Posted By: Anonymous
I don’t really understand this one:
according to: http://www.madboa.com/geek/openssl/#key-rsa , You can generate a public key from a private key.
openssl genrsa -out mykey.pem 1024 openssl rsa -in mykey.pem -pubout > mykey.pub
My initial thinking was that they are generated in a pair together.
Does RSA private key contain the sum? or the public key?
openssl genrsa -out mykey.pem 1024
will actually produce a public – private key pair. The pair is stored in the generated
openssl rsa -in mykey.pem -pubout > mykey.pub
will extract the public key and print that out. Here is a link to a page that describes this better.
EDIT: Check the examples section here. To just output the public part of a private key:
openssl rsa -in key.pem -pubout -out pubkey.pem
To get a usable public key for SSH purposes, use ssh-keygen:
ssh-keygen -y -f key.pem > key.pub