.Dd $Mdocdate: November 11 2015 $
.Dt CMS_GET0_RECIPIENTINFOS 3
.Os
.Sh NAME
.Nm CMS_get0_RecipientInfos ,
.Nm CMS_RecipientInfo_type ,
.Nm CMS_RecipientInfo_ktri_get0_signer_id ,
.Nm CMS_RecipientInfo_ktri_cert_cmp ,
.Nm CMS_RecipientInfo_set0_pkey ,
.Nm CMS_RecipientInfo_kekri_get0_id ,
.Nm CMS_RecipientInfo_kekri_id_cmp ,
.Nm CMS_RecipientInfo_set0_key ,
.Nm CMS_RecipientInfo_decrypt ,
.Nm CMS_RecipientInfo_encrypt
.Nd CMS envelopedData RecipientInfo routines
.Sh SYNOPSIS
.In openssl/cms.h
.Ft STACK_OF(CMS_RecipientInfo) *
.Fo CMS_get0_RecipientInfos
.Fa "CMS_ContentInfo *cms"
.Fc
.Ft int
.Fo CMS_RecipientInfo_type
.Fa "CMS_RecipientInfo *ri"
.Fc
.Ft int
.Fo CMS_RecipientInfo_ktri_get0_signer_id
.Fa "CMS_RecipientInfo *ri"
.Fa "ASN1_OCTET_STRING **keyid"
.Fa "X509_NAME **issuer"
.Fa "ASN1_INTEGER **sno"
.Fc
.Ft int
.Fo CMS_RecipientInfo_ktri_cert_cmp
.Fa "CMS_RecipientInfo *ri"
.Fa "X509 *cert"
.Fc
.Ft int
.Fo CMS_RecipientInfo_set0_pkey
.Fa "CMS_RecipientInfo *ri"
.Fa "EVP_PKEY *pkey"
.Fc
.Ft int
.Fo CMS_RecipientInfo_kekri_get0_id
.Fa "CMS_RecipientInfo *ri"
.Fa "X509_ALGOR **palg"
.Fa "ASN1_OCTET_STRING **pid"
.Fa "ASN1_GENERALIZEDTIME **pdate"
.Fa "ASN1_OBJECT **potherid"
.Fa "ASN1_TYPE **pothertype"
.Fc
.Ft int
.Fo CMS_RecipientInfo_kekri_id_cmp
.Fa "CMS_RecipientInfo *ri"
.Fa "const unsigned char *id"
.Fa "size_t idlen"
.Fc
.Ft int
.Fo CMS_RecipientInfo_set0_key
.Fa "CMS_RecipientInfo *ri"
.Fa "unsigned char *key"
.Fa "size_t keylen"
.Fc
.Ft int
.Fo CMS_RecipientInfo_decrypt
.Fa "CMS_ContentInfo *cms"
.Fa "CMS_RecipientInfo *ri"
.Fc
.Sh DESCRIPTION
The function
.Fn CMS_get0_RecipientInfos
returns all the
.Vt CMS_RecipientInfo
structures associated with a CMS EnvelopedData structure.
.Pp
.Fn CMS_RecipientInfo_type
returns the type of the
.Vt CMS_RecipientInfo
structure
.Fa ri .
It will currently return
.Dv CMS_RECIPINFO_TRANS ,
.Dv CMS_RECIPINFO_AGREE ,
.Dv CMS_RECIPINFO_KEK ,
.Dv CMS_RECIPINFO_PASS ,
or
.Dv CMS_RECIPINFO_OTHER .
.Pp
.Fn CMS_RecipientInfo_ktri_get0_signer_id
retrieves the certificate recipient identifier associated with a
specific
.Vt CMS_RecipientInfo
structure
.Fa ri ,
which must be of type
.Dv CMS_RECIPINFO_TRANS .
Either the keyidentifier will be set in
.Fa keyid
or
.Em both
issuer name and serial number in
.Fa issuer
and
.Fa sno .
.Pp
.Fn CMS_RecipientInfo_ktri_cert_cmp
compares the certificate
.Fa cert
against the
.Vt CMS_RecipientInfo
structure
.Fa ri ,
which must be of type
.Dv CMS_RECIPINFO_TRANS .
It returns zero if the
comparison is successful and non zero if not.
.Pp
.Fn CMS_RecipientInfo_set0_pkey
associates the private key
.Fa pkey
with the
.Vt CMS_RecipientInfo
structure
.Fa ri ,
which must be of type
.Dv CMS_RECIPINFO_TRANS .
.Pp
.Fn CMS_RecipientInfo_kekri_get0_id
retrieves the key information from the
.Vt CMS_RecipientInfo
structure
.Fa ri
which must be of type
.Dv CMS_RECIPINFO_KEK .
Any of the remaining parameters can be
.Dv NULL
if the application is not interested in the value of a field.
Where a field is optional and absent,
.Dv NULL
will be written to the corresponding parameter.
The
.Sy keyEncryptionAlgorithm
field is written to
.Fa palg ,
the
.Sy keyIdentifier
field is written to
.Fa pid ,
the
.Sy date
field if present is written to
.Fa pdate ,
if the
.Sy other
field is present the components
.Sy keyAttrId
and
.Sy keyAttr
are written to the parameters
.Fa potherid
and
.Fa pothertype .
.Pp
.Fn CMS_RecipientInfo_kekri_id_cmp
compares the ID in the
.Fa id
and
.Fa idlen
parameters against the
.Sy keyIdentifier
.Vt CMS_RecipientInfo
structure
.Fa ri ,
which must be of type
.Dv CMS_RECIPINFO_KEK .
It returns zero if the comparison is successful and non zero if not.
.Pp
.Fn CMS_RecipientInfo_set0_key
associates the symmetric key
.Fa key
of length
.Fa keylen
with the
.Vt CMS_RecipientInfo
structure
.Fa ri ,
which must be of type
.Dv CMS_RECIPINFO_KEK .
.Pp
.Fn CMS_RecipientInfo_decrypt
attempts to decrypt the
.Vt CMS_RecipientInfo
structure
.Fa ri
in structure
.Fa cms .
A key must have been associated with the structure first.
.Sh 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
.Xr CMS_decrypt 3
is not appropriate.
.Pp
In typical usage, an application will retrieve all
.Vt CMS_RecipientInfo
structures using
.Fn CMS_get0_RecipientInfos
and check the type of each using
.Fn CMS_RecipientInfo_type .
Depending on the type, the
.Vt 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
.Xr CMS_RecpientInfo_decrypt 3
called.
If successful,
.Xr CMS_decrypt 3
can be called with a
.Dv NULL
key to decrypt the enveloped content.
.Sh RETURN VALUES
.Fn CMS_get0_RecipientInfos
returns all
.Vt CMS_RecipientInfo
structures, or
.Dv NULL
if an error occurs.
.Pp
.Fn CMS_RecipientInfo_ktri_get0_signer_id ,
.Fn CMS_RecipientInfo_set0_pkey ,
.Fn CMS_RecipientInfo_kekri_get0_id ,
.Fn CMS_RecipientInfo_set0_key ,
and
.Fn CMS_RecipientInfo_decrypt
return 1 for success or 0 if an error occurs.
.Pp
.Fn CMS_RecipientInfo_ktri_cert_cmp
and
.Fn CMS_RecipientInfo_kekri_id_cmp
return 0 for a successful comparison and non zero otherwise.
.Pp
Any error can be obtained from
.Xr ERR_get_error 3 .
.Sh SEE ALSO
.Xr CMS_decrypt 3 ,
.Xr ERR_get_error 3
.Sh HISTORY
These functions were first was added to OpenSSL 0.9.8.