updates CMake configuration for SQLite; sqlite: open or create table function.

src/CMakeLists.txt

@@ -10,11 +10,12 @@ target_sources(zbbs-server
 )
 
 add_subdirectory(libs)
+add_subdirectory(db)
 
 target_link_libraries(zbbs-server 
     PRIVATE
+        db
         murmur3
-        PostgreSQL::PostgreSQL
         OpenSSL::Crypto
 )
 

src/db/CMakeLists.txt

@@ -0,0 +1,22 @@
+add_library(db STATIC)
+
+if (USE_POSTGRESQL)
+    target_link_libraries(db
+        PRIVATE
+            PostgreSQL::PostgreSQL
+    )
+else()
+    target_link_libraries(db
+        PRIVATE
+            sqlite
+    )
+endif()
+
+target_sources(db
+    PRIVATE
+        "db.c"
+    PUBLIC
+        FILE_SET HEADERS
+        FILES
+           "db.h"
+)

src/db/db.c

@@ -0,0 +1,5 @@
+#ifdef USE_POSTGRESQL
+#include "db_postgresql.c"
+#else
+#include "db_sqlite.c"
+#endif

src/db/db.h

@@ -3,7 +3,7 @@
 
 #ifndef DB_H
 #define DB_H
-#include "main.h"
+#include "../main.h"
 #include <stdint.h>
 
 /* Auth */

src/db/db_postgresql.c

@@ -1,8 +1,8 @@
 /* SPDX-License-Identifier: MIT */
 /* Copyright (c) 2026 Oleksandr Zhylin */
 
-#include "db.h"
-#include "main.h"
+#include <db.h>
+#include "../main.h"
 #include <endian.h>
 #include <fcntl.h>
 #include <libpq-fe.h>
@@ -24,9 +24,7 @@
 static PGconn *conn = NULL;
 static PGresult *res = NULL;
 
-// #define USR_NOT_FOUND "User with such credentials is not found!"
-
-static void clearRes() {
+static void clearRes(void) {
   PQclear(res);
   res = NULL;
 }

src/db/db_sqlite.c

@@ -0,0 +1,123 @@
+/* SPDX-License-Identifier: MIT */
+/* Copyright (c) 2026 Oleksandr Zhylin */
+
+#include "../main.h"
+#include <db.h>
+#include <endian.h>
+#include <openssl/sha.h>
+#include <sqlite3.h>
+#include <stdio.h>
+#include <string.h>
+
+#define UNUSED(x) (void)(x)
+#define Q_LEN 128
+#define BIN 1
+#define TEXT 0
+#define ENCR_SIZE 2048
+
+static sqlite3 *db;
+
+void print_err(char **err) {
+  if (*err != NULL) {
+    printf("%s\n", *err);
+    sqlite3_free(*err);
+    *err = NULL;
+  }
+}
+
+int check_and_create_tables() {
+  int res = 0;
+  char *err = NULL;
+
+  res = sqlite3_exec(db,
+                     "CREATE TABLE IF NOT EXISTS 'users' ("
+                     "  'id' SERIAL,"
+                     "  'username' VARCHAR(50) NOT NULL,"
+                     "  'password' CHARACTER(64) NOT NULL,"
+                     "  'email' VARCHAR(255) NOT NULL,"
+                     "  'created_at' TIMESTAMP NOT NULL,"
+                     "  'last_login' TIMESTAMP NULL,"
+                     "  'privileges' SMALLINT NOT NULL,"
+                     "  CONSTRAINT 'users_pkey' PRIMARY KEY ('id'),"
+                     "  CONSTRAINT 'users_email_key' UNIQUE ('email'),"
+                     "  CONSTRAINT 'users_username_key' UNIQUE ('username')"
+                     "); ",
+                     NULL, NULL, &err);
+
+  print_err(&err);
+  res = sqlite3_exec(db,
+                     "CREATE UNIQUE INDEX IF NOT EXISTS 'username_idx'"
+                     " ON 'users' ("
+                     " 'username' ASC"
+                     " );",
+                     NULL, NULL, &err);
+  print_err(&err);
+  res = sqlite3_exec(db,
+                     "CREATE UNIQUE INDEX IF NOT EXISTS 'email_idx' "
+                     "ON 'users' ("
+                     "'email' ASC"
+                     ");",
+                     NULL, NULL, &err);
+  print_err(&err);
+  res = sqlite3_exec(db,
+                     "CREATE TABLE IF NOT EXISTS 'files' ("
+                     "  'id' SERIAL,"
+                     "  'user_id' INTEGER NULL,"
+                     "  'name' VARCHAR(255) NOT NULL,"
+                     "  'size' BIGINT NOT NULL,"
+                     "  'created_at' DATE NOT NULL,"
+                     "  'description' TEXT NULL,"
+                     "  'permissions' INTEGER NULL,"
+                     "  'hash' INTEGER NULL,"
+                     "  CONSTRAINT 'files_pkey' PRIMARY KEY ('id'),"
+                     "  CONSTRAINT 'fk_user' FOREIGN KEY ('user_id')"
+                     "  REFERENCES 'users' ('id') ON DELETE NO ACTION"
+                     "  ON UPDATE NO ACTION"
+                     ");",
+                     NULL, NULL, &err);
+  print_err(&err);
+  return res;
+}
+
+int init_db_connection(void) {
+  int res = sqlite3_open("db.sql", &db);
+  char *err = NULL;
+  if (!res) {
+    res = check_and_create_tables();
+  }
+
+  return 0;
+}
+
+void SHA256_raw_to_string(const unsigned char *passHashed, char *restrict out) {
+  int i;
+  for (i = 0; i < 4; i++) {
+    uint64_t *num_pointer = (uint64_t *)(passHashed + i * 8);
+    sprintf(out + 16 * i, "%016lx", htobe64(*num_pointer));
+  }
+}
+
+void string_to_SHA256(const char *str, char *restrict out) {
+  unsigned char md[SHA256_DIGEST_LENGTH];
+  unsigned char *passHashed = SHA256((unsigned char *)str, strlen(str), md);
+  SHA256_raw_to_string(passHashed, out);
+}
+
+int32_t db_user_auth(i_auth_t *c, o_auth_t *r) { return 0; }
+
+int32_t db_user_create(i_db_user_create *args) { return 0; }
+
+int32_t db_save_file(session *s) { return 0; }
+
+// TODO: get file
+s_file_t *db_get_file(i_get_file_db *arg) {
+  s_file_t *sf = NULL;
+
+  return sf;
+}
+
+uint64_t db_get_files_data(i_get_files_db *arg, fl_t **fl_start,
+                           uint64_t *full_count) {
+  fl_t *fl_current = NULL;
+  return 0;
+}

src/file_p.c

@@ -2,7 +2,7 @@
 /* Copyright (c) 2026 Oleksandr Zhylin */
 
 #include "file_p.h"
-#include "db.h"
+#include <db.h>
 #include "main.h"
 #include "session.h"
 #include <arpa/inet.h>

src/main.c

@@ -3,7 +3,7 @@
 
 #include "main.h"
 #include "server.h"
-#include "db.h"
+#include <db.h>
 #include <stdio.h>
 
 /* *** MAIN *** */
@@ -12,6 +12,7 @@ int main(int argc, char *argv[]) {
   prepare_start(argc, argv);
   server_data.welcome_message = get_welcome_mes();
   init_db_connection();
+  return 0;
   server_data.ls = start_server();
   /* TODO: display server port */
   printf("Server is started!\n");

src/session.c

@@ -3,7 +3,7 @@
 
 #include "session.h"
 #include "client.h"
-#include "db.h"
+#include <db.h>
 #include "file_p.h"
 #include "main.h"
 #include "user.h"

src/user.c

@@ -1,7 +1,7 @@
 /* SPDX-License-Identifier: MIT */
 /* Copyright (c) 2026 Oleksandr Zhylin */
 
-#include "db.h"
+#include <db.h>
 #include "main.h"
 #include "session.h"
 #include <stdint.h>