# CMSDecoderCopySignerTimestampWithPolicy(_:_:_:_:) Returns the timestamp of a signer of a CMS message using a given policy, if present. ``` func CMSDecoderCopySignerTimestampWithPolicy(_ cmsDecoder: CMSDecoder, _ timeStampPolicy: CFTypeRef?, _ signerIndex: Int, _ timestamp: UnsafeMutablePointer) -> OSStatus ``` ## Parameters `cmsDecoder` A CMSDecoder reference returned by the [`CMSDecoderCreate(_:)`](/documentation/Security/CMSDecoderCreate(_:)) function. `timeStampPolicy` A timestamp policy. Specify `NULL` (or use the [`CMSDecoderCopySignerTimestamp(_:_:_:)`](/documentation/Security/CMSDecoderCopySignerTimestamp(_:_:_:)) function instead) to get the default, which is a policy using [`kSecPolicyAppleTimeStamping`](/documentation/Security/kSecPolicyAppleTimeStamping). See [Policies](/documentation/Security/policies) in [Certificate, Key, and Trust Services](/documentation/Security/certificate-key-and-trust-services) for more about policies. `signerIndex` A number indicating which signer to examine. Signer index numbers start with 0. Use the [`CMSDecoderGetNumSigners(_:_:)`](/documentation/Security/CMSDecoderGetNumSigners(_:_:)) function to determine the total number of signers for a message. `timestamp` The address of an absolute time value where the result should be stored. ## Return Value A result code. See [Security Framework Result Codes](/documentation/Security/security-framework-result-codes). ## Discussion --- 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)