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Files Reference

pwdhist File


Contains password history information.


The /etc/security/pwdhist.dir and /etc/security/pwdhist.pag files are database files created and maintained by Database Manager (DBM) subroutines. The files maintain a list of previous user passwords.

The pwdhist files store information by user name. User names are the keys of the DBM subroutines. The password list contains multiple pairs of a lastupdate value and an encrypted, null-terminated password. This password list is a key's associated content and the lastupdate value is a 4-byte, unsigned long. The encrypted password is the size of the PW_CRYPTLEN value. Thus, an entry in the database file is of the following format:


The password list is in descending chronological order, with the most recent password appearing first in the list.

To retrieve a user's password history, use the dbm_fetch subroutine. To delete a user's password history, use the dbm_delete subroutine.


Access Control: The files grant read and write access only to the root user.


If user sally has the following previous passwords:

password = 6PugcayXL.1Rw ; lastupdate = 

password = r5MZvr69mGeLE ; 
lastupdate = 746458629

the dbm_fetch subroutine returns the following entry for the key sally:


Related Information

The /etc/security/passwd file, /etc/security/user file.

The passwd command.

For lists of DBM and NDBM Subroutines, see List of NDBM and DBM Programming References in AIX 5L Version 5.2 Communications Programming Concepts.

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