3 # a set of useful functions for managing operations with passwords.
4 # a set of very simple operations, but the file needs to be protected from
5 # undesirable access. a good way to do that is to make the file owned by
6 # root, and for it to have permssions of "600" (full access by owner only),
7 # and to only try to read the password file when in sudo mode. the first
8 # two requirements are done automatically by the store_password function.
11 # provides a way to read a password out of a file.
12 # the return value is an echoed password, so this method should always be
13 # called from within a subshell, e.g.:
14 # mypass="$(load_password /etc/glorp/secret_passcode)"
15 # the returned echo will be blank if the function failed.
16 function load_password()
18 local passfile="$1"; shift
19 if [ -z "$passfile" ]; then
20 echo 'The load_password function needs a filename to read the password from.'
23 if [ ! -f "$passfile" ]; then
24 # no file, which is not an error necessarily, but return a blank password
29 read passwd < "$passfile"
33 # stores a password into a password file. the password file should be the
34 # first parameter and the password should be the second.
35 # this makes sure that only root can read the file.
36 function store_password()
38 local passfile="$1"; shift
39 local passwd="$1"; shift
40 if [ -z "$passfile" -o -z "$passwd" ]; then
42 The store_password function needs (1) the file to store the password into,
43 and (2) the password that should be stored.
48 echo "$passwd" > "$passfile"
49 test_or_die "writing password into the file $passfile"
51 chown root:root "$passfile"
52 test_or_die "chowning the password file to root ownership for: $passfile"
55 test_or_die "restricting permissions on password file for: $passfile"
58 # reads a password from the console, without echoing the letters when they
59 # are typed. the prompt to show the user is required as the first parameter.
60 # the password read in is returned as an echo, like load_password above.
61 function read_password()
66 # turn off echo but remember former setting.
72 # return the password as an echo.