@
 #include <openssl/evp.h>
 #include <openssl/x509.h>
 
-#include <fstream>
-
 // fixme: Placeholder
 #define t_(t) t
 
diff --git a/cdoc/CDocCipher.cpp b/cdoc/CDocCipher.cpp
index 0d49a38e..1ce552b8 100644
--- a/cdoc/CDocCipher.cpp
+++ b/cdoc/CDocCipher.cpp
@@ -468,7 +468,7 @@ int CDocCipher::Decrypt(const unique_ptr<CDocReader>& rdr, unsigned int lock_idx
             fpath = fpath.filename();
         }
         fpath = base_path / fpath;
-        std::ofstream ofs(fpath.string(), std::ios_base::binary);
+        std::ofstream ofs(fpath, std::ios_base::binary);
         if (ofs.bad()) {
             LOG_ERROR("Cannot open file {} for writing", fpath.string());
             return 1;
diff --git a/cdoc/CDocCipher.h b/cdoc/CDocCipher.h
index 3138dc50..92bcc079 100644
--- a/cdoc/CDocCipher.h
+++ b/cdoc/CDocCipher.h
@@ -25,7 +25,6 @@
 #include "ToolConf.h"
 #include "Exports.h"
 
-#include <map>
 #include <memory>
 
 namespace libcdoc
diff --git a/cdoc/Configuration.cpp b/cdoc/Configuration.cpp
index eee0586d..256172a8 100644
--- a/cdoc/Configuration.cpp
+++ b/cdoc/Configuration.cpp
@@ -97,7 +97,7 @@ JSONConfiguration::parse(std::istream& ifs)
 bool
 JSONConfiguration::parse(const std::string& file)
 {
-    std::ifstream ifs(file, std::ios::binary);
+    std::ifstream ifs(std::filesystem::path(encodeName(file)), std::ios::binary);
     if (ifs.bad()) {
         LOG_ERROR("Cannot open {}", file);
         return false;
diff --git a/cdoc/Io.cpp b/cdoc/Io.cpp
index 2860f741..1d845b1d 100644
--- a/cdoc/Io.cpp
+++ b/cdoc/Io.cpp
@@ -18,8 +18,12 @@
 
 #include "Io.h"
 
+#include "Utils.h"
+
 #include <array>
 
+namespace fs = std::filesystem;
+
 namespace libcdoc {
 
 static constexpr size_t BLOCK_SIZE = 65536;
@@ -88,17 +92,32 @@ DataSource::skip(size_t size) {
 }
 
 IStreamSource::IStreamSource(const std::string& path)
-	: IStreamSource(new std::ifstream(path, std::ios_base::in | std::ios_base::binary), true)
+    : IStreamSource(new std::ifstream(fs::path(encodeName(path)), std::ios_base::binary), true)
 {
 }
 
 OStreamConsumer::OStreamConsumer(const std::string& path)
-	: OStreamConsumer(new std::ofstream(path, std::ios_base::binary), true)
+    : OStreamConsumer(new std::ofstream(fs::path(encodeName(path)), std::ios_base::binary), true)
 {
 }
 
+result_t FileListConsumer::open(const std::string &name, int64_t size) {
+    std::string_view fileName = name;
+    if (ofs.is_open()) {
+        ofs.close();
+    }
+    size_t lastSlashPos = fileName.find_last_of("\\/");
+    if (lastSlashPos != std::string::npos) {
+        fileName = fileName.substr(lastSlashPos + 1);
+    }
+    fs::path path(base);
+    path /= encodeName(fileName);
+    ofs.open(path, std::ios_base::binary);
+    return ofs.bad() ? OUTPUT_STREAM_ERROR : OK;
+}
+
 FileListSource::FileListSource(const std::string& base, const std::vector<std::string>& files)
-	: _base(base), _files(files), _current(-1)
+    : _base(encodeName(base)), _files(files)
 {
 }
 
@@ -139,13 +158,15 @@ FileListSource::next(std::string& name, int64_t& size)
 	_ifs.close();
 	_current += 1;
 	if (_current >= _files.size()) return END_OF_STREAM;
-	std::filesystem::path path(_base);
-	path.append(_files[_current]);
-	if (!std::filesystem::exists(path)) return IO_ERROR;
-	_ifs.open(path, std::ios_base::in | std::ios_base::binary);
+    fs::path path(_base);
+    path.append(encodeName(_files[_current]));
+    if (std::error_code ec; !fs::exists(path, ec)) return IO_ERROR;
+    _ifs.open(path, std::ios_base::binary);
 	if (_ifs.bad()) return IO_ERROR;
 	name = _files[_current];
-	size = std::filesystem::file_size(path);
+    std::error_code ec;
+    size = fs::file_size(path, ec);
+    if (!ec) return IO_ERROR;
     return OK;
 }
 
diff --git a/cdoc/Io.h b/cdoc/Io.h
index bd4dcbdd..5bc5eecf 100644
--- a/cdoc/Io.h
+++ b/cdoc/Io.h
@@ -221,7 +221,7 @@ struct CDOC_EXPORT IStreamSource : public DataSource {
         if(_ifs->bad()) return INPUT_STREAM_ERROR;
         _ifs->clear();
 		_ifs->seekg(pos);
-        return bool(_ifs->bad()) ? INPUT_STREAM_ERROR : OK;
+        return _ifs->bad() ? INPUT_STREAM_ERROR : OK;
 	}
 
     result_t read(uint8_t *dst, size_t size) noexcept override try {
@@ -264,7 +264,7 @@ struct CDOC_EXPORT OStreamConsumer : public DataConsumer {
 };
 
 struct CDOC_EXPORT VectorSource : public DataSource {
-	VectorSource(const std::vector<uint8_t>& data) : _data(data), _ptr(0) {}
+    VectorSource(const std::vector<uint8_t>& data) : _data(data) {}
 
     result_t seek(size_t pos) override {
 		if (pos > _data.size()) return INPUT_STREAM_ERROR;
@@ -283,7 +283,7 @@ struct CDOC_EXPORT VectorSource : public DataSource {
     bool isEof() noexcept override { return _ptr >= _data.size(); }
 protected:
 	const std::vector<uint8_t>& _data;
-	size_t _ptr;
+    size_t _ptr{0};
 };
 
 struct CDOC_EXPORT VectorConsumer : public DataConsumer {
@@ -295,7 +295,7 @@ struct CDOC_EXPORT VectorConsumer : public DataConsumer {
         return OUTPUT_STREAM_ERROR;
 	}
     result_t close() noexcept final { return OK; }
-    virtual bool isError() noexcept final { return false; }
+    bool isError() noexcept final { return false; }
 protected:
     std::vector<uint8_t>& _data;
 };
@@ -317,25 +317,7 @@ struct CDOC_EXPORT FileListConsumer : public MultiDataConsumer {
     bool isError() noexcept final {
 		return ofs.bad();
 	}
-    result_t open(const std::string& name, int64_t size) override final {
-        std::string fileName;
-        if (ofs.is_open()) {
-            ofs.close();
-        }
-        size_t lastSlashPos = name.find_last_of("\\/");
-        if (lastSlashPos != std::string::npos)
-        {
-            fileName = name.substr(lastSlashPos + 1);
-        }
-        else
-        {
-            fileName = name;
-        }
-        std::filesystem::path path(base);
-        path /= fileName;
-		ofs.open(path.string(), std::ios_base::binary);
-        return ofs.bad() ? OUTPUT_STREAM_ERROR : OK;
-	}
+    result_t open(const std::string &name, int64_t size) final;
 
 protected:
 	std::filesystem::path base;
@@ -352,7 +334,7 @@ struct CDOC_EXPORT FileListSource : public MultiDataSource {
 protected:
 	std::filesystem::path _base;
 	const std::vector<std::string>& _files;
-	int64_t _current;
+    int64_t _current = -1;
 	std::ifstream _ifs;
 };
 
diff --git a/cdoc/Utils.h b/cdoc/Utils.h
index 4e86400a..392b81b4 100644
--- a/cdoc/Utils.h
+++ b/cdoc/Utils.h
@@ -43,6 +43,11 @@ namespace fmt = std;
 
 namespace libcdoc {
 
+static auto encodeName(std::string_view path)
+{
+    return std::u8string_view(reinterpret_cast<const char8_t*>(path.data()), path.size());
+}
+
 std::string toBase64(const uint8_t *data, size_t len);
 
 static std::string toBase64(const std::vector<uint8_t> &data) {
@@ -76,7 +81,7 @@ fromHex(std::string_view hex) {
         return val;
     val.resize(hex.size() / 2);
     auto p = val.begin();
-    for (auto i = hex.cbegin(), end = hex.cend(); fromHex(i, end, *p); i += 2, ++p);
+    for (auto i = hex.cbegin(), end = hex.cend(); p != val.end() && fromHex(i, end, *p); i += 2, ++p);
     return val;
 }
 
@@ -117,11 +122,11 @@ readAllBytes(std::string_view filename)
 {
     std::vector<uint8_t> dst;
     std::filesystem::path path(filename);
-    if (!std::filesystem::exists(path)) {
+    if (std::error_code ec; !std::filesystem::exists(path, ec)) {
         std::cerr << "readAllBytes(): File '" << filename << "' does not exist" << std::endl;
         return dst;
     }
-    std::ifstream ifs(path, std::ios_base::in | std::ios_base::binary);
+    std::ifstream ifs(path, std::ios_base::binary);
     if (!ifs) {
         std::cerr << "readAllBytes(): Opening '" << filename << "' failed." << std::endl;
         return dst;