Doesn't work with other curves other than secp384r1 and secp521r1...

**Problem:**
- If the private key is generated using a curve different than secp384r1 and secp521r1, generated serials can't be validated.

**Example:**

``` bash
$ openssl ecparam -genkey -name secp256k1 -noout -out private.pem

$ openssl ec -in private.pem -pubout -outform PEM -out public.pem
```
