openssl クライアント証明書の確認

openssl 
### クライアント証明書つかって接続
openssl s_client -connect host:port -cert cert.pem -key key.pem
### CAとクライアントの証明書があっているか
openssl verify -purpose sslclient -CAfile cacert.pem clientcert.pem

## 追記
curl の-E file.p12:password オプション使ったほうが楽なことに気づいたわ。

man curl 抜粋

  -E, --cert <certificate[:password]>
          (SSL)  Tells  curl  to  use  the specified client certificate file when getting a file with HTTPS, FTPS or
          another SSL-based protocol. The certificate must be in PKCS#12 format if using Secure  Transport,  or  PEM
          format if using any other engine.  If the optional password isn't specified, it will be queried for on the
          terminal. Note that this option assumes a "certificate" file that is the private key and the private  cer-
          tificate concatenated! See --cert and --key to specify them independently.