Data protection/security support

The mechanisms for file and data protection automatically supported by DMS (access authorization checks, etc.) can be extended by the user, e.g. with the aid of passwords. Data security is assured by various mechanisms for recovering files or programs, etc.

File protection

Macro	Operands	Brief description
CATAL	SHARE	controls shareability.
	ACCESS	controls the type of access.
	OWNERAR GROUPAR OTHERAR	defines, in the BASIC-ACL,the access rights for user groups (see the “Introductory Guide to DMS” [1]).
	GUARDS	when SECOS is used: provides enhanced access protection for files.
	EXPASS RDPASS WRPASS	define passwords for the various access levels.
	RETPD	specifies a retention period.
	PROTECT	transfers protection attributes
CHKFAR		checks the caller's file access rights.
COPFILE	PROTECT	transfers the protection attributes when a file is copied.
DECFILE		converts an encrypted file into an unencrypted file.
ENCFILE		converts an unencrypted file into an encrypted file.
FILE	RETPD	defines a retention period (valid only if specified when the file is opened)
FCB	PASS	permits access to password-protected files.
	RETPD	defines a retention period for a file.

Data protection

Macro	Operands	Brief description
CATAL	DESTROY	specifies in the catalog entry that disk files or superfluous foreign data on tape files are to be overwritten during deletion (cf. FILE: DESTOC).
ERASE	DESTROY	specifies data destruction in conjunction with deletion.
DECFILE		converts an encrypted file into an unencrypted file.
ENCFILE		converts an unencrypted file into an encrypted file.
FILE	DESTOC	specifies that any data remaining on the tape in the case of a tape swap or after closing a tape file is overwritten.

Data security

Macro	Operands	Brief description
CATAL	BACKUP	specifies the frequency of automatic saving.
	NUM_OF_BACKUP_VERS	defines, if and how many versions of a file can be saved in an version backup archive.
COPFILE	REPLACE	specifies whether an existing file is to be overwritten during copying.
CREPOOL	WROUT	writes updated blocks in ISAM files back to disk immediately.
EXLST		defines exit routines for errors and other events.
FCB	EXIT	the address of an exit routine or of an EXLST macro.
	WRCHK	specifies a read-after-write check as a safeguard against recording errors.
FILE	WRCHK	performs a read-after-write check as a safeguard against recording errors.
	WROUT	writes updated records in ISAM files back to disk immediately.
VERIF		restores file structures, unlocks files.
WRCPT		writes a checkpoint / creates a checkpoint file for restart with the RESTART-PROGRAM command.