.\" Automatically generated by Pod::Man 4.14 (Pod::Simple 3.43)
.\"
.\" Standard preamble:
.\" ========================================================================
.de Sp \" Vertical space (when we can't use .PP)
.if t .sp .5v
.if n .sp
..
.de Vb \" Begin verbatim text
.ft CW
.nf
.ne \\$1
..
.de Ve \" End verbatim text
.ft R
.fi
..
.\" Set up some character translations and predefined strings.  \*(-- will
.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left
.\" double quote, and \*(R" will give a right double quote.  \*(C+ will
.\" give a nicer C++.  Capital omega is used to do unbreakable dashes and
.\" therefore won't be available.  \*(C` and \*(C' expand to `' in nroff,
.\" nothing in troff, for use with C<>.
.tr \(*W-
.ds C+ C\v'-.1v'\h'-1p'\s-2+\h'-1p'+\s0\v'.1v'\h'-1p'
.ie n \{\
.    ds -- \(*W-
.    ds PI pi
.    if (\n(.H=4u)&(1m=24u) .ds -- \(*W\h'-12u'\(*W\h'-12u'-\" diablo 10 pitch
.    if (\n(.H=4u)&(1m=20u) .ds -- \(*W\h'-12u'\(*W\h'-8u'-\"  diablo 12 pitch
.    ds L" ""
.    ds R" ""
.    ds C` ""
.    ds C' ""
'br\}
.el\{\
.    ds -- \|\(em\|
.    ds PI \(*p
.    ds L" ``
.    ds R" ''
.    ds C`
.    ds C'
'br\}
.\"
.\" Escape single quotes in literal strings from groff's Unicode transform.
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.\"
.\" If the F register is >0, we'll generate index entries on stderr for
.\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index
.\" entries marked with X<> in POD.  Of course, you'll have to process the
.\" output yourself in some meaningful fashion.
.\"
.\" Avoid warning from groff about undefined register 'F'.
.de IX
..
.nr rF 0
.if \n(.g .if rF .nr rF 1
.if (\n(rF:(\n(.g==0)) \{\
.    if \nF \{\
.        de IX
.        tm Index:\\$1\t\\n%\t"\\$2"
..
.        if !\nF==2 \{\
.            nr % 0
.            nr F 2
.        \}
.    \}
.\}
.rr rF
.\" ========================================================================
.\"
.IX Title "File::KDBX::IO::HmacBlock 3pm"
.TH File::KDBX::IO::HmacBlock 3pm "2022-11-20" "perl v5.36.0" "User Contributed Perl Documentation"
.\" For nroff, turn off justification.  Always turn off hyphenation; it makes
.\" way too many mistakes in technical documents.
.if n .ad l
.nh
.SH "NAME"
File::KDBX::IO::HmacBlock \- HMAC block stream IO handle
.SH "VERSION"
.IX Header "VERSION"
version 0.906
.SH "DESCRIPTION"
.IX Header "DESCRIPTION"
Writing to a HMAC-block stream handle will transform the data into a series of blocks. An \s-1HMAC\s0 is calculated
for each block and is included in the output.
.PP
Reading from a handle, each block will be verified and authenticated as the blocks are disassembled back into
a data stream.
.PP
This format helps ensure data integrity and authenticity of \s-1KDBX4\s0 files.
.PP
Each block is encoded thusly:
.IP "\(bu" 4
\&\s-1HMAC\s0 \- 32 bytes, calculated over [block index (increments starting with 0), block size and data]
.IP "\(bu" 4
Block size \- Little-endian unsigned 32\-bit (counting only the data)
.IP "\(bu" 4
Data \- String of bytes
.PP
The terminating block is an empty block encoded as usual but block size is 0 and there is no data.
.SH "ATTRIBUTES"
.IX Header "ATTRIBUTES"
.SS "block_size"
.IX Subsection "block_size"
Desired block size when writing (default: \f(CW$File::KDBX::IO::HmacBlock::BLOCK_SIZE\fR or 1,048,576 bytes)
.SS "key"
.IX Subsection "key"
\&\s-1HMAC\-SHA256\s0 key for authenticating the data stream (required)
.SH "METHODS"
.IX Header "METHODS"
.SS "new"
.IX Subsection "new"
.Vb 2
\&    $fh = File::KDBX::IO::HmacBlock\->new(%attributes);
\&    $fh = File::KDBX::IO::HmacBlock\->new($fh, %attributes);
.Ve
.PP
Construct a new HMAC-block stream \s-1IO\s0 handle.
.SH "BUGS"
.IX Header "BUGS"
Please report any bugs or feature requests on the bugtracker website
<https://github.com/chazmcgarvey/File\-KDBX/issues>
.PP
When submitting a bug or request, please include a test-file or a
patch to an existing test-file that illustrates the bug or desired
feature.
.SH "AUTHOR"
.IX Header "AUTHOR"
Charles McGarvey <ccm@cpan.org>
.SH "COPYRIGHT AND LICENSE"
.IX Header "COPYRIGHT AND LICENSE"
This software is copyright (c) 2022 by Charles McGarvey.
.PP
This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.