Include content-type header in Request

The extract method may either produce a v1 or v2 type depending on
its state.

payjoin-cli/src/app/v1.rs

@@ -65,7 +65,7 @@ impl AppTrait for App {
         println!("Sending fallback request to {}", &req.url);
         let response = http
             .post(req.url)
-            .header("Content-Type", payjoin::V1_REQ_CONTENT_TYPE)
+            .header("Content-Type", req.content_type)
             .body(body.clone())
             .send()
             .await

payjoin-cli/src/app/v2.rs

@@ -92,7 +92,7 @@ impl AppTrait for App {
         let http = http_agent()?;
         let ohttp_response = http
             .post(req.url)
-            .header("Content-Type", payjoin::V2_REQ_CONTENT_TYPE)
+            .header("Content-Type", req.content_type)
             .body(req.body)
             .send()
             .await
@@ -156,7 +156,7 @@ impl App {
         let http = http_agent()?;
         let res = http
             .post(req.url)
-            .header("Content-Type", payjoin::V2_REQ_CONTENT_TYPE)
+            .header("Content-Type", req.content_type)
             .body(req.body)
             .send()
             .await
@@ -219,7 +219,7 @@ impl App {
             let http = http_agent()?;
             let response = http
                 .post(req.url)
-                .header("Content-Type", payjoin::V2_REQ_CONTENT_TYPE)
+                .header("Content-Type", req.content_type)
                 .body(req.body)
                 .send()
                 .await
@@ -251,7 +251,7 @@ impl App {
             let http = http_agent()?;
             let ohttp_response = http
                 .post(req.url)
-                .header("Content-Type", payjoin::V2_REQ_CONTENT_TYPE)
+                .header("Content-Type", req.content_type)
                 .body(req.body)
                 .send()
                 .await

payjoin/src/receive/v2/mod.rs

@@ -91,7 +91,7 @@ impl SessionInitializer {
             self.context.directory.as_str(),
             Some(subdirectory.as_bytes()),
         )?;
-        let req = Request { url, body };
+        let req = Request::new_v2(url, body);
         Ok((req, ctx))
     }
 
@@ -130,7 +130,7 @@ impl ActiveSession {
         let (body, ohttp_ctx) =
             self.fallback_req_body().map_err(InternalSessionError::OhttpEncapsulationError)?;
         let url = self.context.ohttp_relay.clone();
-        let req = Request { url, body };
+        let req = Request::new_v2(url, body);
         Ok((req, ohttp_ctx))
     }
 
@@ -479,7 +479,7 @@ impl PayjoinProposal {
             Some(&body),
         )?;
         let url = self.context.ohttp_relay.clone();
-        let req = Request { url, body };
+        let req = Request::new_v2(url, body);
         Ok((req, ctx))
     }
 

payjoin/src/request.rs

@@ -6,6 +6,7 @@ pub const V1_REQ_CONTENT_TYPE: &str = "text/plain";
 pub const V2_REQ_CONTENT_TYPE: &str = "message/ohttp-req";
 
 /// Represents data that needs to be transmitted to the receiver or payjoin directory.
+/// Ensure the `Content-Length` is set to the length of `body`. (most libraries do this automatically)
 #[non_exhaustive]
 #[derive(Debug, Clone)]
 pub struct Request {
@@ -14,10 +15,24 @@ pub struct Request {
     /// This is full URL with scheme etc - you can pass it right to `reqwest` or a similar library.
     pub url: Url,
 
+    /// The `Content-Type` header to use for the request.
+    ///
+    /// `text/plain` for v1 requests and `message/ohttp-req` for v2 requests.
+    pub content_type: &'static str,
+
     /// Bytes to be sent to the receiver.
     ///
-    /// This is properly encoded PSBT, already in base64. You only need to make sure `Content-Type`
-    /// is appropriate (`text/plain` for v1 requests and 'message/ohttp-req' for v2)
-    /// and `Content-Length` is `body.len()` (most libraries do the latter automatically).
+    /// This is properly encoded PSBT payload either in base64 in v1 or an OHTTP encapsulated payload in v2.
     pub body: Vec<u8>,
 }
+
+impl Request {
+    pub fn new_v1(url: Url, body: Vec<u8>) -> Self {
+        Self { url, content_type: V1_REQ_CONTENT_TYPE, body }
+    }
+
+    #[cfg(feature = "v2")]
+    pub fn new_v2(url: Url, body: Vec<u8>) -> Self {
+        Self { url, content_type: V2_REQ_CONTENT_TYPE, body }
+    }
+}

payjoin/src/send/mod.rs

@@ -312,7 +312,7 @@ impl RequestContext {
         .map_err(InternalCreateRequestError::Url)?;
         let body = self.psbt.to_string().as_bytes().to_vec();
         Ok((
-            Request { url, body },
+            Request::new_v1(url, body),
             ContextV1 {
                 original_psbt: self.psbt.clone(),
                 disable_output_substitution: self.disable_output_substitution,
@@ -358,7 +358,7 @@ impl RequestContext {
                         .map_err(InternalCreateRequestError::OhttpEncapsulation)?;
                 log::debug!("ohttp_relay_url: {:?}", ohttp_relay);
                 return Ok((
-                    Request { url: ohttp_relay, body },
+                    Request::new_v2(ohttp_relay, body),
                     // this method may be called more than once to re-construct the ohttp, therefore we must clone (or TODO memoize)
                     ContextV2 {
                         context_v1: ContextV1 {

payjoin/tests/integration.rs

@@ -49,7 +49,7 @@ mod integration {
             let (req, ctx) = RequestBuilder::from_psbt_and_uri(psbt, uri)?
                 .build_with_additional_fee(Amount::from_sat(10000), None, FeeRate::ZERO, false)?
                 .extract_v1()?;
-            let headers = HeaderMock::from_vec(&req.body);
+            let headers = HeaderMock::new(&req.body, req.content_type);
 
             // **********************
             // Inside the Receiver:
@@ -347,11 +347,11 @@ mod integration {
                 let psbt = build_sweep_psbt(&sender, &pj_uri)?;
                 let mut req_ctx = RequestBuilder::from_psbt_and_uri(psbt.clone(), pj_uri.clone())?
                     .build_recommended(payjoin::bitcoin::FeeRate::BROADCAST_MIN)?;
-                let (Request { url, body, .. }, send_ctx) =
+                let (Request { url, body, content_type, .. }, send_ctx) =
                     req_ctx.extract_v2(directory.to_owned())?;
                 let response = agent
                     .post(url.clone())
-                    .header("Content-Type", payjoin::V1_REQ_CONTENT_TYPE)
+                    .header("Content-Type", content_type)
                     .body(body.clone())
                     .send()
                     .await
@@ -419,7 +419,7 @@ mod integration {
             let mut req_ctx = RequestBuilder::from_psbt_and_uri(psbt.clone(), pj_uri.clone())?
                 .build_recommended(payjoin::bitcoin::FeeRate::BROADCAST_MIN)?;
             let (req, ctx) = req_ctx.extract_v2(EXAMPLE_URL.to_owned())?;
-            let headers = HeaderMock::from_vec(&req.body);
+            let headers = HeaderMock::new(&req.body, req.content_type);
 
             // **********************
             // Inside the Receiver:
@@ -488,7 +488,7 @@ mod integration {
                     .check_pj_supported()
                     .unwrap();
                 let psbt = build_original_psbt(&sender, &pj_uri)?;
-                let (Request { url, body, .. }, send_ctx) =
+                let (Request { url, body, content_type, .. }, send_ctx) =
                     RequestBuilder::from_psbt_and_uri(psbt, pj_uri)?
                         .build_with_additional_fee(
                             Amount::from_sat(10000),
@@ -500,7 +500,7 @@ mod integration {
                 log::info!("send fallback v1 to offline receiver fail");
                 let res = agent
                     .post(url.clone())
-                    .header("Content-Type", payjoin::V1_REQ_CONTENT_TYPE)
+                    .header("Content-Type", content_type)
                     .body(body.clone())
                     .send()
                     .await;
@@ -543,12 +543,8 @@ mod integration {
                 // **********************
                 // send fallback v1 to online receiver
                 log::info!("send fallback v1 to online receiver should succeed");
-                let response = agent
-                    .post(url)
-                    .header("Content-Type", payjoin::V1_REQ_CONTENT_TYPE)
-                    .body(body)
-                    .send()
-                    .await?;
+                let response =
+                    agent.post(url).header("Content-Type", content_type).body(body).send().await?;
                 log::info!("Response: {:#?}", &response);
                 assert!(response.status().is_success());
 
@@ -966,9 +962,9 @@ mod integration {
     }
 
     impl HeaderMock {
-        fn from_vec(body: &[u8]) -> HeaderMock {
+        fn new(body: &[u8], content_type: &str) -> HeaderMock {
             let mut h = HashMap::new();
-            h.insert("content-type".to_string(), payjoin::V1_REQ_CONTENT_TYPE.to_string());
+            h.insert("content-type".to_string(), content_type.to_string());
             h.insert("content-length".to_string(), body.len().to_string());
             HeaderMock(h)
         }