1 files changed, 61 insertions, 0 deletions
diff --git a/logic/src/login.rs b/logic/src/login.rs
new file mode 100644
index 0000000..e9c2f93
--- /dev/null
+++ b/logic/src/login.rs
@@ -0,0 +1,61 @@
+/*
+    This file is part of jellything (https://codeberg.org/metamuffin/jellything)
+    which is licensed under the GNU Affero General Public License (version 3); see /COPYING.
+    Copyright (C) 2025 metamuffin <metamuffin.org>
+*/
+use crate::session::create;
+use anyhow::{Result, anyhow};
+use argon2::{Argon2, PasswordHasher, password_hash::Salt};
+use jellybase::{CONF, database::Database};
+use jellycommon::user::UserPermission;
+use std::{collections::HashSet, time::Duration};
+
+pub fn login_logic(
+    database: &Database,
+    username: &str,
+    password: &str,
+    expire: Option<i64>,
+    drop_permissions: Option<HashSet<UserPermission>>,
+) -> Result<String> {
+    // hashing the password regardless if the accounts exists to better resist timing attacks
+    let password = hash_password(username, password);
+
+    let mut user = database
+        .get_user(username)?
+        .ok_or(anyhow!("invalid password"))?;
+
+    if user.password != password {
+        Err(anyhow!("invalid password"))?
+    }
+
+    if let Some(ep) = drop_permissions {
+        // remove all grant perms that are in `ep`
+        user.permissions
+            .0
+            .retain(|p, val| if *val { !ep.contains(p) } else { true })
+    }
+
+    Ok(create(
+        user.name,
+        user.permissions,
+        Duration::from_days(
+            CONF.login_expire
+                .min(expire.unwrap_or(i64::MAX))
+                .try_into()
+                .unwrap(),
+        ),
+    ))
+}
+
+pub fn hash_password(username: &str, password: &str) -> Vec<u8> {
+    Argon2::default()
+        .hash_password(
+            format!("{username}\0{password}").as_bytes(),
+            <&str as TryInto<Salt>>::try_into("IYMa13osbNeLJKnQ1T8LlA").unwrap(),
+        )
+        .unwrap()
+        .hash
+        .unwrap()
+        .as_bytes()
+        .to_vec()
+}