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

=head1 HISTORY

CMS_uncompress() was added to OpenSSL 0.9.8

=cut