mirror of
https://github.com/openssl/openssl.git
synced 2024-12-15 06:01:37 +08:00
ecd4b8fe85
Fixes #5063 Reviewed-by: Rich Salz <rsalz@openssl.org> (Merged from https://github.com/openssl/openssl/pull/6134)
105 lines
3.7 KiB
Plaintext
105 lines
3.7 KiB
Plaintext
=pod
|
|
|
|
=head1 NAME
|
|
|
|
CMS_encrypt - create a CMS envelopedData structure
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/cms.h>
|
|
|
|
CMS_ContentInfo *CMS_encrypt(STACK_OF(X509) *certs, BIO *in,
|
|
const EVP_CIPHER *cipher, unsigned int flags);
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
CMS_encrypt() creates and returns a CMS EnvelopedData structure. B<certs>
|
|
is a list of recipient certificates. B<in> is the content to be encrypted.
|
|
B<cipher> is the symmetric cipher to use. B<flags> is an optional set of flags.
|
|
|
|
=head1 NOTES
|
|
|
|
Only certificates carrying RSA, Diffie-Hellman or EC keys are supported by this
|
|
function.
|
|
|
|
EVP_des_ede3_cbc() (triple DES) is the algorithm of choice for S/MIME use
|
|
because most clients will support it.
|
|
|
|
The algorithm passed in the B<cipher> parameter must support ASN1 encoding of
|
|
its parameters.
|
|
|
|
Many browsers implement a "sign and encrypt" option which is simply an S/MIME
|
|
envelopedData containing an S/MIME signed message. This can be readily produced
|
|
by storing the S/MIME signed message in a memory BIO and passing it to
|
|
CMS_encrypt().
|
|
|
|
The following flags can be passed in the B<flags> parameter.
|
|
|
|
If the B<CMS_TEXT> flag is set MIME headers for type B<text/plain> are
|
|
prepended to the data.
|
|
|
|
Normally the supplied content is translated into MIME canonical format (as
|
|
required by the S/MIME specifications) if B<CMS_BINARY> is set no translation
|
|
occurs. This option should be used if the supplied data is in binary format
|
|
otherwise the translation will corrupt it. If B<CMS_BINARY> is set then
|
|
B<CMS_TEXT> is ignored.
|
|
|
|
OpenSSL will by default identify recipient certificates using issuer name
|
|
and serial number. If B<CMS_USE_KEYID> is set it will use the subject key
|
|
identifier value instead. An error occurs if all recipient certificates do not
|
|
have a subject key identifier extension.
|
|
|
|
If the B<CMS_STREAM> flag is set a partial B<CMS_ContentInfo> structure is
|
|
returned suitable for streaming I/O: no data is read from the BIO B<in>.
|
|
|
|
If the B<CMS_PARTIAL> flag is set a partial B<CMS_ContentInfo> structure is
|
|
returned to which additional recipients and attributes can be added before
|
|
finalization.
|
|
|
|
The data being encrypted is included in the CMS_ContentInfo structure, unless
|
|
B<CMS_DETACHED> is set in which case it is omitted. This is rarely used in
|
|
practice and is not supported by SMIME_write_CMS().
|
|
|
|
=head1 NOTES
|
|
|
|
If the flag B<CMS_STREAM> is set the returned B<CMS_ContentInfo> structure is
|
|
B<not> complete and outputting its contents via a function that does not
|
|
properly finalize the B<CMS_ContentInfo> structure will give unpredictable
|
|
results.
|
|
|
|
Several functions including SMIME_write_CMS(), i2d_CMS_bio_stream(),
|
|
PEM_write_bio_CMS_stream() finalize the structure. Alternatively finalization
|
|
can be performed by obtaining the streaming ASN1 B<BIO> directly using
|
|
BIO_new_CMS().
|
|
|
|
The recipients specified in B<certs> use a CMS KeyTransRecipientInfo info
|
|
structure. KEKRecipientInfo is also supported using the flag B<CMS_PARTIAL>
|
|
and CMS_add0_recipient_key().
|
|
|
|
The parameter B<certs> may be NULL if B<CMS_PARTIAL> is set and recipients
|
|
added later using CMS_add1_recipient_cert() or CMS_add0_recipient_key().
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
CMS_encrypt() returns either a CMS_ContentInfo structure or NULL if an error
|
|
occurred. The error can be obtained from ERR_get_error(3).
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<ERR_get_error(3)>, L<CMS_decrypt(3)>
|
|
|
|
=head1 HISTORY
|
|
|
|
The B<CMS_STREAM> flag was first supported in OpenSSL 1.0.0.
|
|
|
|
=head1 COPYRIGHT
|
|
|
|
Copyright 2008-2016 The OpenSSL Project Authors. All Rights Reserved.
|
|
|
|
Licensed under the OpenSSL license (the "License"). You may not use
|
|
this file except in compliance with the License. You can obtain a copy
|
|
in the file LICENSE in the source distribution or at
|
|
L<https://www.openssl.org/source/license.html>.
|
|
|
|
=cut
|