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# CMSEncoderAddSignedAttributes(_:_:)

Specifies attributes for a signed message.

```
func CMSEncoderAddSignedAttributes(_ cmsEncoder: CMSEncoder, _ signedAttributes: CMSSignedAttributes) -> OSStatus
```

## Parameters

`cmsEncoder`

The CMSEncoder reference returned by the `CMSEncoderCreate` function.

`signedAttributes`

Attribute flags as defined in [`CMSSignedAttributes`](/documentation/Security/CMSSignedAttributes).

## Return Value

A result code. See [Security Framework Result Codes](/documentation/Security/security-framework-result-codes).

## Discussion

Attributes are optional for signed messages. They are not used for other types of CMS messages.  The use of attributes is described in section 2.5 of the S/MIME 3.1 specification.

If you do call this function, you must call it before the first call to the [`CMSEncoderUpdateContent(_:_:_:)`](/documentation/Security/CMSEncoderUpdateContent(_:_:_:)) function.

## See Also

[`CMSEncoderUpdateContent(_:_:_:)`](/documentation/Security/CMSEncoderUpdateContent(_:_:_:))

Feeds content bytes into the encoder.

[`CMSEncoderCreate(_:)`](/documentation/Security/CMSEncoderCreate(_:))

Creates a CMSEncoder reference.


---

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