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Diffstat (limited to 'openssl-1.1.0h/doc/crypto/BIO_new_CMS.pod')
| -rw-r--r-- | openssl-1.1.0h/doc/crypto/BIO_new_CMS.pod | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/openssl-1.1.0h/doc/crypto/BIO_new_CMS.pod b/openssl-1.1.0h/doc/crypto/BIO_new_CMS.pod new file mode 100644 index 0000000..b06c224 --- /dev/null +++ b/openssl-1.1.0h/doc/crypto/BIO_new_CMS.pod @@ -0,0 +1,75 @@ +=pod + +=head1 NAME + +BIO_new_CMS - CMS streaming filter BIO + +=head1 SYNOPSIS + + #include <openssl/cms.h> + + BIO *BIO_new_CMS(BIO *out, CMS_ContentInfo *cms); + +=head1 DESCRIPTION + +BIO_new_CMS() returns a streaming filter BIO chain based on B<cms>. The output +of the filter is written to B<out>. Any data written to the chain is +automatically translated to a BER format CMS structure of the appropriate type. + +=head1 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 B<CMS_STREAM> flag must be included in the corresponding B<flags> +parameter of the B<cms> creation function. + +If an application wishes to write additional data to B<out> BIOs should be +removed from the chain using BIO_pop() and freed with BIO_free() until B<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. + +=head1 BUGS + +There is currently no corresponding inverse BIO: i.e. one which can decode +a CMS structure on the fly. + +=head1 RETURN VALUES + +BIO_new_CMS() returns a BIO chain when successful or NULL if an error +occurred. The error can be obtained from ERR_get_error(3). + +=head1 SEE ALSO + +L<ERR_get_error(3)>, L<CMS_sign(3)>, +L<CMS_encrypt(3)> + +=head1 HISTORY + +BIO_new_CMS() was added to OpenSSL 1.0.0 + +=head1 COPYRIGHT + +Copyright 2008-2016 The OpenSSL Project Authors. All Rights Reserved. + +Licensed under the OpenSSL license (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>. + +=cut |