1 /* 2 * gen_uuid_nt.c -- Use NT api to generate uuid 3 * 4 * Written by Andrey Shedel (andreys (at) ns.cr.cyco.com) 5 */ 6 7 8 #include "uuidP.h" 9 10 #pragma warning(push,4) 11 12 #pragma comment(lib, "ntdll.lib") 13 14 // 15 // Here is a nice example why it's not a good idea 16 // to use native API in ordinary applications. 17 // Number of parameters in function below was changed from 3 to 4 18 // for NT5. 19 // 20 // 21 // NTSYSAPI 22 // NTSTATUS 23 // NTAPI 24 // NtAllocateUuids( 25 // OUT PULONG p1, 26 // OUT PULONG p2, 27 // OUT PULONG p3, 28 // OUT PUCHAR Seed // 6 bytes 29 // ); 30 // 31 // 32 33 unsigned long 34 __stdcall 35 NtAllocateUuids( 36 void* p1, // 8 bytes 37 void* p2, // 4 bytes 38 void* p3 // 4 bytes 39 ); 40 41 typedef 42 unsigned long 43 (__stdcall* 44 NtAllocateUuids_2000)( 45 void* p1, // 8 bytes 46 void* p2, // 4 bytes 47 void* p3, // 4 bytes 48 void* seed // 6 bytes 49 ); 50 51 52 53 // 54 // Nice, but instead of including ntddk.h ot winnt.h 55 // I should define it here because they MISSED __stdcall in those headers. 56 // 57 58 __declspec(dllimport) 59 struct _TEB* 60 __stdcall 61 NtCurrentTeb(void); 62 63 64 // 65 // The only way to get version information from the system is to examine 66 // one stored in PEB. But it's pretty dangerouse because this value could 67 // be altered in image header. 68 // 69 70 static 71 int 72 Nt5(void) 73 { 74 //return NtCuttentTeb()->Peb->OSMajorVersion >= 5; 75 return (int)*(int*)((char*)(int)(*(int*)((char*)NtCurrentTeb() + 0x30)) + 0xA4) >= 5; 76 } 77 78 79 80 81 void uuid_generate(uuid_t out) 82 { 83 if(Nt5()) 84 { 85 unsigned char seed[6]; 86 ((NtAllocateUuids_2000)NtAllocateUuids)(out, ((char*)out)+8, ((char*)out)+12, &seed[0] ); 87 } 88 else 89 { 90 NtAllocateUuids(out, ((char*)out)+8, ((char*)out)+12); 91 } 92 } 93
