1=pod 2 3=head1 NAME 4 5SMIME_read_CMS_ex, SMIME_read_CMS - parse S/MIME message 6 7=head1 SYNOPSIS 8 9 #include <openssl/cms.h> 10 11 CMS_ContentInfo *SMIME_read_CMS_ex(BIO *bio, int flags, BIO **bcont, 12 CMS_ContentInfo **cms); 13 CMS_ContentInfo *SMIME_read_CMS(BIO *in, BIO **bcont); 14 15=head1 DESCRIPTION 16 17SMIME_read_CMS() parses a message in S/MIME format. 18 19B<in> is a BIO to read the message from. 20 21If cleartext signing is used then the content is saved in a memory bio which is 22written to B<*bcont>, otherwise B<*bcont> is set to NULL. 23 24The parsed CMS_ContentInfo structure is returned or NULL if an 25error occurred. 26 27SMIME_read_CMS_ex() is similar to SMIME_read_CMS() but optionally a previously 28created I<cms> CMS_ContentInfo object can be supplied as well as some I<flags>. 29To create a I<cms> object use L<CMS_ContentInfo_new_ex(3)>. 30If the I<flags> argument contains B<CMS_BINARY> then the input is assumed to be 31in binary format and is not translated to canonical form. 32If in addition B<SMIME_ASCIICRLF> is set then the binary input is assumed 33to be followed by B<CR> and B<LF> characters, else only by an B<LF> character. 34If I<flags> is 0 and I<cms> is NULL then it is identical to SMIME_read_CMS(). 35 36=head1 NOTES 37 38If B<*bcont> is not NULL then the message is clear text signed. B<*bcont> can 39then be passed to CMS_verify() with the B<CMS_DETACHED> flag set. 40 41Otherwise the type of the returned structure can be determined 42using CMS_get0_type(). 43 44To support future functionality if B<bcont> is not NULL B<*bcont> should be 45initialized to NULL. For example: 46 47 BIO *cont = NULL; 48 CMS_ContentInfo *cms; 49 50 cms = SMIME_read_CMS(in, &cont); 51 52=head1 BUGS 53 54The MIME parser used by SMIME_read_CMS() is somewhat primitive. While it will 55handle most S/MIME messages more complex compound formats may not work. 56 57The parser assumes that the CMS_ContentInfo structure is always base64 encoded 58and will not handle the case where it is in binary format or uses quoted 59printable format. 60 61The use of a memory BIO to hold the signed content limits the size of message 62which can be processed due to memory restraints: a streaming single pass option 63should be available. 64 65=head1 RETURN VALUES 66 67SMIME_read_CMS_ex() and SMIME_read_CMS() return a valid B<CMS_ContentInfo> 68structure or B<NULL> if an error occurred. The error can be obtained from 69ERR_get_error(3). 70 71=head1 SEE ALSO 72 73L<ERR_get_error(3)>, 74L<CMS_sign(3)>, 75L<CMS_verify(3)>, 76L<CMS_encrypt(3)>, 77L<CMS_decrypt(3)> 78 79=head1 HISTORY 80 81The function SMIME_read_CMS_ex() was added in OpenSSL 3.0. 82 83=head1 COPYRIGHT 84 85Copyright 2008-2021 The OpenSSL Project Authors. All Rights Reserved. 86 87Licensed under the Apache License 2.0 (the "License"). You may not use 88this file except in compliance with the License. You can obtain a copy 89in the file LICENSE in the source distribution or at 90L<https://www.openssl.org/source/license.html>. 91 92=cut 93