openssl/doc/crypto/CMS_add1_recipient_cert.pod
2008-04-10 23:28:25 +00:00

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2.3 KiB
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=pod
=head1 NAME
CMS_add1_recipient_cert, CMS_add0_recipient_key - add recipients to a CMS enveloped data structure
=head1 SYNOPSIS
#include <openssl/cms.h>
CMS_RecipientInfo *CMS_add1_recipient_cert(CMS_ContentInfo *cms, X509 *recip, unsigned int flags);
CMS_RecipientInfo *CMS_add0_recipient_key(CMS_ContentInfo *cms, int nid, unsigned char *key, size_t keylen, unsigned char *id, size_t idlen, ASN1_GENERALIZEDTIME *date, ASN1_OBJECT *otherTypeId, ASN1_TYPE *otherType);
=head1 DESCRIPTION
CMS_add1_recipient_cert() adds recipient B<recip> to CMS_ContentInfo enveloped
data structure B<cms> as a KeyTransRecipientInfo structure.
CMS_add0_recipient_key() adds symmetric key B<key> of length B<keylen> using
wrapping algorithm B<nid>, identifier B<id> of length B<idlen> and optional
values B<date>, B<otherTypeId> and B<otherType> to CMS_ContentInfo enveloped
data structure B<cms> as a KEKRecipientInfo structure.
The CMS_ContentInfo structure should be obtained from an initial call to
CMS_encrypt() with the flag B<CMS_PARTIAL> set.
=head1 NOTES
The main purpose of this function is to provide finer control over a CMS
enveloped data structure where the simpler CMS_encrypt() function defaults are
not appropriate. For example if one or more KEKRecipientInfo structures
need to be added. New attributes can also be added using the returned
CMS_RecipientInfo structure and the CMS attribute utility functions.
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.
Currently only AES based key wrapping algorithms are supported for B<nid>,
specifically: NID_id_aes128_wrap, NID_id_aes192_wrap and NID_id_aes256_wrap.
If B<nid> is set to B<NID_undef> then an AES wrap algorithm will be used
consistent with B<keylen>.
=head1 RETURN VALUES
CMS_add1_recipient_cert() and CMS_add0_recipient_key() return an internal
pointer to the CMS_RecipientInfo structure just added or NULL if an error
occurs.
=head1 SEE ALSO
L<ERR_get_error(3)|ERR_get_error(3)>, L<CMS_decrypt(3)|CMS_decrypt(3)>,
L<CMS_final(3)|CMS_final(3)>,
=head1 HISTORY
CMS_add1_recipient_cert() and CMS_add0_recipient_key() were added to OpenSSL
0.9.8
=cut