shadow(F)                       19 June 1992                       shadow(F)


 Name

    shadow - shadow password file

 Description

    /etc/shadow is an access-restricted ASCII system file.  The fields for
    each user entry are separated by colons.  Each user entry is separated
    from the next by a newline.  Unlike the /etc/passwd file, /etc/shadow is
    not generally readable.

    The /etc/shadow file contains the following information for each user:

    username    The user's login name (ID).

    password    The encrypted password for the user, prefixed with the string
                *LK* when the account is locked, the string *RETIRED* when
                the account has been retired, or no string when the account
                does not have a password.

    lastchanged The number of days between January 1, 1970, and the date that
                the password was last modified.

    minimum     The minimum number of days required between password changes.

    maximum     The maximum number of days for which the password is valid.

    The encrypted password consists of characters chosen from a 64-character
    alphabet ( ., /, 0-9, A-Z, a-z).  An encrypted password may be up to 112
    characters long, the length being controlled by the length of cleartext
    password field on the Accounts -> Default -> System selection.  Every 8
    characters of cleartext uses 11 characters of encrypted text. Encrypted
    passwords are always prefixed by a 2 character salt. The minimum length
    of an encrypted password is 13 characters.

 Files

    /etc/passwd
    /tcb/files/auth/*/?

 See also

    passwd(F) passwd(C) login(M) sysadmsh(ADM) rmuser(ADM) unretire(ADM)
    getprpwent(S)