```

Add user authentication with password hashing

- Integrated Argon2 for password hashing and verification
- Added bcrypt and thiserror dependencies
- Updated database schema with admin and ban flags
- Implemented user account creation and login logic
- Enhanced error handling for database operations
```

src/client/mod.rs

@@ -4,6 +4,7 @@ pub(crate) mod handlers {
         Aes256Gcm, Key, Nonce,
     };
 
+    use crate::db::users::{check_for_account, create_user, hash_password, verify_password};
     use base64::{engine::general_purpose::STANDARD as BASE64, Engine as _};
     use log::{debug, error, info};
     use serde::Deserialize;
@@ -12,8 +13,6 @@ pub(crate) mod handlers {
     use tokio::net::TcpStream;
     use tokio::sync::broadcast;
     use x25519_dalek::{EphemeralSecret, PublicKey};
-
-    use crate::db::users::create_user;
     /*
         Specifications of the packet
         32 bytes - Command name
@@ -86,8 +85,90 @@ pub(crate) mod handlers {
         let username = Arc::new(String::from_utf8(decrypted)?);
         let username_read = Arc::clone(&username); // Clone the Arc for read task
         let username_write = Arc::clone(&username); // Clone the Arc for write task
+        info!("Username received: {}", username);
 
-        create_user(&username, "1234").await?;
+        // Check if the user already exists in the database
+        if check_for_account(&username).await? {
+            info!("User {} already exists", username);
+            // Send a message to the client
+            let message = format!("User {} is registered, input your password", username);
+            let encrypted = match cipher_writer.encrypt(&nonce_writer, message.as_bytes()) {
+                Ok(encrypted) => encrypted,
+                Err(e) => {
+                    error!("Encryption error: {}", e);
+                    return Ok(());
+                }
+            };
+            let message = format!("{}\n", BASE64.encode(&encrypted));
+            writer.write_all(message.as_bytes()).await?;
+
+            // Read the password from the client
+            line.clear();
+            reader.read_line(&mut line).await?;
+            let decoded = BASE64.decode(line.trim().as_bytes())?;
+            let decrypted = cipher_reader
+                .decrypt(&nonce_reader, decoded.as_ref())
+                .unwrap();
+            // verifiy password
+            let password = String::from_utf8(decrypted)?;
+            if verify_password(&password, &username).await.is_ok() {
+                info!("Password verified successfully");
+                // Send a success message to the client
+                let message = format!("Welcome back, {}!", username);
+                let encrypted = match cipher_writer.encrypt(&nonce_writer, message.as_bytes()) {
+                    Ok(encrypted) => encrypted,
+                    Err(e) => {
+                        error!("Encryption error: {}", e);
+                        return Ok(());
+                    }
+                };
+                let message = format!("{}\n", BASE64.encode(&encrypted));
+                writer.write_all(message.as_bytes()).await?;
+            } else {
+                info!("Password verification failed");
+                // Send an error message to the client
+                let message = format!("Invalid password for user {}", username);
+                let encrypted = match cipher_writer.encrypt(&nonce_writer, message.as_bytes()) {
+                    Ok(encrypted) => encrypted,
+                    Err(e) => {
+                        error!("Encryption error: {}", e);
+                        return Ok(());
+                    }
+                };
+                let message = format!("{}\n", BASE64.encode(&encrypted));
+                writer.write_all(message.as_bytes()).await?;
+                return Ok(());
+            }
+        } else {
+            // User does not exist, create a new account
+            // Send a message to the client
+            let message = format!("User {} is not registered, input your password", username);
+            let encrypted = match cipher_writer.encrypt(&nonce_writer, message.as_bytes()) {
+                Ok(encrypted) => encrypted,
+                Err(e) => {
+                    error!("Encryption error: {}", e);
+                    return Ok(());
+                }
+            };
+            let message = format!("{}\n", BASE64.encode(&encrypted));
+            writer.write_all(message.as_bytes()).await?;
+            // Read the password from the client
+            line.clear();
+            reader.read_line(&mut line).await?;
+            let decoded = BASE64.decode(line.trim().as_bytes())?;
+            let decrypted = cipher_reader
+                .decrypt(&nonce_reader, decoded.as_ref())
+                .unwrap();
+            let password = String::from_utf8(decrypted)?;
+            info!("Password received");
+            // Hash the password
+            let password_hash = hash_password(&password).await;
+            let password_hash = password_hash.as_str();
+            info!("Password hashed successfully");
+            debug!("Hash: {}", password_hash);
+            // Create the user in the database
+            create_user(&username, password_hash).await?;
+        }
 
         // Read task for receiving messages from the client
         let read_task = tokio::spawn(async move {

src/db/mod.rs

@@ -1,5 +1,21 @@
 pub(crate) mod users {
-    use sqlx::sqlite::SqlitePool;
+    use argon2::{
+        password_hash::{PasswordHash, PasswordHasher, PasswordVerifier, SaltString},
+        Argon2,
+    };
+    use log::info;
+    use sqlx::{sqlite::SqlitePool, Row};
+    use thiserror::Error;
+
+    #[derive(Error, Debug)]
+    pub enum DbError {
+        #[error("Database error: {0}")]
+        Database(#[from] sqlx::Error),
+        #[error("Password hashing error: {0}")]
+        Hashing(argon2::password_hash::Error),
+        #[error("User not found")]
+        UserNotFound,
+    }
 
     pub async fn connect_to_db() -> Result<SqlitePool, sqlx::Error> {
         let pool = SqlitePool::connect("sqlite:./db.sqlite").await?;
@@ -12,6 +28,46 @@ pub(crate) mod users {
         Ok(pool)
     }
 
+    pub async fn get_user_by_username(
+        username: &str,
+    ) -> Result<Option<(i64, String)>, sqlx::Error> {
+        let pool = create_db_pool().await?;
+
+        let user = sqlx::query(
+            r#"
+            SELECT id, username
+            FROM users
+            WHERE username = ?
+            "#,
+        )
+        .bind(username)
+        .fetch_optional(&pool)
+        .await?;
+
+        Ok(user.map(|row| (row.get(0), row.get(1))))
+    }
+
+    pub async fn check_for_account(username: &str) -> Result<bool, sqlx::Error> {
+        // Fixed error type
+        let pool = create_db_pool().await?;
+
+        let exists = sqlx::query(
+            r#"
+            SELECT EXISTS(
+                SELECT 1
+                FROM users
+                WHERE username = ?
+            )
+            "#,
+        )
+        .bind(username)
+        .fetch_one(&pool)
+        .await?
+        .get::<i64, _>(0);
+
+        Ok(exists == 1)
+    }
+
     pub async fn create_user(username: &str, password_hash: &str) -> Result<(), sqlx::Error> {
         let pool = create_db_pool().await?;
 
@@ -27,4 +83,67 @@ pub(crate) mod users {
         .await?;
         Ok(())
     }
+
+    pub async fn hash_password(password: &str) -> String {
+        let salt = SaltString::generate(&mut rand::thread_rng());
+        let argon2 = Argon2::default();
+        let password_hash = argon2
+            .hash_password(password.as_bytes(), &salt)
+            .expect("Failed to hash password");
+        password_hash.to_string()
+    }
+
+    pub async fn verify_password(
+        // Use clearer argument names
+        username: &str,
+        provided_password: &str,
+    ) -> Result<bool, DbError> {
+        let pool = create_db_pool().await?; // Propagates sqlx::Error
+
+        // Fetch the stored hash for the user
+        let user_row = sqlx::query(
+            r#"
+            SELECT password_hash
+            FROM users
+            WHERE username = ?
+            "#,
+        )
+        .bind(username)
+        .fetch_optional(&pool) // Use fetch_optional to handle not found case
+        .await?;
+
+        // Get the stored hash string or return error if user not found
+        let stored_hash_str = match user_row {
+            Some(row) => row.get::<String, _>(0),
+            None => return Err(DbError::UserNotFound),
+        };
+
+        // Parse the stored hash
+        let parsed_hash = PasswordHash::new(&stored_hash_str).map_err(DbError::Hashing)?; // Manually map the error
+
+        let argon2 = Argon2::default();
+
+        let verification_result =
+            argon2.verify_password(provided_password.as_bytes(), &parsed_hash);
+
+        // Check the result and return true/false accordingly
+        match verification_result {
+            Ok(()) => {
+                info!("Password check successful for user: {}", username);
+                Ok(true)
+            }
+            Err(argon2::password_hash::Error::Password) => {
+                info!("Password check failed (mismatch) for user: {}", username);
+                Ok(false)
+            }
+            Err(e) => {
+                // Handle other potential argon2 errors (e.g., invalid hash format)
+                info!(
+                    "Password check failed for user {} with error: {}",
+                    username, e
+                );
+                Err(DbError::Hashing(e))
+            }
+        }
+    }
 }

src/main.rs

@@ -1,6 +1,6 @@
 mod client;
-mod tui; // Add this new module
 mod db;
+mod tui;
 
 use client::handlers::handle_client;
 use db::users::create_db_pool;