My organization routes all device traffic through a network security device that performs TLS intercept (SSL inspection). As might be expected, this breaks passkey Cross-Device Authentication (CDA) functionality, since the thumbprints don't match end-to-end between the authenticator (iPhone) and the client (laptop). As soon as I disable the VPN tunnel through our security device, the passkey login works as expected.
The security team is willing to exclude the relay servers from SSL inspection, but we are unable to find a list of the relevant endpoints. Is there a list of Apple relay servers that are used for passkey tunnelling? We can review the network logs to find the traffic, but I'd prefer an authoritative list.
For full context: we are using device-bound passkeys via Microsoft Authenticator to login to Entra but, as I understand it, the passkey is still handled via Apple's standard passkey infrastructure and APIs.
Thanks!