Allow for specifying the preferred auth schemes in http requests.

README.org

@@ -1075,6 +1075,26 @@ missed, etc:
 
 #+END_SRC
 
+
+** Preferred Authentication
+:PROPERTIES:
+:CUSTOM_ID: h-c29486f9-8c54-11e9-acb1-90b11c96f2d2
+:END:
+
+To select the preferred authentication scheme:
+
+#+BEGIN_SRC clojure
+
+(client/get "http://example.com/protected" {:auth-schemes ["NTLM"]})
+
+#+END_SRC
+
+#+BEGIN_SRC clojure
+
+(client/get "http://example.com/protected" {:proxy-auth-schemes ["BASIC" "DIGEST"]})
+
+#+END_SRC
+
 * Advanced Usage
 :PROPERTIES:
 :CUSTOM_ID: h-d52ca837-a575-402f-81fe-53241d85f2db

src/clj_http/core.clj

@@ -186,7 +186,9 @@
                               cookie-spec
                               ; deprecated
                               conn-request-timeout
-                              conn-timeout]
+                              conn-timeout
+                              auth-schemes
+                              proxy-auth-schemes]
                        :as req}]
   (let [config (-> (RequestConfig/custom)
                    (.setConnectTimeout (or connection-timeout conn-timeout -1))
@@ -198,7 +200,9 @@
                     (boolean (opt req :allow-circular-redirects)))
                    (.setRelativeRedirectsAllowed
                     ((complement false?)
-                     (opt req :allow-relative-redirects))))]
+                     (opt req :allow-relative-redirects)))
+                   (.setTargetPreferredAuthSchemes auth-schemes)
+                   (.setProxyPreferredAuthSchemes proxy-auth-schemes))]
     (if cookie-spec
       (.setCookieSpec config CUSTOM_COOKIE_POLICY)
       (.setCookieSpec config (get-cookie-policy req)))