Ubuntu Manpage: rollerd - DNSSEC-Tools daemon to manage DNSSEC key rollover

NAME

       rollerd - DNSSEC-Tools daemon to manage DNSSEC key rollover

SYNOPSIS

         rollerd [-options] -rrfile <rollrec_file>

DESCRIPTION

The rollerd daemon manages key rollover for zones. rollerd is just a scheduler for zone rollover; it
uses zonesigner to perform the actual key generation, zone signing, and key manipulation.

rollerd manages both KSK and ZSK rollover, though only one rollover type per zone may take place at a
time. Initiation of KSK rollovers takes precedence over the initiation of ZSK rollovers.

rollerd uses two methods of key rollover. The Pre-Publish Method of key rollover is used for ZSK key
rollovers. The Double Signature Method of key rollover is used for KSK rollovers. These methods are
described more fully below.

rollerd maintains zone rollover state in files called rollrec files; zone/key mappings are stored in
keyrec files. rollerd only modifies rollrec files. For the most part, rollerd does not modify keyrec
directly, but relies on zonesigner to update those files as needed. (The exceptions where rollerd
modifies keyrec files. At start-up, it will mark each managed zone's keyrec file to indicate the zone is
under rollerd's control. During the course of rollover, rollerd will also update a zone's rollover times
in its keyrec file.)

The administrator may control rollerd with the rollctl command. A large number of commands are available
to control and modify rollerd's operation, as well as to retrieve information about rollover and daemon
status.

The zone administrator will need to update their zone files periodically. If rollerd is managing zones,
then problems could arise if modified zones were signed without rollerd's knowledge. To prevent such
problems, rollerd can be configured to automatically re-sign a zone when its zonefile is found to be
newer than its corresponding signed zonefile. (The files' "last modification" timestamps are compared.)
The zone will be re-signed without any other rollover actions taking place, so no new keys will be
generated, no key rollovers will occur, and the various rollover timers will be unaffected.

rollerd will perform these re-signs by default, but this can be further controlled by the autosign
configuration parameter and rollerd's -autosign/-noautosign command line options. If rollerd is
configured to not perform automatic re-signing, the administrator can still get this controlled behavior
by use of the zonesigner or rollctl commands.

If the rollrec file does not exist or is of zero length, rollerd will give an error message and continue
running. It will periodically wake up and check for a usable rollrec file. Once it finds the specified
rollrec file exists and isn't empty, then it will proceed with normal rollover management.

ZSK Rollover Using the Pre-Publish Method
The Pre-Publish Method has four phases that are entered when it is time to perform ZSK rollover:

1. wait for old zone data to expire from caches
2. sign the zone with the KSK and Published ZSK
3. wait for old zone data to expire from caches
4. adjust keys in keyrec and sign the zone with new Current ZSK

rollerd uses the zonesigner command during ZSK rollover phases 2 and 4. zonesigner will generate keys as
required and sign the zone during these two phases.

The Pre-Publish Method of key rollover is defined in the Step-by-Step DNS Security Operator Guidance
Document. See that document for more detailed information.

KSK Rollover Using the Double Signature Method
The Double Signature Method has seven phases that are entered when it is time to perform KSK rollover:

1 - wait for cache data to expire
2 - generate a new (published) KSK and load zone
3 - wait for the old DNSKEY RRset to expire from caches
4 - transfer new keyset to the parent
5 - wait for parent to publish DS record
6 - wait for cache data to expire
7 - roll the KSKs and load the zone

This is a modification of the original Double Signature Method. In the original method, the KSK keys
were rolled before the new keyset was transferred to the parent. The new method rolls the KSK keys after
the parent has published the new DS records and old data has expired for caches. This addresses a
potential problem with signing zones during key rollovers.

rollerd uses the zonesigner command during KSK rollover phases 2 and 7. zonesigner will generate keys as
required and sign the zone during these two phases.

Currently, leaving the waiting period in step 5 is handled manually. In step 4, rollerd informs the
administrator via email that the zone's keyset must be transferred to its parent in order for rollover to
continue. In step 5, after the keyset has been transferred to the parent and the parent has published a
new DS record, the administrator uses rollctl to inform rollerd that the DS record has been published and
rollover may continue.

The Double Signature Method of key rollover is defined in the Step-by-Step DNS Security Operator Guidance
Document. See that document for more detailed information.

KSK Rollover Using the Double Signature Method and RFC5011
RFC5011 describes how remote-validating resolvers must track KSK changes within a zone. If configured
for RFC5011 behavior, rollerd and zonesigner add an extra-long period of time between the point a new KSK
is created and published and the point where the actual switch to using it takes place. RFC5011
specifies that remote validators should add a "hold-down timer" to the rollover process, such that the
new key is not added as a trust-anchor until 30 days have past. Thus, rollerd will wait for 60 days (by
default) during phase 3 of the KSK rollover process if the "istrustanchor" field of the rollrec
definition has been set to either 1 or "yes". To wait for a different length of time other than 60 days,
use the holddowntime field.

At this time, the other conventions of RFC5011 are not being followed. Specifically, it's not waiting
for a while before removing the old key and it's not adding the revoke bit to the old key after
switching.

Site-Specific Rollover Actions
An administrator can specify site-specific commands to be run during the various rollover phases. The
commands can be run in place of the default rollerd rollover actions, or in addition to them. This
subsection describes how to make use of site-specific rollover actions.

This capability is provided to allow different installations to handle rollover according to their
specific needs. For example, it is anticipated that this might be helpful to sites using HSM hardware,
or to allow for enhanced reporting to administrators. This has been used with simple test programs to
ensure that it actually works. However, it has not yet been used in actual HSM environment or with other
production-level software replacements.

See the ZSK Rollover Using the Pre-Publish Method and KSK Rollover Using the Double Signature Method
sections for descriptions of the default rollover actions.

WARNING: This has the potential of being a dangerous capability. Be very careful when setting up and
using it. Take care with the site-specific commands to be executed and the permissions and ownership of
rollerd and its data files.

DNSSEC-Tools Configuration File Changes

The DNSSEC-Tools configuration file must be modified to tell rollerd what must be run for the non-default
rollover phase actions. Key/value pairs may be set for each rollover phase to control how that phase
differs from the default.

The value portion of the configuration entry contains the path to the site-specific phase command, along
with any arguments it might need. Multiple commands are separated by bangs.

The reserved default command tells rollerd to use its normal rollover action for a particular phase.
This may be combined with other commands to provide things such as specialized logging or notifications.

rollerd will only alter the behavior of a rollover phase if the configuration file contains an entry for
that phase. If not, the default action will be taken.

For example, this configuration line tells rollerd that for ZSK rollover phase 2, instead of using its
normal zonesigner executions it should run the hsm-signer command.

prog-zsk2 hsm-signer

In this example, this configuration line informs rollerd that when entering KSK rollover phase 1 and ZSK
rollover phase 1, it should execute the log-and-mail command, then use the normal rollover action for
those phases.

prog-ksk1 /usr/local/sbin/log-and-mail mary ! default
prog-zsk1 /usr/local/sbin/log-and-mail bob!default

The following configuration keys are used for controlling KSK rollover phases: prog-ksk1, prog-ksk2,
prog-ksk3, prog-ksk4, prog-ksk5, prog-ksk6, and prog-ksk7,

The following configuration keys are used for controlling ZSK rollover phases: prog-zsk1, prog-zsk2,
prog-zsk3, and prog-zsk4.

The prog-normal configuration key controls the normal, non-rollover state.

Site-Specific Commands

To be generally useful, the site-specific commands executed by rollerd will be given a standard set of
arguments, and a standard set of exit values will be recognized.

The standard arguments from rollerd are:
1. zonename - Zone to be handled.
2. phase - Zone's current rollover phase (e.g., zsk1, ksk6, normal.)
3. rollrec name - Zone's entry key in the rollrec file.
4. rollrec file - The path to the rollrec file.
5. keyrec file - The path to the zone's keyrec file.

The prog-phase entry in the configuration file may specify additional options and arguments for a
command. These will be included on the execution command line prior to the standard arguments.

The standard exit values expected by rollerd are:
0. The zone can move to the next rollover phase.
This is only applicable to the current command; other
commands in this phase's command list must still be run.
1. The zone should stay in the current rollover phase.
This is not necessarily the result of an error.
2. An error was found in the arguments given to the command.
3. An error was encountered during execution.

If a rollover phase's configuration entry lists multiple commands, they will be executed in the order
listed. If any command in that command list fails, processing stops there.

The rp-wrapper command shows how a site-specific command may be written. rp-wrapper may be used as a
skeleton on which to build a more useful rollover-phase command.

Considerations for Site-Specific Commands

The following should be taken into consideration when writing a site-specific command for a rollover
phase.

execution length
A phase command should not execute very long. As currently written, rollerd serializes zone
rollover. So the longer a phase command takes to execute, the longer it will take to get to the next
zone. If a phase command sleeps or actively waits, so to speak, for the next phase timeout, then
every zone rollerd manages will be left waiting.

follow interface guidelines
Follow the standards for arguments and exit values. Not following the standards is likely to
negatively affect zone rollover.

frequency of command execution
If rollerd is operating in its traditional "full list" processing mode, a phase command list will be
executed every time rollerd cycles through its zone list and a zone is in that particular command's
phase. For example, if <i>prog_zsk1</i> is defined for example.com, that command list will be
executed for example.com every time rollerd runs its zone list and finds example.com is in the ZSK
phase 1 rollover state. A phase command must take this into account so it doesn't perform its
actions more frequently than necessary. This is most likely an issue for the various rollover wait
states, and possibly the normal state.

If rollerd is operating in the experimental "soon queue" processing mode, a phase command list will
be executed for a zone only when a phase change occurs. Since phase changes are time queued, this
should not happen more than once per phase. A phase command should take this into account, in case
the soon queue is reordered before the zone leaves the queue, or queue timing is relatively swift.
This is most likely an issue for the various rollover wait states.

WARNING: "soon queue" processing is experimental. Care should be taken when using this processing
method, as it may still have some lingering bugs.

Zone Reloading
rollerd has the opportunity to inform the DNS daemon to reload a zone in KSK phase 2, KSK phase 7, ZSK
phase 2, and ZSK phase 4. This is the rollerd's default behavior. However, there are situations where
this shouldn't be done, such as for off-line signing.

The roll_loadzone field of the DNSSEC-Tools configuration file is a boolean field that overrides the
default to force the zone-reload behavior either on or off. This field takes precedence over the
default.

Similarly, the -noreload option prevents rollerd from requesting a zone reload, and it takes precedence
over the roll_loadzone configuration field and the default.

rollrec Files
The zones to be managed by rollerd are described in a rollrec file. Generally speaking most people will
want to use the rollinit command to create an initial rollrec file instead of typing their own from
scratch. See the INITIALIZATION AND USAGE section below and the rollinit manual page for details. Each
zone's entry contains data needed by rollerd and some data useful to a user. Below is a sample rollrec
entry:

roll "example.com"
zonename "example.com"
zonefile "example.com.signed"
keyrec "example.com.krf"
zonegroup "demo-zones"
directory "dir-example.com"
kskphase "0"
zskphase "3"
ksk_rollsecs "1172614842"
ksk_rolldate "Tue Feb 27 22:20:42 2007"
zsk_rollsecs "1172615087"
zsk_rolldate "Tue Feb 27 22:24:47 2007"
maxttl "60"
display "1"
phasestart "Tue Feb 27 22:25:07 2007"
# optional records for RFC5011 rolling:
istrustanchor "no"
holddowntime "60D"

The first line gives the rollrec entry's name. The name distinguishes it from other rollrec entries and
must be unique. This may be the zone's name, but this is not a requirement. The following lines give
the zone's name, the zone's signed zone file, keyrec file, the current rollover phases, the rollover
timestamps, and other information. The zone group is optional and allows a set of related zones to be
controlled with a single rollctl execution, rather than one execution per zone.

If either of the zonefile or keyrec files do not exist, then a "roll" rollrec will be changed into a
"skip" rollrec. That record will not be processed.

A more detailed explanation may be found in rollrec(5).

Directories
rollerd's execution directory is either the directory in which it is executed or the directory passed in
the -directory command-line option. Any files used by rollerd that were not specified with absolute
paths use this directory as their base.

A rollrec file's directory field informs rollerd where the zone's files may be found. For that zone,
rollerd will move into that directory, then return to its execution directory when it finishes rollover
operations for that zone. If the directory value is a relative path, it will be appended to rollerd's
execution directory. If the directory value is an absolute path, it will be used as is.

Controlling rollerd with rollctl
The rollctl command is used to control the behavior of rollerd. A number of commands are available, such
as starting or stopping rollover for a selected zone or all zones, turning on or off a GUI rollover
display, and halting rollerd execution. The communications path between rollerd and rollctl is operating
system-dependent. On Unix-like systems, it is a Unix pipe that should only be writable by the user which
runs rollerd. A more detailed explanation of rollctl may be found in rollctl(8).

A Note About Files and Filenames
There are a number of files and filenames used by rollerd and zonesigner. The user must be aware of the
files used by these programs, where the files are located, and where the programs are executed.

By default, rollerd will change directory to the DNSSEC-Tools directory, though this may be changed by
the -directory option. Any programs started by rollerd, most importantly zonesigner, will run in this
same directory. If files and directories referenced by these programs are named with relative paths,
those paths must be relative to this directory.

The rollrec entry name is used as a key to the rollrec file and to the zone's keyrec file. This entry
does not have to be the name of the entry's domain, but it is a very good idea to make it so. Whatever
is used for this entry name, the same name must be used for the zone keyrec in that zone's keyrec file.

It is probably easiest to store rollrec files, keyrec files, zone files, and key files in a single
directory.

INITIALIZATION AND USAGE

The following steps must be taken to initialize and use rollerd. This assumes that zone files have been
created, and that BIND and DNSSEC-Tools have been installed.

0. sign zones
The zones to be managed by rollerd must be signed. Use zonesigner to create the signed zone files
and the keyrec files needed by rollerd. The rollrec file created in the next step must use the
keyrec file names and the signed zone file names created here.

This step is optional. If it is bypassed, then (in step 4 and later) rollerd will perform the
initial key creation and zone signing of your zones using the defaults found in the DNSSEC-Tools
configuration file. rollerd determines if it must perform these initial operations by whether it can
find the keyrec file for a zone (as specified in the rollrec file. If it can't, it performs the
initial operations; if it can, it assumes the zone's initial operations have been performed.

1. create rollrec file
Before rollerd may be used, a rollrec file must first be created. While this file may be built by
hand, the rollinit command was written specifically to build the file.

2. select operational parameters
A number of rollerd's operational parameters are taken from the DNSSEC-Tools configuration file.
However, these may be overridden by command-line options. See the OPTIONS section below for more
details. If non-standard parameters are desired to always be used, the appropriate fields in the
DNSSEC-Tools configuration file may be modified to use these values.

3. install the rollover configuration
The complete rollover configuration -- rollerd, rollrec file, DNSSEC-Tools configuration file values,
zone files -- should be installed. The appropriate places for these locations are both installation-
dependent and operating system-dependent.

4. test the rollover configuration
The complete rollover configuration should be tested.

Edit the zone files so that their zones have short TTL values. A minute TTL should be sufficient.
Test rollovers of this speed should only be done in a test environment without the real signed zone.

Run the following command:

rollerd -rrfile test.rollrec -logfile - -loglevel info -sleep 60

This command assumes the test rollrec file is test.rollrec. It writes a fair amount of log messages
to the terminal, and checks its queue every 60 seconds. Follow the messages to ensure that the
appropriate actions, as required by the Pre-Publish Method, are taking place.

5. set rollerd to start at boot
Once the configuration is found to work, rollerd should be set to start at system boot. The actual
operations required for this step are operating system-dependent.

6. reboot and verify
The system should be rebooted and the rollerd logfile checked to ensure that rollerd is operating
properly.

OPTIONS

There are a number of operational parameters that define how rollerd works. These parameters define
things such as the rollrec file, the logging level, and the log file. These parameters can be set in the
DNSSEC-Tools configuration file or given as options on the rollerd command line. The command line
options override values in the configuration file.

The following options are recognized:

-alwayssign
Tells rollerd to sign the zones that aren't in the middle of being rolled. This allows rollerd to
refresh signed zone signatures and allows complete management of zone signing to be taken over by
rollerd.

The downside to using this option is that all the non-rolling zones will be signed after every sleep,
which may be expensive computationally.

Note: The zone files are not updated or installed at this time. Manual copying and installation are
still needed.

-autosign | -noautosign
Automatic zone-signing flag. If this is set, then a zone's zonefile will be re-signed (and only re-
signed) if it is found to be newer than the corresponding signed zonefile.

-directory dir
Sets the rollerd execution directory. This must be a valid directory.

-display
Starts the blinkenlights graphical display program to show the status of zones managed by rollerd.

-dtconfig config_file
Name of an alternate DNSSEC-Tools configuration file to be processed. If specified, this
configuration file is used in place of the normal DNSSEC-Tools configuration file not in addition to
it. Also, it will be handled prior to keyrec files, rollrec files, and command-line options.

-foreground
Run in the foreground and do not fork into a daemon.

-logfile log_file
Sets the rollerd log file to log_file. This must be a valid logging file, meaning that if log_file
already exists, it must be a regular file. The only exceptions to this are if logfile is
/dev/stdout, /dev/tty, -. Of these three, using a log_file of - is preferable since Perl will
properly convert the - to the process' standard output.

-loglevel level
Sets rollerd's logging level to level. rollmgr.pm(3) contains a list of the valid logging levels.

-noreload
Prevents rollerd from telling the DNS daemon to reload zones.

-parameters
Prints a set of rollerd parameters and then exits. This shows the parameters with which rollerd will
execute, but very little parameter validation is performed.

-pidfile pid_file
Stores the running process PID into pid_file. This defaults to /var/run/rollerd.pid on most systems.

-rrfile rollrec_file
Name of the rollrec file to be processed. This is the only required "option".

-realm realm_name
Name of the realm in which rollerd is running. This is for use with the DNSSEC-Tools realms facility
as a means of easily identifying different instantiations of rollerd. It is informational only
(e.g., ps output and log files) and is not used for anything else.

-singlerun
Processes all needed steps once and exits. This is not the ideal way to run rollerd, but it is
potentially useful for environments where keying material is only available when specific hardware
tokens have been made available.

The timing between the steps will be potentially longer since the time between rollerd runs is
dependent on when rollerd is executed. "cmd" lines must be added to the rollrec file to do
particular actions.

The following lines should serve as examples:

cmd "rollzsk example.com"
cmd "rollksk example.com"
cmd "dspub example.com" # (for when the parent publishes
# the new ksk)

The -singlerun option implicitly implies -foreground as well.

-sleep sleeptime
Sets rollerd's sleep time to sleeptime. The sleep time is the amount of time (in seconds) rollerd
waits between processing its rollrec-based queue.

-username username
username is the user for which the rollerd daemon will be executed. The rollerd process' effective
uid will be set to the uid corresponding to username.

If username is a username, it must correspond to a valid uid; if it is a uid, it must correspond to a
valid username.

If rollerd does not have the appropriate O/S magic (e.g., for Unix, installed as setuid program and
owned by root) then it will only be able to switch to those users to which the executing user has
privilege to switch. This restriction is dependent on the operating system and the manner by which
rollerd is installed.

When using this option, the target user must have access to the various directories, logs, and data
files that rollerd requires to execute. Without this access, proper execution cannot occur.

-zsargs arglist
Additional zonesigner arguments that will be passed to all zonesigner executions. These arguments
will override the corresponding arguments in the DNSSEC-Tools configuration file, and the zones'
keyrec files. If a zone's rollrec entry contains a zsargs field, then it will be used instead of
those specified by this argument.

Given the rollerd argument processing, the new arguments for zonesigner cannot be specified as
expected. Instead, the arguments should be given in the following manner. The leading dash should
be replaced with an equals sign. If the option takes an argument, the space that would separate the
option from the option's argument should also be replaced by an equals sign. If multiple arguments
will be passed via -zsargs, quotes must be used to group them into a single argument.

rollerd translates these arguments to the appropriate format for zonesigner. These examples should
clarify the modifications:

normal zonesigner option rollerd -zsargs option
------------------------ ----------------------
-nokrfile -zsargs =nokrfile
-zskcount 5 -kskcount 3 -zsargs "=zskcount=5 =kskcount=3"

-Version
Displays the version information for rollerd and the DNSSEC-Tools package.

-help
Display a usage message.

-verbose
Verbose output will be given.

ASSUMPTIONS

       rollerd uses the rndc command to communicate with the BIND named daemon.  Therefore, it assumes that
       appropriate measures have been taken so that this communication is possible.

KNOWN PROBLEMS

       The following problems (or potential problems) are known:

       -   Any process that can write to the rollover socket can send commands to rollerd.  This is probably not
           a Good Thing.

COPYRIGHT

       Copyright 2005-2013 SPARTA, Inc.  All rights reserved.  See the COPYING file included with the DNSSEC-
       Tools package for details.

AUTHOR

       Wayne Morrison, tewok@tislabs.com