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CS4105 - Software Security
Assignment I3
Samuel Austin & Tim van Rossum

Design and Implementation Decisions

Null-character

In C, many standard library functions rely on strings ending with a null-character (\0) for correct behaviour. Strings that do not contain a null-character or have a null-character in the wrong place can cause overflows or other issues that may result in security flaws. 

For the BufferC language our aim was to prevent the user of the buffer from making mistakes regarding the null-character. We achieve this by taking away the handling of the null-character from the user and implementing this functionality in our buffer related functions.

This means that whenever a user creates a new buffer, copies a buffer or assigns a buffer, we make sure there is always a null-character present at the end of the buffer internally. As a result, the real internal size of our character array inside the buffer structure is one bigger than what the user specifies in order to make room for the null-character.