From 9296b24c434eedac61a3154c32750d42a11674ea Mon Sep 17 00:00:00 2001 From: BlackDex Date: Sun, 26 Apr 2026 14:27:09 +0200 Subject: [PATCH] Ensure SSO token is only usable on the same client This commit adds an extra check via cookies to ensure the same browser/client is used to request and provide the SSO token. Previously it would be able to provide a custom link which attackers could use to steal data. While an attacker would still need the Master Password to be able to decrypt or execute specific actions, they were able to fetch encrypted data. Solved with some help of Claude Code. Signed-off-by: BlackDex --- .../down.sql | 1 + .../2026-04-25-120000_sso_auth_binding/up.sql | 1 + .../down.sql | 1 + .../2026-04-25-120000_sso_auth_binding/up.sql | 1 + .../down.sql | 1 + .../2026-04-25-120000_sso_auth_binding/up.sql | 1 + src/api/identity.rs | 43 +++++++++++++++++-- src/crypto.rs | 7 +++ src/db/models/sso_auth.rs | 10 ++++- src/db/schema.rs | 1 + src/sso.rs | 3 +- src/sso_client.rs | 3 +- 12 files changed, 66 insertions(+), 7 deletions(-) create mode 100644 migrations/mysql/2026-04-25-120000_sso_auth_binding/down.sql create mode 100644 migrations/mysql/2026-04-25-120000_sso_auth_binding/up.sql create mode 100644 migrations/postgresql/2026-04-25-120000_sso_auth_binding/down.sql create mode 100644 migrations/postgresql/2026-04-25-120000_sso_auth_binding/up.sql create mode 100644 migrations/sqlite/2026-04-25-120000_sso_auth_binding/down.sql create mode 100644 migrations/sqlite/2026-04-25-120000_sso_auth_binding/up.sql diff --git a/migrations/mysql/2026-04-25-120000_sso_auth_binding/down.sql b/migrations/mysql/2026-04-25-120000_sso_auth_binding/down.sql new file mode 100644 index 00000000..17e3d8c7 --- /dev/null +++ b/migrations/mysql/2026-04-25-120000_sso_auth_binding/down.sql @@ -0,0 +1 @@ +ALTER TABLE sso_auth DROP COLUMN binding_hash; diff --git a/migrations/mysql/2026-04-25-120000_sso_auth_binding/up.sql b/migrations/mysql/2026-04-25-120000_sso_auth_binding/up.sql new file mode 100644 index 00000000..53ee8063 --- /dev/null +++ b/migrations/mysql/2026-04-25-120000_sso_auth_binding/up.sql @@ -0,0 +1 @@ +ALTER TABLE sso_auth ADD COLUMN binding_hash TEXT; diff --git a/migrations/postgresql/2026-04-25-120000_sso_auth_binding/down.sql b/migrations/postgresql/2026-04-25-120000_sso_auth_binding/down.sql new file mode 100644 index 00000000..17e3d8c7 --- /dev/null +++ b/migrations/postgresql/2026-04-25-120000_sso_auth_binding/down.sql @@ -0,0 +1 @@ +ALTER TABLE sso_auth DROP COLUMN binding_hash; diff --git a/migrations/postgresql/2026-04-25-120000_sso_auth_binding/up.sql b/migrations/postgresql/2026-04-25-120000_sso_auth_binding/up.sql new file mode 100644 index 00000000..53ee8063 --- /dev/null +++ b/migrations/postgresql/2026-04-25-120000_sso_auth_binding/up.sql @@ -0,0 +1 @@ +ALTER TABLE sso_auth ADD COLUMN binding_hash TEXT; diff --git a/migrations/sqlite/2026-04-25-120000_sso_auth_binding/down.sql b/migrations/sqlite/2026-04-25-120000_sso_auth_binding/down.sql new file mode 100644 index 00000000..17e3d8c7 --- /dev/null +++ b/migrations/sqlite/2026-04-25-120000_sso_auth_binding/down.sql @@ -0,0 +1 @@ +ALTER TABLE sso_auth DROP COLUMN binding_hash; diff --git a/migrations/sqlite/2026-04-25-120000_sso_auth_binding/up.sql b/migrations/sqlite/2026-04-25-120000_sso_auth_binding/up.sql new file mode 100644 index 00000000..53ee8063 --- /dev/null +++ b/migrations/sqlite/2026-04-25-120000_sso_auth_binding/up.sql @@ -0,0 +1 @@ +ALTER TABLE sso_auth ADD COLUMN binding_hash TEXT; diff --git a/src/api/identity.rs b/src/api/identity.rs index 72323f73..f9f581bb 100644 --- a/src/api/identity.rs +++ b/src/api/identity.rs @@ -2,6 +2,7 @@ use chrono::Utc; use num_traits::FromPrimitive; use rocket::{ form::{Form, FromForm}, + http::{Cookie, CookieJar, SameSite}, response::Redirect, serde::json::Json, Route, @@ -23,7 +24,8 @@ use crate::{ ApiResult, EmptyResult, JsonResult, }, auth, - auth::{generate_organization_api_key_login_claims, AuthMethod, ClientHeaders, ClientIp, ClientVersion}, + auth::{generate_organization_api_key_login_claims, AuthMethod, ClientHeaders, ClientIp, ClientVersion, Secure}, + crypto, db::{ models::{ AuthRequest, AuthRequestId, Device, DeviceId, EventType, Invitation, OIDCCodeWrapper, OrganizationApiKey, @@ -1133,13 +1135,16 @@ fn prevalidate() -> JsonResult { } } +const SSO_BINDING_COOKIE: &str = "VW_SSO_BINDING"; + #[get("/connect/oidc-signin?&", rank = 1)] -async fn oidcsignin(code: OIDCCode, state: String, mut conn: DbConn) -> ApiResult { +async fn oidcsignin(code: OIDCCode, state: String, cookies: &CookieJar<'_>, mut conn: DbConn) -> ApiResult { _oidcsignin_redirect( state, OIDCCodeWrapper::Ok { code, }, + cookies, &mut conn, ) .await @@ -1152,6 +1157,7 @@ async fn oidcsignin_error( state: String, error: String, error_description: Option, + cookies: &CookieJar<'_>, mut conn: DbConn, ) -> ApiResult { _oidcsignin_redirect( @@ -1160,6 +1166,7 @@ async fn oidcsignin_error( error, error_description, }, + cookies, &mut conn, ) .await @@ -1171,6 +1178,7 @@ async fn oidcsignin_error( async fn _oidcsignin_redirect( base64_state: String, code_response: OIDCCodeWrapper, + cookies: &CookieJar<'_>, conn: &mut DbConn, ) -> ApiResult { let state = sso::decode_state(&base64_state)?; @@ -1179,6 +1187,17 @@ async fn _oidcsignin_redirect( None => err!(format!("Cannot retrieve sso_auth for {state}")), Some(sso_auth) => sso_auth, }; + + // Browser-binding check + // The cookie was set on /connect/authorize and must come from the same browser that initiated the flow. + let cookie_value = cookies.get(SSO_BINDING_COOKIE).map(|c| c.value().to_string()); + let provided_hash = cookie_value.as_deref().map(|v| crypto::sha256_hex(v.as_bytes())); + match (sso_auth.binding_hash.as_deref(), provided_hash.as_deref()) { + (Some(expected), Some(actual)) if crypto::ct_eq(expected, actual) => {} + _ => err!(format!("SSO session binding mismatch for {state}")), + } + cookies.remove(Cookie::build(SSO_BINDING_COOKIE).path("/identity/connect/").build()); + sso_auth.code_response = Some(code_response); sso_auth.updated_at = Utc::now().naive_utc(); sso_auth.save(conn).await?; @@ -1225,7 +1244,7 @@ struct AuthorizeData { // The `redirect_uri` will change depending of the client (web, android, ios ..) #[get("/connect/authorize?")] -async fn authorize(data: AuthorizeData, conn: DbConn) -> ApiResult { +async fn authorize(data: AuthorizeData, cookies: &CookieJar<'_>, secure: Secure, conn: DbConn) -> ApiResult { let AuthorizeData { client_id, redirect_uri, @@ -1239,7 +1258,23 @@ async fn authorize(data: AuthorizeData, conn: DbConn) -> ApiResult { err!("Unsupported code challenge method"); } - let auth_url = sso::authorize_url(state, code_challenge, &client_id, &redirect_uri, conn).await?; + // Generate browser-binding token. Stored hashed in DB; raw value handed to the browser as a cookie. + // Validated on /connect/oidc-signin + let binding_token = data_encoding::BASE64URL_NOPAD.encode(&crypto::get_random_bytes::<32>()); + let binding_hash = crypto::sha256_hex(binding_token.as_bytes()); + + let auth_url = + sso::authorize_url(state, code_challenge, &client_id, &redirect_uri, Some(binding_hash), conn).await?; + + cookies.add( + Cookie::build((SSO_BINDING_COOKIE, binding_token)) + .path("/identity/connect/") + .max_age(time::Duration::seconds(sso::SSO_AUTH_EXPIRATION.num_seconds())) + .same_site(SameSite::Lax) // Lax is needed because the IdP runs on a different FQDN + .http_only(true) + .secure(secure.https) + .build(), + ); Ok(Redirect::temporary(String::from(auth_url))) } diff --git a/src/crypto.rs b/src/crypto.rs index 1930f380..46d305a5 100644 --- a/src/crypto.rs +++ b/src/crypto.rs @@ -113,3 +113,10 @@ pub fn ct_eq, U: AsRef<[u8]>>(a: T, b: U) -> bool { use subtle::ConstantTimeEq; a.as_ref().ct_eq(b.as_ref()).into() } + +// +// SHA256 +// +pub fn sha256_hex(data: &[u8]) -> String { + HEXLOWER.encode(digest::digest(&digest::SHA256, data).as_ref()) +} diff --git a/src/db/models/sso_auth.rs b/src/db/models/sso_auth.rs index fec0433a..2c6eec6d 100644 --- a/src/db/models/sso_auth.rs +++ b/src/db/models/sso_auth.rs @@ -54,11 +54,18 @@ pub struct SsoAuth { pub auth_response: Option, pub created_at: NaiveDateTime, pub updated_at: NaiveDateTime, + pub binding_hash: Option, } /// Local methods impl SsoAuth { - pub fn new(state: OIDCState, client_challenge: OIDCCodeChallenge, nonce: String, redirect_uri: String) -> Self { + pub fn new( + state: OIDCState, + client_challenge: OIDCCodeChallenge, + nonce: String, + redirect_uri: String, + binding_hash: Option, + ) -> Self { let now = Utc::now().naive_utc(); SsoAuth { @@ -70,6 +77,7 @@ impl SsoAuth { updated_at: now, code_response: None, auth_response: None, + binding_hash, } } } diff --git a/src/db/schema.rs b/src/db/schema.rs index 914b4fe9..147440e5 100644 --- a/src/db/schema.rs +++ b/src/db/schema.rs @@ -265,6 +265,7 @@ table! { auth_response -> Nullable, created_at -> Timestamp, updated_at -> Timestamp, + binding_hash -> Nullable, } } diff --git a/src/sso.rs b/src/sso.rs index 26ea7375..7505f84f 100644 --- a/src/sso.rs +++ b/src/sso.rs @@ -188,6 +188,7 @@ pub async fn authorize_url( client_challenge: OIDCCodeChallenge, client_id: &str, raw_redirect_uri: &str, + binding_hash: Option, conn: DbConn, ) -> ApiResult { let redirect_uri = match client_id { @@ -203,7 +204,7 @@ pub async fn authorize_url( _ => err!(format!("Unsupported client {client_id}")), }; - let (auth_url, sso_auth) = Client::authorize_url(state, client_challenge, redirect_uri).await?; + let (auth_url, sso_auth) = Client::authorize_url(state, client_challenge, redirect_uri, binding_hash).await?; sso_auth.save(&conn).await?; Ok(auth_url) } diff --git a/src/sso_client.rs b/src/sso_client.rs index 6204ab48..abff6bcb 100644 --- a/src/sso_client.rs +++ b/src/sso_client.rs @@ -117,6 +117,7 @@ impl Client { state: OIDCState, client_challenge: OIDCCodeChallenge, redirect_uri: String, + binding_hash: Option, ) -> ApiResult<(Url, SsoAuth)> { let scopes = CONFIG.sso_scopes_vec().into_iter().map(Scope::new); let base64_state = data_encoding::BASE64.encode(state.to_string().as_bytes()); @@ -139,7 +140,7 @@ impl Client { } let (auth_url, _, nonce) = auth_req.url(); - Ok((auth_url, SsoAuth::new(state, client_challenge, nonce.secret().clone(), redirect_uri))) + Ok((auth_url, SsoAuth::new(state, client_challenge, nonce.secret().clone(), redirect_uri, binding_hash))) } pub async fn exchange_code(