I am trying to create a DNS over HTTPS and DNS over TLS server that requires authentication with a client certificate and configure it in the Device Management Profile for use from the iPhone. I have set the PayloadCertificateUUID in DNSSettings, but it appears that the client certificate is not being used. Is there anything I should check in advance when using a p12 file with PayloadCertificateUUID? Configuration Profile <?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd"> <plist version="1.0"> <dict> <key>PayloadType</key> <string>Configuration</string> <key>PayloadVersion</key> <integer>1</integer> <key>PayloadUUID</key> <string>295E68E5-39F0-46D1-94E4-4A49EC8392E2</string> <key>PayloadIdentifier</key> <string>com.example.dns</string> <key>PayloadDisplayName</key> <string>My DNS</string> <key>PayloadRemovalDisallowed</key> <false/> <key>PayloadContent</key> <array> <dict> <key>PayloadType</key> <string>com.apple.dnsSettings.managed</string> <key>PayloadVersion</key> <integer>1</integer> <key>PayloadUUID</key> <string>4CCEE94D-7B72-46AB-87AD-5A368F937339</string> <key>PayloadIdentifier</key> <string>com.example.dns.names</string> <key>PayloadDisplayName</key> <string>My DNS</string> <key>PayloadDescription</key> <string>DNS Settings</string> <key>PayloadCertificateUUID</key> <string>07A96080-5FAE-4026-937D-F578530E1444</string> <key>DNSSettings</key> <dict> <key>DNSProtocol</key> <string>TLS</string> <key>ServerName</key> <string><!-- my DoT server name --></string> </dict> <key>ProhibitDisablement</key> <false/> </dict> <dict> <key>PayloadType</key> <string>com.apple.security.pkcs1</string> <key>PayloadVersion</key> <integer>1</integer> <key>PayloadUUID</key> <string>260CC26A-2DD1-4B16-B8C0-AF1E655576AD</string> <key>PayloadIdentifier</key> <string>com.example.certs.intermediate-ca</string> <key>PayloadDisplayName</key> <string>Intermediate CA</string> <key>PayloadDescription</key> <string>Intermediate CA</string> <key>PayloadCertificateFileName</key> <string>ca-chain.cert.cer</string> <key>PayloadContent</key> <data><!-- contents of Intermediate CA certificate --></data> </dict> <dict> <key>PayloadType</key> <string>com.apple.security.root</string> <key>PayloadVersion</key> <integer>1</integer> <key>PayloadUUID</key> <string>E5DB74AA-3C5F-470B-AAE0-DF072095A2EC</string> <key>PayloadIdentifier</key> <string>com.example.certs.root-ca</string> <key>PayloadDisplayName</key> <string>Root CA</string> <key>PayloadDescription</key> <string>Root CA</string> <key>PayloadCertificateFileName</key> <string>ca.cert.cer</string> <key>PayloadContent</key> <data><!-- contents of Root CA certificate --></data> </dict> <dict> <key>PayloadType</key> <string>com.apple.security.pkcs12</string> <key>PayloadVersion</key> <integer>1</integer> <key>PayloadUUID</key> <string>07A96080-5FAE-4026-937D-F578530E1444</string> <key>PayloadIdentifier</key> <string>com.example.certs.client.iseebi</string> <key>PayloadDisplayName</key> <string>Client Certificate</string> <key>PayloadDescription</key> <string>Client Certificate</string> <key>Password</key> <string><!-- password of p12 --></string> <key>PayloadCertificateFileName</key> <string>Key.p12</string> <key>PayloadContent</key> <data><!-- contents of p12 --></data> </dict> </array> </dict> </plist> iPhone console log Connection 3742: enabling TLS Connection 3742: starting, TC(0x0) Connection 3742: asked to evaluate TLS Trust Connection 3742: TLS Trust result 0 Connection 3742: asked for TLS Client Certificates Connection 3742: issuing challenge for client certificates, DNs(1) Connection 3742: asked for TLS Client Certificates Connection 3742: received response for client certificates (-1 elements) Connection 3742: providing TLS Client Identity (-1 elements) Connection 3742: providing TLS Client Identity (-1 elements) Connection 3742: connected successfully Connection 3742: TLS handshake complete Connection 3742: ready C(N) E(N) Connection 3742: received viability advisory(Y) Connection 3742: read-side closed Connection 3742: read-side closed Connection 3742: read-side closed Connection 3742: cleaning up Connection 3742: done server log (stunnel) LOG5[9]: Service [dns] accepted connection from <IP> LOG6[9]: Peer certificate required LOG7[9]: TLS state (accept): before SSL initialization LOG7[9]: TLS state (accept): before SSL initialization LOG7[9]: Initializing application specific data for session authenticated LOG7[9]: SNI: no virtual services defined LOG7[9]: OCSP stapling: Server callback called LOG7[9]: OCSP: Validate the OCSP response LOG6[9]: OCSP: Status: good LOG6[9]: OCSP: This update: 2024.12.06 08:32:00 LOG6[9]: OCSP: Next update: 2024.12.13 08:31:58 LOG5[9]: OCSP: Certificate accepted LOG7[9]: OCSP: Use the cached OCSP response LOG7[9]: OCSP stapling: OCSP response sent back LOG7[9]: TLS state (accept): SSLv3/TLS read client hello LOG7[9]: TLS state (accept): SSLv3/TLS write server hello LOG7[9]: TLS state (accept): SSLv3/TLS write change cipher spec LOG7[9]: TLS state (accept): TLSv1.3 write encrypted extensions LOG7[9]: TLS state (accept): SSLv3/TLS write certificate request LOG7[9]: TLS state (accept): SSLv3/TLS write certificate LOG7[9]: TLS state (accept): TLSv1.3 write server certificate verify LOG7[9]: TLS state (accept): SSLv3/TLS write finished LOG7[9]: TLS state (accept): TLSv1.3 early data LOG7[9]: TLS state (accept): TLSv1.3 early data LOG7[9]: TLS alert (write): fatal: unknown LOG3[9]: SSL_accept: ssl/statem/statem_srvr.c:3510: error:0A0000C7:SSL routines::peer did not return a certificate LOG5[9]: Connection reset/closed: 0 byte(s) sent to TLS, 0 byte(s) sent to socket LOG7[9]: Deallocating application specific data for session connect address LOG7[9]: Local descriptor (FD=10) closed LOG7[9]: Service [dns] finished (0 left)