EntireX Broker ACI for COBOL

Advanced communication interface. ACI-based programming is the base technology of EntireX. It uses a traditional Application Programming Interface (API) approach for conducting client/server and peer-to-peer dialog between distributed processes.

This document describes the EntireX Broker ACI from the perspective of the programming language COBOL and covers the following topics:


Call Format

Calls to EntireX Broker use the following arguments:

  1. The ACI control block is the first argument.

  2. The send buffer is the second argument.

  3. The receive buffer is the third argument.

  4. The error text buffer is the last argument. It can provide a short text of the error code, if desired. Sufficient buffer length must be supplied to allow the standard 40-byte long message to be returned by EntireX Broker. For ACI version 9 and above, the error text buffer can be greater than 40 bytes as specified in the ACI field ERRTEXT-LENGTH.

The send buffer and the receive buffer must always be provided. If they are not required by the selected EntireX Broker function, you can define them as PIC X(1) fields.

The API is called with a statement such as the following:

  • Under all platforms (except under IBM i) with all Broker stubs:

    CALL 'BROKER'USING
       ETBCB G-SEND-BUFF G-RECV-BUFF ERROR-TEXT
  • additionally, under z/OS you can invoke CICSETB, using the following EXEC CICS LINK command. See CICSETB. The length of the COMMAREA is always 24. For example:

    EXEC CICS LINK PROGRAM('CICSETB') COMMAREA(commarea) LENGTH(24)

    The COMMAREA must specify an area in working storage with the following information:

    • 8-byte character field "ETBCOMM*"

    • one full word containing the address of the Broker control block

    • one full word containing the address of send buffer

    • one full word containing the address of receive buffer

    • one full word containing the address of error text buffer

  • under IBM i:

    CALL LINKAGE TYPE IS PROCEDURE "broker" USING
         ETBCB G-SEND-BUFF G-RECV-BUFF ERROR-TEXT

    or

    CALL "broker" USING
         ETBCB G-SEND-BUFF G-RECV-BUFF ERROR-TEXT
         with compiler option LINKLIT(*PRC)

If 00000000 (zeros) are returned in the ERROR-CODE field in the EntireX Broker control block, the operation has been performed successfully. However, function results other than 00000000 (zeros) do not necessarily indicate an error. See Error Handling for client and server | publish and subscribe.

Broker ACI Control Block Layout

The following table shows the Broker fields in order of the physical layout of the Broker ACI control block and provides a brief description of each field. The fields are described in more detail under Broker ACI Fields. See the actual copybook for COBOL in Broker ACI Control Block Copybook below.

Note:
Header files and examples are provided as models if you want to write your own ACI applications (see ACI Examples and Copybooks for location). The list below does not include unused fields that are for internal purposes only. Check the included header files for the full layout.

Broker ACI Field COBOL Definition Description /
Related Information
API
Vers.
Notes
API-TYPE ETBCB-TYPE PIC X API type. See API-TYPE and API-VERSION for client and server | publish and subscribe. 1  
API-VERSION ETBCB-VERSION PIC X API version. 1  
FUNCTION ETBCB-FUNCTION PIC X See Broker ACI Functions to perform Broker function. 1  
OPTION ETBCB-OPTION PIC X See OPTION. 1  
  RESERVED PIC X(16) Reserved for future use. 1 1
SEND-LENGTH SEND-LENGTH PIC 9(9) COMP Send length. See Using Send and Receive Buffers for client and server | publish and subscribe. 1  
RECEIVE-LENGTH RECEIVE-LENGTH PIC 9(9) COMP Receive length. 1  
RETURN-LENGTH RETURN-LENGTH PIC 9(9) COMP Return length. 1  
ERRTEXT-LENGTH ERRTEXT-LENGTH PIC 9(9) COMP Error text length. 1  
BROKER-ID BROKER-ID PIC X(32) Broker ID. See Using the Broker ID in Applications. 1  
SERVER-CLASS
SERVER-NAME
SERVICE
SERVER-CLASS PIC X(32)
SERVER-NAME PIC X(32)
SERVICE-NAME PIC X(32)
Service. See Control Block Fields and Verbs. 1 3, 5
USER-ID USER-ID PIC X(32) User ID. See USER-ID and TOKEN for client and server | publish and subscribe. 1  
PASSWORD PASSWD PIC X(32) Password. See Authentication. 1 4,5
TOKEN TOKEN PIC X(32) Reconnection token. See USER-ID and TOKEN for client and server | publish and subscribe. 1 3, 5
SECURITY-TOKEN SECURITY-TOKEN PIC X(32) Security token. See Writing Applications using EntireX Security. 1 4, 5
CONV-ID CONV-ID PIC X(16) Conversation ID. See Conversational and Non-conversational Mode. 1 3, 5
WAIT WAIT-TIMEOUT PIC X(8) Wait value. See Blocked and Non-blocked Broker Calls for client and server | publish and subscribe. 1 3, 5
ERROR-CODE ERROR-CODE PIC X(8) Error code. See Error Handling for client and server | publish and subscribe. 1  
ENVIRONMENT ENVIRONMNT PIC X(32) Environment. See Using Internationalization for client and server | publish and subscribe. 1 3, 5
ADCOUNT ADCOUNT PIC 9(9) COMP Attempted delivery count. See Writing Applications: Units of Work. 2  
USER-DATA USER-DATA PIC X(16) Conversation User Data. See Managing Conversation Contexts. 2 3, 5
Not used. MESSAGE-ID PIC X(32) Message ID. 2 4, 5
Not used. MESSAGE-TYPE PIC X(16) Message type. 2 3, 5
  LIFE-TIME PIC X(8) Reserved for future use. 2 1, 3, 5
NEWPASSWORD NEW-PASSWD PIC X(32) New password. See Authentication. 2 4, 5
Not used. ADAPTER-ERROR PIC X(8) Adapter error. 2  
CLIENT-UID CLIENT-USER-ID PIC X(32) Client User ID. See Client User ID. 2  
CONV-STAT CONVSTAT PIC X(1) Conversation status. See Conversational and Non-conversational Mode. 2  
STORE STORE PIC X(1) Persistence or non-persistence of a UOW. See Writing Applications: Units of Work. 2  
  STATUS PIC X(1) Reserved for future use. 2 1
UOWSTATUS UOWSTATUS PIC X(1) UOW Status. See Writing Applications: Units of Work. 3 3, 5
UWTIME UOWTIME PIC X(8) UOW lifetime. 3 3, 5
UOWID UOWID PIC X(16) UOW unique identifier. 3 3, 5
USTATUS USERSTATUS PIC X(32) User status. 3  
UOW-STATUS-PERSIST UOWSTATUSPER PIC X(1) Multiplier for persistent status lifetime. See Writing Applications: Units of Work. 3 2
  RESVD2 PIC X(3) Reserved for future use. 3 1
LOCALE-STRING LOCALE-STR PIC X(40) Locale string. To be used to override or provide codepages. See Using Internationalization for client and server | publish and subscribe. 4  
DATA-ARCH DATA-ARCH PIC X(1) Data architecture. See ICU Conversion. 4 2
FORCE-LOGON FORCE-LOGON PIC X(1) Override Broke AUTOLOGON. See Authentication. 6  
ENCRYPTION-LEVEL ENC-LEVEL PIC X(1) Deprecated. For encrypted transport we strongly recommend using the Secure Sockets Layer/Transport Layer Security protocol. See SSL/TLS and Certificates with EntireX. 6 2
KERNELSECURITY KERSEC PIC X(1) Kernel security. See Writing Applications using EntireX Security 7  
COMMITTIME COMMTIME PIC X(17) Commit time. See Writing Applications: Units of Work. 7  
COMPRESSLEVEL COMPLVL PIC X(1) Compression level.
See Data Compression for client and server | publish and subscribe.
7  
  RESVD3 PIC X(2) Reserved for future use. 7 1
  RESVD4 PIC 9(9) COMP Reserved for future use. 7 1
UWSTAT-LIFETIME UWSTAT-LIFETIME PIC X(8) Add value for persistent status lifetime. See UWSTAT-LIFETIME. 8  
TOPIC TOPIC PIC X(96) Topic name for publish and subscribe. See Key ACI Field Names. 8  
PUBLICATION-ID PUBLICATION-ID PIC X(16) Publication ID for publish and subscribe. 8  
CLIENT-ID CLIENT-ID PIC 9(9) Returns to a server application the unique instance number of a client application. It is returned on receipt of a message (RECEIVE or SEND with WAIT). 9  
LOG-COMMAND LOG-COMMAND PIC X(1) Log the current command. See also Programmatically Turning on Command Logging for client and server | publish and subscribe. 9  
CREDENTIALS-TYPE CRED-TYPE PIC X(1) Indicates the credentials type to be used to authenticate a user. The default is to use user ID and password. 9  
VARLIST-OFFSET VAR-LIST-OFF PIC 9(9) Internal Software AG field. 10  
LONG-BROKER-ID-LENGTH LONG-BID-LEN PIC 9(9) See LONG-BROKER-ID-LENGTH. 10  

Notes:

  1. Reserved for future use.
  2. You must set this field to a LOW VALUE (X'00') if you do not intend to use it.
  3. The field is transmitted up to the first blank or LOW VALUE (X'00'). It is not transmitted if the first character is a blank or a LOW VALUE (X'00').
  4. All trailing LOW VALUES (X'00') are truncated. The field is not transmitted if the entire field is a LOW VALUE (X'00').
  5. If fields are not needed for a specific command function, suppress their transmission by initializing them to blanks or LOW VALUE (X'00').

Broker ACI Control Block Copybook

The Developer's Kit provides a copybook with the ACI control block definition. See ACI Examples and Copybooks for where it is provided on your platform:

      ******************************************************************
      * Product        : EntireX Broker
      * Copyright      : Copyright (c) 1997 - 2015 Software AG,
      *                  Darmstadt, Germany and/or Software AG USA,
      *                  Inc., Reston, VA, United States of America,
      *                  and/or their licensors.
      * Version        : 9.9
      * File Version   : $Revision: 1.48 $
      * File           : COBDEF
      * Description    : COBOL ACI control block definitions.
      ******************************************************************
      * Note: When an option value is used it must be added to the
      * previous assigned function value.
      ******************************************************************
      *
      * --- ENTIRE BROKER API Type Constants ---------------------------
      *
       01  TYPE-1             PIC 9(4)  BINARY VALUE 256.
      *
      * --- ENTIRE BROKER API Version Constants ------------------------
      *
       01  VERSION-1          PIC 9(4)  BINARY VALUE 1.
       01  VERSION-2          PIC 9(4)  BINARY VALUE 2.
       01  VERSION-3          PIC 9(4)  BINARY VALUE 3.
       01  VERSION-4          PIC 9(4)  BINARY VALUE 4.
       01  VERSION-5          PIC 9(4)  BINARY VALUE 5.
       01  VERSION-6          PIC 9(4)  BINARY VALUE 6.
       01  VERSION-7          PIC 9(4)  BINARY VALUE 7.
       01  VERSION-8          PIC 9(4)  BINARY VALUE 8.
       01  VERSION-9          PIC 9(4)  BINARY VALUE 9.
       01  VERSION-10         PIC 9(4)  BINARY VALUE 10.
      *
      * --- ENTIRE BROKER API Function Constants -----------------------
      *
       01  FCT-SEND                PIC 9(4)  BINARY VALUE 256.
       01  FCT-RECEIVE             PIC 9(4)  BINARY VALUE 512.
       01  FCT-UNDO                PIC 9(4)  BINARY VALUE 1024.
       01  FCT-EOC                 PIC 9(4)  BINARY VALUE 1280.
       01  FCT-REGISTER            PIC 9(4)  BINARY VALUE 1536.
       01  FCT-DEREGISTER          PIC 9(4)  BINARY VALUE 1792.
       01  FCT-VERSION             PIC 9(4)  BINARY VALUE 2048.
       01  FCT-LOGON               PIC 9(4)  BINARY VALUE 2304.
       01  FCT-LOGOFF              PIC 9(4)  BINARY VALUE 2560.
       01  FCT-SET                 PIC 9(4)  BINARY VALUE 2816.
       01  FCT-GET                 PIC 9(4)  BINARY VALUE 3072.
       01  FCT-SYNC                PIC 9(4)  BINARY VALUE 3328.
       01  FCT-KERNELVERS          PIC 9(4)  BINARY VALUE 3584.
       01  FCT-LOCTRANS            PIC 9(4)  BINARY VALUE 3840.
       01  FCT-SETSSLPARMS         PIC 9(4)  BINARY VALUE 4096.
       01  FCT-SEND-PUBLICATION    PIC 9(4)  BINARY VALUE 4352.
       01  FCT-RECEIVE-PUBLICATION PIC 9(4)  BINARY VALUE 4608.
       01  FCT-SUBSCRIBE           PIC 9(4)  BINARY VALUE 4864.
       01  FCT-UNSUBSCRIBE         PIC 9(4)  BINARY VALUE 5120.
       01  FCT-CONTROL-PUBLICATION PIC 9(4)  BINARY VALUE 5376.
       01  FCT-REPLY-ERROR         PIC 9(4)  BINARY VALUE 5632.
      *
      * --- ENTIRE BROKER API Option Constants -------------------------
      *
       01  OPT-MSG            PIC 9(4)  BINARY VALUE 1.
       01  OPT-HOLD           PIC 9(4)  BINARY VALUE 2.
       01  OPT-IMMED          PIC 9(4)  BINARY VALUE 3.
       01  OPT-QUIESCE        PIC 9(4)  BINARY VALUE 4.
       01  OPT-EOC            PIC 9(4)  BINARY VALUE 5.
       01  OPT-CANCEL         PIC 9(4)  BINARY VALUE 6.
       01  OPT-LAST           PIC 9(4)  BINARY VALUE 7.
       01  OPT-NEXT           PIC 9(4)  BINARY VALUE 8.
       01  OPT-PREVIEW        PIC 9(4)  BINARY VALUE 9.
       01  OPT-COMMIT         PIC 9(4)  BINARY VALUE 10.
       01  OPT-BACKOUT        PIC 9(4)  BINARY VALUE 11.
       01  OPT-SYNCPOINT      PIC 9(4)  BINARY VALUE 12.
       01  OPT-ATTACH         PIC 9(4)  BINARY VALUE 13.
       01  OPT-DELETE         PIC 9(4)  BINARY VALUE 14.
       01  OPT-EOCCANCEL      PIC 9(4)  BINARY VALUE 15.
       01  OPT-QUERY          PIC 9(4)  BINARY VALUE 16.
       01  OPT-SETUSTATUS     PIC 9(4)  BINARY VALUE 17.
       01  OPT-ANY            PIC 9(4)  BINARY VALUE 18.
       01  OPT-TERMINATE      PIC 9(4)  BINARY VALUE 19.
       01  OPT-DURABLE        PIC 9(4)  BINARY VALUE 20.
       01  OPT-CHECKSERVICE   PIC 9(4)  BINARY VALUE 21.
      *
      * --- ENTIRE BROKER API Conversation Status Constants ------------
      *
       01  CNV-NEW            PIC 9(4)  BINARY VALUE 256.
       01  CNV-OLD            PIC 9(4)  BINARY VALUE 512.
       01  CNV-NONE           PIC 9(4)  BINARY VALUE 768.
      *
      * --- ENTIRE BROKER API Store Constants --------------------------
      *
       01  STORE-OFF          PIC 9(4)  BINARY VALUE 1.
       01  STORE-BROKER       PIC 9(4)  BINARY VALUE 2.
      *
      * --- ENTIRE BROKER API Status Constants -------------------------
      *
       01  STATUS-OFF         PIC 9(4)  BINARY VALUE 256.
       01  STATUS-STORED      PIC 9(4)  BINARY VALUE 512.
       01  STATUS-DEL-ATTEMPT PIC 9(4)  BINARY VALUE 768.
       01  STATUS-DELIVERED   PIC 9(4)  BINARY VALUE 1024.
       01  STATUS-PROCESSED   PIC 9(4)  BINARY VALUE 1280.
       01  STATUS-DEAD        PIC 9(4)  BINARY VALUE 1536.
      *
      * --- ENTIRE BROKER API Control Block Definition -----------------
      *
       01  ETBCB.
           02  TYPE-VERSION   PIC 9(4)  BINARY VALUE 0.
           02 FILLER REDEFINES TYPE-VERSION.
              04 ETBCB-TYPE    PIC X.
              04 ETBCB-VERSION PIC X.
           02  FCT-OPT        PIC 9(4)  BINARY VALUE 0.
           02 FILLER REDEFINES FCT-OPT.
              04 ETBCB-FUNCTION PIC  X.
              04 ETBCB-OPTION   PIC  X.
           02  RESERVED       PIC X(16) VALUE SPACES.
           02  SEND-LENGTH    PIC 9(9)  BINARY VALUE 0.
           02  RECEIVE-LENGTH PIC 9(9)  BINARY VALUE 0.
           02  RETURN-LENGTH  PIC 9(9)  BINARY VALUE 0.
           02  ERRTEXT-LENGTH PIC 9(9)  BINARY VALUE 0.
           02  BROKER-ID      PIC X(32) VALUE SPACES.
           02  SERVER-CLASS   PIC X(32) VALUE SPACES.
           02  SERVER-NAME    PIC X(32) VALUE SPACES.
           02  SERVICE-NAME   PIC X(32) VALUE SPACES.
      *                                               SERVICE
           02  USER-ID        PIC X(32) VALUE SPACES.
           02  PASSWD         PIC X(32) VALUE SPACES.
      *                                               PASSWORD
           02  TOKEN          PIC X(32) VALUE SPACES.
           02  SECURITY-TOKEN PIC X(32) VALUE SPACES.
           02  CONV-ID        PIC X(16) VALUE SPACES.
           02  WAIT-TIMEOUT   PIC X(8)  VALUE SPACES.
           02  ERROR-CODE     PIC X(8)  VALUE SPACES.
           02  ERROR-CODE-X REDEFINES ERROR-CODE.
             03  ERROR-CLASS  PIC X(4).
             03  ERROR-NUMBER PIC X(4).
           02  ENVIRONMNT     PIC X(32) VALUE SPACES.
      *                                               ENVIRONMENT
      *                                  V2 additions
           02  ADCOUNT        PIC 9(9)  BINARY VALUE 0.
      *                                  ATTEMPTED DELIVERY COUNT
           02  USER-DATA      PIC X(16) VALUE SPACES.
           02  MESSAGE-ID     PIC X(32) VALUE SPACES.
           02  MESSAGE-TYPE   PIC X(16) VALUE SPACES.
           02  LIFE-TIME      PIC X(8)  VALUE SPACES.
           02  NEW-PASSWD     PIC X(32) VALUE SPACES.
           02  ADAPTER-ERROR  PIC X(8)  VALUE SPACES.
           02  CLIENT-USER-ID PIC X(32) VALUE SPACES.
           02  CONVSTAT-STORE PIC 9(4)    BINARY VALUE 0.
           02  FILLER REDEFINES CONVSTAT-STORE.
             03 ETBCB-CONVSTAT  PIC X.
             03 ETBCB-STORE     PIC X.
           02  STATUS-UOWSTATUS PIC 9(4) BINARY VALUE 0.
           02  FILLER REDEFINES STATUS-UOWSTATUS.
             03 ETBCB-STATUS    PIC X.
             03 ETBCB-UOWSTATUS PIC X.
      *                                  V3 additions
           02  UOWTIME        PIC X(8)  VALUE SPACES.
           02  UOWID          PIC X(16) VALUE SPACES.
           02  USERSTATUS     PIC X(32) VALUE SPACES.
           02  UOWSTATUSPER   PIC X(1).
           02  RESVD2         PIC X(3)  VALUE SPACES.
      *                                  V4 additions
           02  LOCALE-STR     PIC X(40) VALUE SPACES.
           02  DATA-ARCH      PIC X(1).
      *                                  V6 additions
           02  FORCE-LOGON    PIC X(1)  VALUE SPACES.
           02  ENC-LEVEL      PIC X(1).
      *                                  V7 additions
           02  KERSEC         PIC X(1)  VALUE SPACES.
           02  COMMTIME       PIC X(17) VALUE SPACES.
           02  COMPLVL        PIC X(1)  VALUE SPACES.
           02  RESVD3         PIC X(2)  VALUE SPACES.
           02  RESVD4         PIC 9(9)  BINARY VALUE 0.
      *                                  V8 additions
           02  UWSTAT-LIFETIME PIC X(8) VALUE SPACES.
           02  TOPIC          PIC X(96) VALUE SPACES.
           02  PUBLICATION-ID PIC X(16) VALUE SPACES.
      *                                  V9 additions
           02  RESVD-V99-1    PIC X(32) VALUE SPACE.
           02  RESVD-V73-1    PIC 9(9)  BINARY VALUE 0.
           02  RESVD-V73-2    PIC 9(9)  BINARY VALUE 0.
           02  RESVD-V73-3    PIC 9(9)  BINARY VALUE 0.
           02  CLIENT-ID      PIC 9(9)  BINARY VALUE 0.
           02  RESVD-V73-4    PIC X(32) VALUE SPACES.
           02  LOG-COMMAND    PIC X(1)  VALUE SPACES.
           02  CRED-TYPE      PIC X(1).
           02  RESVD-V73-5    PIC X(32) VALUE SPACES.
           02  RESVD5         PIC X(2)  VALUE SPACES.
      *                                  V10 additions
           02  VAR-LIST-OFF   PIC 9(9)  BINARY VALUE 0.
           02  LONG-BID-LEN   PIC 9(9)  BINARY VALUE 0.
      *
      * --- ENTIRE BROKER Attach Manager Control Block -----------------
      *
       01  ETBATMCB.
           02  A-VERSION      PIC 9(4)  BINARY VALUE 0.
           02  A-NOT-USED     PIC 9(4)  BINARY VALUE 0.
           02  A-N-ATTACH     PIC 9(9)  BINARY VALUE 0.
      *                       NUMBER OF FAILED SERVER LOOKUPS
           02  A-N-SERVER     PIC 9(9)  BINARY VALUE 0.
      *                       NUMBER OF REGISTERED SERVERS
           02  A-N-PEND-CONV  PIC 9(9)  BINARY VALUE 0.
           02  A-N-ACT-CONV   PIC 9(9)  BINARY VALUE 0.
           02  A-SERVER-CLASS PIC X(32) VALUE SPACES.
           02  A-SERVER-NAME  PIC X(32) VALUE SPACES.
           02  A-SERVICE-NAME PIC X(32) VALUE SPACES.
      *
      * *END*

Using the Broker ACI with SSL/TLS

ACI applications can use Secure Sockets Layer/Transport Layer Security (SSL/TLS) as the transport medium. The term "SSL" in this section refers to both SSL and TLS. ACI-based clients or servers are always SSL clients. The SSL server can be either the EntireX Broker or the Broker SSL Agent. For an introduction see SSL/TLS and Certificates in the Security documentation. This section describes using the Broker ACI with SSL on the following platforms:

z/OS

SSL delivered on a z/OS mainframe will typically use the Resource Access Control Facility (RACF) as the certificate authority (CA). Certificates managed by RACF can only be accessed through the RACF keyring container. A keyring is a collection of certificates that identify a networking trust relationship (also called a trust policy). In an SSL client/server network environment, entities identify themselves using digital certificates called through a keyring. Server applications on z/OS that wish to establish network connections to other entities can use keyrings and their certificate contents to determine the trustworthiness of the client or peer entity. Note that certificates can belong to more than one keyring, and you can assign different users to the same keyring. Because of the way RACF internally references certificates, they must be uniquely identifiable by owner and label, and also unique by serial number plus data set name (DSN).

The following options are available under z/OS:

Using IBM's Application Transparent Transport Layer Security (AT-TLS)

With the Broker ACI for COBOL you can use IBM's Application Transparent Transport Layer Security, where the establishment of the SSL connection is pushed down the stack into the TCP layer.

Configure the AT-TLS rules for the policy agent (PAGENT) graphics/no4.gif using an appropriate client graphics/no1.gif and the z/OS Management Facility (z/OSMF) graphics/no2.gif. Together with SSL parameters (to provide certificates stored in z/OS as RACF keyrings) define AT-TLS rules, for example by using the application graphics/no5.gif job name and remote TCP port number. If the rules match, the TCP connection is turned into an SSL connection graphics/no6.gif. Refer to your IBM documentation for more information, for example the IBM Redbook Communications Server for z/OS VxRy TCP/IP Implementation Volume 4: Security and Policy-Based Networking.

graphics/adminRpc_ssl_config-cob.png

graphics/no1.gif Client to interact with z/OS Management Facility (z/OSMF).
graphics/no2.gif AT-TLS rules are defined with z/OSMF policy management.
graphics/no3.gif Policy Repository with AT-TLS rules stored as z/OS files.
graphics/no4.gif Policy Agent, MVS task PAGENT, provides AT-TLS rules through a policy enforcement point (PEP) to TCP/IP stack.
graphics/no5.gif Application using TCP connection.
graphics/no6.gif If AT-TLS rules match, the TCP connection is turned into an SSL connection.

Notes:

  1. The client graphics/no1.gif may vary per operating system, for example a Web browser for z/OS 2.1.
  2. z/OSMF graphics/no2.gif includes other administration and management tasks in addition to policy management.
  3. Policy Management graphics/no3.gif includes other rules, such as IP filtering, network address translation etc.

Start of instruction setTo set up SSL with AT-TLS

  1. To operate with SSL, certificates need to be provided and maintained. Depending on the platform, Software AG provides default certificates, but we strongly recommend that you create your own. See Default Certificates Delivered with EntireX under SSL/TLS and Certificates with EntireX in the Security documentation.

  2. Set up the ACI application (client or server) for a TCP/IP connection. On mainframe platforms, use Transport-method-style Broker ID. Example

    ETB024:1699:TCP
  3. Configure AT-TLS to turn the TCP/IP connection to an SSL connection, see above.

  4. Make sure the SSL server to which the ACI application (client or server) connects is prepared for SSL connections as well. The SSL server can be EntireX Broker, Broker SSL Agent, or Direct RPC in Integration Server (IS inbound). See:

Using Broker ACI Function SETSSLPARMS

Note:
Not available under CICS.

With the Broker ACI for COBOL, the SSL parameters (e.g. certificates stored in z/OS as RACF keyrings only) are provided with the function SETSSLPARMS.

Start of instruction setTo use SSL

  1. To operate with SSL, certificates need to be provided and maintained. Depending on the platform, Software AG provides default certificates, but we strongly recommend that you create your own. See Default Certificates Delivered with EntireX under SSL/TLS and Certificates with EntireX in the Security documentation.

  2. On mainframe platforms, use Transport-method-style Broker ID for the Broker ID, for example:

    ETB024:1609:SSL

    If no port number is specified, port 1958 is used as default.

  3. Specify SSL parameters in the second parameter, for example:

    'broker' etbcb "VERIFY_SERVER=N&TRUST_STORE=<racf_uid>/<racf_keyring>" 

    If the SSL client checks the validity of the SSL server only, this is known as one-way SSL. The mandatory trust_store parameter specifies the file name of a keystore that must contain the list of trusted certificate authorities for the certificate of the SSL server. By default a check is made that the certificate of the SSL server is issued for the hostname specified in the Broker ID. The common name of the subject entry in the server's certificate is checked against the hostname. If they do not match, the connection will be refused. You can disable this check with SSL parameter verify_server=no.

    If the SSL server additionally checks the identity of the SSL client, this is known as two-way SSL. In this case the SSL server requests a client certificate (the parameter verify_client=yes is defined in the configuration of the SSL server). Two additional SSL parameters must be specified on the SSL client side: key_store and key_passwd. This keystore must contain the private key of the SSL client. The password that protects the private key is specified with key_passwd.

    The ampersand (&) character cannot appear in the password.

    SSL parameters are separated by ampersand (&). See also SSL/TLS Parameters for EntireX Clients and Servers.

  4. Make sure the SSL server to which the ACI application (client or server) connects is prepared for SSL connections as well. The SSL server can be EntireX Broker or Broker SSL Agent. See:

    • Running Broker with SSL/TLS Transport under z/OS | UNIX | Windows | z/VSE

    • Settting up and Administering the EntireX Broker SSL Agent under UNIX | Windows

z/VSE

Establishing an SSL connection on z/VSE requires BSI's Automatic Transport Layer Security (ATLS). This facility is similar to z/OS Application Transparent - Transport Layer Security (AT-TLS). ATLS is supported by the BSI stack only.

Using BSI's Automatic Transport Layer Security (ATLS)

Together with SSL parameters (to provide certificates), define ATLS rules for socket interception in the ATLS daemon startup job BSTTATLS graphics/no2.gif. If the rules match, the socket connection is turned into an SSL connection graphics/no5.gif. Refer to your IBM documentation for further information. For an overview, refer to the IBM Redbook Enhanced Networking on IBM z/VSE; for a more detailed description, refer to BSI SSL Installation, Programming and User's Guide.

graphics/adminRpc_ssl_config-vse.png

graphics/no1.gif BSI TCP/IP Stack, either BSTTINET (IPv4) or BSTT6NET (IPv6).
graphics/no2.gif ATLS rules are defined manually. See Sample ATLS Daemon Configuration below.
graphics/no3.gif BSTTATLS is associated with a TCP/IP stack.
graphics/no4.gif Application using TCP connection.
graphics/no5.gif BSTTATLS intercepts outbound TCP connection and converts it to SSL connection. For inbound, SSL connections can also be intercepted and converted to TCP connections.

Start of instruction setTo set up SSL with AT-TLS

  1. To operate with SSL, certificates need to be provided and maintained. Depending on the platform, Software AG provides default certificates, but we strongly recommend that you create your own. See Default Certificates Delivered with EntireX under SSL/TLS and Certificates with EntireX in the Security documentation.

  2. Set up the RPC component for a TCP/IP connection. On mainframe platforms, use Transport-method-style Broker ID. Example:

    ETB024:1699:TCP
  3. Configure AT-TLS to turn the TCP/IP connection to an SSL connection, see above.

  4. Make sure the SSL server to which the RPC component connects is prepared for SSL connections as well. The SSL server can be EntireX Broker, Broker SSL Agent, or Direct RPC in webMethods Integration Server (IS inbound). See:

Sample ATLS Daemon Configuration

* Converting inbound EntireX Broker connection 
* Converts listen port 1971 to SSL listen port 1972
OPTION SERVER 
ATTLS 1971 AS 2071 SSL
*
* Converting outbound client connection
* Converts connect to 192.168.2.100:1972:TCP to 192.168.2.100:2072:SSL
OPTION CLIENT
ATTLS 1972 TO 192.168.2.100 AS 2072 SSL

Note:
We recommend setting SETPARM value SUBTASK to a value greater than 0 in the ATLS daemon startup job (valid values 0-16, default=0). For example:

// SETPARM SUBTASK=8

See also BSI SSL Installation, Programming and User's Guide.

For additional information see also Using the BSI TCP/IP Stack under Hints for Setting up Broker JCL in z/VSE in the z/VSE Installation documentation and SSL/TLS and Certificates with EntireX.

ACI Examples and Copybooks

When you begin to write your first broker ACI program, you can use the client example BCOCCBL and server example BCOSCBL as a model for your own implementation. If the examples are not available on your platform, transfer them (for example using FTP) from a platform where they are delivered.

Depending on your platform for COBOL, you will find the files with the examples, copybooks, etc., at the following locations:

Platform Copybooks / Examples Location Notes
z/OS Broker ACI Control Block copybook See member COBDEF in the mainframe source library EXX990.SRCE. 2, 3
Broker Command and Info Services Control Block copybook See member COBINF in the mainframe source library EXX990.SRCE. 2, 3, 6
COMMAREA example (used with EXEC LINK) See member ETBCOMM in the mainframe source library EXX811.SRCE. 2, 3
CIS example to perform INFO server, psf and publication calls See member BRKCNTL in the mainframe source library EXX811.SRCE. 2, 3, 6
BS2000/OSD Broker ACI Control Block copybook See element COBDEF in the LMS library EXX811.LIB.  
Broker Command and Info Services Control Block copybook See element COBINFF in the LMS library EXX811.LIB.  
IBM i Broker ACI Control Block copybook See member COBDEF in include source file QCBLLESRC. 1
Broker Command and Info Services Control Block copybook See member COBINF in include source file QCBLLESRC. 1
Sample procedure for compiling See member CRT_CBLMOD in source file EXASRC. 1
Sample procedure for binding See member EXABNDPGM in source file EXASRC. 1
Client example See member BCOCCBL of type CBLLE in source file EXASRC. 1, 5
Procedure to call client example See the CL member EXABCOC in source file EXASRC. 1, 4
Procedure to call client example with Security parameters See the CL member EXABCOCSEC in source file EXASRC. 1, 4
Server example See member BCOSCBL of type CBLLE in source file EXASRC. 1, 5
Procedure to call server example See the CL member EXABCOS in source file EXASRC. 1, 4
Procedure to call server example with Security parameters See the CL member EXABCOSSEC in source file EXASRC. 1, 4
z/VM Broker ACI Control Block copybook See member COBDEF in MACLIB EXX990.MACLIB. 7
Broker Command and Info Services Control Block copybook See member COBINF in MACLIB EXX990.MACLIB. 7

Notes:

  1. See Installing EntireX under IBM i.
  2. See Installing EntireX under z/OS.
  3. Where vrs represents the version, release and service pack.
  4. By default, these CL procedures call the C type of client and server programs (BCOC and BCOS). To use the relevant COBOL programs BCOCCBL and BCOSCBL, you must modify the procedures accordingly. After adjusting the Broker ID, Broker Version and Security parameters, you must compile the sources and bind the created modules to executable *PGM programs. For compiling, use the procedure CRT_CBLMOD. For binding, use the procedure EXABNDPGM. All sample programs copy the Broker ACI control block definitions COBDEF during compilation.
  5. See also Verifying the Installation of the Broker Stubs.
  6. The Broker CIS API requires selection fields to be terminated with binary nulls - i.e., NULLS or LOW-VALUES - or to be initialized with binary nulls if the fields are not being used.

    Note:
    Initializing these fields with spaces is not recommended.

  7. See Installing Broker Stubs under z/VM.

Creating a COBOL User Application under IBM i

On the IBM i system, the broker stub is implemented as an object of type *SRVPGM (Service Program). This object type has the advantage that its program code can be shared by several programs. It exists as an object on its own and can therefore be easily replaced without rebinding the user's application, when a newer version becomes available.

The service program EXA supplied by Software AG contains all the functions necessary for controlling and communicating with the remote broker. To create an executable Broker application on IBM i, you need to develop, in any ILE-enabled programming language, at least one main module to which the EXA service program is bound.

  • For compilation use the command CRTCBLMOD with the options:

    ...OPTION(*NOMONOPRC ...) 
    ...EXTDSPOPT(*NODFRWRT)
    ...LINKLIT(*PRC)
  • For binding use the command CRTPGM with the option:

    ...BNDSRVPGM(*LIBL/EXA)...

Example:

The following steps show how to create a server application using the program BCOSCBL. See ACI Examples and Copybooks.

Step 1: Set the Environment

The library EXX must be located in the *LIBL list.

To set the library list, you can use the command:

 CHGCURLIB CURLIB(EXX)

Step 2: Compile the User Program

To compile BCOSCBL, use the command CRTCBLMOD with options similar to the following:

MODULE(BCOSCBL) SRCFILE(*CURLIB/EXASRC) OUTPUT(*PRINT)
OPTION(*NOMONOPRC *MAP *UNREF) EXTDSPOPT(*NODFRWRT)
LINKLIT(*PGM)

Or, use the sample procedure CRT_CBLMOD.

If the program has been successfully compiled, the module BCOSCBL will be created.

Step 3: Bind EXA to the User Program

To produce an executable program, bind the user program BCOSCBL to the service program EXA supplied by Software AG. Use the command CRTPGM similar to the following:

CRTPGM PGM(EXX/BCOSCBL) MODULE(*PGM) ENTMOD(*PGM)
BNDSRVPGM(EXX/EXA) BNDDIR(*NONE) OPTION(*GEN *WARN *DUPVAR)
DETAIL(*EXTENDED)

Or, use the sample program EXABNDPGM.

If the programs have been bound successfully, the object BCOSCBL with type *PGM will be created.

To test the program, you can modify/use the sample procedure EXABCOS as described in the package delivered.

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