'\" t
.\"     Title: cryptsetup-fvault2dump
.\"    Author: [see the "AUTHOR(S)" section]
.\" Generator: Asciidoctor 2.0.20
.\"      Date: 2024-01-05
.\"    Manual: Maintenance Commands
.\"    Source: cryptsetup 2.6.1
.\"  Language: English
.\"
.TH "CRYPTSETUP\-FVAULT2DUMP" "8" "2024-01-05" "cryptsetup 2.6.1" "Maintenance Commands"
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.SH "NAME"
cryptsetup-fvault2Dump \- dump the header information of a FVAULT2 (FileVault2 compatible) device
.SH "SYNOPSIS"
.sp
\fBcryptsetup \fIfvault2Dump\fP [<options>] <device>\fP
.SH "DESCRIPTION"
.sp
Dump the header information of a FVAULT2 (FileVault2 compatible) device.
.sp
If the \-\-dump\-volume\-key option is used, the FVAULT2 device volume key
is dumped instead of header information. You have to provide password
or keyfile to dump volume key.
.sp
Beware that the volume key can be used to decrypt the data stored in
the container without a passphrase.
This means that if the volume key is compromised, the whole device has
to be erased to prevent further access. Use this option carefully.
.sp
\fB<options>\fP can be [\-\-dump\-volume\-key, \-\-volume\-key\-file, \-\-key\-file,
\-\-keyfile\-offset, \-\-keyfile\-size, \-\-timeout].
.SH "OPTIONS"
.sp
\fB\-\-key\-file, \-d\fP \fIname\fP
.RS 4
Read the passphrase from file.
.sp
If the name given is "\-", then the passphrase will be read from stdin.
In this case, reading will not stop at newline characters.
.sp
See section \fINOTES ON PASSPHRASE PROCESSING\fP in \fBcryptsetup\fP(8) for more information.
.RE
.sp
\fB\-\-keyfile\-offset\fP \fIvalue\fP
.RS 4
Skip \fIvalue\fP bytes at the beginning of the key file.
.RE
.sp
\fB\-\-keyfile\-size, \-l\fP \fIvalue\fP
.RS 4
Read a maximum of \fIvalue\fP bytes from the key file. The default is to
read the whole file up to the compiled\-in maximum that can be queried
with \-\-help. Supplying more data than the compiled\-in maximum aborts
the operation.
.sp
This option is useful to cut trailing newlines, for example. If
\-\-keyfile\-offset is also given, the size count starts after the offset.
.RE
.sp
\fB\-\-volume\-key\-file, \-\-master\-key\-file (OBSOLETE alias)\fP
.RS 4
Use a volume key stored in a file.
The volume key is stored in a file instead of being printed out to standard output.
.br
.RE
.sp
\fB\-\-dump\-volume\-key, \-\-dump\-master\-key (OBSOLETE alias)\fP
.RS 4
Print the volume key in the displayed information. Use with care,
as the volume key can be used to bypass
the passphrases, see also option \-\-volume\-key\-file.
.RE
.sp
\fB\-\-timeout, \-t <number of seconds>\fP
.RS 4
The number of seconds to wait before timeout on passphrase input via
terminal. It is relevant every time a passphrase is asked.
It has no effect if used in conjunction with \-\-key\-file.
.sp
This option is useful when the system should not stall if the user
does not input a passphrase, e.g. during boot. The default is a value
of 0 seconds, which means to wait forever.
.RE
.sp
\fB\-\-batch\-mode, \-q\fP
.RS 4
Suppresses all confirmation questions. Use with care!
.sp
If the \-\-verify\-passphrase option is not specified, this option also
switches off the passphrase verification.
.RE
.sp
\fB\-\-debug or \-\-debug\-json\fP
.RS 4
Run in debug mode with full diagnostic logs. Debug output lines are
always prefixed by \fB#\fP.
.sp
If \-\-debug\-json is used, additional LUKS2 JSON data structures are printed.
.RE
.sp
\fB\-\-version, \-V\fP
.RS 4
Show the program version.
.RE
.sp
\fB\-\-usage\fP
.RS 4
Show short option help.
.RE
.sp
\fB\-\-help, \-?\fP
.RS 4
Show help text and default parameters.
.RE
.SH "REPORTING BUGS"
.sp
Report bugs at \c
.MTO "cryptsetup\(atlists.linux.dev" "\fBcryptsetup mailing list\fP"
or in \c
.URL "https://gitlab.com/cryptsetup/cryptsetup/\-/issues/new" "\fBIssues project section\fP" "."
.sp
Please attach output of the failed command with \-\-debug option added.
.SH "SEE ALSO"
.sp
.URL "https://gitlab.com/cryptsetup/cryptsetup/wikis/FrequentlyAskedQuestions" "\fBCryptsetup FAQ\fP" ""
.sp
\fBcryptsetup\fP(8), \fBintegritysetup\fP(8) and \fBveritysetup\fP(8)
.SH "CRYPTSETUP"
.sp
Part of \c
.URL "https://gitlab.com/cryptsetup/cryptsetup/" "\fBcryptsetup project\fP" "."