putty/noise.c

151 строка
3.5 KiB
C

/*
* Noise generation for PuTTY's cryptographic random number
* generator.
*/
#include <windows.h>
#include <stdio.h>
#include "putty.h"
#include "ssh.h"
static char seedpath[2*MAX_PATH+10] = "\0";
/*
* Find the random seed file path and store it in `seedpath'.
*/
static void get_seedpath(void) {
HKEY rkey;
DWORD type, size;
size = sizeof(seedpath);
if (RegOpenKey(HKEY_CURRENT_USER, PUTTY_REG_POS, &rkey)==ERROR_SUCCESS) {
int ret = RegQueryValueEx(rkey, "RandSeedFile",
0, &type, seedpath, &size);
if (ret != ERROR_SUCCESS || type != REG_SZ)
seedpath[0] = '\0';
RegCloseKey(rkey);
} else
seedpath[0] = '\0';
if (!seedpath[0]) {
int len, ret;
len = GetEnvironmentVariable("HOMEDRIVE", seedpath, sizeof(seedpath));
ret = GetEnvironmentVariable("HOMEPATH", seedpath+len,
sizeof(seedpath)-len);
if (ret == 0) { /* probably win95; store in \WINDOWS */
GetWindowsDirectory(seedpath, sizeof(seedpath));
len = strlen(seedpath);
} else
len += ret;
strcpy(seedpath+len, "\\PUTTY.RND");
}
}
/*
* This function is called once, at PuTTY startup, and will do some
* seriously silly things like listing directories and getting disk
* free space and a process snapshot.
*/
void noise_get_heavy(void (*func) (void *, int)) {
HANDLE srch;
HANDLE seedf;
WIN32_FIND_DATA finddata;
char winpath[MAX_PATH+3];
GetWindowsDirectory(winpath, sizeof(winpath));
strcat(winpath, "\\*");
srch = FindFirstFile(winpath, &finddata);
if (srch != INVALID_HANDLE_VALUE) {
do {
func(&finddata, sizeof(finddata));
} while (FindNextFile(srch, &finddata));
FindClose(srch);
}
if (!seedpath[0])
get_seedpath();
seedf = CreateFile(seedpath, GENERIC_READ,
FILE_SHARE_READ | FILE_SHARE_WRITE,
NULL, OPEN_EXISTING, 0, NULL);
if (seedf != INVALID_HANDLE_VALUE) {
while (1) {
char buf[1024];
DWORD len;
if (ReadFile(seedf, buf, sizeof(buf), &len, NULL) && len)
func(buf, len);
else
break;
}
CloseHandle(seedf);
}
}
void random_save_seed(void) {
HANDLE seedf;
if (!seedpath[0])
get_seedpath();
seedf = CreateFile(seedpath, GENERIC_WRITE, 0,
NULL, CREATE_ALWAYS, FILE_ATTRIBUTE_NORMAL, NULL);
if (seedf != INVALID_HANDLE_VALUE) {
int len;
DWORD lenwritten;
void *data;
random_get_savedata(&data, &len);
WriteFile(seedf, data, len, &lenwritten, NULL);
CloseHandle(seedf);
}
}
/*
* This function is called every time the random pool needs
* stirring, and will acquire the system time in all available
* forms and the battery status.
*/
void noise_get_light(void (*func) (void *, int)) {
SYSTEMTIME systime;
DWORD adjust[2];
BOOL rubbish;
SYSTEM_POWER_STATUS pwrstat;
GetSystemTime(&systime);
func(&systime, sizeof(systime));
GetSystemTimeAdjustment(&adjust[0], &adjust[1], &rubbish);
func(&adjust, sizeof(adjust));
#ifndef WIN32S_COMPAT
if (GetSystemPowerStatus(&pwrstat))
func(&pwrstat, sizeof(pwrstat));
#endif
}
/*
* This function is called on every keypress or mouse move, and
* will add the current Windows time and performance monitor
* counter to the noise pool. It gets the scan code or mouse
* position passed in.
*/
void noise_ultralight(DWORD data) {
DWORD wintime;
LARGE_INTEGER perftime;
random_add_noise(&data, sizeof(DWORD));
wintime = GetTickCount();
random_add_noise(&wintime, sizeof(DWORD));
if (QueryPerformanceCounter(&perftime))
random_add_noise(&perftime, sizeof(perftime));
}