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0store-secure-add − add an implementation to the system cache


0store-secure-add DIGEST


This command imports the current directory into the system-wide shared Zero Install cache (by default, as /var/cache/ This allows a program downloaded by one user to be shared with other users.

The current directory must contain a file called ’.manifest’ listing all the files to be added (in the format required by DIGEST), and this file must have the given digest. If not, the import is refused. Therefore, it is only possible to add a directory to the cache if its name matches its contents.

It is intended that it be safe to grant untrusted users permission to call this command with elevated privileges. To set this up, see below.


To enable sharing, the system administrator should follow these steps:

Create a new system user to own the cache:

adduser --system zeroinst

Create the shared directory, owned by this new user:

mkdir /var/cache/

chown zeroinst /var/cache/

Use visudo(8) to add these lines to /etc/sudoers:

Defaults>zeroinst env_reset

ALL ALL=(zeroinst) NOPASSWD: /usr/bin/0store-secure-add

Create a script called 0store-secure-add-helper in PATH to call it. This script must be executable and contain these two lines:


exec sudo -S -u zeroinst /usr/bin/0store-secure-add "$@" < /dev/null

The other Zero Install programs will call this helper script automatically.



Default system-wide Zero Install cache.


List of system cache directories, one per line.


Copyright (C) 2007 Thomas Leonard.

You may redistribute copies of this program under the terms of the GNU Lesser General Public License.


This program is EXPERIMENTAL. It has not been audited. Do not use it yet in security-critial environments.

The env_reset line in sudoers may not be required. sudo(1) seems to do it automatically.

If sudo let us check whether we could call a command then we could switch to using it automatically, instead of needing to add the helper script. Currently, sudo delays for one second and writes to auth.log if we try to use this system when it hasn’t been set up.

Please report bugs to the developer mailing list:


Zero Install was created by Thomas Leonard.



The Zero Install web-site: