i get crt file from a partner, i want to let nginx do ssl connection so i follow this note : https://docs.nginx.com/nginx/admin-guide/security-controls/securing-http-traffic-upstream/ i don't have client pem file and client key file. Can i generate this files with crt to fille this directives:

location /upstream { proxy_pass https://backend.example.com; proxy_ssl_certificate /etc/nginx/client.pem; proxy_ssl_certificate_key /etc/nginx/client.key; }

actually my location :

location /api {

access_log /var/log/nginx/api.log upstream_logging ;

proxy_ssl_trusted_certificate /etc/nginx/partner.crt;

# proxy_ssl_certificate_key /etc/nginx/client.key;
# proxy_ssl_certificate /etc/nginx/client.pem;
proxy_ssl_verify off;
proxy_ssl_verify_depth 2;
proxy_ssl_session_reuse on;
proxy_ssl_server_name on;
#proxy_ssl_protocols TLSv1 ;



proxy_pass https://api$uri$is_args$args;

}

with this setting i get this error: SSL_do_handshake() failed (SSL: error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol) while SSL handshaking to upstream

how to get client.key? is this generated from crt file?