| 1 | /* |
| 2 | * Noise generation for PuTTY's cryptographic random number |
| 3 | * generator. |
| 4 | */ |
| 5 | |
| 6 | #include <stdio.h> |
| 7 | |
| 8 | #include "putty.h" |
| 9 | #include "ssh.h" |
| 10 | #include "storage.h" |
| 11 | |
| 12 | #include <wincrypt.h> |
| 13 | |
| 14 | DECL_WINDOWS_FUNCTION(static, BOOL, CryptAcquireContextA, |
| 15 | (HCRYPTPROV *, LPCTSTR, LPCTSTR, DWORD, DWORD)); |
| 16 | DECL_WINDOWS_FUNCTION(static, BOOL, CryptGenRandom, |
| 17 | (HCRYPTPROV, DWORD, BYTE *)); |
| 18 | DECL_WINDOWS_FUNCTION(static, BOOL, CryptReleaseContext, |
| 19 | (HCRYPTPROV, DWORD)); |
| 20 | static HMODULE wincrypt_module = NULL; |
| 21 | |
| 22 | /* |
| 23 | * This function is called once, at PuTTY startup. |
| 24 | */ |
| 25 | |
| 26 | void noise_get_heavy(void (*func) (void *, int)) |
| 27 | { |
| 28 | HANDLE srch; |
| 29 | WIN32_FIND_DATA finddata; |
| 30 | DWORD pid; |
| 31 | HCRYPTPROV crypt_provider; |
| 32 | char winpath[MAX_PATH + 3]; |
| 33 | |
| 34 | GetWindowsDirectory(winpath, sizeof(winpath)); |
| 35 | strcat(winpath, "\\*"); |
| 36 | srch = FindFirstFile(winpath, &finddata); |
| 37 | if (srch != INVALID_HANDLE_VALUE) { |
| 38 | do { |
| 39 | func(&finddata, sizeof(finddata)); |
| 40 | } while (FindNextFile(srch, &finddata)); |
| 41 | FindClose(srch); |
| 42 | } |
| 43 | |
| 44 | pid = GetCurrentProcessId(); |
| 45 | func(&pid, sizeof(pid)); |
| 46 | |
| 47 | if (!wincrypt_module) { |
| 48 | wincrypt_module = load_system32_dll("advapi32.dll"); |
| 49 | GET_WINDOWS_FUNCTION(wincrypt_module, CryptAcquireContextA); |
| 50 | GET_WINDOWS_FUNCTION(wincrypt_module, CryptGenRandom); |
| 51 | GET_WINDOWS_FUNCTION(wincrypt_module, CryptReleaseContext); |
| 52 | } |
| 53 | |
| 54 | if (wincrypt_module && p_CryptAcquireContextA && |
| 55 | p_CryptGenRandom && p_CryptReleaseContext && |
| 56 | p_CryptAcquireContextA(&crypt_provider, NULL, NULL, PROV_RSA_FULL, |
| 57 | CRYPT_VERIFYCONTEXT)) { |
| 58 | BYTE buf[32]; |
| 59 | if (p_CryptGenRandom(crypt_provider, 32, buf)) { |
| 60 | func(buf, sizeof(buf)); |
| 61 | } |
| 62 | p_CryptReleaseContext(crypt_provider, 0); |
| 63 | } |
| 64 | |
| 65 | read_random_seed(func); |
| 66 | /* Update the seed immediately, in case another instance uses it. */ |
| 67 | random_save_seed(); |
| 68 | } |
| 69 | |
| 70 | void random_save_seed(void) |
| 71 | { |
| 72 | int len; |
| 73 | void *data; |
| 74 | |
| 75 | if (random_active) { |
| 76 | random_get_savedata(&data, &len); |
| 77 | write_random_seed(data, len); |
| 78 | sfree(data); |
| 79 | } |
| 80 | } |
| 81 | |
| 82 | /* |
| 83 | * This function is called every time the random pool needs |
| 84 | * stirring, and will acquire the system time in all available |
| 85 | * forms. |
| 86 | */ |
| 87 | void noise_get_light(void (*func) (void *, int)) |
| 88 | { |
| 89 | SYSTEMTIME systime; |
| 90 | DWORD adjust[2]; |
| 91 | BOOL rubbish; |
| 92 | |
| 93 | GetSystemTime(&systime); |
| 94 | func(&systime, sizeof(systime)); |
| 95 | |
| 96 | GetSystemTimeAdjustment(&adjust[0], &adjust[1], &rubbish); |
| 97 | func(&adjust, sizeof(adjust)); |
| 98 | } |
| 99 | |
| 100 | /* |
| 101 | * This function is called on a timer, and it will monitor |
| 102 | * frequently changing quantities such as the state of physical and |
| 103 | * virtual memory, the state of the process's message queue, which |
| 104 | * window is in the foreground, which owns the clipboard, etc. |
| 105 | */ |
| 106 | void noise_regular(void) |
| 107 | { |
| 108 | HWND w; |
| 109 | DWORD z; |
| 110 | POINT pt; |
| 111 | MEMORYSTATUS memstat; |
| 112 | FILETIME times[4]; |
| 113 | |
| 114 | w = GetForegroundWindow(); |
| 115 | random_add_noise(&w, sizeof(w)); |
| 116 | w = GetCapture(); |
| 117 | random_add_noise(&w, sizeof(w)); |
| 118 | w = GetClipboardOwner(); |
| 119 | random_add_noise(&w, sizeof(w)); |
| 120 | z = GetQueueStatus(QS_ALLEVENTS); |
| 121 | random_add_noise(&z, sizeof(z)); |
| 122 | |
| 123 | GetCursorPos(&pt); |
| 124 | random_add_noise(&pt, sizeof(pt)); |
| 125 | |
| 126 | GlobalMemoryStatus(&memstat); |
| 127 | random_add_noise(&memstat, sizeof(memstat)); |
| 128 | |
| 129 | GetThreadTimes(GetCurrentThread(), times, times + 1, times + 2, |
| 130 | times + 3); |
| 131 | random_add_noise(×, sizeof(times)); |
| 132 | GetProcessTimes(GetCurrentProcess(), times, times + 1, times + 2, |
| 133 | times + 3); |
| 134 | random_add_noise(×, sizeof(times)); |
| 135 | } |
| 136 | |
| 137 | /* |
| 138 | * This function is called on every keypress or mouse move, and |
| 139 | * will add the current Windows time and performance monitor |
| 140 | * counter to the noise pool. It gets the scan code or mouse |
| 141 | * position passed in. |
| 142 | */ |
| 143 | void noise_ultralight(unsigned long data) |
| 144 | { |
| 145 | DWORD wintime; |
| 146 | LARGE_INTEGER perftime; |
| 147 | |
| 148 | random_add_noise(&data, sizeof(DWORD)); |
| 149 | |
| 150 | wintime = GetTickCount(); |
| 151 | random_add_noise(&wintime, sizeof(DWORD)); |
| 152 | |
| 153 | if (QueryPerformanceCounter(&perftime)) |
| 154 | random_add_noise(&perftime, sizeof(perftime)); |
| 155 | } |