From b61f36579c195682d38584604e59677a90322a5a Mon Sep 17 00:00:00 2001
From: yhirose <yuji.hirose.bug@gmail.com>
Date: Thu, 20 Jan 2022 15:21:33 -0500
Subject: [PATCH] Fix #1166

---
 httplib.h | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/httplib.h b/httplib.h
index 0a6734b..b5e1e0f 100644
--- a/httplib.h
+++ b/httplib.h
@@ -4239,14 +4239,16 @@ inline std::pair<std::string, std::string> make_digest_authentication_header(
     }
   }
 
-  auto field =
-      "Digest username=\"" + username + "\", realm=\"" + auth.at("realm") +
-      "\", nonce=\"" + auth.at("nonce") + "\", uri=\"" + req.path +
-      "\", algorithm=" + algo +
-      (qop.empty() ? ", response=\""
-                   : ", qop=" + qop + ", nc=\"" + nc + "\", cnonce=\"" +
-                         cnonce + "\", response=\"") +
-      response + "\"";
+  auto opaque = (auth.find("opaque") != auth.end()) ? auth.at("opaque") : "";
+
+  auto field = "Digest username=\"" + username + "\", realm=\"" +
+               auth.at("realm") + "\", nonce=\"" + auth.at("nonce") +
+               "\", uri=\"" + req.path + "\", algorithm=" + algo +
+               (qop.empty() ? ", response=\""
+                            : ", qop=" + qop + ", nc=" + nc + ", cnonce=\"" +
+                                  cnonce + "\", response=\"") +
+               response + "\"" +
+               (opaque.empty() ? "" : ", opaque=\"" + opaque + "\"");
 
   auto key = is_proxy ? "Proxy-Authorization" : "Authorization";
   return std::make_pair(key, field);