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NAME

Mail::Run::Crypt - Encrypt and mail output from command runs

VERSION

Version 0.07

DESCRIPTION

This module runs a system command with IPC::Run3, and collects any standard output and standard error it emits. If there is any standard output or standard error content, it is encrypted and optionally signed with GnuPG, and then each stream's content is mailed separately to a specified recipient address.

The idea is to allow you to view the output of automated commands while having the content encrypted as it passes through to your mailserver, and optionally to have some assurance that the content was actually generated by the server concerned. cron(8) scripts are the ideal use case, but this would also work with at(1), or anything else that might non-interactively run jobs for which output is significant.

You will probably want to call this with the runcrypt(1) program provided by this distribution, which includes a means to set the properties for the module via environment variables or command line options.

SYNOPSIS

use Mail::Run::Crypt;
...
my $mrc = Mail::Run::Crypt->new(
    mailto => 'you@example.net',
);
$mrc->run($command, @args);
...
my $mrc = Mail::Run::Crypt->new(
    sign       => 1,
    keyid      => '0x1234DEAD5678BEEF',
    passphrase => 'able was i ere i saw elba',
    mailto     => 'you@example.net',
);
$mrc->run($command, @args);

SUBROUTINES/METHODS

new(%opts)

Constructor method; accepts the following named parameters:

  • mailto

    The recipient email address for the content. This is always required.

  • encrypt

    Whether to encrypt the command output. This defaults to 1.

  • sign

    Whether to sign the command output. This defaults to 0. A keyid and passphrase will be required for signing.

    It is strongly recommended that a dedicated key and passphrase be used for signatures if this is needed. You should carefully consider the consequences of a compromised key.

  • keyid

    The GnuPG key ID that should be used to sign messages. This is required for signing, and has no effect without sign. It can be any means of identifying the key acceptable to GnuPG; the key's 8-byte ("long") hexadecimal ID prefixed with 0x is probably the best way.

  • passphrase

    The passphrase used to decrypt the key. This is required for signing, and has no effect without sign.

  • name

    (Optional) The name of the object. When called from the runcrypt(1) program, this will be the string "runcrypt". Otherwise, it will default to this package's name.

run(@command)

Run the specified arguments as a command with IPC::Run3, and email any output or error content to the email recipient, encrypting and/or signing as configured. Returns 1 if the command succeeded, 0 otherwise. Use bail() to get the actual exit code if needed.

bail()

Return the exit status of the most recently run command, or 127 if no command has been successfully run.

DIAGNOSTICS

  • mailto required

    The required mailto property was not passed in the constructor.

  • keyid required for signing

    Signing was specified, but no keyid attribute was passed in the constructor.

  • passphrase required for signing

    Signing was specified, but no passphrase attribute was passed in the constructor.

  • command failed: %s

    The command could not be run at all, raising the given error string. This is typically due to problems finding the executable.

CONFIGURATION AND ENVIRONMENT

You will need to have a functioning GnuPG public key setup for this to work, including stored keys or a key retrieval system for your recipients. You will also need a secret key if you want to sign the messages.

You should definitely not use your personal key for this; generate one specifically for mail signing and encryption instead.

I wrote a tutorial on GnuPG key setup, including agent configuration, as part of this series:

https://sanctum.geek.nz/arabesque/series/gnu-linux-crypto/

DEPENDENCIES

INCOMPATIBILITIES

This module uses Mail::GnuPG and other GnuPG-specific code, so it won't work with other OpenPGP implementations.

BUGS AND LIMITATIONS

Definitely. This code is not production-ready. The test suite coverage is still not great, but should improve in newer versions.

AUTHOR

Tom Ryder <tom@sanctum.geek.nz>

LICENSE AND COPYRIGHT

Copyright (C) 2017 Tom Ryder

This program is free software; you can redistribute it and/or modify it under the terms of the Artistic License (2.0). You may obtain a copy of the full license at:

http://www.perlfoundation.org/artistic_license_2_0

Any use, modification, and distribution of the Standard or Modified Versions is governed by this Artistic License. By using, modifying or distributing the Package, you accept this license. Do not use, modify, or distribute the Package, if you do not accept this license.

If your Modified Version has been derived from a Modified Version made by someone other than you, you are nevertheless required to ensure that your Modified Version complies with the requirements of this license.

This license does not grant you the right to use any trademark, service mark, tradename, or logo of the Copyright Holder.

This license includes the non-exclusive, worldwide, free-of-charge patent license to make, have made, use, offer to sell, sell, import and otherwise transfer the Package with respect to any patent claims licensable by the Copyright Holder that are necessarily infringed by the Package. If you institute patent litigation (including a cross-claim or counterclaim) against any party alleging that the Package constitutes direct or contributory patent infringement, then this Artistic License to you shall terminate on the date that such litigation is filed.

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