IBM System/360 System Programmer's Guide

data set name and the password must be left-justified in their areas and
any unused bytes filled with blanks (X'40'). The password assigned may
be from one to eight alphameric characters.
The operating system increments the binary counter by one each time
the data set is successfully opened (except for performance of SCRATCH
or RENAME functions on the data set). When you originate the password
record, the value in the counter may be set at zero (X'OOOO') or any
starting value your installation desires.
The protection mode indicator is set to indicate that the data set is
to be read-only, or that it may be read or written. You set the
indicator as follows:
• To zero (X'OO') if the data set is to be read-only •
•
To one (X'Ol') if the data set may be read or written.
You may use the 77-byte logging field to record any information about
the data set under protection that your installation may desire, e.g.,
date of counter reset, previous password used with this data set, etc.
PROTECTING THE PASSWORD DATA SET
You protect the PASSWORD data set itself by creating a password
record for it when your program initially builds the data set.
Thereafter, the PASSWORD data set cannot be opened (except by the
operating system routines that scan the data set) unless the operator
enters the password.
CREATING PROTECTED DATA SETS
A data definit:ion (DD) statement parameter (LABEL=) is used to
indicate that a data set is to be placed under protection. You may
create a data set:, and set the protection indicator in its label,
without entering a password record for it in the PASSWORD data set.
However, once the data set is closed, any subsequent opening results in
termination of the program attempting to open the data set, unless the
password record is available and the operator can honor the request for
the password. Operating procedures at your installation must ensure
that password records for all data sets currently under protection are
entered in the PASSWORD data set.
PROTECTION FEATURE OPERATING CHARACTERISTICS
This section provides informaticn concerning actions of the protec-
tion feature in relation to termination of processing, volume switching,
data set concatE~nation, SCRATCH and RENAME functions, and counter
maintenance.
Termination of Processing
Processing is terminated when:
1. The operator cannot supply the correct password for the protected
data set being opened.
2. A password l:ecord does not exist in the PASSWORD data set for the
protected data set being opened.
3. The protection mode indicator setting in the password record, and
the method of I/O processing specified in the open routine do not
Implementing Data Set Protection 113

IBM System/360 Specifications

General

Brand	IBM
Model	System/360
Category	Desktop
Language	English