---
name: "CMS_get0_type"
section: "3ssl"
platform: "linux"
package: "openssl"
version: "3.6.5-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/CMS_get0_type"
---

# CMS\_get0\_type(3ssl)

get and set CMS content types and content

## 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(const 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 an 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 (such as **CMS\_sign**(3), **CMS\_encrypt**(3)) 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 an 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**(3)

## COPYRIGHT

Copyright 2008-2016 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License").  You may not use this file except in compliance with the License.  You can obtain a copy in the file LICENSE in the source distribution or at \<https://www.openssl.org/source/license.html\>.