add custom entry in step2.py

[gogo2464]

Start to fix #8

Sorry for the delay I was busy.

I created a new function. The base does not sounds pertinent I should find another function to start exploit coding.

I just need to choose a good one to start encrypting the 0x00 and 0x02 for padding.

[gogo2464]

@tomato42 I suggest to add input for headers to no_header_with_payload() so that we could start the exploit dev quickly.

[gogo2464]

I would like to add more input to the function types["no_structure_with_chosen_plaintext"] = len(chosen_plaintext) can I remove the confusing for me variable types.