Bugfix HTTPS SNI and IP Address (#139)

* Bugfix HTTPS SNI and IP Address

Motivation:

Solving the SNI Bug

Modifications:

Added an internal extension on String for checking if the hostname is an IP Address -- see the private extension on SNI. Additionally using the IPv4Address and IPv6Address Function from Network above 10.14 as protecting with #availabe.
Adding the test for HTTPS and IP in as hostname

Result:

We get results with an IP as Hostname

Author: StrangeDays

Diff for: Sources/AsyncHTTPClient/HTTPClient.swift

@@ -290,7 +290,6 @@ public class HTTPClient {
                 channel.writeAndFlush(request)
             }
             .cascadeFailure(to: task.promise)
-
         return task
     }
 
@@ -501,7 +500,7 @@ private extension ChannelPipeline {
         do {
             let tlsConfiguration = tlsConfiguration ?? TLSConfiguration.forClient()
             let context = try NIOSSLContext(configuration: tlsConfiguration)
-            return self.addHandler(try NIOSSLClientHandler(context: context, serverHostname: request.host),
+            return self.addHandler(try NIOSSLClientHandler(context: context, serverHostname: request.host.isIPAddress ? nil : request.host),
                                    position: .first)
         } catch {
             return self.eventLoop.makeFailedFuture(error)

Diff for: Sources/AsyncHTTPClient/Utils.swift

@@ -15,6 +15,32 @@
 import NIO
 import NIOHTTP1
 
+#if canImport(Network)
+    import Network
+
+    internal extension String {
+        var isIPAddress: Bool {
+            if IPv4Address(self) != nil || IPv6Address(self) != nil {
+                return true
+            }
+            return false
+        }
+    }
+
+#else
+    internal extension String {
+        var isIPAddress: Bool {
+            var ipv4Addr = in_addr()
+            var ipv6Addr = in6_addr()
+
+            return self.withCString { ptr in
+                inet_pton(AF_INET, ptr, &ipv4Addr) == 1 ||
+                    inet_pton(AF_INET6, ptr, &ipv6Addr) == 1
+            }
+        }
+    }
+#endif
+
 public final class HTTPClientCopyingDelegate: HTTPClientResponseDelegate {
     public typealias Response = Void
 

Diff for: Tests/AsyncHTTPClientTests/HTTPClientTests+XCTest.swift

@@ -32,6 +32,7 @@ extension HTTPClientTests {
             ("testGetWithDifferentEventLoopBackpressure", testGetWithDifferentEventLoopBackpressure),
             ("testPost", testPost),
             ("testGetHttps", testGetHttps),
+            ("testGetHttpsWithIP", testGetHttpsWithIP),
             ("testPostHttps", testPostHttps),
             ("testHttpRedirect", testHttpRedirect),
             ("testHttpHostRedirect", testHttpHostRedirect),

Diff for: Tests/AsyncHTTPClientTests/HTTPClientTests.swift

@@ -122,6 +122,19 @@ class HTTPClientTests: XCTestCase {
         XCTAssertEqual(.ok, response.status)
     }
 
+    func testGetHttpsWithIP() throws {
+        let httpBin = HTTPBin(ssl: true)
+        let httpClient = HTTPClient(eventLoopGroupProvider: .createNew,
+                                    configuration: HTTPClient.Configuration(certificateVerification: .none))
+        defer {
+            XCTAssertNoThrow(try httpClient.syncShutdown())
+            XCTAssertNoThrow(try httpBin.shutdown())
+        }
+
+        let response = try httpClient.get(url: "https://127.0.0.1:\(httpBin.port)/get").wait()
+        XCTAssertEqual(.ok, response.status)
+    }
+
     func testPostHttps() throws {
         let httpBin = HTTPBin(ssl: true)
         let httpClient = HTTPClient(eventLoopGroupProvider: .createNew,