Support for extracting certificates from digitally signed binaries

[jweyrich]

A compact overview of the most important commits on this branch, in reverse order:

8a2a85f pesec: Show all signers and whether certificate signature is valid.
6005050 pesec: Support new CLI parameters --certoutform and --certout.
1d00753 Fix sign conversion warning.
8fa06d3 Parse certificates from digitally signed PE's.
e9accc4 README now contains instructions on how to build in Mac OS X.
8f185fe libpe: Fix missing cert types.
pesec: Handle unsupported/unknown values, and adjust printed data.
f8ace9e libpe: Fix indentation and line-breaks.
fcfe946 libpe: Add very basic support for the security directory.
bbe12bd libpe: Introduce new function pe_get_data_directory().
46a8153 Fix possible memory leaks in pe_get_directories().

Please, review those commits prefixed with "libpe" as they replace some #defines with enums, introduce new APIs, etc.
I felt it would be good to split the headers in order to avoid code duplication (mainly lib/libpe/types.h). Also though it would be positive to have separate headers for specific directory types (example, lib/libpe/dir_entry_security.h), so we don't clutter libpe.h with specifics.

I've tested only on Mac OS X, so I'd love some feedback from various users and systems.

Hope everyone enjoys it.

[jweyrich]

Now this PR should merge cleanly against your current master branch.
It does include some extra commits to fix a variety of warnings in peres, but it does not fix other problems. E.g.:

jweyrich@pharao$:pev [* win_certificate]$ ./src/peres -x samples/windows-live-messenger.exe 
Resource Table:                  0x152000 (14224 bytes)

!SAVE RESOURCES!
Save On:                         resources/bitmaps/1.bmp
Save On:                         resources/icons/2.ico
Save On:                         resources/icons/3.ico
Save On:                         resources/icons/4.ico
Save On:                         resources/icons/5.ico
Save On:                         resources/dialogs/6.dlg
Save On:                         resources/groupicons/7.ico
Save On:                         resources/groupicons/8.ico
peres(17206) malloc: *** error for object 0x10f601830: incorrect checksum for freed object - object was probably modified after being freed.
*** set a breakpoint in malloc_error_break to debug
Abort trap: 6

It also seems to enter an infinite loop when trying to extract resources from a specific PE.
If necessary, I can open an issue for each of these including a step-by-step on how to reproduce.

[marcelomf]

Nice work jweyrich! Thank you for testing and understand code of peres.
Please, send me PEs, by email or file sharing.
[]s

[jweyrich]

@marcelomf, I uploaded 2 PE samples to Dropbox and shared the folder with you. You probably got an email about it. If you prefer, I can upload it elsewhere. Just let me know.

1. The 1st bug I mentioned seems to be fixed by a368dd3.
2. The infinite loop is pending. I tested it under gdb and found that it occurs in lastNodeByTypeAndLevel. Looks like currentNode = currentNode->lastNode results in a circular reference at some point during the traversal, therefore the while-loop never ends. This is definitely something that would require me to study your data structure, so I'd be glad if you could take a look at this - If you accept a suggestion, I'd start by recursively printing out all NODE_PERES to find where the circular reference is (supposing I'm correct about it).
3. If this is not asking too much, it would be nice to have a simple documentation explaining how your NODE_PERES structure should look like after parsing a simple PE that contains enough resources to exemplify.