test: fetch ohttp keys (#1354)

Remove io module from payjoin-ffi and implement fetch_ohttp_keys natively in C#

Author: ValeraFinebits

payjoin-ffi/Cargo.toml

@@ -6,11 +6,10 @@ license = "MIT OR Apache-2.0"
 exclude = ["tests"]
 
 [features]
-default = ["io"]
+default = []
 csharp = ["dep:uniffi-bindgen-cs"]
 dart = ["dep:uniffi-dart"]
-io = ["payjoin/io"]
-_test-utils = ["payjoin-test-utils", "tokio", "io"]
+_test-utils = ["payjoin-test-utils", "tokio"]
 _manual-tls = ["payjoin/_manual-tls"]
 wasm_js = ["getrandom/js"]
 

payjoin-ffi/csharp/IntegrationTests.cs

@@ -1,5 +1,6 @@
+using Payjoin.Http;
 using System.Text.Json;
-using uniffi.payjoin;
+using Payjoin;
 using Xunit;
 
 namespace Payjoin.Tests
@@ -323,6 +324,21 @@ public ValueTask DisposeAsync()
             return ValueTask.CompletedTask;
         }
 
+        [Fact]
+        public async Task FetchAndDecodeOhttpKeysViaRelayProxy()
+        {
+            var cancellationToken = TestContext.Current.CancellationToken;
+
+            _services!.WaitForServicesReady();
+            var ohttpRelay = _services.OhttpRelayUrl();
+            var directory = _services.DirectoryUrl();
+            var cert = _services.Cert();
+
+            using var keys = await OhttpKeysClient.GetOhttpKeysAsync(new System.Uri(ohttpRelay), new System.Uri(directory), cert, cancellationToken);
+
+            Assert.NotNull(keys);
+        }
+
         [Fact]
         public void TestFfiValidation()
         {
@@ -395,7 +411,7 @@ public void TestFfiValidation()
                 );
                 new InputPair(txin, psbtIn, new PlainWeight(0));
             });
-            
+
             var directory = _services!.DirectoryUrl();
             _services.WaitForServicesReady();
             var ohttpKeys = _services.FetchOhttpKeys();
@@ -432,9 +448,9 @@ public async Task TestIntegrationV2ToV2()
                 Assert.Skip($"test-utils are not available: {ex.GetType().Name}: {ex.Message}");
             }
 
-            _ = _env.GetBitcoind();
-            var receiver = _env.GetReceiver();
-            var sender = _env.GetSender();
+            using var bitcoind = _env.GetBitcoind();
+            using var receiver = _env.GetReceiver();
+            using var sender = _env.GetSender();
 
             var receiverAddressJson = RpcCall(receiver, "getnewaddress");
             var receiverAddress = JsonSerializer.Deserialize<string>(receiverAddressJson)!;

payjoin-ffi/csharp/Payjoin.Http.cs

@@ -0,0 +1,44 @@
+using Payjoin;
+
+namespace Payjoin.Http
+{
+    internal static class OhttpKeysClient
+    {
+        /// <summary>
+        /// Fetches the OHTTP keys from the specified payjoin directory via proxy.
+        /// </summary>
+        /// <param name="ohttpRelayUrl">
+        /// The HTTP CONNECT method proxy to request the OHTTP keys from a payjoin directory.
+        /// Proxying requests for OHTTP keys ensures a client IP address is never revealed to
+        /// the payjoin directory.
+        /// </param>
+        /// <param name="directoryUrl">
+        /// The payjoin directory from which to fetch the OHTTP keys. This directory stores
+        /// and forwards payjoin client payloads.
+        /// </param>
+        /// <param name="certificate">The DER-encoded certificate to use for local HTTPS connections.</param>
+        /// <param name="cancellationToken">A token to cancel the asynchronous operation.</param>
+        /// <returns>The decoded <see cref="OhttpKeys"/> from the payjoin directory.</returns>
+        internal static async Task<OhttpKeys> GetOhttpKeysAsync(System.Uri ohttpRelayUrl, System.Uri directoryUrl, byte[] certificate, CancellationToken cancellationToken = default)
+        {
+            var keysUrl = new System.Uri(directoryUrl, "/.well-known/ohttp-gateway");
+
+            using var handler = new HttpClientHandler
+            {
+                Proxy = new System.Net.WebProxy(ohttpRelayUrl),
+                UseProxy = true,
+                ServerCertificateCustomValidationCallback = (_, serverCert, _, _) => serverCert != null && serverCert.GetRawCertData().SequenceEqual(certificate)
+            };
+
+            using var client = new HttpClient(handler);
+            using var request = new HttpRequestMessage(HttpMethod.Get, keysUrl);
+            request.Headers.Accept.ParseAdd("application/ohttp-keys");
+
+            using var response = await client.SendAsync(request, cancellationToken);
+            response.EnsureSuccessStatusCode();
+
+            var ohttpKeysBytes = await response.Content.ReadAsByteArrayAsync(cancellationToken);
+            return OhttpKeys.Decode(ohttpKeysBytes);
+        }
+    }
+}

payjoin-ffi/csharp/Payjoin.nuspec

@@ -15,12 +15,14 @@
     <tags>bitcoin payjoin bip78 ffi csharp dotnet</tags>
     <contentFiles>
       <files include="cs/any/payjoin.cs" buildAction="Compile" copyToOutput="false" flatten="true" />
+      <files include="cs/any/Payjoin.Http.cs" buildAction="Compile" copyToOutput="false" flatten="true" />
     </contentFiles>
   </metadata>
 
   <files>
     <file src="README.md" target="README.md" />
     <file src="src/payjoin.cs" target="contentFiles/cs/any/payjoin.cs" />
+    <file src="Payjoin.Http.cs" target="contentFiles/cs/any/Payjoin.Http.cs" />
     <file src="lib/*" target="runtimes/any/native" />
   </files>
 </package>

payjoin-ffi/csharp/UnitTests.cs

@@ -1,5 +1,5 @@
 using Xunit;
-using uniffi.payjoin;
+using Payjoin;
 
 namespace Payjoin.Tests;
 

payjoin-ffi/src/io.rs

@@ -1,8 +1,6 @@
 #![crate_name = "payjoin_ffi"]
 
 pub mod error;
-#[cfg(feature = "io")]
-pub mod io;
 pub mod ohttp;
 pub mod output_substitution;
 pub mod receive;

payjoin-ffi/src/lib.rs

@@ -163,10 +163,16 @@ impl TestServices {
         })
     }
 
-    pub fn fetch_ohttp_keys(&self) -> Result<crate::OhttpKeys, crate::io::IoError> {
+    pub fn fetch_ohttp_keys(&self) -> Result<crate::OhttpKeys, BoxSendSyncError> {
         let runtime = RUNTIME.lock().expect("Lock should not be poisoned");
         runtime.block_on(async {
-            self.0.lock().await.fetch_ohttp_keys().await.map_err(Into::into).map(Into::into)
+            self.0
+                .lock()
+                .await
+                .fetch_ohttp_keys()
+                .await
+                .map(Into::into)
+                .map_err(|e| payjoin_test_utils::BoxSendSyncError::from(e).into())
         })
     }
 }

payjoin-ffi/src/test_utils.rs

@@ -11,3 +11,7 @@ cdylib_name = "payjoin_ffi"
 [bindings.dart]
 cdylib_name = "payjoin_ffi"
 package_name = "payjoin"
+
+[bindings.csharp]
+namespace = "Payjoin"
+cdylib_name = "payjoin_ffi"