diff -ur nagios-plugins-1.4.15.orig/plugins/check_http.c nagios-plugins-1.4.15/plugins/check_http.c
--- nagios-plugins-1.4.15.orig/plugins/check_http.c	2010-07-27 20:47:16.000000000 +0000
+++ nagios-plugins-1.4.15/plugins/check_http.c	2011-09-09 14:03:49.000000000 +0000
@@ -805,9 +805,34 @@
   /* try to connect to the host at the given port number */
   if (my_tcp_connect (server_address, server_port, &sd) != STATE_OK)
     die (STATE_CRITICAL, _("HTTP CRITICAL - Unable to open TCP socket\n"));
+
+  /* if we are called with the -I option, the -j method is CONNECT and */
+  /* we received -S for SSL, then we tunnel the request through a proxy*/
+  /* @20100414, public[at]frank4dd.com, http://www.frank4dd.com/howto  */
+
+  if ( server_address != NULL && strcmp(http_method, "CONNECT") == 0
+    && host_name != NULL && use_ssl == TRUE) {
+
+    if (verbose) printf ("Entering CONNECT tunnel mode with proxy %s:%d to dst %s:%d\n", server_address, server_port, host_name, HTTPS_PORT);
+    asprintf (&buf, "%s %s:%d HTTP/1.1\r\n%s\r\n", http_method, host_name, HTTPS_PORT, user_agent);
+    asprintf (&buf, "%sProxy-Connection: keep-alive\r\n", buf);
+    asprintf (&buf, "%sHost: %s\r\n", buf, host_name);
+    /* we finished our request, send empty line with CRLF */
+    asprintf (&buf, "%s%s", buf, CRLF);
+    if (verbose) printf ("%s\n", buf);
+    send(sd, buf, strlen (buf), 0);
+    buf[0]='\0';
+
+    if (verbose) printf ("Receive response from proxy\n");
+    read (sd, buffer, MAX_INPUT_BUFFER-1);
+    if (verbose) printf ("%s", buffer);
+    /* Here we should check if we got HTTP/1.1 200 Connection established */
+  }
+    
 #ifdef HAVE_SSL
   if (use_ssl == TRUE) {
     np_net_ssl_init_with_hostname(sd, (use_sni ? host_name : NULL));
+    if (verbose) printf ("SSL initialized\n");
     if (check_cert == TRUE) {
       result = np_net_ssl_check_cert(days_till_exp);
       np_net_ssl_cleanup();
@@ -817,7 +842,11 @@
   }
 #endif /* HAVE_SSL */
 
-  asprintf (&buf, "%s %s %s\r\n%s\r\n", http_method, server_url, host_name ? "HTTP/1.1" : "HTTP/1.0", user_agent);
+  if ( server_address != NULL && strcmp(http_method, "CONNECT") == 0
+      && host_name != NULL && use_ssl == TRUE)
+    asprintf (&buf, "%s %s %s\r\n%s\r\n", "GET", server_url, host_name ? "HTTP/1.1" : "HTTP/1.0", user_agent);
+  else
+    asprintf (&buf, "%s %s %s\r\n%s\r\n", http_method, server_url, host_name ? "HTTP/1.1" : "HTTP/1.0", user_agent);
 
   /* tell HTTP/1.1 servers not to keep the connection alive */
   asprintf (&buf, "%sConnection: close\r\n", buf);
@@ -830,7 +859,9 @@
      * (default) port is explicitly specified in the "Host:" header line.
      */
     if ((use_ssl == FALSE && server_port == HTTP_PORT) ||
-        (use_ssl == TRUE && server_port == HTTPS_PORT))
+        (use_ssl == TRUE && server_port == HTTPS_PORT) ||
+        ( server_address != NULL && strcmp(http_method, "CONNECT") == 0
+          && host_name != NULL && use_ssl == TRUE))
       asprintf (&buf, "%sHost: %s\r\n", buf, host_name);
     else
       asprintf (&buf, "%sHost: %s:%d\r\n", buf, host_name, server_port);
@@ -1355,7 +1386,7 @@
   printf ("    %s\n", _("URL to GET or POST (default: /)"));
   printf (" %s\n", "-P, --post=STRING");
   printf ("    %s\n", _("URL encoded http POST data"));
-  printf (" %s\n", "-j, --method=STRING  (for example: HEAD, OPTIONS, TRACE, PUT, DELETE)");
+  printf (" %s\n", "-j, --method=STRING  (for example: HEAD, OPTIONS, TRACE, PUT, DELETE, CONNECT)");
   printf ("    %s\n", _("Set HTTP method."));
   printf (" %s\n", "-N, --no-body");
   printf ("    %s\n", _("Don't wait for document body: stop reading after headers."));
@@ -1423,7 +1454,15 @@
   printf (" %s\n", _("When the certificate of 'www.verisign.com' is valid for more than 14 days,"));
   printf (" %s\n", _("a STATE_OK is returned. When the certificate is still valid, but for less than"));
   printf (" %s\n", _("14 days, a STATE_WARNING is returned. A STATE_CRITICAL will be returned when"));
-  printf (" %s\n", _("the certificate is expired."));
+  printf (" %s\n\n", _("the certificate is expired."));
+
+  printf (" %s\n\n", "CHECK SSL WEBSERVER CONTENT VIA PROXY USING HTTP 1.1 CONNECT: ");
+  printf (" %s\n\n", _("check_http -I 192.168.100.35 -p 80 -u https://www.verisign.com/ -S -j CONNECT -H www.verisign.com "));
+  printf (" %s\n", _("All these options are needed: -I <proxy> -p <proxy-port> -u <check-url> -S(sl) -j CONNECT -H <webserver>"));
+  printf (" %s\n", _("A STATE_OK will be returned. When the server returns its content but exceeds"));
+  printf (" %s\n", _("the 5-second threshold, a STATE_WARNING will be returned. When an error occurs,"));
+  printf (" %s\n", _("a STATE_CRITICAL will be returned."));
+
 #endif
 
   printf (UT_SUPPORT);