---
title: "CMSDecoderCopyEncapsulatedContentType(_:_:)"
framework: security
role: symbol
role_heading: Function
path: "security/cmsdecodercopyencapsulatedcontenttype(_:_:)"
---

# CMSDecoderCopyEncapsulatedContentType(_:_:)

Obtains the object identifier for the encapsulated data of a signed message.

## Declaration

```swift
func CMSDecoderCopyEncapsulatedContentType(_ cmsDecoder: CMSDecoder, _ eContentTypeOut: UnsafeMutablePointer<CFData?>) -> OSStatus
```

## Parameters

- `cmsDecoder`: The CMSDecoder reference returned by the CMSDecoderCreate function.
- `eContentTypeOut`: On return, the object identifier for the encapsulated data in a signed message. Returns NULL if the message was not signed.

## Return Value

Return Value A result code. See Security Framework Result Codes.

## Discussion

Discussion In a signed message, the signed data consists of any type of content (referred to as the encapsulated content, because it is encapsulated in the signed data) plus the signature values. The content type of the encapsulated data is indicated by an object identifier. The default value for the OID is id-data, which indicates MIME-encoded content. You cannot call this function until after you have called the CMSDecoderFinalizeMessage function.