More CMS API documentation.

doc/crypto/CMS_get0_RecipientInfos.pod

+=pod
+
+=head1 NAME
+
+CMS_get0_RecipientInfos, CMS_RecipientInfo_type, CMS_RecipientInfo_ktri_get0_signer_id,CMS_RecipientInfo_ktri_cert_cmp, CMS_RecipientInfo_set0_pkey, CMS_RecipientInfo_kekri_get0_id, CMS_RecipientInfo_kekri_id_cmp, CMS_RecipientInfo_set0_key, CMS_RecipientInfo_decrypt - CMS envelopedData RecipientInfo routines
+
+=head1 SYNOPSIS
+
+ #include <openssl/cms.h>
+
+ STACK_OF(CMS_RecipientInfo) *CMS_get0_RecipientInfos(CMS_ContentInfo *cms);
+ int CMS_RecipientInfo_type(CMS_RecipientInfo *ri);
+
+ int CMS_RecipientInfo_ktri_get0_signer_id(CMS_RecipientInfo *ri, ASN1_OCTET_STRING **keyid, X509_NAME **issuer, ASN1_INTEGER **sno);
+ int CMS_RecipientInfo_ktri_cert_cmp(CMS_RecipientInfo *ri, X509 *cert);
+ int CMS_RecipientInfo_set0_pkey(CMS_RecipientInfo *ri, EVP_PKEY *pkey);
+
+ int CMS_RecipientInfo_kekri_get0_id(CMS_RecipientInfo *ri, X509_ALGOR **palg, ASN1_OCTET_STRING **pid, ASN1_GENERALIZEDTIME **pdate, ASN1_OBJECT **potherid, ASN1_TYPE **pothertype);
+ int CMS_RecipientInfo_kekri_id_cmp(CMS_RecipientInfo *ri, const unsigned char *id, size_t idlen);
+ int CMS_RecipientInfo_set0_key(CMS_RecipientInfo *ri, unsigned char *key, size_t keylen);
+
+ int CMS_RecipientInfo_decrypt(CMS_ContentInfo *cms, CMS_RecipientInfo *ri);
+
+=head1 DESCRIPTION
+
+The function CMS_get0_RecipientInfos() returns all the CMS_RecipientInfo
+structures associated with a CMS envelopedData structure.
+
+CMS_RecipientInfo_type() returns the type of CMS_RecipientInfo structure B<ri>.
+It will currently return CMS_RECIPINFO_TRANS, CMS_RECIPINFO_AGREE,
+CMS_RECIPINFO_KEK, CMS_RECIPINFO_PASS, or CMS_RECIPINFO_OTHER.
+
+CMS_RecipientInfo_ktri_get0_signer_id() retrieves the certificate recipient
+identifier associated with a specific CMS_RecipientInfo structure B<ri>, which
+must be of type CMS_RECIPINFO_TRANS. Either the keyidentifier will be set in
+B<keyid> or B<both> issuer name and serial number in B<issuer> and B<sno>. 
+
+CMS_RecipientInfo_ktri_cert_cmp() compares the cerificate B<cert> against the
+CMS_RecipientInfo structure B<ri>, which must be of type CMS_RECIPINFO_TRANS.
+It returns zero if the comparison is successful and non zero if not.
+
+CMS_RecipientInfo_set0_pkey() associates the private key B<pkey> with
+the CMS_RecipientInfo structure B<ri>, which must be of type
+CMS_RECIPINFO_TRANS.
+
+CMS_RecipientInfo_kekri_get0_id() retrieves the key information from the
+CMS_RecipientInfo structure B<ri> which must be of type CMS_RECIPINFO_KEK.  Any
+of the remaining parameters can be NULL if the application is not interested in
+the value of a field. Where a field is optional and absent NULL will be written
+to the corresponding parameter. The keyEncryptionAlgorithm field is written to
+B<palg>, the B<keyIdentifier> field is written to B<pid>, the B<date> field if
+present is written to B<pdate>, if the B<other> field is present the components
+B<keyAttrId> and B<keyAttr> are written to parameters B<potherid> and
+B<pothertype>.
+
+CMS_RecipientInfo_kekri_id_cmp() compares the ID in the B<id> and B<idlen>
+parameters against the B<keyIdentifier> CMS_RecipientInfo structure B<ri>,
+which must be of type CMS_RECIPINFO_KEK.  It returns zero if the comparison is
+successful and non zero if not.
+
+CMS_RecipientInfo_set0_key() associates the symmetric key B<key> of length
+B<keylen> with the CMS_RecipientInfo structure B<ri>, which must be of type
+CMS_RECIPINFO_KEK.
+
+CMS_RecipientInfo_decrypt() attempts to decrypt CMS_RecipientInfo structure
+B<ri> in structure B<cms>. A key must have been associated with the structure
+first.
+
+=head1 NOTES
+
+The main purpose of these functions is to enable an application to lookup
+recipient keys using any appropriate technique when the simpler method
+of CMS_decrypt() is not appropriate.
+
+In typical usage and application will retrieve all CMS_RecipientInfo structures
+using CMS_get0_RecipientInfos() and check the type of each using
+CMS_RecpientInfo_type(). Depending on the type the CMS_RecipientInfo structure
+can be ignored or its key identifier data retrieved using an appropriate
+function.  Then if the corresponding secret or private key can be obtained by
+any appropriate means it can then associated with the structure and
+CMS_RecpientInfo_decrypt() called. If successful CMS_decrypt() can be called
+with a NULL key to decrypt the enveloped content.
+
+=head1 RETURN VALUES
+
+CMS_get0_RecipientInfos() returns all CMS_RecipientInfo structures, or NULL if
+an error occurs.
+
+CMS_RecipientInfo_ktri_get0_signer_id(), CMS_RecipientInfo_set0_pkey(),
+CMS_RecipientInfo_kekri_get0_id(), CMS_RecipientInfo_set0_key() and
+CMS_RecipientInfo_decrypt() return 1 for success or 0 if an error occurs.
+
+CMS_RecipientInfo_ktri_cert_cmp() and CMS_RecipientInfo_kekri_cmp() return 0
+for a successul comparison and non zero otherwise.
+
+Any error can be obtained from L<ERR_get_error(3)|ERR_get_error(3)>.
+
+=head1 SEE ALSO
+
+L<ERR_get_error(3)|ERR_get_error(3)>, L<CMS_decrypt(3)|CMS_decrypt(3)>
+
+=head1 HISTORY
+
+These functions were first was added to OpenSSL 0.9.8
+
+=cut