md_curl: reset curl handle before reusing it

Author: mkauf

ChangeLog

@@ -1,4 +1,5 @@
  * Fix a small memory leak when using OpenSSL's BIGNUMs. [Theo Buehler]
+ * Fix reuse of curl easy handles by resetting them. [Michael Kaufmann]
 
 v2.6.5
 ----------------------------------------------------------------------------------------------------

src/md_curl.c

@@ -255,17 +255,19 @@ static apr_status_t internals_setup(md_http_request_t *req)
             rv = APR_EGENERAL;
             goto leave;
         }
-        curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, header_cb);
-        curl_easy_setopt(curl, CURLOPT_HEADERDATA, NULL);
-        curl_easy_setopt(curl, CURLOPT_READFUNCTION, req_data_cb);
-        curl_easy_setopt(curl, CURLOPT_READDATA, NULL);
-        curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, resp_data_cb);
-        curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
     }
     else {
         md_log_perror(MD_LOG_MARK, MD_LOG_TRACE3, 0, req->pool, "reusing curl instance from http");
+        curl_easy_reset(curl);
     }
 
+    curl_easy_setopt(curl, CURLOPT_HEADERFUNCTION, header_cb);
+    curl_easy_setopt(curl, CURLOPT_HEADERDATA, NULL);
+    curl_easy_setopt(curl, CURLOPT_READFUNCTION, req_data_cb);
+    curl_easy_setopt(curl, CURLOPT_READDATA, NULL);
+    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, resp_data_cb);
+    curl_easy_setopt(curl, CURLOPT_WRITEDATA, NULL);
+
     internals = apr_pcalloc(req->pool, sizeof(*internals));
     internals->curl = curl;