1BIO_NEW_CMS(3) OpenSSL BIO_NEW_CMS(3)
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6 BIO_new_CMS - CMS streaming filter BIO
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9 #include <openssl/cms.h>
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11 BIO *BIO_new_CMS(BIO *out, CMS_ContentInfo *cms);
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14 BIO_new_CMS() returns a streaming filter BIO chain based on cms. The
15 output of the filter is written to out. Any data written to the chain
16 is automatically translated to a BER format CMS structure of the
17 appropriate type.
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20 The chain returned by this function behaves like a standard filter BIO.
21 It supports non blocking I/O. Content is processed and streamed on the
22 fly and not all held in memory at once: so it is possible to encode
23 very large structures. After all content has been written through the
24 chain BIO_flush() must be called to finalise the structure.
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26 The CMS_STREAM flag must be included in the corresponding flags
27 parameter of the cms creation function.
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29 If an application wishes to write additional data to out BIOs should be
30 removed from the chain using BIO_pop() and freed with BIO_free() until
31 out is reached. If no additional data needs to be written
32 BIO_free_all() can be called to free up the whole chain.
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34 Any content written through the filter is used verbatim: no canonical
35 translation is performed.
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37 It is possible to chain multiple BIOs to, for example, create a triple
38 wrapped signed, enveloped, signed structure. In this case it is the
39 applications responsibility to set the inner content type of any outer
40 CMS_ContentInfo structures.
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42 Large numbers of small writes through the chain should be avoided as
43 this will produce an output consisting of lots of OCTET STRING
44 structures. Prepending a BIO_f_buffer() buffering BIO will prevent
45 this.
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48 There is currently no corresponding inverse BIO: i.e. one which can
49 decode a CMS structure on the fly.
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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).
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56 ERR_get_error(3), CMS_sign(3), CMS_encrypt(3)
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59 The BIO_new_CMS() function was added in OpenSSL 1.0.0.
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62 Copyright 2008-2016 The OpenSSL Project Authors. All Rights Reserved.
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64 Licensed under the OpenSSL license (the "License"). You may not use
65 this file except in compliance with the License. You can obtain a copy
66 in the file LICENSE in the source distribution or at
67 <https://www.openssl.org/source/license.html>.
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711.1.1q 2023-02-06 BIO_NEW_CMS(3)