I'm trying to implement ACME managed device attestation, I have ACME server code written in C# and I've been able to get all of the steps working except for the very last one - issuing the certificate. I so far have not been able to get the device to accept the certificate, the device logs show: Got certificate {length = ......} ACME request flow failed at step 9: Error Domain=NSOSStatusErrorDomain Code=-67673 "failed to obtain certificate" UserInfo={NSLocalizedDescription=failed to obtain certificate} The certificate is issued by an internal CA and the correct root certificate is in the device's trusted certs. I have tried returning the certificate chain as a file response or content response to the device as a "application/pem-certificate-chain" mime type (as outlined as the default in the ACME RFC), returning just the leaf certificate as PEM, returning the leaf certificate as DER with mime type "application/pkix-cert", "application/pkcs7-mime", "application/x-pkcs12" or "application/x-x509-ca-cert", but none of this has worked. Can anyone point me in the right direction to figure out what the issue is?

Hi, I'm looking into ACME Managed Deice Attestation and was wondering about one of the values in the payload - AllowAllAppsAccess. From the documentation: "If true, all apps have access to the private key" but what is the case that you would have this set to true? seems like it opens up the device to potentially malicious software. Also, if this were set to true, how would an app access this private key when it is stored in the Secure Enclave? is there a specific tag that it is stored with?

I'm trying to figure out how to encrypt the Configuration profile sent to an iPhone, but can only find references to "use CMS" but nothing about what key/certificate I should be using to encrypt... Can anyone point me in the right direction?

I'm trying to figure out how to encrypt a configuration profile sent from an MDM. There is a certificate sent to the MDM during the call to get configuration, is this what I need to be using to encrypt? and does this certificate use the UID mentioned in the below quote? "The Secure Enclave includes a unique ID (UID) root cryptographic key. The UID is unique to each individual device and isn’t related to any other identifier on the device."