0,安装openssl

1.生成RSA私钥：

openssl genrsa -out rsa_private_key.pem 1024

2,把RSA私钥转换成PKCS8格式

openssl pkcs8 -topk8 -inform PEM -in rsa_private_key.pem -outform PEM –nocrypt

3,生成公钥

openssl rsa -in rsa_private_key.pem -out rsa_public_key.pem -pubout

4,上传公钥到支付宝