git.distorted.org.uk Git - u/mdw/putty/blob - noise.c

   1 /*
   2  * Noise generation for PuTTY's cryptographic random number
   3  * generator.
   4  */
   5
   6 #include <windows.h>
   7 #include <stdio.h>
   8
   9 #include "putty.h"
  10 #include "ssh.h"
  11 #include "storage.h"
  12
  13 /*
  14  * GetSystemPowerStatus function.
  15  */
  16 typedef BOOL (WINAPI *gsps_t)(LPSYSTEM_POWER_STATUS);
  17 gsps_t gsps;
  18
  19 /*
  20  * This function is called once, at PuTTY startup, and will do some
  21  * seriously silly things like listing directories and getting disk
  22  * free space and a process snapshot.
  23  */
  24
  25 void noise_get_heavy(void (*func) (void *, int)) {
  26     HANDLE srch;
  27     WIN32_FIND_DATA finddata;
  28     char winpath[MAX_PATH+3];
  29     HMODULE mod;
  30
  31     GetWindowsDirectory(winpath, sizeof(winpath));
  32     strcat(winpath, "\\*");
  33     srch = FindFirstFile(winpath, &finddata);
  34     if (srch != INVALID_HANDLE_VALUE) {
  35         do {
  36             func(&finddata, sizeof(finddata));
  37         } while (FindNextFile(srch, &finddata));
  38         FindClose(srch);
  39     }
  40
  41     read_random_seed(func);
  42
  43     gsps = NULL;
  44     mod = GetModuleHandle("KERNEL32");
  45     if (mod) {
  46         gsps = (gsps_t)GetProcAddress(mod, "GetSystemPowerStatus");
  47         debug(("got gsps=%p\n", gsps));
  48     }
  49 }
  50
  51 void random_save_seed(void) {
  52     int len;
  53     void *data;
  54
  55     random_get_savedata(&data, &len);
  56     write_random_seed(data, len);
  57 }
  58
  59 /*
  60  * This function is called every time the random pool needs
  61  * stirring, and will acquire the system time in all available
  62  * forms and the battery status.
  63  */
  64 void noise_get_light(void (*func) (void *, int)) {
  65     SYSTEMTIME systime;
  66     DWORD adjust[2];
  67     BOOL rubbish;
  68     SYSTEM_POWER_STATUS pwrstat;
  69
  70     GetSystemTime(&systime);
  71     func(&systime, sizeof(systime));
  72
  73     GetSystemTimeAdjustment(&adjust[0], &adjust[1], &rubbish);
  74     func(&adjust, sizeof(adjust));
  75
  76     /*
  77      * Call GetSystemPowerStatus if present.
  78      */
  79     if (gsps) {
  80         if (gsps(&pwrstat))
  81             func(&pwrstat, sizeof(pwrstat));
  82     }
  83 }
  84
  85 /*
  86  * This function is called on every keypress or mouse move, and
  87  * will add the current Windows time and performance monitor
  88  * counter to the noise pool. It gets the scan code or mouse
  89  * position passed in.
  90  */
  91 void noise_ultralight(DWORD data) {
  92     DWORD wintime;
  93     LARGE_INTEGER perftime;
  94
  95     random_add_noise(&data, sizeof(DWORD));
  96
  97     wintime = GetTickCount();
  98     random_add_noise(&wintime, sizeof(DWORD));
  99
 100     if (QueryPerformanceCounter(&perftime))
 101         random_add_noise(&perftime, sizeof(perftime));
 102 }