1bc74519a2
Add doc-nit-check to help find future issues. Make podchecker be almost clean. Remove trailing whitespace. Tab expansion Reviewed-by: Richard Levitte <levitte@openssl.org>
90 lines
3 KiB
Text
90 lines
3 KiB
Text
=pod
|
|
|
|
=head1 NAME
|
|
|
|
PKCS7_encrypt - create a PKCS#7 envelopedData structure
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/pkcs7.h>
|
|
|
|
PKCS7 *PKCS7_encrypt(STACK_OF(X509) *certs, BIO *in, const EVP_CIPHER *cipher, int flags);
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
PKCS7_encrypt() creates and returns a PKCS#7 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 RSA keys are supported in PKCS#7 and envelopedData so the recipient
|
|
certificates supplied to this function must all contain RSA public keys, though
|
|
they do not have to be signed using the RSA algorithm.
|
|
|
|
EVP_des_ede3_cbc() (triple DES) is the algorithm of choice for S/MIME use
|
|
because most clients will support it.
|
|
|
|
Some old "export grade" clients may only support weak encryption using 40 or 64
|
|
bit RC2. These can be used by passing EVP_rc2_40_cbc() and EVP_rc2_64_cbc()
|
|
respectively.
|
|
|
|
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
|
|
PKCS7_encrypt().
|
|
|
|
The following flags can be passed in the B<flags> parameter.
|
|
|
|
If the B<PKCS7_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<PKCS7_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<PKCS7_BINARY> is set then
|
|
B<PKCS7_TEXT> is ignored.
|
|
|
|
If the B<PKCS7_STREAM> flag is set a partial B<PKCS7> structure is output
|
|
suitable for streaming I/O: no data is read from the BIO B<in>.
|
|
|
|
=head1 NOTES
|
|
|
|
If the flag B<PKCS7_STREAM> is set the returned B<PKCS7> structure is B<not>
|
|
complete and outputting its contents via a function that does not
|
|
properly finalize the B<PKCS7> structure will give unpredictable
|
|
results.
|
|
|
|
Several functions including SMIME_write_PKCS7(), i2d_PKCS7_bio_stream(),
|
|
PEM_write_bio_PKCS7_stream() finalize the structure. Alternatively finalization
|
|
can be performed by obtaining the streaming ASN1 B<BIO> directly using
|
|
BIO_new_PKCS7().
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
PKCS7_encrypt() returns either a PKCS7 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<PKCS7_decrypt(3)>
|
|
|
|
=head1 HISTORY
|
|
|
|
The B<PKCS7_STREAM> flag was added in OpenSSL 1.0.0.
|
|
|
|
=cut
|
|
|
|
=head1 COPYRIGHT
|
|
|
|
Copyright 2002-2016 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
|