Consume authorization code on use

crates/core/sqlx-data.json

@@ -661,6 +661,18 @@
       ]
     }
   },
+  "eaddc1e33715ad31b4195fda72dbe870f179dd8da53a88d0543b72a278ed1d3d": {
+    "query": "\n            DELETE FROM oauth2_codes\n            WHERE id = $1\n        ",
+    "describe": {
+      "columns": [],
+      "parameters": {
+        "Left": [
+          "Int8"
+        ]
+      },
+      "nullable": []
+    }
+  },
   "f9a09ff53b6f221649f4f050e3d5ade114f852ddf50a78610a6c0ef0689af681": {
     "query": "\n            INSERT INTO users (username, hashed_password)\n            VALUES ($1, $2)\n            RETURNING id\n        ",
     "describe": {

crates/core/src/handlers/oauth2/token.rs

@@ -47,7 +47,7 @@ use crate::{
     },
     storage::oauth2::{
         access_token::{add_access_token, revoke_access_token},
-        authorization_code::lookup_code,
+        authorization_code::{consume_code, lookup_code},
         refresh_token::{add_refresh_token, lookup_refresh_token, replace_refresh_token},
     },
     tokens,
@@ -154,13 +154,13 @@ async fn authorization_code_grant(
     conn: &mut PoolConnection<Postgres>,
 ) -> Result<AccessTokenResponse, Rejection> {
     let mut txn = conn.begin().await.wrap_error()?;
+    // TODO: recover from failed code lookup with invalid_grant instead
     let code = lookup_code(&mut txn, &grant.code).await.wrap_error()?;
     if client.client_id != code.client_id {
         return error(UnauthorizedClient);
     }
 
     // TODO: verify PKCE
-    // TODO: make the code invalid
     let ttl = Duration::minutes(5);
     let (access_token, refresh_token) = {
         let mut rng = thread_rng();
@@ -208,6 +208,8 @@ async fn authorization_code_grant(
         .with_refresh_token(refresh_token.token)
         .with_id_token(id_token);
 
+    consume_code(&mut txn, code.id).await.wrap_error()?;
+
     txn.commit().await.wrap_error()?;
 
     Ok(params)

crates/core/src/storage/oauth2/authorization_code.rs

@@ -90,3 +90,29 @@ pub async fn lookup_code(
     .await
     .context("could not lookup oauth2 code")
 }
+
+pub async fn consume_code(
+    executor: impl Executor<'_, Database = Postgres>,
+    code_id: i64,
+) -> anyhow::Result<()> {
+    // TODO: mark the code as invalid instead to allow invalidating the whole
+    // session on code reuse
+    let res = sqlx::query!(
+        r#"
+            DELETE FROM oauth2_codes
+            WHERE id = $1
+        "#,
+        code_id,
+    )
+    .execute(executor)
+    .await
+    .context("could not consume authorization code")?;
+
+    if res.rows_affected() == 1 {
+        Ok(())
+    } else {
+        Err(anyhow::anyhow!(
+            "no row were affected when consuming authorization code"
+        ))
+    }
+}