Getting X509 Certificate from Signed envelop data

Question

I want to convert following Java code into iOS. Please help me out.

CMSSignedDataParser sp = new CMSSignedDataParser(new JcaDigestCalculatorProviderBuilder().setProvider("BC").build(), contents.getBuffer());

sp.getSignedContent().drain();

Store                   certStore = sp.getCertificates();
SignerInformationStore  signers = sp.getSignerInfos();

Collection              c = signers.getSigners();
Iterator                it = c.iterator();

while (it.hasNext())
{
    SignerInformation   signer = (SignerInformation)it.next();
    Collection          certCollection = certStore.getMatches(signer.getSID());

    Iterator        certIt = certCollection.iterator();
    X509CertificateHolder cert = (X509CertificateHolder)certIt.next();
    X509Certificate certificate = new JcaX509CertificateConverter().setProvider( "BC" ).getCertificate( cert );
}

Here in Java extracting X509 Certificate from Signed Info. How to achieve same thing in iOS?

Answer 1

Check out CMSDecoder.h in the Security.framework. That plus the openssl framework you get you started.

WRONG
The Cryptographic Message Syntax API is not public on iOS. I guess it's openssl all the way. Sorry!