Hi you can check on our wiki to more information about client certificats.
https://wiki.linphone.org/wiki/index.php/Security:ClientCertAuth
Security:ClientCertAuth
1. Creating Client certificate
Generate a Certificate Signing Request
Creates a new private key and a certificate request with CN=username@domain
example test@test.linphone.org
openssl req -new -keyout key.pem -out newreq.pem
Sign the client certificate
Creates newcert.pem certificate signed by root certificate. You will need to enter the passphrase of the cacert.pem
openssl ca -policy policy_anything -out newcert.pem -infiles newreq.pem
Then extract the private key in a new file
openssl rsa -in key.pem -out clientkey.pem
Parameters for linphone
In linphonerc add path to client/key certificate
[sip]
client_cert_chain=/pathTo/newcert.pem
client_cert_key=/pathTo/clientkey.pem