1=pod
2
3=head1 NAME
4
5CMS_get0_type, CMS_set1_eContentType, CMS_get0_eContentType, CMS_get0_content - get and set CMS content types and content
6
7=head1 SYNOPSIS
8
9 #include <openssl/cms.h>
10
11 const ASN1_OBJECT *CMS_get0_type(const CMS_ContentInfo *cms);
12 int CMS_set1_eContentType(CMS_ContentInfo *cms, const ASN1_OBJECT *oid);
13 const ASN1_OBJECT *CMS_get0_eContentType(CMS_ContentInfo *cms);
14 ASN1_OCTET_STRING **CMS_get0_content(CMS_ContentInfo *cms);
15
16=head1 DESCRIPTION
17
18CMS_get0_type() returns the content type of a CMS_ContentInfo structure as
19an ASN1_OBJECT pointer. An application can then decide how to process the
20CMS_ContentInfo structure based on this value.
21
22CMS_set1_eContentType() sets the embedded content type of a CMS_ContentInfo
23structure. It should be called with CMS functions (such as L<CMS_sign>, L<CMS_encrypt>)
24with the B<CMS_PARTIAL>
25flag and B<before> the structure is finalised, otherwise the results are
26undefined.
27
28ASN1_OBJECT *CMS_get0_eContentType() returns a pointer to the embedded
29content type.
30
31CMS_get0_content() returns a pointer to the B<ASN1_OCTET_STRING> pointer
32containing the embedded content.
33
34=head1 NOTES
35
36As the B<0> implies CMS_get0_type(), CMS_get0_eContentType() and
37CMS_get0_content() return internal pointers which should B<not> be freed up.
38CMS_set1_eContentType() copies the supplied OID and it B<should> be freed up
39after use.
40
41The B<ASN1_OBJECT> values returned can be converted to an integer B<NID> value
42using OBJ_obj2nid(). For the currently supported content types the following
43values are returned:
44
45 NID_pkcs7_data
46 NID_pkcs7_signed
47 NID_pkcs7_digest
48 NID_id_smime_ct_compressedData:
49 NID_pkcs7_encrypted
50 NID_pkcs7_enveloped
51
52The return value of CMS_get0_content() is a pointer to the B<ASN1_OCTET_STRING>
53content pointer. That means that for example:
54
55 ASN1_OCTET_STRING **pconf = CMS_get0_content(cms);
56
57B<*pconf> could be NULL if there is no embedded content. Applications can
58access, modify or create the embedded content in a B<CMS_ContentInfo> structure
59using this function. Applications usually will not need to modify the
60embedded content as it is normally set by higher level functions.
61
62=head1 RETURN VALUES
63
64CMS_get0_type() and CMS_get0_eContentType() return an ASN1_OBJECT structure.
65
66CMS_set1_eContentType() returns 1 for success or 0 if an error occurred.  The
67error can be obtained from ERR_get_error(3).
68
69=head1 SEE ALSO
70
71L<ERR_get_error(3)>
72
73=head1 COPYRIGHT
74
75Copyright 2008-2019 The OpenSSL Project Authors. All Rights Reserved.
76
77Licensed under the OpenSSL license (the "License").  You may not use
78this file except in compliance with the License.  You can obtain a copy
79in the file LICENSE in the source distribution or at
80L<https://www.openssl.org/source/license.html>.
81
82=cut
83