Test files were generated as follows:

openssl ecparam -name prime192v1 -genkey > key.pem

openssl ec -in key.pem -pubout -outform PEM > pub.pem
openssl ec -in key.pem -pubout -outform DER > pub.der

openssl ec -in key.pem -outform pem > prv.sec1.pem
openssl ec -in key.pem -outform der > prv.sec1.der
openssl ec -in key.pem -des -passout pass:polar -outform pem > prv.sec1.pw.pem

openssl pkcs8 -topk8 -in key.pem -nocrypt -outform pem > prv.pk8.pem
openssl pkcs8 -topk8 -in key.pem -nocrypt -outform der > prv.pk8.der
openssl pkcs8 -topk8 -in key.pem -passout pass:polar -outform der \
    > prv.pk8.pw.der
openssl pkcs8 -topk8 -in key.pem -passout pass:polar -outform pem \
    > prv.pk8.pw.pem