# CMSEncodeContent(_:_:_:_:_:_:_:_:) Encodes a message and obtains the result in one high-level function call. ``` func CMSEncodeContent(_ signers: CFTypeRef?, _ recipients: CFTypeRef?, _ eContentTypeOID: CFTypeRef?, _ detachedContent: Bool, _ signedAttributes: CMSSignedAttributes, _ content: UnsafeRawPointer, _ contentLen: Int, _ encodedContentOut: UnsafeMutablePointer?) -> OSStatus ``` ## Parameters `signers` The identity object for the identity of one signer, specified as type `SecIdentityRef`, or a `CFArray` of identity objects of type`SecIdentityRef`. Pass `NULL` for this parameter if you do not want to sign the message. `recipients` A certificate containing a public encryption key for one message recipient, specified as a certificate object (type `SecCertificateRef`), or a `CFArray` of certificate objects. Pass NULL for this parameter if you do not want to encrypt the message. `eContentTypeOID` The object identifier for the encapsulated data in a signed message, in the form of a Core Foundation string—`CFSTR("1.2.840.113549.1.7.1")`, for example. This parameter is optional. If you pass `NULL` , the value `id-data` is used. (This is the normal encapsulated content type for applications such as S/MIME, which uses it to indicate MIME-encoded content.) You can pass any value that is meaningful to your application. `detachedContent` Specify `TRUE` if the signed data is to be separate from the message; that is, if the message is_not_ to include the data to be signed. You cannot specify `TRUE` for this parameter for an encrypted message. `signedAttributes` Attribute flags as defined in [`CMSSignedAttributes`](/documentation/Security/CMSSignedAttributes). Attributes are optional for signed messages and are not used in other types of CMS messages. The use of attributes is described in section 2.5 of the S/MIME 3.1 specification. `content` The content that you want to add to the message. The content must conform to the type set in the [`CMSEncoderSetEncapsulatedContentType`](/documentation/Security/CMSEncoderSetEncapsulatedContentType) parameter (or type `id-data` if that function has not been called). `contentLen` The length of the content being added, in bytes. `encodedContentOut` On return, points to the encoded message. You must use the `CFRelease` function to free this reference when you are finished using it. ## Return Value A result code. See [Security Framework Result Codes](/documentation/Security/security-framework-result-codes). ## Discussion If you use this function, you must include content and you must provide valid non-`NULL` input for at least one of the `signers` and `recipients` parameters. You can both encrypt and sign a message; however, you cannot use detached content with an encrypted message. If you want to create a message that contains certificates and no other content, you must use the [`CMSEncoderAddSupportingCerts(_:_:)`](/documentation/Security/CMSEncoderAddSupportingCerts(_:_:)) function instead of this one. To gain more control over the process of encoding a message, call the sequence of functions beginning with the [`CMSEncoderCreate(_:)`](/documentation/Security/CMSEncoderCreate(_:)) function instead of this one. ## See Also [`CMSEncoderCreate(_:)`](/documentation/Security/CMSEncoderCreate(_:)) Creates a CMSEncoder reference. [`CMSEncoderAddSupportingCerts(_:_:)`](/documentation/Security/CMSEncoderAddSupportingCerts(_:_:)) Adds certificates to a message. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)