IDA Pro - Applying function signatures

Question

I have three files:

ELF executable,
ELF dynamically linked library (.so),
C headers file (.h) with function signatures and related structures for that library.

#1 imports a number of functions from #2.

Is there a way for me to leverage #3 to automatically apply signatures from #3 to:

Willem Hengeveld · Accepted Answer · 2017-09-26 22:13:25Z

There are several functions in the SDK, in typeinf.hpp or ida_typeinf.py that could be of use here, with the python API being much easier to use.

parse_decls - for converting a header file to a til_t type library.
- this function seems to skip plain function declarations.
- but does store typedefs by name.
parse_decl - for converting a single declaration to a tinfo_t object.
- this does work for function declarations, but loses the function name.
get_named_type - for looking up a type in the til_t.
apply_type - for applying a type to a function.

So you could either parse the name from the function declaration yourself, and then use parse_decl to parse each declaration seperately.

Or you could add typedef to the start of each declaration, so ida will store all your declarations, by name in a type libary.

joxeankoret · Accepted Answer · 2017-06-28 09:37:08Z

0

Try using File -> Load File -> Parse C Header File (Ctrl+F9). You might need to tweak some things in the header file.

answered Jun 28 '17 at 9:37

joxeankoret

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Thank you for your response. I have tried this and it did not work. IDA successfully parses the file. I can manually fix function signatures by telling IDA what the arguments are, including custom structure pointers. However, this is very time consuming and feels unnecessary. Is there a way for it to automatically or semi-automatically apply signatures from the header file to functions matched by name? – pandasauce Jun 28 '17 at 11:23
Yes. that way is the feature described above. It does not parse complicated C constructs and as mentioned you may need to tweak the file to make it usable by IDA. You can write a script to do that. – NirIzr Jun 28 '17 at 14:52
I managed to get first scenario to work using tilib. What changes would I need to make to the header file to get the second scenario to work, i.e. apply function signatures to the library file? – pandasauce Jun 28 '17 at 16:09

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