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

# NAME

     CMS_get0_type, CMS_set1_eContentType, CMS_get0_eContentType, CMS_get0_content - get and set CMS content types and content

# SYNOPSIS

     #include <openssl/cms.h>

     const ASN1_OBJECT *CMS_get0_type(CMS_ContentInfo *cms);
     int CMS_set1_eContentType(CMS_ContentInfo *cms, const ASN1_OBJECT *oid);
     const ASN1_OBJECT *CMS_get0_eContentType(CMS_ContentInfo *cms);
     ASN1_OCTET_STRING **CMS_get0_content(CMS_ContentInfo *cms);

# DESCRIPTION

`CMS_get0_type()` returns the content type of a CMS_ContentInfo structure as and ASN1_OBJECT pointer. An application can then decide how to process the CMS_ContentInfo structure based on this value.

`CMS_set1_eContentType()` sets the embedded content type of a CMS_ContentInfo structure. It should be called with CMS functions with the CMS_PARTIAL flag and before the structure is finalised, otherwise the results are undefined.

ASN1_OBJECT *CMS_get0_eContentType() returns a pointer to the embedded content type.

`CMS_get0_content()` returns a pointer to the ASN1_OCTET_STRING pointer containing the embedded content.

# NOTES

As the 0 implies CMS_get0_type(), `CMS_get0_eContentType()` and `CMS_get0_content()` return internal pointers which should not be freed up. `CMS_set1_eContentType()` copies the supplied OID and it should be freed up after use.

The ASN1_OBJECT values returned can be converted to an integer NID value using OBJ_obj2nid(). For the currently supported content types the following values are returned:

     NID_pkcs7_data
     NID_pkcs7_signed
     NID_pkcs7_digest
     NID_id_smime_ct_compressedData:
     NID_pkcs7_encrypted
     NID_pkcs7_enveloped

The return value of `CMS_get0_content()` is a pointer to the ASN1_OCTET_STRING content pointer. That means that for example:

     ASN1_OCTET_STRING **pconf = CMS_get0_content(cms);

*pconf could be NULL if there is no embedded content. Applications can access, modify or create the embedded content in a CMS_ContentInfo structure using this function. Applications usually will not need to modify the embedded content as it is normally set by higher level functions.

# RETURN VALUES

`CMS_get0_type()` and `CMS_get0_eContentType()` return and ASN1_OBJECT structure.

`CMS_set1_eContentType()` returns 1 for success or 0 if an error occurred. The error can be obtained from ERR_get_error(3).

# SEE ALSO

ERR_get_error

# HISTORY

CMS_get0_type(), `CMS_set1_eContentType()` and `CMS_get0_eContentType()` were all first added to OpenSSL 0.9.8