A few options to deal with padding in ECB, CBC:
1. Error out if length not dividable by blocksize.
2. Just fill with zeros when encrypting, return full block when decrypting.
3. Fill with PKCS7 pad, remove when decrypting (but prone to errors with 1/256 chance).
4. Always pad, append 0x10 filled block for even sizes. Can be safely removed.

	pad	pad	pkcs7	always	behavior
OpenSSL	0	0	NA	NA	
OpenSSL	1	0	NA	NA
OpenSSL	0	1	NA	NA
OpenSSL	1	1	NA	NA
OWN	NA	NA	0	0
OWN	NA	NA	1	0
OWN	NA	NA	0	1
OWN	NA	NA	1	1
	

