Q&A
 Alex Ionescu (AlexIonescu) <aionescu gmail com> |
Sunday, August 13 2006 18:54.51 CDT |
Q:
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In your blog entry titled "Debugging/Reversing NT System Binaries" you mention:
"Version1 14 of MSC (in the WDK or MSVC 2005) has many intrinsics that are portable when recompiled, including stuff like getting the return address, reading eflags, setting/reading/writng fs/gs/dr*/cr*, etc."
How can you get the return address and what are the other intrinsics that you talk about? Where are they documented?
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A: _AddressOfReturnAddress() is the intrinsic to get the return address. __getcallerseflags() is the one to get EFLAGS. http://msdn2.microsoft.com/en-us/library/w5405h95.aspx has the documentation and listing of the other ones. Have fun, and please use them! Help support the removal of unportable/ugly ASM code!
Q: Regarding your latest blog entry. I agree with you, however there is in my opinion one legitimate use of hooking and that is for registry operations because historically there hasn't been any legal and documented way of monitoring registry access.
A: No, there really isn't. Developers that hook are developers that can't RTFM (the DDK/WDK docs). I'm not accusing you of this, since it's possible to have skipped over the right documentation, especially as it's only really been of high quality since about last year. In either case, CmRegisterCallback and CmUnregisterCallback are documented, exported routines which allow you to hook the following:
RegNtDeleteKey
RegNtPreDeleteKey
RegNtPostDeleteKey
RegNtSetValueKey
RegNtPreSetValueKey
RegNtPostSetValueKey
RegNtDeleteValueKey
RegNtPreDeleteValueKey
RegNtPostDeleteValueKey
RegNtSetInformationKey
RegNtPreSetInformationKey
RegNtPostSetInformationKey
RegNtRenameKey
RegNtPreRenameKey
RegNtPostRenameKey
RegNtEnumerateKey
RegNtPreEnumerateKey
RegNtPostEnumerateKey
RegNtEnumerateValueKey
RegNtPreEnumerateValueKey
RegNtPostEnumerateValueKey
RegNtQueryKey
RegNtPreQueryKey
RegNtPostQueryKey
RegNtQueryValueKey
RegNtPreQueryValueKey
RegNtPostQueryValueKey
RegNtQueryMultipleValueKey
RegNtPreQueryMultipleValueKey
RegNtPostQueryMultipleValueKey
RegNtPreCreateKey
RegNtPreCreateKeyEx
RegNtPostCreateKey
RegNtPostCreateKeyEx
RegNtPreOpenKey
RegNtPreOpenKeyEx
RegNtPostOpenKey
RegNtPostOpenKeyEx
RegNtKeyHandleClose
RegNtPreKeyHandleClose
RegNtPostKeyHandleClose
Not only do you get PRE/ACTUAL/POST notifications for every single API out there, you also get them for actual HANDLE commands, which cannot be hooked through the system call table (you'd have to hook the CmpKeyObject type callbacks).
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| Posted: Wednesday, December 31 1969 18:00.00 CST | |