libressl-CMS_add1_recipient_cert3
Add recipients to a cms envelopeddata structure
Usage
Crypto Library
(libcrypto,
-lcrypto)
CMS_RecipientInfo *
CMS_RecipientInfo *
Overview
These functions add a new RecipientInfo structure to the recipientInfos field of the EnvelopedData structure cms, which should have been obtained from an initial call to CMS_encrypt(3) with the flag CMS_PARTIAL set.
CMS_add1_recipient_cert() adds the recipient certificate as a KeyTransRecipientInfo structure.
CMS_add0_recipient_key() adds the symmetric key of length keylen using the wrapping algorithm nid, the identifier id of length idlen, and the optional values date, otherTypeId and otherType as a KEKRecipientInfo structure.
The main purpose of these functions is to provide finer control over a CMS EnvelopedData structure where the simpler CMS_encrypt(3) 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.
By default, recipient certificates are identified using issuer name and serial number. If the flag CMS_USE_KEYID is set, the subject key identifier value is used 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.