CMS_ADD1_RECIPIENT_CERT(3)                            Library Functions Manual

NAME
     CMS_add1_recipient_cert, CMS_add0_recipient_key - add recipients to a CMS
     EnvelopedData structure

SYNOPSIS
     #include <openssl/cms.h>

     CMS_RecipientInfo *
     CMS_add1_recipient_cert(CMS_ContentInfo *cms, X509 *certificate,
         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);

DESCRIPTION
     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.

SEE ALSO
     CMS_ContentInfo_new(3), CMS_encrypt(3), CMS_final(3), ERR_get_error(3)

STANDARDS
     RFC 5652: Cryptographic Message Syntax
           -   section 6.1: EnvelopedData Type
           -   section 6.2.1: KeyTransRecipientInfo Type
           -   section 6.2.3: KEKRecipientInfo Type

HISTORY
     CMS_add1_recipient_cert() and CMS_add0_recipient_key() first appeared in
     OpenSSL 0.9.8h and have been available since OpenBSD 6.7.

Linux 6.8.7-arch1-1            November 2, 2019            Linux 6.8.7-arch1-1