PM36149: ABEND S0C4 IN EZBTCRD (UK59397 10.246)+01515E WHEN SSL CLIENT SENDS SSL APPLICATION DATA DURING SSL HANDSHAKE.

Obtain the fix for this APAR.

APAR status

• Closed as program error.

Error description

• AT-TLS is being used to secure a connection.  The SSL handshake
  starts with the SSL client sending in the client hello.  The
  next data from the SSL client includes a SSL application record
  and then a handshake record:
  17030000 057C4040 FFEF1603 000084
  .
  AT-TLS abends trying to decrypt the application data record
  because a control block needed for decryption is not available
  until after the handshake completes.
  .
  The SSL handshake should fail without an abend.
  VERIFICATION STEPS:
  1) S0C4 abend in EZBTCRD attempting to store into the location
  pointed to by Reg 8 at offset 01515E.
  2) Reg 8 will be zero.  It was loaded from Reg 12(TCBTTLSX CB) +
  108, which is also zero.
  3) A packet trace will show an invalid sequence of data sent by
  the SSL client, similar to the data shown above.
  

Local fix

Problem summary

• ****************************************************************
  * USERS AFFECTED: All users of the IBM Communications Server   *
  *                 for z/OS Version 1 Release 12 IP: AT-TLS     *
  ****************************************************************
  * PROBLEM DESCRIPTION: Abend in EZBTCRD when AT-TLS receives   *
  *                      SSL application data during SSL         *
  *                      handshake                               *
  ****************************************************************
  * RECOMMENDATION:                                              *
  ****************************************************************
  The remote client initiated a SSL handshake with an
  local application using AT-TLS.  During the SSL
  handshake, an SSL application data record is sent
  along with SSL handshake records.  AT-TLS tries to
  decrypt the SSL application data but abends because
  the TLSX_Dec_Parms@ area is not allocated yet.
  +-------------------------------------------------------------+
  + Please check our Communications Server for OS/390 homepages +
  + for common networking tips and fixes.  The URL for these    +
  + homepages can be found in Informational APAR II11334.       +
  +-------------------------------------------------------------+
  

Problem conclusion

• Module EZBTLCWK has been changed to allocate the
  TLSX_Dec_Parm@ when the SSL handshake starts.
  
  * Cross Reference between External and Internal Names
  

Temporary fix

Comments

APAR Information

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

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

  UK66702 PM38843

Modules/Macros

• EZBTLCWK
  

Fix information

• Fixed component name

  TCP/IP V3 MVS

• Fixed component ID

  5655HAL00

Applicable component levels

• R1C0 PSY UK66702

     UP11/05/21 P F105

Fix is available

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