PK20166: CCRL GETS A UNABLE TO ACCESS RETURNED ON A WEB SEND HTTP REQUEST TO OBTAIN THE CERTIFICATE REVOCATION LIST.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• CCRL issues a WEB SEND to send the HTTP request to the remote
  server to obtain the certificate revocation list, and gets a
  "UNABLE TO ACCESS" returned.
  The CCRL transaction connects to the remote host specified in
  the URL entered at the terminal. DFHWBCL function OPEN_SESSION
  opens this connection (driven by the EXEC CICS WEB OPEN command
  from DFHSOCRL). DFHWBCL sends an HTTP 1.1 OPTIONS request to the
  remote server as part of OPEN_SESSION processing. The server
  responds with the following :-
  HTTP/1.1 200 OK..Date: Wed, 18 J
  an 2006 11:20:40 GMT..Server: Ap
  ache..Allow: GET,HEAD,POST,OPTIO
  NS,TRACE..Keep-Alive: timeout=15
  , max=100..Connection: Keep-Aliv
  e..Transfer-Encoding: chunked..C
  ontent-Type: text/plain....
  followed by the hex secuence 300D0A0D 0A
  The unusual thing about this response is the presence of the
  'Transfer-Encoding: chunked'.
  This indicates that there is a chunked body attached to this
  HTTP response to the CICS OPTIONS request.
  The headers above are followed by the X'300D0A0D 0A'. The first
  byte is an ASCII zero indicating a chunk length of 0 followed
  by a CRLF chunk terminator. This is handled by DFHWBCL but the
  presence of the Transfer-Encoding header causes a flag to be set
  in the outbound HTTP session control block -
  WBO_CHUNKED_RESPONSE.
   This is set so that we know the response body from the remote
  server is returned chunked (in 1 or more parts) rather than the
  more conventional single contiguous HTTP response.
  We complete the DFHWBCL OPEN_SESSION with WBO_CHUNKED_RESPONSE
  on. CCRL now issues a WEB SEND to send the HTTP request to the
  remote server to obtain the certificate revocation list.
  The SEND completes normally and a WEB RECEIVE is issued by CCRL
  driving DFHWBCL for function READ_RESPONSE. The response arrives
  and it is conventional (not chunked) as signified by the
  CONTENT-LENGTH header (and the absence of a Transfer-Encoding:
  chunked header).
  However, flag WBO_CHUNKED_RESPONSE is still on from the previous
  call to DFHWBCL OPEN_SESSION. This causes DFHWBCL to start
  looking for a chunk header in the response. None is present so
  DFHWBCL returns with RESPONSE(EXCEPTION) REASON(INVALID_CHUNK).
  CCRL sends an error message to the screen: "UNABLE TO ACCESS",
  and terminates.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All.                                         *
  ****************************************************************
  * PROBLEM DESCRIPTION: CCRL gets 'Unable to access' returned   *
  *                      from a Web SEND HTTP request to obtain  *
  *                      the certificate revocation list.        *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  CCRL suffers an error receiving an HTTP response from a
  remote certificate revocation list server. DFHWBCL has left
  a flag on from the EXEC CICS WEB OPEN request which causes
  the response to be treated as chunked, even though it is not.
  This causes DFHWBCL READ_RESPONSE to invalidly return
  response(EXCEPTION) reason(INVALID_CHUNK).
  A different symptom, if the response is less than X'400' bytes
  long, is that DFHWBCL will issue an unnecessary socket receive
  request which will hang.
  Similar problems could occur whenever a non-chunked HTTP
  response follows a chunked response.
  Additional keywords: wbo_chunked_response
  

Problem conclusion

• DFHWBCL has been altered to reset wbo_chunked_response before
  processing each HTTP response.
  

Temporary fix

• FIX AVAILABLE BY PTF ONLY
  

Comments

APAR Information

• APAR is sysrouted FROM one or more of the following:

• APAR is sysrouted TO one or more of the following:

  UK12958

Modules/Macros

•    DESWBCL  DFHWBCL
  

Fix information

• Fixed component name

  CICSTS 3.1 Z/OS

• Fixed component ID

  5655M1500

Applicable component levels

• R400 PSY UK12958

     UP06/03/28 P F603

Fix is available

• Select the PTF appropriate for your component level. You will be required to sign in. Distribution on physical media is not available in all countries.