An ssl authentication error occurred in nginx configuration self-generated certificate bidirectional authentication

  c++, question

Certificate generation follows this methodFrom the visa book generation
Nginx configuration

server {
 listen       8443;
 server_name   mydomain.com ;
 #ssi on;
 #ssi_silent_errors on;
 #ssi_types text/shtml;
 
 ssl on;
 ssl_certificate      /home/simplesslife/ssl/certs/server.cer;   #/home/simplesslife/ssl/demoCA/test.com.crt;
 ssl_certificate_key  /home/simplesslife/ssl/private/server.key;   #/home/simplesslife/ssl/demoCA/test.com.key;
 ssl_client_certificate /home/simplesslife/ssl/certs/ca.cer;   #/home/simplesslife/ssl/demoCA/ca.crt;
 
 ssl_session_timeout  5m;
 ssl_verify_client on;
 
 ssl_protocols  SSLv2 SSLv3 TLSv1;
 #ssl_ciphers ALL:!  ADH:!  EXPORT56:RC4+RSA:+HIGH:+MEDIUM:+LOW:+SSLv2:+EXP;
 ssl_ciphers ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-AES257-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-GCM-SHA256:E
 CDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256:ECDHE-ECDSA-RC4-SHA:!  ECDHE-RSA-RC4-SHA:ECDH-ECDSA-RC4-SHA:ECDH-RSA-RC4-SHA:ECDHE-R
 SA-AES256-SHA:!  RC4-SHA:HIGH:!  aNULL:!  eNULL:!  LOW:!  3DES:!  MD5:!  EXP:!  CBC:!  EDH:!  kEDH:!  PSK:!  SRP:!  kECDH;
 #ssl_ciphers     'AES128+EECDH:AES128+EDH:!  aNULL';
 ssl_prefer_server_ciphers   on;
 location / {
 root   html;
 index   index.html  index.htm ;
 }
 }

Curl command

curl  -E certs/client.cer --key private/client.key --cacert certs/ca.cer  https://www.mydomain.com:8443 -k

Report an error

<html>
 <head><title>400 The SSL certificate error</title></head>
 <body bgcolor="white">
 <center><h1>400 Bad Request</h1></center>
 <center>The SSL certificate error</center>
 <hr><center>nginx/1.8.0</center>
 </body>
 </html>

Help me see what went wrong.