From ce5834ab8060742de992d8792f5be97e8cc3d9b0 Mon Sep 17 00:00:00 2001
From: David Pedersen <david.pdrsn@gmail.com>
Date: Fri, 8 Oct 2021 16:51:22 +0200
Subject: [PATCH] Expand accepted content types for JSON requests (#378)

* Expand accepted content types for JSON requests

Fixes https://github.com/tokio-rs/axum/issues/375

* changelog

* add test for content type without spaces

* Don't accept `text/json`

* small clean up
---
 CHANGELOG.md     |  2 ++
 Cargo.toml       |  2 +-
 src/json.rs      | 33 +++++++++++++++++++++++++++++++--
 src/tests/mod.rs | 28 ++++++++++++++++++++++++++--
 4 files changed, 60 insertions(+), 5 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 68e4b00c..023bb58c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 # Unreleased
 
 - Improve performance of `BoxRoute` ([#339])
+- Expand accepted content types for JSON requests ([#378])
 - **breaking:** Automatically do percent decoding in `extract::Path`
   ([#272])
 - **breaking:** `Router::boxed` now the inner service to implement `Clone` and
@@ -19,6 +20,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 [#339]: https://github.com/tokio-rs/axum/pull/339
 [#286]: https://github.com/tokio-rs/axum/pull/286
 [#272]: https://github.com/tokio-rs/axum/pull/272
+[#378]: https://github.com/tokio-rs/axum/pull/378
 
 # 0.2.8 (07. October, 2021)
 
diff --git a/Cargo.toml b/Cargo.toml
index 682b92f2..6709a533 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -18,7 +18,7 @@ members = ["examples/*"]
 default = ["http1", "json", "tower-log"]
 http1 = ["hyper/http1"]
 http2 = ["hyper/http2"]
-json = ["serde_json"]
+json = ["serde_json", "mime"]
 multipart = ["multer", "mime"]
 tower-log = ["tower/log"]
 ws = ["tokio-tungstenite", "sha-1", "base64"]
diff --git a/src/json.rs b/src/json.rs
index 38d20593..11db3360 100644
--- a/src/json.rs
+++ b/src/json.rs
@@ -1,6 +1,6 @@
 use crate::BoxError;
 use crate::{
-    extract::{has_content_type, rejection::*, take_body, FromRequest, RequestParts},
+    extract::{rejection::*, take_body, FromRequest, RequestParts},
     response::IntoResponse,
 };
 use async_trait::async_trait;
@@ -103,7 +103,7 @@ where
     async fn from_request(req: &mut RequestParts<B>) -> Result<Self, Self::Rejection> {
         use bytes::Buf;
 
-        if has_content_type(req, "application/json")? {
+        if json_content_type(req)? {
             let body = take_body(req)?;
 
             let buf = hyper::body::aggregate(body)
@@ -119,6 +119,35 @@ where
     }
 }
 
+fn json_content_type<B>(req: &RequestParts<B>) -> Result<bool, HeadersAlreadyExtracted> {
+    let content_type = if let Some(content_type) = req
+        .headers()
+        .ok_or(HeadersAlreadyExtracted)?
+        .get(header::CONTENT_TYPE)
+    {
+        content_type
+    } else {
+        return Ok(false);
+    };
+
+    let content_type = if let Ok(content_type) = content_type.to_str() {
+        content_type
+    } else {
+        return Ok(false);
+    };
+
+    let mime = if let Ok(mime) = content_type.parse::<mime::Mime>() {
+        mime
+    } else {
+        return Ok(false);
+    };
+
+    let is_json_content_type = mime.type_() == "application"
+        && (mime.subtype() == "json" || mime.suffix().filter(|name| *name == "json").is_some());
+
+    Ok(is_json_content_type)
+}
+
 impl<T> Deref for Json<T> {
     type Target = T;
 
diff --git a/src/tests/mod.rs b/src/tests/mod.rs
index 6a8f0255..5d8d1516 100644
--- a/src/tests/mod.rs
+++ b/src/tests/mod.rs
@@ -6,7 +6,7 @@ use crate::{
     handler::{any, delete, get, on, patch, post, Handler},
     response::IntoResponse,
     routing::MethodFilter,
-    service, Router,
+    service, Json, Router,
 };
 use bytes::Bytes;
 use http::{
@@ -15,7 +15,7 @@ use http::{
 };
 use hyper::Body;
 use serde::Deserialize;
-use serde_json::json;
+use serde_json::{json, Value};
 use std::future::Ready;
 use std::{
     collections::HashMap,
@@ -515,6 +515,30 @@ async fn captures_dont_match_empty_segments() {
     assert_eq!(res.status(), StatusCode::OK);
 }
 
+#[tokio::test]
+async fn json_content_types() {
+    async fn valid_json_content_type(content_type: &str) -> bool {
+        println!("testing {:?}", content_type);
+
+        let app = Router::new().route("/", post(|Json(_): Json<Value>| async {}));
+
+        let res = TestClient::new(app)
+            .post("/")
+            .header("content-type", content_type)
+            .body("{}")
+            .send()
+            .await;
+
+        res.status() == StatusCode::OK
+    }
+
+    assert!(valid_json_content_type("application/json").await);
+    assert!(valid_json_content_type("application/json; charset=utf-8").await);
+    assert!(valid_json_content_type("application/json;charset=utf-8").await);
+    assert!(valid_json_content_type("application/cloudevents+json").await);
+    assert!(!valid_json_content_type("text/json").await);
+}
+
 pub(crate) fn assert_send<T: Send>() {}
 pub(crate) fn assert_sync<T: Sync>() {}
 pub(crate) fn assert_unpin<T: Unpin>() {}