In Swift, I need to create a CMS to input a web service. In Android we used 'spongycastle' https://www.bouncycastle.org/docs/pkixdocs1.4/org/bouncycastle/cms/CMSSignedData.html But I did not find a sample or solution for Swift or objective C. I also read Apple related documents https://developer.apple.com/documentation/security/cryptographic_message_syntax_services#1677736 , but still nothing special. Does anyone have experience working with a specific solution for Swift or objective C code to do this? thank you.