BIO_NEW_CMS(3ossl) OpenSSL BIO_NEW_CMS(3ossl)
NAME
BIO_new_CMS - CMS streaming filter BIO
SYNOPSIS
#include <openssl/cms.h>
BIO *BIO_new_CMS(BIO *out, CMS_ContentInfo *cms);
DESCRIPTION
BIO_new_CMS(3) returns a streaming filter BIO chain based on cms. The
output of the filter is written to out. Any data written to the chain
is automatically translated to a BER format CMS structure of the
appropriate type.
NOTES
The chain returned by this function behaves like a standard filter BIO.
It supports non blocking I/O. Content is processed and streamed on the
fly and not all held in memory at once: so it is possible to encode
very large structures. After all content has been written through the
chain BIO_flush() must be called to finalise the structure.
The CMS_STREAM flag must be included in the corresponding flags
parameter of the cms creation function.
If an application wishes to write additional data to out BIOs should be
removed from the chain using BIO_pop() and freed with BIO_free() until
out is reached. If no additional data needs to be written
BIO_free_all() can be called to free up the whole chain.
Any content written through the filter is used verbatim: no canonical
translation is performed.
It is possible to chain multiple BIOs to, for example, create a triple
wrapped signed, enveloped, signed structure. In this case it is the
applications responsibility to set the inner content type of any outer
CMS_ContentInfo structures.
Large numbers of small writes through the chain should be avoided as
this will produce an output consisting of lots of OCTET STRING
structures. Prepending a BIO_f_buffer() buffering BIO will prevent
this.
BUGS
There is currently no corresponding inverse BIO: i.e. one which can
decode a CMS structure on the fly.
RETURN VALUES
BIO_new_CMS(3) returns a BIO chain when successful or NULL if an error
occurred. The error can be obtained from ERR_get_error(3).
SEE ALSO
ERR_get_error(3), CMS_sign(3), CMS_encrypt(3)
HISTORY
The BIO_new_CMS(3) function was added in OpenSSL 1.0.0.
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
<https://www.openssl.org/source/license.html>.
3.4.0 2024-10-29 BIO_NEW_CMS(3ossl)
openssl 3.4.0 - Generated Sat Nov 2 06:07:35 CDT 2024