인증서 형식변환

PKCS#12 에서 개인키 추출
> openssl pkcs12 -in nine4u.pfx -nocerts -nodes -out nine4u.key

PKCS#12 에서 인증서 추출
> openssl pkcs12 -in nine4u.pfx -nokeys -out nine4u.crt

PEM -> PKCS#12
> openssl pkcs12 -export -in nine4u.crt -inkey nine4u.key -out nine4u.p12

DER => PEM
> openssl rsa -inform DER -outform PEM -in nine4u.der -out nine4u.pem

PEM => DER
> openssl rsa -inform PEM -outform DER -in nine4u.pem -out nine4u.der