feat(auth): AuthUser extractor, password helpers, token generation

crates/archivr-server/src/auth.rs

@@ -0,0 +1,127 @@
+use anyhow::Result;
+use argon2::{Argon2, PasswordHash, PasswordHasher, PasswordVerifier};
+use argon2::password_hash::{SaltString, rand_core::OsRng};
+use axum::{async_trait, extract::FromRequestParts, http::request::Parts};
+use axum_extra::extract::CookieJar;
+use rand::RngCore;
+
+use crate::routes::{ApiError, AppState};
+use archivr_core::database;
+
+// Role bit constants
+pub const ROLE_GUEST: u32 = 1;  // bit 0
+pub const ROLE_USER:  u32 = 2;  // bit 1
+pub const ROLE_ADMIN: u32 = 4;  // bit 2
+pub const ROLE_OWNER: u32 = 8;  // bit 3
+
+#[derive(Clone, Debug)]
+pub enum AuthUser {
+    Guest,
+    Authenticated { user_id: i64, role_bits: u32 },
+}
+
+impl AuthUser {
+    pub fn require_auth(&self) -> Result<(i64, u32), ApiError> {
+        match self {
+            AuthUser::Authenticated { user_id, role_bits } => Ok((*user_id, *role_bits)),
+            AuthUser::Guest => Err(ApiError::unauthorized("login required")),
+        }
+    }
+
+    pub fn require_role(&self, bit: u32) -> Result<(), ApiError> {
+        match self {
+            AuthUser::Authenticated { role_bits, .. } if role_bits & bit != 0 => Ok(()),
+            AuthUser::Authenticated { .. } => Err(ApiError::forbidden("insufficient permissions")),
+            AuthUser::Guest => Err(ApiError::unauthorized("login required")),
+        }
+    }
+
+    pub fn has_role(&self, bit: u32) -> bool {
+        matches!(self, AuthUser::Authenticated { role_bits, .. } if role_bits & bit != 0)
+    }
+}
+
+#[async_trait]
+impl FromRequestParts<AppState> for AuthUser {
+    type Rejection = std::convert::Infallible;
+
+    async fn from_request_parts(
+        parts: &mut Parts,
+        state: &AppState,
+    ) -> Result<Self, std::convert::Infallible> {
+        let auth_db_path = state.auth_db_path.as_ref();
+
+        // 1. Try session cookie
+        let jar = CookieJar::from_headers(&parts.headers);
+        if let Some(cookie) = jar.get("session") {
+            let session_uid = cookie.value().to_string();
+            if let Ok(conn) = database::open_auth_db(auth_db_path) {
+                if let Ok(Some(session)) = database::get_session(&conn, &session_uid) {
+                    // Conditional touch: only update if >60s since last_seen_at
+                    let should_touch = chrono::DateTime::parse_from_rfc3339(&session.last_seen_at)
+                        .map(|last| {
+                            chrono::Utc::now() - last.with_timezone(&chrono::Utc)
+                                > chrono::Duration::seconds(60)
+                        })
+                        .unwrap_or(true);
+                    if should_touch {
+                        let _ = database::touch_session(&conn, &session_uid);
+                    }
+                    return Ok(AuthUser::Authenticated {
+                        user_id: session.user_id,
+                        role_bits: session.role_bits,
+                    });
+                }
+            }
+        }
+
+        // 2. Try Bearer token
+        if let Some(auth_header) = parts.headers.get("Authorization") {
+            if let Ok(header_str) = auth_header.to_str() {
+                if let Some(raw_token) = header_str.strip_prefix("Bearer ") {
+                    let token_hash = hash_token(raw_token);
+                    if let Ok(conn) = database::open_auth_db(auth_db_path) {
+                        if let Ok(Some(user_id)) = database::get_user_for_token(&conn, &token_hash) {
+                            if let Ok(role_bits) = database::compute_role_bits(&conn, user_id) {
+                                return Ok(AuthUser::Authenticated { user_id, role_bits });
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        Ok(AuthUser::Guest)
+    }
+}
+
+// Password helpers
+
+pub fn hash_password(password: &str) -> Result<String> {
+    let salt = SaltString::generate(&mut OsRng);
+    let hash = Argon2::default()
+        .hash_password(password.as_bytes(), &salt)
+        .map_err(|e| anyhow::anyhow!("password hashing failed: {e}"))?
+        .to_string();
+    Ok(hash)
+}
+
+pub fn verify_password(password: &str, hash: &str) -> Result<bool> {
+    let parsed = PasswordHash::new(hash)
+        .map_err(|e| anyhow::anyhow!("invalid password hash: {e}"))?;
+    Ok(Argon2::default()
+        .verify_password(password.as_bytes(), &parsed)
+        .is_ok())
+}
+
+// Token helpers
+
+pub fn generate_token() -> String {
+    let mut bytes = [0u8; 32];
+    rand::thread_rng().fill_bytes(&mut bytes);
+    base64::Engine::encode(&base64::engine::general_purpose::URL_SAFE_NO_PAD, bytes)
+}
+
+pub fn hash_token(raw: &str) -> String {
+    archivr_core::hash::hash_bytes(raw.as_bytes())
+}