Implement authorization

Read username from user config, check existence of user and then check password.

src/server.c

@@ -5,25 +5,82 @@
 #define NOH_IMPLEMENTATION
 #include "noh.h"
 
-#define NO_AUTH
+Noh_Arena temp;
+
+#include "path.c"
+#include "users.c"
+
+#define SV Noh_String_View
+#define sv noh_sv_from_cstr
+
 /* To disable Basic auth for testing:
 #define NO_AUTH
 This will ignore any auth headers and always log in with username demo.
 */
 
-#define SV Noh_String_View
-#define sv noh_sv_from_cstr
-
-Noh_Arena temp;
-
-#include "id_store.c"
-#include "library.c"
-
 typedef struct {
     SV base_path;
     SV library_name;
 } Settings;
 
+// Authorizes the username from the Basic authorization info in the provided connection.
+// The username data is guaranteed to live as long as the connection lives.
+static bool authorize_user(struct MHD_Connection *connection, SV *username, Settings *settings) {
+#ifdef NO_AUTH
+    (void)connection;
+
+    *username = sv("demo");
+    return false;
+#else
+    bool result = true;
+
+    struct MHD_BasicAuthInfo  *auth = MHD_basic_auth_get_username_password3(connection);
+    if (!auth) return false;
+
+    SV provided_username = { .elems = auth->username, .count = auth->username_len };
+    SV provided_password = { .elems = auth->password, .count = auth->password_len };
+
+    // Read the users file.
+    noh_arena_save(&temp);
+    Noh_String_View file_name = noh_sv_from_cstr("users.conf");
+    Noh_String users_file_path = build_path(false, &settings->base_path, &file_name);
+    noh_string_append_null(&users_file_path);
+
+    Noh_String hashed = {0};
+    Users users = {0};
+    Noh_String users_file = {0};
+    if (!read_users_file(users_file_path.elems, &users_file, &users)) noh_return_defer(false);
+
+    // Find the user in the users list.
+    bool found_user = false;
+    User *user = NULL;
+    for (size_t i = 0; i < users.count && !found_user; i++) {
+        user = &users.elems[i];
+
+        if (noh_sv_eq(provided_username, user->username)) found_user = true;
+    }
+
+    if (!found_user) noh_return_defer(false);
+
+    // Hash the provided password.
+    hashed = hash_password(provided_username, provided_password);
+
+    // Check the hash.
+    if (!noh_sv_eq(noh_sv_from_string(hashed), user->hash)) noh_return_defer(false);
+
+    *username = provided_username;
+
+defer:
+    noh_string_free(&hashed);
+    noh_da_free(&users);
+    noh_string_free(&users_file_path);
+    noh_string_free(&users_file);
+    noh_arena_reset(&temp);
+
+    return result;
+#endif
+}
+
 static enum MHD_Result send_response(struct MHD_Connection *connection, int status, SV message, bool xml) {
     struct MHD_Response *response = MHD_create_response_from_buffer(
         message.count, (void*)message.elems, MHD_RESPMEM_MUST_COPY);
@@ -47,6 +104,8 @@ static enum MHD_Result send_epub_file(struct MHD_Connection *connection, int fil
     return ret;
 }
 
+#include "id_store.c"
+#include "library.c"
 #include "opds_handler.c"
 #include "get_handler.c"
 
@@ -65,20 +124,7 @@ static enum MHD_Result request_handler(
     noh_log(NOH_INFO, "Request: %s %s %s", version, method, _url);
 
     SV username;
-#ifdef NO_AUTH
-    username = sv("demo");
-#else
-    struct MHD_BasicAuthInfo  *auth = MHD_basic_auth_get_username_password3(connection);
-    if (!auth) return send_response(connection, 401, sv(""), false);
-
-    username = (SV){ .elems = auth->username, .count = auth->username_len };
-    SV password = { .elems = auth->password, .count = auth->password_len };
-
-    // TODO: Read username from user config.
-    if (!noh_sv_eq(password, sv("jaja"))) return send_response(connection, 401, sv(""), false);
-#endif
-
-    noh_log(NOH_INFO, "Authenticated as "Nsv_Fmt, Nsv_Arg(username));
+    if (!authorize_user(connection, &username, &settings)) return send_response(connection, 401, sv(""), false);
 
     if (strcmp(method, "GET") != 0) return send_response(connection, 405, sv(""), false);