SiteMinder : The application behind the web agent is receiving a truncated header

Products

• CA Single Sign On Agents (SiteMinder)

Issue/Introduction

Even if the configuration of the agent is the same, for a specific page where it is requested a big header (not generated by a siteminder response but from the application), the application returns a 400 return code and application developers reports that the header was truncated.

Customer increased the apache parameter LimitRequestFieldSize but it has no effect.

Environment

Webagent R12.52 SP1 CR11

Webserver : Apache 2.4.x

Access Gateway :R12.8.x

Cause

The root cause was the location of "LimitRequestFieldSize" inside the http.conf and httpd-ssl.conf file which was wrong.

Resolution

1.Open the httpd.conf file of both Apache webserver and Access Gateway's Apache and add the below parameters under the Error log section and save the file.

LogLevel debug http:trace5
LimitRequestFieldSize 65536

2. Open the http-ssl.conf file and add the below parameters (LoadModule headers , LimitRequestFieldSize)  under the virtual host section of both Apache webserver and Access Gateway's Apache after the line next to the "SSLProtocol All -SSLv3 -SSLv2 -TLSv1"  and save the file.

LoadModule headers_module modules/mod_headers.so
LimitRequestFieldSize 16384

3. On the Access Gateway servers , Open the server.conf file and add the below parameters under the sections "max_packet_size" and save the file.

 ajp13.maxHttpHeaderSize=16384
 ajp13.maxHttpResponseHeaderSize=16384
 
4. Start the Apache webserver services and Access Gateway services.