wallet-backend

(Wallet server for storing and retrieving secure data)

SYNOPSIS

wallet-backend [-q] command [args ...]

wallet-backend implements the interface between remctld and the wallet system. It is written to run under remctld and expects the authenticated identity of the remote user in the REMOTE_USER environment variable. It uses REMOTE_HOST or REMOTE_ADDR if REMOTE_HOST isn't set for additional trace information. It accepts the command from remctld on the command line, creates a Wallet::Server object, and calls the appropriate methods.

This program is a fairly thin wrapper around Wallet::Server that translates command strings into method calls and returns the results. It does check all arguments except for the <data> argument to the store command and rejects any argument not matching ^[\w_/.-]+\z; in other words, only alphanumerics, underscore (_), slash (/), period (.), and hyphen (-) are permitted in arguments. This provides some additional security over and above the checking already done by the rest of the wallet code.

OPTIONS

--quiet, -q: If this option is given, wallet-backend will not log its actions to syslog.

COMMANDS

Most commands are only available to wallet administrators (users on the ADMIN ACL). The exceptions are acl check, check, get, store, show, destroy, flag clear, flag set, getattr, setattr, and history. acl check and check can be run by anyone. All of the rest of those commands have their own ACLs except getattr and history, which use the show ACL, setattr, which uses the store ACL, and comment, which uses the owner or show ACL depending on whether one is setting or retrieving the comment. If the appropriate ACL is set, it alone is checked to see if the user has access. Otherwise, destroy, get, store, show, getattr, setattr, history, and comment access is permitted if the user is authorized by the owner ACL of the object.

Administrators can run any command on any object or ACL except for get and store. For get and store, they must still be authorized by either the appropriate specific ACL or the owner ACL.

If the locked flag is set on an object, no commands can be run on that object that change data except the flags commands, nor can the get command be used on that object. show, history, getacl, getattr, and owner, comment, or expires without an argument can still be used on that object.

For more information on attributes, see ATTRIBUTES.

acl add <id> <scheme> <identifier>

Add an entry with <scheme> and <identifier> to the ACL <id>. <id> may be either the name of an ACL or its numeric identifier.

acl check <id>

Check whether an ACL with the ID <id> already exists. If it does, prints yes; if not, prints no.

acl create <name>

Create a new, empty ACL with name <name>. When setting an ACL on an object with a set of entries that don't match an existing ACL, first create a new ACL with acl create, add the appropriate entries to it with acl add, and then set the ACL on an object with the owner or setacl commands.

acl destroy <id>

Destroy the ACL <id>. This ACL must no longer be referenced by any object or the ACL destruction will fail. The special ACL named ADMIN cannot be destroyed.

acl history <id>

Display the history of the ACL <id>. Each change to the ACL (not including changes to the name of the ACL) will be represented by two lines. The first line will have a timestamp of the change followed by a description of the change, and the second line will give the user who made the change and the host from which the change was made.

acl remove <id> <scheme> <identifier>

Remove the entry with <scheme> and <identifier> from the ACL <id>. <id> may be either the name of an ACL or its numeric identifier. The last entry in the special ACL ADMIN cannot be removed to protect against accidental lockout, but administrators can remove themselves from the ADMIN ACL and can leave only a non-functioning entry on the ACL. Use caution when removing entries from the ADMIN ACL.

acl rename <id> <name>

Renames the ACL identified by <id> to <name>. This changes the human-readable name, not the underlying numeric ID, so the ACL's associations with objects will be unchanged. The ADMIN ACL may not be renamed. <id> may be either the current name or the numeric ID. <name> must not be all-numeric. To rename an ACL, the current user must be authorized by the ADMIN ACL.

acl replace <id> <new-id>

Find any objects owned by <id>, and then change their ownership to <new_id> instead. <new-id> should already exist, and may already have some objects owned by it. <id> is not deleted afterwards, though in most cases that is probably your next step. The ADMIN ACL may not be replaced from. <id> and <new-id> may be either the current name or the numeric ID. To replace an ACL, the current user must be authorized by the ADMIN ACL.

acl show <id>

Display the name, numeric ID, and entries of the ACL <id>.

autocreate <type> <name>

Create a new object of type <type> with name <name>. The user must be listed in the default ACL for an object with that type and name, and the object will be created with that default ACL set as the object owner.

check <type> <name>

Check whether an object of type <type> and name <name> already exists. If it does, prints yes; if not, prints no.

comment <type> <name> [<comment>]

If <comment> is not given, displays the current comment for the object identified by <type> and <name>, or No comment set if none is set.

If <comment> is given, sets the comment on the object identified by <type> and <name> to <comment>. If <comment> is the empty string, clears the comment.

create <type> <name>

Create a new object of type <type> with name <name>. With some backends, this will trigger creation of an entry in an external system as well. The new object will have no ACLs and no owner set, so usually the administrator will want to then set an owner with owner so that the object will be usable.

destroy <type> <name>

Destroy the object identified by <type> and <name>. With some backends, this will trigger destruction of an object in an external system as well.

expires <type> <name> [<date> [<time>]]

If <date> is not given, displays the current expiration of the object identified by <type> and <name>, or No expiration set if none is set. The expiration will be displayed in seconds since epoch.

If <date> is given, sets the expiration on the object identified by <type> and <name> to <date> and (if given) <time>. <date> and <time> must be in some format that can be parsed by the Perl Date::Parse module. Most common formats are supported; if in doubt, use YYYY-MM-DD HH:MM:SS. If <date> is the empty string, clears the expiration of the object.

Currently, the expiration of an object is not used.

flag clear <type> <name> <flag>

Clears the flag <flag> on the object identified by <type> and <name>.

flag set <type> <name> <flag>

Sets the flag <flag> on the object identified by <type> and <name>. Recognized flags are locked, which prevents all further actions on that object until the flag is cleared, and unchanging, which tells the object backend to not generate new data on get but instead return the same data as previously returned. The unchanging flag is not meaningful for objects that do not generate new data on the fly.

get <type> <name>

Prints to standard output the data associated with the object identified by <type> and <name>. This may trigger generation of new data and invalidate old data for that object depending on the object type.

getacl <type> <name> <acl>

Prints the ACL <acl>, which must be one of get, store, show, destroy, or flags, for the object identified by <type> and <name>. Prints No ACL set if that ACL isn't set on that object. Remember that if the get, store, or show ACLs aren't set, authorization falls back to checking the owner ACL. See the owner command for displaying or setting it.

getattr <type> <name> <attr>

Prints the object attribute <attr> for the object identified by <type> and <name>. Attributes are used to store backend-specific information for a particular object type, and <attr> must be an attribute type known to the underlying object implementation. The attribute values, if any, are printed one per line. If the attribute is not set on this object, nothing is printed.

history <type> <name>

Displays the history for the object identified by <type> and <name>. This human-readable output will have two lines for each action that changes the object, plus for any get action. The first line has the timestamp of the action and the action, and the second line gives the user who performed the action and the host from which they performed it.

owner <type> <name> [<owner>]

If <owner> is not given, displays the current owner ACL of the object identified by <type> and <name>, or No owner set if none is set. The result will be the name of an ACL.

If <owner> is given, sets the owner of the object identified by <type> and <name> to <owner>. If <owner> is the empty string, clears the owner of the object.

rename <type> <name> <new-name>

Renames an existing object. This currently only supports file objects, where it renames the object itself, then the name and location of the object in the file store.

setacl <type> <name> <acl> <id>

Sets the ACL <acl>, which must be one of get, store, show, destroy, or flags, to <id> on the object identified by <type> and <name>. If <id> is the empty string, clears that ACL on the object.

setattr <type> <name> <attr> <value> [<value> ...]

Sets the object attribute <attr> for the object identified by <type> and <name>. Attributes are used to store backend-specific information for a particular object type, and <attr> must be an attribute type known to the underlying object implementation. To clear the attribute for this object, pass in a <value> of the empty string ('').

show <type> <name>

Displays the current object metadata for the object identified by <type> and <name>. This human-readable output will show the object type and name, the owner, any specific ACLs set on the object, the expiration if any, and the user, remote host, and time when the object was created, last stored, and last downloaded.

store <type> <name> [<data>]

Stores <data> for the object identified by <type> and <name> for later retrieval with get. Not all object types support this. If <data> is not given as an argument, it will be read from standard input.

update <type> <name>

Prints to standard output the data associated with the object identified by <type> and <name>. If the object is one that can have changing information, such as a keytab or password, then we generate new data for that object regardless of whether there is current data or the unchanging flag is set.

ATTRIBUTES

Object attributes store additional properties and configuration information for objects stored in the wallet. They are displayed as part of the object data with show, retrieved with getattr, and set with setattr.

Keytab Attributes

Keytab objects support the following attributes:

enctypes

Restricts the generated keytab to a specific set of encryption types. The values of this attribute must be enctype strings recognized by Kerberos (strings like aes256-cts-hmac-sha1-96 or des-cbc-crc). Note that the salt should not be included; since the salt is irrelevant for keytab keys, it will always be set to normal by the wallet.

If this attribute is set, the specified enctype list will be passed to ktadd when get() is called for that keytab. If it is not set, the default set in the KDC will be used.

This attribute is ignored if the unchanging flag is set on a keytab. Keytabs retrieved with unchanging set will contain all keys present in the KDC for that Kerberos principal and therefore may contain different enctypes than those requested by this attribute.

AUTHOR

Russ Allbery <eagle@eyrie.org>

COPYRIGHT AND LICENSE

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

SPDX-License-Identifier: MIT