SMIME_read_CMS.pod revision 290135 
1208963Srdivacky=pod
2208963Srdivacky
3310618Sdim=head1 NAME
4310618Sdim
5310618Sdim SMIME_read_CMS - parse S/MIME message.
6310618Sdim
7335875Sdim=head1 SYNOPSIS
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9335875Sdim #include <openssl/cms.h>
10335875Sdim
11218893Sdim CMS_ContentInfo *SMIME_read_CMS(BIO *in, BIO **bcont);
12335875Sdim
13346296Sdim=head1 DESCRIPTION
14346296Sdim
15346296SdimSMIME_read_CMS() parses a message in S/MIME format.
16335875Sdim
17210299SedB<in> is a BIO to read the message from.
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19335875SdimIf cleartext signing is used then the content is saved in a memory bio which is
20210299Sedwritten to B<*bcont>, otherwise B<*bcont> is set to NULL.
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22346891SmhorneThe parsed CMS_ContentInfo structure is returned or NULL if an
23346891Smhorneerror occurred.
24346891Smhorne
25335875Sdim=head1 NOTES
26262613Sdim
27335875SdimIf B<*bcont> is not NULL then the message is clear text signed. B<*bcont> can
28335875Sdimthen be passed to CMS_verify() with the B<CMS_DETACHED> flag set.
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30335875SdimOtherwise the type of the returned structure can be determined
31208963Srdivackyusing CMS_get0_type().
32208963Srdivacky
33To support future functionality if B<bcont> is not NULL B<*bcont> should be
34initialized to NULL. For example:
35
36 BIO *cont = NULL;
37 CMS_ContentInfo *cms;
38
39 cms = SMIME_read_CMS(in, &cont);
40
41=head1 BUGS
42
43The MIME parser used by SMIME_read_CMS() is somewhat primitive.  While it will
44handle most S/MIME messages more complex compound formats may not work.
45
46The parser assumes that the CMS_ContentInfo structure is always base64 encoded
47and will not handle the case where it is in binary format or uses quoted
48printable format.
49
50The use of a memory BIO to hold the signed content limits the size of message
51which can be processed due to memory restraints: a streaming single pass option
52should be available.
53
54=head1 RETURN VALUES
55
56SMIME_read_CMS() returns a valid B<CMS_ContentInfo> structure or B<NULL>
57if an error occurred. The error can be obtained from ERR_get_error(3).
58
59=head1 SEE ALSO
60
61L<ERR_get_error(3)|ERR_get_error(3)>, L<CMS_type(3)|CMS_type(3)>
62L<SMIME_read_CMS(3)|SMIME_read_CMS(3)>, L<CMS_sign(3)|CMS_sign(3)>,
63L<CMS_verify(3)|CMS_verify(3)>, L<CMS_encrypt(3)|CMS_encrypt(3)>
64L<CMS_decrypt(3)|CMS_decrypt(3)>
65
66=head1 HISTORY
67
68SMIME_read_CMS() was added to OpenSSL 0.9.8
69
70=cut
71