Oops, forgot to commit in between. :-)

CMakeLists.txt

@@ -1,23 +1,32 @@
 cmake_minimum_required (VERSION 3.2)
 project(libravatarserv
-        VERSION 0.0.0
+        VERSION 0.1.0
         LANGUAGES CXX
 )
 
 include(GNUInstallDirs)
 find_package(PkgConfig REQUIRED)
-pkg_check_modules(LIBPNG REQUIRED libpng)
+pkg_check_modules(MAGICPP REQUIRED Magick++)
+pkg_check_modules(LIBCRYPTOPP REQUIRED libcryptopp)
+pkg_check_modules(LIBXDG_BASEDIR REQUIRED libxdg-basedir)
 
 set(CMAKE_CXX_STANDARD 14)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 set(CMAKE_CXX_EXTENSIONS OFF)
 
-set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -Wall -g -Og")
+string(REPLACE ";" " " MAGICPP_CFLAGS_STRING "${MAGICPP_CFLAGS}")
+set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} ${MAGICPP_CFLAGS_STRING}")
+set(CMAKE_CXX_FLAGS_DEBUG
+    "${CMAKE_CXX_FLAGS_DEBUG} -Wall -pedantic -Wextra -g -Og")
 
 include_directories(${PROJECT_BINARY_DIR})
-include_directories(${LIBPNG_INCLUDE_DIRS})
+include_directories(${MAGICPP_INCLUDE_DIRS})
+include_directories(${LIBCRYPTOPP_INCLUDE_DIRS})
+include_directories(${LIBXDG_BASEDIR_INCLUDE_DIRS})
 
-link_directories(${LIBPNG_LIBRARY_DIRS})
+link_directories(${MAGICPP_LIBRARY_DIRS})
+link_directories(${LIBCRYPTOPP_LIBRARY_DIRS})
+link_directories(${LIBXDG_BASEDIR_LIBRARY_DIRS})
 
 # Write version in header
 configure_file(
@@ -26,6 +35,8 @@ configure_file(
 )
 
 file(GLOB sources src/*.cpp)
-add_executable(${CMAKE_PROJECT_NAME} ${sources})
-target_link_libraries(${CMAKE_PROJECT_NAME} ${LIBPNG_LIBRARIES})
+add_executable(${CMAKE_PROJECT_NAME} "${sources}")
+target_link_libraries(${CMAKE_PROJECT_NAME}
+                      "${MAGICPP_LDFLAGS} ${LIBCRYPTOPP_LDFLAGS}"
+                      "${LIBXDG_BASEDIR_LDFLAGS} -lstdc++fs")
 install(TARGETS ${CMAKE_PROJECT_NAME} DESTINATION ${CMAKE_INSTALL_BINDIR})

src/hash.cpp

@@ -0,0 +1,71 @@
+/*  This file is part of libravatarserv.
+ *  Copyright © 2018 tastytea <tastytea@tastytea.de>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, version 3.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <algorithm>
+#define CRYPTOPP_ENABLE_NAMESPACE_WEAK 1
+#include <cryptopp/md5.h>
+#include <cryptopp/sha.h>
+#include <cryptopp/filters.h>
+#include <cryptopp/hex.h>
+#include "libravatarserv.hpp"
+
+using global::avatar_dir;
+using namespace hash;
+
+const string hash::md5(const string &text)
+{
+    using namespace CryptoPP;
+    Weak::MD5 hash;
+    string digest;
+
+    StringSource s(text, true,
+                   new HashFilter(hash,
+                                  new HexEncoder(new StringSink(digest))));
+    std::transform(digest.begin(), digest.end(), digest.begin(), ::tolower);
+    return digest;
+}
+
+const string hash::sha256(const string &text)
+{
+    using namespace CryptoPP;
+    SHA256 hash;
+    string digest;
+
+    StringSource s(text, true,
+                   new HashFilter(hash,
+                                  new HexEncoder(new StringSink(digest))));
+
+    std::transform(digest.begin(), digest.end(), digest.begin(), ::tolower);
+    return digest;
+}
+
+bool hash::fill_table()
+{
+    
+
+
+    for (const fs::path &path : fs::recursive_directory_iterator(avatar_dir))
+    {
+        if (fs::is_regular_file(path))
+        {
+            string email = path.filename();
+            std::transform(email.begin(), email.end(), email.begin(), ::tolower);
+            table.insert({ md5(email), email });
+            table.insert({ sha256(email), email });
+        }
+    }
+    return true;
+}

src/image.cpp

@@ -0,0 +1,63 @@
+/*  This file is part of libravatarserv.
+ *  Copyright © 2018 tastytea <tastytea@tastytea.de>
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation, version 3.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License
+ *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <iostream>
+#include "libravatarserv.hpp"
+
+using std::cerr;
+using std::endl;
+using global::avatar_dir;
+using namespace image;
+
+const Image image::get(const string &digest, const uint16_t size)
+{
+    uint8_t error = 0;
+    Magick::Image img;
+    fs::path filename;
+
+    const auto &entry = hash::table.find(digest);
+    if (entry == hash::table.end())
+    {
+        filename = avatar_dir / "default.png";
+        if (!fs::is_regular_file(filename))
+        {
+            cerr << "Error: User not found and no default image set.\n";
+            return { 2, img };
+        }
+    }
+    else
+    {
+        filename = avatar_dir / entry->second;
+    }
+
+    try
+    {
+        img.read(filename);
+        img.resize(Magick::Geometry(size, size));
+    }
+    catch (const Magick::Exception &e)
+    {
+        cerr << "Error: " << e.what() << endl;
+        error = 2;
+    }
+    catch (const std::exception &e)
+    {
+        cerr << "Error: " << e.what() << endl;
+        error = 5;
+    }
+
+    return { error, img };
+}

src/libravatarserv.cpp

@@ -16,18 +16,101 @@
 
 #include <iostream>
 #include <cstdlib>  // getenv()
-#include <png++/png.hpp>
+#include <basedir.h>
+#include "libravatarserv.hpp"
 
 using std::cout;
+using std::cerr;
+using std::endl;
+using global::avatar_dir;
 
-int main(int argc, char *argv[])
+// Global variables
+std::map<const string, const string> hash::table;
+fs::path global::avatar_dir = "";
+
+
+int main()
 {
-    cout << "Content-type: image/png\r\n\r\n";
-    cout << std::getenv("REQUEST_URI") << "\r\n";
+    const char *tmp = std::getenv("REQUEST_URI");
+    if (tmp == nullptr)
+    {
+        cout << "Status: 404 Not Found\n\n";
+        cerr << "Error: ${REQUEST_URI} is empty.\n";
+        return 1;
+    }
+    const string request = tmp;
 
-    png::image<png::rgba_pixel> image(argv[1]);
+    if (!find_avatar_dir())
+    {
+        cout << "Status: 404 Not Found\n\n";
+        cerr << "Error: No avatars found.\n";
+        return 3;
+    }
+    hash::fill_table();
 
-    image.write("/dev/stdout");
+    if (request.substr(0, 8) != "/avatar/" ||
+        request.find('/', 8) != std::string::npos)
+    {
+        cout << "Status: 404 Not Found\n\n";
+        cerr << "Error: Invalid URL.\n";
+        return 1;
+    }
+    cout << "Content-type: image/png\n\n";
+    cout.flush();   // We need to flush before we use /dev/stdout directly.
+
+    string digest = request.substr(8);
+    std::transform(digest.begin(), digest.end(), digest.begin(), ::tolower);
+
+    image::Image answer = image::get(digest, 80);
+    if (answer.error == 0)
+    {
+        // answer.image.write("test.png");
+        answer.image.write("/dev/stdout");
+    }
+    else
+    {
+        cerr << "Error " << std::to_string(answer.error) << ": Could not open file.\n";
+    }
 
     return 0;
 }
+
+bool find_avatar_dir()
+{
+    const char *envdir = std::getenv("AVATAR_DIR");
+    if (envdir != nullptr)
+    {
+        if (fs::is_directory(envdir))
+        {
+            avatar_dir = envdir;
+        }
+        else
+        {
+            return false;
+        }
+    }
+    else
+    {
+        xdgHandle xdg;
+        xdgInitHandle(&xdg);
+        auto data_dirs = xdgDataDirectories(&xdg);
+        const uint8_t size = sizeof(data_dirs) / sizeof(*data_dirs);
+
+        for (uint8_t index = 0; index <= size; ++index)
+        {
+            const string searchdir = data_dirs[index] + string("/libravatarserv");
+            if (fs::is_directory(searchdir))
+            {
+                avatar_dir = searchdir;
+                break;
+            }
+        }
+        xdgWipeHandle(&xdg);
+        if (avatar_dir.empty())
+        {
+            return false;
+        }
+    }
+
+    return true;
+}

src/libravatarserv.hpp

@@ -17,6 +17,50 @@
 #ifndef LIBRAVATARSERV_HPP
 #define LIBRAVATARSERV_HPP
 
+#if __cplusplus >= 201703L
+    #include <filesystem>
+#else
+    #include <experimental/filesystem>
+#endif
+#include <string>
+#include <map>
+#include <Magick++.h>
 
+#if __cplusplus >= 201703L
+    namespace fs = std::filesystem;
+#else
+    namespace fs = std::experimental::filesystem;
+#endif
+using std::string;
+using std::uint16_t;
+using std::uint8_t;
+
+int main();
+bool find_avatar_dir();
+
+namespace global
+{
+    extern fs::path avatar_dir;
+}
+
+namespace hash  // hash.cpp
+{
+    extern std::map<const string, const string> table;
+
+    const string md5(const string &text);
+    const string sha256(const string &text);
+    bool fill_table();
+}
+
+namespace image //image.cpp
+{
+    struct Image
+    {
+        const uint8_t error;
+        Magick::Image image;
+    };
+
+    const Image get(const string &digest, const uint16_t size);
+}
 
 #endif  // LIBRAVATARSERV_HPP