Generates new key when new DNS-record is created.
True if the key has been generated successfully.
Use this method when you need to generate public key during new DNS-record creating.
If PrivateKey parameter is nil or PrivateKeySize value is not enough for private key the method will set PrivateKeySize to necessary memory size and return False.
Note, the Bits maximum value is 2048 because of DNS-record size limitation. The standard defines the following possible lengths: 512, 768, 1024, 1536 and 2048 bits.