Openssl pkey命令

openssl pkey [-inform PEM|DER] [-outform PE|DER] [-in filename] [-passin arg] [-out filename] [-passout arg] 
[-cipher] [-text] [-text_pub] [-noout] [-pubin] [-pubout] [-engine id]

-in file        input file
-inform X       input format (DER or PEM)
-passin arg     input file pass phrase source
-outform X      output format (DER or PEM)
-out file       output file
-passout arg    output file pass phrase source
-engine e       use engine e, possibly a hardware device.

openssl pkey -in prikey.pem -out keyout.pem

openssl pkey –in prikey.pem -des3 -out keyout.pem

openssl pkey –in prikey.pem -outform DER –out prikey.der

openssl pkey –in prikey.pem -pubout -out pubkey.pem

参考：http://blog.csdn.net/as3luyuan123/article/details/16330909