Get APi from the address

[Fyyre]

You want custom GetProcAddress?

PVOID FastGetProcAddress(PCHAR DllBase, PCHAR RoutineName)
{
	USHORT OrdinalNumber;
	PULONG NameTableBase;
	PUSHORT NameOrdinalTableBase;
	PULONG Addr;
	ULONG High;
	ULONG Low;
	ULONG Middle;
	LONG Result;
	ULONG ExportSize;
	PVOID FunctionAddress;
	PIMAGE_EXPORT_DIRECTORY ExportDirectory;


	ExportDirectory = (PIMAGE_EXPORT_DIRECTORY)
		RtlImageDirectoryEntryToData(DllBase, TRUE, IMAGE_DIRECTORY_ENTRY_EXPORT, &ExportSize);
	NameTableBase = (PULONG)(DllBase + (ULONG)ExportDirectory->AddressOfNames);
	NameOrdinalTableBase = (PUSHORT)(DllBase + (ULONG)ExportDirectory->AddressOfNameOrdinals);
	Low = 0;
	High = ExportDirectory->NumberOfNames - 1;
	while (High >= Low)
	{
		Middle = (Low + High) >> 1;
		Result = strcmp(RoutineName,
						(PCHAR)(DllBase + NameTableBase[Middle]));
		if (Result < 0)
		{
			High = Middle - 1;
		}
		else if (Result > 0)
		{
			Low = Middle + 1;
		}
		else
		{
			break;
		};
	};
	if (High < Low)
	{
		return NULL;
	};
	OrdinalNumber = NameOrdinalTableBase[Middle];
	if ((ULONG)OrdinalNumber >= ExportDirectory->NumberOfFunctions)
	{
		return NULL;
	};
	Addr = (PULONG)(DllBase + (ULONG)ExportDirectory->AddressOfFunctions);
	FunctionAddress = (PVOID)(DllBase + Addr[OrdinalNumber]);
	return FunctionAddress;
};

Originally Posted by ahmadmansoor

we always do this to get the API addresss

GetAPIAddress = GetProcAddress(GetModuleHandle("Kernel.dll),FunctionName)

to get the Address of the API .
but what the programmatic way to get the API of the address .
like if we have this :


if I have 2FEB1344 how I could know for which API it relative too !!

( I need the reverse way of GetProcAddress )
Thanks in adv