- NAME
- SYNOPSIS
- DESCRIPTION
- NOTES
- RETURN VALUES
- SEE ALSO
- HISTORY

# NAME

     CMS_add1_recipient_cert, CMS_add0_recipient_key - add recipients to a CMS enveloped data structure

# 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);

# DESCRIPTION

`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.

# SEE ALSO

ERR_get_error, CMS_decrypt, CMS_final,

# HISTORY

`CMS_add1_recipient_cert()` and `CMS_add0_recipient_key()` were added to OpenSSL 0.9.8