initial impl for file

src/backends/file/be_file.cpp

@@ -1,14 +1,65 @@
 #include "be_file.h"
 
+#include <fstream>
 #include <mosquitto.h>
+#include <sstream>
+#include <string>
+
+constexpr const char* c_file_opt_key = "creds_file";
 
 BE_File::BE_File(const std::map<const char*, const char*, KeysEqual>& options)
 {
     mosquitto_log_printf(MOSQ_LOG_DEBUG, "*** auth-plugin: backend %s initializing", BE_File::kind);
+
+    if (options.count(c_file_opt_key) == 0)
+    {
+        mosquitto_log_printf(MOSQ_LOG_ERR, "*** auth-plugin: required config `%s` is missing", c_file_opt_key);
+        return;
+    }
+
+    const char* credentialsFilePath = options.at(c_file_opt_key);
+    loadFile(credentialsFilePath);
+}
+
+void BE_File::loadFile(const char* filePath)
+{
+    mosquitto_log_printf(MOSQ_LOG_DEBUG, "*** auth-plugin: loading credentials from `%s`", filePath);
+
+    auto file = std::ifstream(filePath);
+    if (file.eof())
+    {
+        mosquitto_log_printf(MOSQ_LOG_ERR, "*** auth-plugin: file not found: `%s`", filePath);
+        return;;
+    }
+
+    std::string line, username, password;
+    int lineNb = 1;
+    while (getline(file, line))
+    {
+        std::stringstream lineStream(line);
+
+        if (getline(lineStream, username, ':') && getline(lineStream, password))
+        {
+            m_credentials.emplace_back(make_pair(username, password));
+        }
+        else
+        {
+            mosquitto_log_printf(MOSQ_LOG_DEBUG, "*** auth-plugin: line %i is malformed, skipping it", lineNb);
+        }
+
+        ++lineNb;
+    }
 }
 
 bool BE_File::authenticate(const std::string& username, const std::string& password)
 {
-    mosquitto_log_printf(MOSQ_LOG_ERR, "*** auth-plugin: username %s with password %s", username.c_str(), password.c_str());
+    for (const auto& item: m_credentials)
+    {
+        if (item.first == username && item.second == password)
+        {
+            return true;
+        }
+    }
+
     return false;
 }

src/backends/file/be_file.h

@@ -2,6 +2,8 @@
 
 #include "../backend.h"
 
+#include <vector>
+
 /**
  * Represents a file based store.
  * Stores valid username and encrypted password combinations in a file.
@@ -26,4 +28,14 @@ class BE_File: public IBackend
      * of credentials
      */
     static constexpr const char* kind = "file";
+
+private:
+    /**
+     * Loads the given path and stores valid credentials listed in it, in memory
+     * @param filePath The path to the file containing the credentials
+     */
+    void loadFile(const char* filePath);
+
+    using Credentials = std::pair<std::string, std::string>;
+    std::vector<Credentials> m_credentials;
 };

src/plugin.cpp

@@ -3,9 +3,7 @@
 #include <algorithm>
 #include <iostream>
 #include <mosquitto.h>
-#include <ranges>
 #include <sstream>
-#include <string_view>
 #include <string>
 
 constexpr const char* c_backends_opt_key = "backends";
@@ -47,7 +45,6 @@ void Plugin::initializeBackends() noexcept
             continue;
         }
 
-        mosquitto_log_printf(MOSQ_LOG_INFO, "*** auth-plugin: moving ownership");
         m_backends.push_back(std::move(backend));
     }