.\" Copyright (c) 2016 Konrad Witaszczyk <def@FreeBSD.org>
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.Dd January 29, 2018
.Dt DECRYPTCORE 8
.Os
.Sh NAME
.Nm decryptcore
.Nd "decrypt a core dump of the operating system"
.Sh SYNOPSIS
.Nm
.Op Fl fLv
.Fl p Ar privatekeyfile
.Fl k Ar keyfile
.Fl e Ar encryptedcore
.Fl c Ar core
.Nm
.Op Fl fLv
.Op Fl d Ar crashdir
.Fl p Ar privatekeyfile
.Fl n Ar dumpnr
.Sh DESCRIPTION
The
.Nm
utility first decrypts
.Ar keyfile
using
.Ar privatekeyfile
and then uses the resulting key to decrypt
.Ar encryptedcore
saved by
.Xr savecore 8 .
The result is saved in
.Ar core .
.Pp
Alternatively a user can decrypt a core dump numbered
.Ar dumpnr
from the
.Ar crashdir
directory.
In this case a dump key from the
.Pa key.#
file is used and the result is saved in the
.Pa vmcore.#
file where
.Dq #
corresponds to
.Ar dumpnr .
.Pp
By default
.Nm
does not overwrite an old core dump as a user might want to store the core
somewhere else for the future.
This behaviour can be changed using the
.Fl f
flag.
.Pp
The
.Nm
utility can be started with the following command line arguments:
.Bl -tag -width ".Fl e Ar encryptedcore"
.It Fl f
Remove a decryped core dump if it already exists.
.It Fl L
Write log messages to
.Xr syslogd 8 .
.It Fl v
Print or log verbose/debugging information.
This option can be specified multiple times to raise the verbosity
level.
.It Fl p Ar privatekeyfile
Specify location of a private key file which will be used to decrypt a dump key
file.
.It Fl k Ar keyfile
Specify location of a dump key file.
.It Fl e Ar encryptedcore
Specify location of an encrypted core.
.It Fl c Ar core
Specify location of a resulting decrypted core dump.
.It Fl d Ar crashdir
Specify an alternative crash dump directory.
The default crash dump directory is
.Pa /var/crash .
.It Fl n Ar dumpnr
Specify a number of a crash dump to be decrypted.
.El
.Sh EXIT STATUS
.Ex -std
.Sh SEE ALSO
.Xr kgdb 1 Pq Pa ports/devel/gdb ,
.Xr capsicum 4 ,
.Xr dumpon 8 ,
.Xr savecore 8 ,
.Xr syslogd 8
.Sh AUTHORS
The
.Nm
utility was implemented by
.An Konrad Witaszczyk Aq Mt def@FreeBSD.org .