I have a .cer certificate file, and need to extract the Public Key. I can only extract to PEM format. The "outform" parameter does nothing.
openssl x509 -inform PEM -in certificate.cer -outform DER -pubkey -noout > publickey.der
Is it possible to extract in DER format?
Solved decoding the base64 PEM file:
openssl x509 -in certificate.cer -pubkey -noout | openssl enc -base64 -d > publickey.der
Any other idea is welcome.
来源：https://stackoverflow.com/questions/13539535/extract-public-key-from-certificate-in-der-format