5 BIO_new_CMS - CMS streaming filter BIO
9 #include <openssl/cms.h>
11 BIO *BIO_new_CMS(BIO *out, CMS_ContentInfo *cms);
15 BIO_new_CMS() returns a streaming filter BIO chain based on B<cms>. The output
16 of the filter is written to B<out>. Any data written to the returned BIO
17 is automatically translated to a BER format CMS structure.
21 The BIO returned by this functions behaves like a standard filter BIO. It
22 supports non blocking I/O. Content is processes and streamed on the fly and not
23 all held in memory at once: so it is possible to encode very large structures.
24 After all content has been written through the BIO BIO_flush() must be called
25 to finalise the structure.
27 The B<CMS_STREAM> flag must be included in the corresponding B<flags>
28 parameter of the B<cms> creation function.
30 After use BIOs should be removed from the filter using BIO_pop() until
31 the output BIO B<out> is reached.
33 Any content written through the filter is uses "as-is" and no canonical
34 translation is performed.
36 It is possible to chain multiple BIOs to for example create a triple wrapped
37 signed, enveloped signed structure. In this case it is the applications
38 responsibility to set the inner content type of any outer CMS_ContentInfo
41 Large numbers of small writes through the chain should be avoided as this will
42 produce an output consisting of lots of OCTET STRING structures. Prepending
43 a BIO_f_buffer() buffering BIO will prevent this.
47 There is currently no corresponding inverse BIO: i.e. one which can decode
48 a CMS structure on the fly.
52 BIO_new_CMS() returns a BIO chain when successful or NULL if an error
53 occurred. The error can be obtained from ERR_get_error(3).
57 L<ERR_get_error(3)|ERR_get_error(3)>, L<CMS_sign(3)|CMS_sign(3)>,
58 L<CMS_encrypt(3)|CMS_encrypt(3)>
62 BIO_new_CMS() was added to OpenSSL 0.9.9