CMS_add1_recipient_cert() adds recipient recip to CMS_ContentInfo enveloped data
structure cms as a
KeyTransRecipientInfo structure.
CMS_add0_recipient_key() adds symmetric key key of length keylen using wrapping algorithm nid, identifier id of length idlen and optional values date, otherTypeId and otherType to CMS_ContentInfo enveloped data
structure cms as a KEKRecipientInfo
structure.
The CMS_ContentInfo structure should be obtained from an initial call
to CMS_encrypt() with the flag CMS_PARTIAL set.
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 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
nid, specifically:
NID_id_aes128_wrap, NID_id_aes192_wrap and NID_id_aes256_wrap. If
nid is set to NID_undef then an AES wrap algorithm will be
used consistent with keylen.
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.
