Newer
Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
=pod
=head1 NAME
SMIME_read_CMS - parse S/MIME message.
=head1 SYNOPSIS
#include <openssl/cms.h>
CMS_ContentInfo *SMIME_read_CMS(BIO *in, BIO **bcont);
=head1 DESCRIPTION
SMIME_read_CMS() parses a message in S/MIME format.
B<in> is a BIO to read the message from.
If cleartext signing is used then the content is saved in a memory bio which is
written to B<*bcont>, otherwise B<*bcont> is set to NULL.
The parsed CMS_ContentInfo structure is returned or NULL if an
error occurred.
=head1 NOTES
If B<*bcont> is not NULL then the message is clear text signed. B<*bcont> can
then be passed to CMS_verify() with the B<CMS_DETACHED> flag set.
Otherwise the type of the returned structure can be determined
using CMS_get0_type().
To support future functionality if B<bcont> is not NULL B<*bcont> should be
initialized to NULL. For example:
BIO *cont = NULL;
CMS_ContentInfo *cms;
cms = SMIME_read_CMS(in, &cont);
=head1 BUGS
The MIME parser used by SMIME_read_CMS() is somewhat primitive. While it will
handle most S/MIME messages more complex compound formats may not work.
The parser assumes that the CMS_ContentInfo structure is always base64 encoded
and will not handle the case where it is in binary format or uses quoted
printable format.
The use of a memory BIO to hold the signed content limits the size of message
which can be processed due to memory restraints: a streaming single pass option
should be available.
=head1 RETURN VALUES
SMIME_read_CMS() returns a valid B<CMS_ContentInfo> structure or B<NULL>
if an error occurred. The error can be obtained from ERR_get_error(3).
=head1 SEE ALSO
L<ERR_get_error(3)|ERR_get_error(3)>, L<CMS_type(3)|CMS_type(3)>
L<SMIME_read_CMS(3)|SMIME_read_CMS(3)>, L<CMS_sign(3)|CMS_sign(3)>,
L<CMS_verify(3)|CMS_verify(3)>, L<CMS_encrypt(3)|CMS_encrypt(3)>
L<CMS_decrypt(3)|CMS_decrypt(3)>
=head1 HISTORY
SMIME_read_CMS() was added to OpenSSL 0.9.8
=cut