1=pod 2 3=head1 NAME 4 5SMIME_read_PKCS7_ex, SMIME_read_PKCS7 - parse S/MIME message 6 7=head1 SYNOPSIS 8 9 #include <openssl/pkcs7.h> 10 11 PKCS7 *SMIME_read_PKCS7_ex(BIO *bio, BIO **bcont, PKCS7 **p7); 12 PKCS7 *SMIME_read_PKCS7(BIO *in, BIO **bcont); 13 14=head1 DESCRIPTION 15 16SMIME_read_PKCS7() parses a message in S/MIME format. 17 18B<in> is a BIO to read the message from. 19 20If cleartext signing is used then the content is saved in 21a memory bio which is written to B<*bcont>, otherwise 22B<*bcont> is set to B<NULL>. 23 24The parsed PKCS#7 structure is returned or B<NULL> if an 25error occurred. 26 27SMIME_read_PKCS7_ex() is similar to SMIME_read_PKCS7() but can optionally supply 28a previously created I<p7> PKCS#7 object. If I<p7> is NULL then it is identical 29to SMIME_read_PKCS7(). 30To create a I<p7> object use L<PKCS7_new_ex(3)>. 31 32=head1 NOTES 33 34If B<*bcont> is not B<NULL> then the message is clear text 35signed. B<*bcont> can then be passed to PKCS7_verify() with 36the B<PKCS7_DETACHED> flag set. 37 38Otherwise the type of the returned structure can be determined 39using PKCS7_type_is_enveloped(), etc. 40 41To support future functionality if B<bcont> is not B<NULL> 42B<*bcont> should be initialized to B<NULL>. For example: 43 44 BIO *cont = NULL; 45 PKCS7 *p7; 46 47 p7 = SMIME_read_PKCS7(in, &cont); 48 49=head1 BUGS 50 51The MIME parser used by SMIME_read_PKCS7() is somewhat primitive. 52While it will handle most S/MIME messages more complex compound 53formats may not work. 54 55The parser assumes that the PKCS7 structure is always base64 56encoded and will not handle the case where it is in binary format 57or uses quoted printable format. 58 59The use of a memory BIO to hold the signed content limits the size 60of message which can be processed due to memory restraints: a 61streaming single pass option should be available. 62 63=head1 RETURN VALUES 64 65SMIME_read_PKCS7_ex() and SMIME_read_PKCS7() return a valid B<PKCS7> structure 66or B<NULL> if an error occurred. The error can be obtained from ERR_get_error(3). 67 68=head1 SEE ALSO 69 70L<ERR_get_error(3)>, 71L<SMIME_read_PKCS7(3)>, L<PKCS7_sign(3)>, 72L<PKCS7_verify(3)>, L<PKCS7_encrypt(3)> 73L<PKCS7_decrypt(3)> 74 75=head1 HISTORY 76 77The function SMIME_read_PKCS7_ex() was added in OpenSSL 3.0. 78 79=head1 COPYRIGHT 80 81Copyright 2002-2020 The OpenSSL Project Authors. All Rights Reserved. 82 83Licensed under the Apache License 2.0 (the "License"). You may not use 84this file except in compliance with the License. You can obtain a copy 85in the file LICENSE in the source distribution or at 86L<https://www.openssl.org/source/license.html>. 87 88=cut 89