added mobile auth support

src/auth.rs

@@ -1,7 +1,13 @@
+use chrono::{Duration, Utc};
 use cot::Body;
-use cot::db::Database;
+use cot::db::{Auto, Database, LimitedString, Model};
+use cot::http::header::AUTHORIZATION;
+use cot::request::RequestHead;
+use cot::request::extractors::FromRequestHead;
 use cot::response::IntoResponse;
 use cot::session::Session;
+use serde::Serialize;
+use sha2::{Digest, Sha256};
 
 use crate::user::User;
 
@@ -46,11 +52,7 @@ pub struct AuthenticatedUser {
     pub role: Role,
 }
 
-/// Read `user_id` from the session, fetch the `User` from DB, return
-/// `AuthenticatedUser` if the user exists and is active.
-pub async fn get_session_user(session: &Session, db: &Database) -> Option<AuthenticatedUser> {
-    let user_id: i64 = session.get(SESSION_USER_ID).await.ok()??;
-    let user = User::get_by_id(db, user_id).await.ok()??;
+fn authenticated_user_from_user(user: User) -> Option<AuthenticatedUser> {
     if !user.is_active() {
         return None;
     }
@@ -70,6 +72,362 @@ pub async fn get_session_user(session: &Session, db: &Database) -> Option<Authen
     })
 }
 
+/// Read `user_id` from the session, fetch the `User` from DB, return
+/// `AuthenticatedUser` if the user exists and is active.
+pub async fn get_session_user(session: &Session, db: &Database) -> Option<AuthenticatedUser> {
+    let user_id: i64 = session.get(SESSION_USER_ID).await.ok()??;
+    let user = User::get_by_id(db, user_id).await.ok()??;
+    authenticated_user_from_user(user)
+}
+
+// ---------------------------------------------------------------------------
+// API bearer-token auth
+// ---------------------------------------------------------------------------
+
+const ACCESS_TOKEN_PREFIX: &str = "furu_at_";
+const REFRESH_TOKEN_PREFIX: &str = "furu_rt_";
+const MOBILE_EXCHANGE_CODE_PREFIX: &str = "furu_mx_";
+const ACCESS_TOKEN_TTL_MINUTES: i64 = 15;
+const REFRESH_TOKEN_TTL_DAYS: i64 = 60;
+const MOBILE_EXCHANGE_CODE_TTL_MINUTES: i64 = 3;
+
+#[derive(Debug, Clone, Default)]
+pub struct AuthContext {
+    bearer_token: Option<String>,
+}
+
+impl AuthContext {
+    pub fn bearer_token(&self) -> Option<&str> {
+        self.bearer_token.as_deref()
+    }
+}
+
+impl FromRequestHead for AuthContext {
+    async fn from_request_head(head: &RequestHead) -> cot::Result<Self> {
+        let bearer_token = head
+            .headers
+            .get(AUTHORIZATION)
+            .and_then(|value| value.to_str().ok())
+            .and_then(parse_bearer_token)
+            .map(str::to_owned);
+        Ok(Self { bearer_token })
+    }
+}
+
+fn parse_bearer_token(header: &str) -> Option<&str> {
+    let header = header.trim();
+    let (scheme, token) = header.split_once(' ')?;
+    if !scheme.eq_ignore_ascii_case("Bearer") {
+        return None;
+    }
+    let token = token.trim();
+    if token.is_empty() || token.len() > 512 {
+        return None;
+    }
+    Some(token)
+}
+
+#[derive(Debug, Serialize)]
+pub struct ApiTokenPair {
+    pub access_token: String,
+    pub refresh_token: String,
+    pub token_type: &'static str,
+    pub expires_in_seconds: i64,
+}
+
+#[derive(Debug, Clone)]
+#[cot::db::model]
+pub struct ApiSession {
+    #[model(primary_key)]
+    id: Auto<i64>,
+    user_id: i64,
+    device_name: Option<String>,
+    access_token_hash: LimitedString<128>,
+    refresh_token_hash: LimitedString<128>,
+    access_expires_at: String,
+    refresh_expires_at: String,
+    created_at: String,
+    last_used_at: Option<String>,
+    revoked_at: Option<String>,
+}
+
+#[derive(Debug, Clone)]
+#[cot::db::model]
+pub struct MobileExchangeCode {
+    #[model(primary_key)]
+    id: Auto<i64>,
+    code_hash: LimitedString<128>,
+    user_id: i64,
+    created_at: String,
+    expires_at: String,
+    consumed_at: Option<String>,
+}
+
+impl ApiSession {
+    pub async fn create_for_user(
+        db: &Database,
+        user_id: i64,
+        device_name: Option<&str>,
+    ) -> cot::db::Result<ApiTokenPair> {
+        let tokens = fresh_token_pair();
+        let now = now_iso();
+        let mut session = Self {
+            id: Auto::auto(),
+            user_id,
+            device_name: device_name.and_then(normalize_device_name),
+            access_token_hash: LimitedString::new(&token_hash(&tokens.access_token)).unwrap(),
+            refresh_token_hash: LimitedString::new(&token_hash(&tokens.refresh_token)).unwrap(),
+            access_expires_at: access_expires_at(),
+            refresh_expires_at: refresh_expires_at(),
+            created_at: now.clone(),
+            last_used_at: Some(now),
+            revoked_at: None,
+        };
+        session.insert(db).await?;
+        Ok(tokens)
+    }
+
+    async fn find_by_access_token(db: &Database, token: &str) -> cot::db::Result<Option<Self>> {
+        let Ok(hash) = LimitedString::<128>::new(&token_hash(token)) else {
+            return Ok(None);
+        };
+        cot::db::query!(ApiSession, $access_token_hash == hash)
+            .get(db)
+            .await
+    }
+
+    async fn find_by_refresh_token(db: &Database, token: &str) -> cot::db::Result<Option<Self>> {
+        let Ok(hash) = LimitedString::<128>::new(&token_hash(token)) else {
+            return Ok(None);
+        };
+        cot::db::query!(ApiSession, $refresh_token_hash == hash)
+            .get(db)
+            .await
+    }
+
+    fn is_revoked(&self) -> bool {
+        self.revoked_at.is_some()
+    }
+
+    fn access_token_valid(&self) -> bool {
+        !self.is_revoked() && self.access_expires_at > now_iso()
+    }
+
+    fn refresh_token_valid(&self) -> bool {
+        !self.is_revoked() && self.refresh_expires_at > now_iso()
+    }
+
+    async fn rotate(&mut self, db: &Database) -> cot::db::Result<ApiTokenPair> {
+        let tokens = fresh_token_pair();
+        self.access_token_hash = LimitedString::new(&token_hash(&tokens.access_token)).unwrap();
+        self.refresh_token_hash = LimitedString::new(&token_hash(&tokens.refresh_token)).unwrap();
+        self.access_expires_at = access_expires_at();
+        self.refresh_expires_at = refresh_expires_at();
+        self.last_used_at = Some(now_iso());
+        self.save(db).await?;
+        Ok(tokens)
+    }
+
+    async fn revoke(&mut self, db: &Database) -> cot::db::Result<()> {
+        if self.revoked_at.is_none() {
+            self.revoked_at = Some(now_iso());
+            self.save(db).await?;
+        }
+        Ok(())
+    }
+}
+
+pub async fn create_api_session(
+    db: &Database,
+    user_id: i64,
+    device_name: Option<&str>,
+) -> cot::db::Result<ApiTokenPair> {
+    ApiSession::create_for_user(db, user_id, device_name).await
+}
+
+pub async fn get_bearer_user(db: &Database, token: &str) -> Option<AuthenticatedUser> {
+    let session = ApiSession::find_by_access_token(db, token).await.ok()??;
+    if !session.access_token_valid() {
+        return None;
+    }
+    let user = User::get_by_id(db, session.user_id).await.ok()??;
+    authenticated_user_from_user(user)
+}
+
+pub async fn get_request_user(
+    auth: &AuthContext,
+    session: &Session,
+    db: &Database,
+) -> Option<AuthenticatedUser> {
+    if let Some(token) = auth.bearer_token() {
+        return get_bearer_user(db, token).await;
+    }
+    get_session_user(session, db).await
+}
+
+pub async fn refresh_api_session(
+    db: &Database,
+    refresh_token: &str,
+) -> cot::db::Result<Option<ApiTokenPair>> {
+    let Some(mut session) = ApiSession::find_by_refresh_token(db, refresh_token).await? else {
+        return Ok(None);
+    };
+    if !session.refresh_token_valid() {
+        session.revoke(db).await?;
+        return Ok(None);
+    }
+    let Some(user) = User::get_by_id(db, session.user_id).await? else {
+        session.revoke(db).await?;
+        return Ok(None);
+    };
+    if !user.is_active() {
+        session.revoke(db).await?;
+        return Ok(None);
+    }
+    Ok(Some(session.rotate(db).await?))
+}
+
+pub async fn revoke_api_session(
+    db: &Database,
+    access_token: Option<&str>,
+    refresh_token: Option<&str>,
+) -> cot::db::Result<bool> {
+    let mut session = if let Some(token) = access_token {
+        ApiSession::find_by_access_token(db, token).await?
+    } else {
+        None
+    };
+    if session.is_none() {
+        if let Some(token) = refresh_token {
+            session = ApiSession::find_by_refresh_token(db, token).await?;
+        }
+    }
+    let Some(mut session) = session else {
+        return Ok(false);
+    };
+    session.revoke(db).await?;
+    Ok(true)
+}
+
+impl MobileExchangeCode {
+    pub async fn create_for_user(db: &Database, user_id: i64) -> cot::db::Result<String> {
+        let code = random_token(MOBILE_EXCHANGE_CODE_PREFIX);
+        let now = now_iso();
+        let mut row = Self {
+            id: Auto::auto(),
+            code_hash: LimitedString::new(&token_hash(&code)).unwrap(),
+            user_id,
+            created_at: now,
+            expires_at: mobile_exchange_code_expires_at(),
+            consumed_at: None,
+        };
+        row.insert(db).await?;
+        Ok(code)
+    }
+
+    async fn find_by_code(db: &Database, code: &str) -> cot::db::Result<Option<Self>> {
+        let Ok(hash) = LimitedString::<128>::new(&token_hash(code)) else {
+            return Ok(None);
+        };
+        cot::db::query!(MobileExchangeCode, $code_hash == hash)
+            .get(db)
+            .await
+    }
+
+    fn is_valid(&self) -> bool {
+        self.consumed_at.is_none() && self.expires_at > now_iso()
+    }
+
+    async fn consume(&mut self, db: &Database) -> cot::db::Result<()> {
+        self.consumed_at = Some(now_iso());
+        self.save(db).await
+    }
+}
+
+pub async fn create_mobile_exchange_code(db: &Database, user_id: i64) -> cot::db::Result<String> {
+    MobileExchangeCode::create_for_user(db, user_id).await
+}
+
+pub async fn exchange_mobile_code_for_api_session(
+    db: &Database,
+    code: &str,
+    device_name: Option<&str>,
+) -> cot::db::Result<Option<(AuthenticatedUser, ApiTokenPair)>> {
+    let Some(mut exchange_code) = MobileExchangeCode::find_by_code(db, code).await? else {
+        return Ok(None);
+    };
+    if !exchange_code.is_valid() {
+        return Ok(None);
+    }
+    let Some(user) = User::get_by_id(db, exchange_code.user_id).await? else {
+        exchange_code.consume(db).await?;
+        return Ok(None);
+    };
+    let Some(auth_user) = authenticated_user_from_user(user) else {
+        exchange_code.consume(db).await?;
+        return Ok(None);
+    };
+    exchange_code.consume(db).await?;
+    let tokens = ApiSession::create_for_user(db, auth_user.id, device_name).await?;
+    Ok(Some((auth_user, tokens)))
+}
+
+fn fresh_token_pair() -> ApiTokenPair {
+    ApiTokenPair {
+        access_token: random_token(ACCESS_TOKEN_PREFIX),
+        refresh_token: random_token(REFRESH_TOKEN_PREFIX),
+        token_type: "Bearer",
+        expires_in_seconds: ACCESS_TOKEN_TTL_MINUTES * 60,
+    }
+}
+
+fn random_token(prefix: &str) -> String {
+    format!(
+        "{prefix}{}{}",
+        uuid::Uuid::new_v4().simple(),
+        uuid::Uuid::new_v4().simple()
+    )
+}
+
+fn token_hash(token: &str) -> String {
+    let digest = Sha256::digest(token.as_bytes());
+    let mut out = String::with_capacity(digest.len() * 2);
+    for byte in digest {
+        out.push_str(&format!("{byte:02x}"));
+    }
+    out
+}
+
+fn normalize_device_name(name: &str) -> Option<String> {
+    let trimmed = name.trim();
+    if trimmed.is_empty() {
+        return None;
+    }
+    Some(trimmed.chars().take(255).collect())
+}
+
+fn now_iso() -> String {
+    Utc::now().format("%Y-%m-%dT%H:%M:%SZ").to_string()
+}
+
+fn access_expires_at() -> String {
+    (Utc::now() + Duration::minutes(ACCESS_TOKEN_TTL_MINUTES))
+        .format("%Y-%m-%dT%H:%M:%SZ")
+        .to_string()
+}
+
+fn refresh_expires_at() -> String {
+    (Utc::now() + Duration::days(REFRESH_TOKEN_TTL_DAYS))
+        .format("%Y-%m-%dT%H:%M:%SZ")
+        .to_string()
+}
+
+fn mobile_exchange_code_expires_at() -> String {
+    (Utc::now() + Duration::minutes(MOBILE_EXCHANGE_CODE_TTL_MINUTES))
+        .format("%Y-%m-%dT%H:%M:%SZ")
+        .to_string()
+}
+
 /// Return `Ok(user)` if the session belongs to an active admin, otherwise
 /// `Err(response)` — a redirect to `/login` or a 403.
 pub async fn require_admin_or_redirect(
@@ -159,6 +517,192 @@ pub fn redirect(location: &str) -> cot::response::Response {
         .expect("valid response")
 }
 
+// ---------------------------------------------------------------------------
+// Migrations
+// ---------------------------------------------------------------------------
+
+pub mod db_migrations {
+    use cot::db::migrations::{self, Field, Operation, SyncDynMigration};
+    use cot::db::{DatabaseField, Identifier, LimitedString};
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0038CreateApiSession;
+
+    impl migrations::Migration for M0038CreateApiSession {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0038_create_api_session";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0003_create_user",
+            )];
+        const OPERATIONS: &'static [Operation] = &[Operation::create_model()
+            .table_name(Identifier::new("furumusic__api_session"))
+            .fields(&[
+                Field::new(Identifier::new("id"), <i64 as DatabaseField>::TYPE)
+                    .primary_key()
+                    .auto(),
+                Field::new(Identifier::new("user_id"), <i64 as DatabaseField>::TYPE),
+                Field::new(
+                    Identifier::new("device_name"),
+                    <String as DatabaseField>::TYPE,
+                )
+                .set_null(true),
+                Field::new(
+                    Identifier::new("access_token_hash"),
+                    <LimitedString<128> as DatabaseField>::TYPE,
+                ),
+                Field::new(
+                    Identifier::new("refresh_token_hash"),
+                    <LimitedString<128> as DatabaseField>::TYPE,
+                ),
+                Field::new(
+                    Identifier::new("access_expires_at"),
+                    <String as DatabaseField>::TYPE,
+                ),
+                Field::new(
+                    Identifier::new("refresh_expires_at"),
+                    <String as DatabaseField>::TYPE,
+                ),
+                Field::new(
+                    Identifier::new("created_at"),
+                    <String as DatabaseField>::TYPE,
+                ),
+                Field::new(
+                    Identifier::new("last_used_at"),
+                    <String as DatabaseField>::TYPE,
+                )
+                .set_null(true),
+                Field::new(
+                    Identifier::new("revoked_at"),
+                    <String as DatabaseField>::TYPE,
+                )
+                .set_null(true),
+            ])
+            .build()];
+    }
+
+    #[cot::db::migrations::migration_op]
+    async fn create_api_session_indexes(
+        ctx: migrations::MigrationContext<'_>,
+    ) -> cot::db::Result<()> {
+        ctx.db
+            .raw(
+                "CREATE UNIQUE INDEX idx_api_session_access_token_hash \
+                     ON furumusic__api_session (access_token_hash)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE UNIQUE INDEX idx_api_session_refresh_token_hash \
+                     ON furumusic__api_session (refresh_token_hash)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX idx_api_session_user_id \
+                     ON furumusic__api_session (user_id)",
+            )
+            .await?;
+        Ok(())
+    }
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0039CreateApiSessionIndexes;
+
+    impl migrations::Migration for M0039CreateApiSessionIndexes {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0039_create_api_session_indexes";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0038_create_api_session",
+            )];
+        const OPERATIONS: &'static [Operation] =
+            &[Operation::custom(create_api_session_indexes).build()];
+    }
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0040CreateMobileExchangeCode;
+
+    impl migrations::Migration for M0040CreateMobileExchangeCode {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0040_create_mobile_exchange_code";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0039_create_api_session_indexes",
+            )];
+        const OPERATIONS: &'static [Operation] = &[Operation::create_model()
+            .table_name(Identifier::new("furumusic__mobile_exchange_code"))
+            .fields(&[
+                Field::new(Identifier::new("id"), <i64 as DatabaseField>::TYPE)
+                    .primary_key()
+                    .auto(),
+                Field::new(
+                    Identifier::new("code_hash"),
+                    <LimitedString<128> as DatabaseField>::TYPE,
+                ),
+                Field::new(Identifier::new("user_id"), <i64 as DatabaseField>::TYPE),
+                Field::new(
+                    Identifier::new("created_at"),
+                    <String as DatabaseField>::TYPE,
+                ),
+                Field::new(
+                    Identifier::new("expires_at"),
+                    <String as DatabaseField>::TYPE,
+                ),
+                Field::new(
+                    Identifier::new("consumed_at"),
+                    <String as DatabaseField>::TYPE,
+                )
+                .set_null(true),
+            ])
+            .build()];
+    }
+
+    #[cot::db::migrations::migration_op]
+    async fn create_mobile_exchange_code_indexes(
+        ctx: migrations::MigrationContext<'_>,
+    ) -> cot::db::Result<()> {
+        ctx.db
+            .raw(
+                "CREATE UNIQUE INDEX idx_mobile_exchange_code_hash \
+                     ON furumusic__mobile_exchange_code (code_hash)",
+            )
+            .await?;
+        ctx.db
+            .raw(
+                "CREATE INDEX idx_mobile_exchange_code_user_id \
+                     ON furumusic__mobile_exchange_code (user_id)",
+            )
+            .await?;
+        Ok(())
+    }
+
+    #[derive(Debug, Copy, Clone)]
+    pub struct M0041CreateMobileExchangeCodeIndexes;
+
+    impl migrations::Migration for M0041CreateMobileExchangeCodeIndexes {
+        const APP_NAME: &'static str = "furumusic";
+        const MIGRATION_NAME: &'static str = "m_0041_create_mobile_exchange_code_indexes";
+        const DEPENDENCIES: &'static [migrations::MigrationDependency] =
+            &[migrations::MigrationDependency::migration(
+                "furumusic",
+                "m_0040_create_mobile_exchange_code",
+            )];
+        const OPERATIONS: &'static [Operation] =
+            &[Operation::custom(create_mobile_exchange_code_indexes).build()];
+    }
+
+    pub const MIGRATIONS: &[&SyncDynMigration] = &[
+        &M0038CreateApiSession,
+        &M0039CreateApiSessionIndexes,
+        &M0040CreateMobileExchangeCode,
+        &M0041CreateMobileExchangeCodeIndexes,
+    ];
+}
+
 // ---------------------------------------------------------------------------
 // Tests
 // ---------------------------------------------------------------------------