Fixing memory allocations for NUL-terminated strings #2

[lonerr]

I'm submitting this patch on behalf of Ruslan Ermilov ([email protected]), who is an nginx developer. You can reach out to him directly in case of any questions. Also, please note, that there are two possible approaches to fixing the problem. This one is more efficient while the second one (previous pull request) is more straightforward. Below is the author's original commit log:

ngx_http_cookie_flag_filter_handler() allocated not enough memory for "cookie_name". The strcat() call would write '\0' outside the allocated buffer. The current code also incorrectly matches any cookie whose name ends in "foo" if "set_cookie_flag foo ..." is specified. Both bugs fixed by rewriting the code that matches cookies by name.

ngx_http_cookie_flag_filter_append() allocated not enough memory when editing cookie values. Generally, strings in nginx are not NUL-terminated, but there are some exceptions, including the values of request/response headers. While that assumption allows searching for substrings with ngx_strcasestrn(), the edited values were not NUL-terminated. This is fixed by allocating enough memory to have NUL-terminated strings.