=pod

=head1 NAME

CMS_uncompress - uncompress a CMS CompressedData structure

=head1 SYNOPSIS

 #include <openssl/cms.h>

 int CMS_uncompress(CMS_ContentInfo *cms, BIO *dcont, BIO *out, unsigned int flags);

=head1 DESCRIPTION

CMS_uncompress() extracts and uncompresses the content from a CMS
CompressedData structure B<cms>. B<data> is a BIO to write the content to and
B<flags> is an optional set of flags.

The B<dcont> parameter is used in the rare case where the compressed content
is detached. It will normally be set to NULL.

=head1 NOTES

The only currently supported compression algorithm is zlib: if the structure
indicates the use of any other algorithm an error is returned.

If zlib support is not compiled into OpenSSL then CMS_uncompress() will always
return an error.

The following flags can be passed in the B<flags> parameter.

If the B<CMS_TEXT> flag is set MIME headers for type B<text/plain> are deleted
from the content. If the content is not of type B<text/plain> then an error is
returned.

=head1 RETURN VALUES

CMS_uncompress() returns either 1 for success or 0 for failure. The error can
be obtained from ERR_get_error(3)

=head1 BUGS

The lack of single pass processing and the need to hold all data in memory as
mentioned in CMS_verify() also applies to CMS_decompress().

=head1 SEE ALSO

L<ERR_get_error(3)>, L<CMS_compress(3)>

=head1 COPYRIGHT

Copyright 2008-2016 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License").  You may not use
this file except in compliance with the License.  You can obtain a copy
in the file LICENSE in the source distribution or at
L<https://www.openssl.org/source/license.html>.

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