feat: Allow using default credentials for proxy (box/box-codegen#623) (#334)

Fixes: #333

Author: box-sdk-build

.codegen.json

@@ -1 +1 @@
-{ "engineHash": "f073ce3", "specHash": "544d370", "version": "1.4.0" }
+{ "engineHash": "a839036", "specHash": "544d370", "version": "1.4.0" }

Box.Sdk.Gen/Networking/Fetch.cs

@@ -170,15 +170,24 @@ private static HttpClient GetOrCreateHttpClient(NetworkSession networkSession)
 
         private static HttpClient CreateProxyClient(ProxyConfig proxyConfig)
         {
+            var webProxy = new WebProxy(proxyConfig.Url)
+            {
+                UseDefaultCredentials = proxyConfig.UseDefaultCredentials
+            };
+
+            if (!proxyConfig.UseDefaultCredentials)
+            {
+                webProxy.Credentials = new NetworkCredential(
+                    proxyConfig.Username,
+                    proxyConfig.Password,
+                    proxyConfig.Domain);
+            }
+
             var handler = new HttpClientHandler
             {
-                Proxy = new WebProxy(proxyConfig.Url)
-                {
-                    Credentials = new NetworkCredential(proxyConfig.Username, proxyConfig.Password, proxyConfig.Domain)
-                },
+                Proxy = webProxy,
                 UseProxy = true,
-                PreAuthenticate = true,
-                UseDefaultCredentials = false
+                PreAuthenticate = true
             };
 
             return new HttpClient(handler, disposeHandler: true);

Box.Sdk.Gen/Networking/ProxyConfig/ProxyConfig.cs

@@ -10,8 +10,11 @@ public class ProxyConfig {
 
         public string? Domain { get; init; }
 
-        public ProxyConfig(string url) {
+        public bool UseDefaultCredentials { get; }
+
+        public ProxyConfig(string url, bool useDefaultCredentials = false) {
             Url = url;
+            UseDefaultCredentials = useDefaultCredentials;
         }
     }
 }

docs/Client.md

@@ -131,8 +131,17 @@ var newClient = client.WithCustomBaseUrls(new BaseUrls(
 
 # Use Proxy for API calls
 
-In order to use a proxy for API calls, calling the `client.WithProxy(proxyConfig)` method creates a new client, leaving the original client unmodified, with the username and password being optional.
+In order to use a proxy for API calls, call the `client.WithProxy(proxyConfig)` method that creates a new client with proxy, leaving the original client unmodified.
+In config, you can specify the username, password and domain for the proxy server.
+Alternatively you can set 'UseDefaultCredentials' to true to use the credentials of the currently logged on user - `DefaultCredentials`.
+NOTE: Setting UseDefaultCredentials takes precedence over Username, Password and Domain fields. If UseDefaultCredentials is set to true, the Username, Password and Domain fields will be ignored.
 
 ```c#
 var newClient = client.WithProxy(new ProxyConfig("http://proxy.com") { Username = "username", Password = "password", Domain = "example" });
 ```
+
+To use proxy with default credentials:
+
+```c#
+var newClient = client.WithProxy(new ProxyConfig("http://proxy.com") { UseDefaultCredentials = true });
+```