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1 /* Capstone Driver */
2 /* By Satoshi Tanda <tanda.sat@gmail.com>, 2016 */
3 
4 // Firstly, compile capstone_static_winkernel and
5 // generate capstone_static_winkernel.lib. It can be done by adding the
6 // capstone_static_winkernel project to your solution and compiling it first.
7 //
8 // Then, configure your driver project (cs_driver in this example) to locate to
9 // capstone.h and capstone_static_winkernel.lib. To do it, open project
10 // properties of the project and set Configuration to "All Configurations" and
11 // Platform to "All Platforms". Then, add the following entries:
12 //    - C/C++ > General > Additional Include Directories
13 //      - $(SolutionDir)capstone\include
14 //    - Linker > Input > Additional Dependencies
15 //      - $(OutDir)capstone_static_winkernel.lib
16 //      - ntstrsafe.lib
17 //
18 // Note that ntstrsafe.lib is required to resolve __fltused indirectly used in
19 // Capstone.
20 
21 #include <ntddk.h>
22 #include <capstone.h>
23 
24 // 'conversion' : from function pointer 'type1' to data pointer 'type2'
25 #pragma warning(disable : 4054)
26 
27 
28 DRIVER_INITIALIZE DriverEntry;
29 static NTSTATUS cs_driver_hello();
30 
31 
32 // Driver entry point
DriverEntry(PDRIVER_OBJECT DriverObject,PUNICODE_STRING RegistryPath)33 EXTERN_C NTSTATUS DriverEntry(PDRIVER_OBJECT DriverObject,
34                               PUNICODE_STRING RegistryPath) {
35   printf("Entering DriverEntry()\n");
36 
37   cs_driver_hello();
38 
39   printf("Leaving DriverEntry()\n");
40   return STATUS_CANCELLED;
41 }
42 
43 // Hello, Capstone!
cs_driver_hello()44 static NTSTATUS cs_driver_hello() {
45   csh handle;
46   cs_insn *insn;
47   size_t count;
48   KFLOATING_SAVE float_save;
49   NTSTATUS status = STATUS_UNSUCCESSFUL;
50 
51   // Any of Capstone APIs cannot be called at IRQL higher than DISPATCH_LEVEL
52   // since our malloc implementation based on ExAllocatePoolWithTag() is not able
53   // to allocate memory at higher IRQL than the DISPATCH_LEVEL level.
54   NT_ASSERT(KeGetCurrentIrql() <= DISPATCH_LEVEL);
55 
56   // On a 32bit driver, KeSaveFloatingPointState() is required before using any
57   // Capstone function because Capstone can access to the MMX/x87 registers and
58   // 32bit Windows requires drivers to use KeSaveFloatingPointState() before and
59   // KeRestoreFloatingPointState() after accessing them. See "Using Floating
60   // Point or MMX in a WDM Driver" on MSDN for more details.
61   status = KeSaveFloatingPointState(&float_save);
62   if (!NT_SUCCESS(status)) {
63     return status;
64   }
65 
66   // Do stuff just like user-mode. All functionalities are supported.
67   if (cs_open(CS_ARCH_X86, (sizeof(void *) == 4) ? CS_MODE_32 : CS_MODE_64,
68               &handle) != CS_ERR_OK) {
69     goto exit;
70   }
71 
72   count = cs_disasm(handle, (uint8_t *)&cs_driver_hello, 0x80,
73                     (uint64_t)&cs_driver_hello, 0, &insn);
74   if (count > 0) {
75     printf("cs_driver!cs_driver_hello:\n");
76     for (size_t j = 0; j < count; j++) {
77       printf("0x%p\t%s\t\t%s\n", (void *)(uintptr_t)insn[j].address,
78              insn[j].mnemonic, insn[j].op_str);
79     }
80     cs_free(insn, count);
81   }
82   cs_close(&handle);
83 
84 exit:;
85   // Restores the nonvolatile floating-point context.
86   KeRestoreFloatingPointState(&float_save);
87   return status;
88 }
89 
90 // printf()
printf(const char * _Format,...)91 _Use_decl_annotations_ int __cdecl printf(const char *_Format, ...) {
92   NTSTATUS status;
93   va_list args;
94 
95   va_start(args, _Format);
96   status = vDbgPrintEx(DPFLTR_DEFAULT_ID, DPFLTR_ERROR_LEVEL, _Format, args);
97   va_end(args);
98   return NT_SUCCESS(status);
99 }
100