client使用的文件有：ca.crt,client.crt,client.key
server使用的文件有：ca.crt,server.crt,server.key
.crt文件和.key可以合到一个文件里面，本人把2个文件合成了一个.pem文件（直接拷贝过去就行了）
openssl req 命令参数：
openssl req[-inform PEM|DER] [-outform PEM|DER] [-in filename] [-passin arg] [-out filename] [-passout arg] [-text] [-pubkey] [-noout] [-verify] [-modulus] [-new] [-rand file(s)] [-newkey rsa:bits] [-newkey alg:file] [-nodes] [-key filename] [-keyform PEM|DER] [-keyout filename] [-keygen_engine id] [-[digest]] [-config filename] [-subj arg] [-multivalue-rdn] [-x509] [-days n] [-set_serial n] [-asn1-kludge] [-no-asn1-kludge] [-newhdr] [-extensions section] [-reqexts section] [-utf8] [-nameopt] [-reqopt] [-subject] [-subj arg] [-batch] [-verbose] [-engine id]