Add a new COMPAT option for environments lacking SecureZeroMemory(),
[sgt/putty] / windows / winmisc.c
CommitLineData
e0e7dff8 1/*
f4ff9455 2 * winmisc.c: miscellaneous Windows-specific things
e0e7dff8 3 */
4
e0e7dff8 5#include <stdio.h>
6#include <stdlib.h>
7#include "putty.h"
4c26bb50 8#include <security.h>
e0e7dff8 9
4c48c989 10OSVERSIONINFO osVersion;
11
46ed7b64 12char *platform_get_x_display(void) {
13 /* We may as well check for DISPLAY in case it's useful. */
14 return dupstr(getenv("DISPLAY"));
15}
16
962468d4 17Filename *filename_from_str(const char *str)
9a30e26b 18{
962468d4 19 Filename *ret = snew(Filename);
20 ret->path = dupstr(str);
9a30e26b 21 return ret;
22}
23
962468d4 24Filename *filename_copy(const Filename *fn)
25{
26 return filename_from_str(fn->path);
27}
28
9fab77dc 29const char *filename_to_str(const Filename *fn)
9a30e26b 30{
9fab77dc 31 return fn->path;
9a30e26b 32}
33
962468d4 34int filename_equal(const Filename *f1, const Filename *f2)
35{
36 return !strcmp(f1->path, f2->path);
37}
38
39int filename_is_null(const Filename *fn)
9a30e26b 40{
962468d4 41 return !*fn->path;
9a30e26b 42}
43
962468d4 44void filename_free(Filename *fn)
45{
46 sfree(fn->path);
47 sfree(fn);
48}
49
50int filename_serialise(const Filename *f, void *vdata)
51{
52 char *data = (char *)vdata;
53 int len = strlen(f->path) + 1; /* include trailing NUL */
54 if (data) {
55 strcpy(data, f->path);
56 }
57 return len;
58}
59Filename *filename_deserialise(void *vdata, int maxsize, int *used)
9a30e26b 60{
962468d4 61 char *data = (char *)vdata;
62 char *end;
63 end = memchr(data, '\0', maxsize);
64 if (!end)
65 return NULL;
66 end++;
67 *used = end - data;
68 return filename_from_str(data);
9a30e26b 69}
d0912d1f 70
540bb4b5 71#ifndef NO_SECUREZEROMEMORY
dfb88efd 72/*
73 * Windows implementation of smemclr (see misc.c) using SecureZeroMemory.
74 */
75void smemclr(void *b, size_t n) {
76 if (b && n > 0)
77 SecureZeroMemory(b, n);
78}
da6768b9 79#endif
dfb88efd 80
799dfcfa 81char *get_username(void)
82{
83 DWORD namelen;
84 char *user;
4c26bb50 85 int got_username = FALSE;
86 DECL_WINDOWS_FUNCTION(static, BOOLEAN, GetUserNameExA,
87 (EXTENDED_NAME_FORMAT, LPSTR, PULONG));
799dfcfa 88
4c26bb50 89 {
90 static int tried_usernameex = FALSE;
91 if (!tried_usernameex) {
92 /* Not available on Win9x, so load dynamically */
bda368a5 93 HMODULE secur32 = load_system32_dll("secur32.dll");
4c26bb50 94 GET_WINDOWS_FUNCTION(secur32, GetUserNameExA);
95 tried_usernameex = TRUE;
96 }
97 }
98
99 if (p_GetUserNameExA) {
05581745 100 /*
4c26bb50 101 * If available, use the principal -- this avoids the problem
102 * that the local username is case-insensitive but Kerberos
103 * usernames are case-sensitive.
05581745 104 */
4c26bb50 105
106 /* Get the length */
107 namelen = 0;
108 (void) p_GetUserNameExA(NameUserPrincipal, NULL, &namelen);
109
110 user = snewn(namelen, char);
111 got_username = p_GetUserNameExA(NameUserPrincipal, user, &namelen);
112 if (got_username) {
113 char *p = strchr(user, '@');
114 if (p) *p = 0;
115 } else {
116 sfree(user);
117 }
05581745 118 }
799dfcfa 119
4c26bb50 120 if (!got_username) {
121 /* Fall back to local user name */
122 namelen = 0;
123 if (GetUserName(NULL, &namelen) == FALSE) {
124 /*
125 * Apparently this doesn't work at least on Windows XP SP2.
126 * Thus assume a maximum of 256. It will fail again if it
127 * doesn't fit.
128 */
129 namelen = 256;
130 }
131
132 user = snewn(namelen, char);
133 got_username = GetUserName(user, &namelen);
134 if (!got_username) {
135 sfree(user);
136 }
137 }
799dfcfa 138
4c26bb50 139 return got_username ? user : NULL;
799dfcfa 140}
141
4c48c989 142BOOL init_winver(void)
143{
144 ZeroMemory(&osVersion, sizeof(osVersion));
145 osVersion.dwOSVersionInfoSize = sizeof (OSVERSIONINFO);
146 return GetVersionEx ( (OSVERSIONINFO *) &osVersion);
147}
148
bda368a5 149HMODULE load_system32_dll(const char *libname)
150{
151 /*
152 * Wrapper function to load a DLL out of c:\windows\system32
153 * without going through the full DLL search path. (Hence no
154 * attack is possible by placing a substitute DLL earlier on that
155 * path.)
156 */
157 static char *sysdir = NULL;
158 char *fullpath;
159 HMODULE ret;
160
161 if (!sysdir) {
162 int size = 0, len;
163 do {
164 size = 3*size/2 + 512;
165 sysdir = sresize(sysdir, size, char);
166 len = GetSystemDirectory(sysdir, size);
167 } while (len >= size);
168 }
169
170 fullpath = dupcat(sysdir, "\\", libname, NULL);
171 ret = LoadLibrary(fullpath);
172 sfree(fullpath);
173 return ret;
174}
175
d0912d1f 176#ifdef DEBUG
177static FILE *debug_fp = NULL;
178static HANDLE debug_hdl = INVALID_HANDLE_VALUE;
179static int debug_got_console = 0;
180
181void dputs(char *buf)
182{
183 DWORD dw;
184
185 if (!debug_got_console) {
186 if (AllocConsole()) {
187 debug_got_console = 1;
188 debug_hdl = GetStdHandle(STD_OUTPUT_HANDLE);
189 }
190 }
191 if (!debug_fp) {
192 debug_fp = fopen("debug.log", "w");
193 }
194
195 if (debug_hdl != INVALID_HANDLE_VALUE) {
196 WriteFile(debug_hdl, buf, strlen(buf), &dw, NULL);
197 }
198 fputs(buf, debug_fp);
199 fflush(debug_fp);
200}
201#endif
202
203#ifdef MINEFIELD
204/*
205 * Minefield - a Windows equivalent for Electric Fence
206 */
207
208#define PAGESIZE 4096
209
210/*
211 * Design:
212 *
213 * We start by reserving as much virtual address space as Windows
214 * will sensibly (or not sensibly) let us have. We flag it all as
215 * invalid memory.
216 *
217 * Any allocation attempt is satisfied by committing one or more
218 * pages, with an uncommitted page on either side. The returned
219 * memory region is jammed up against the _end_ of the pages.
220 *
221 * Freeing anything causes instantaneous decommitment of the pages
222 * involved, so stale pointers are caught as soon as possible.
223 */
224
225static int minefield_initialised = 0;
226static void *minefield_region = NULL;
227static long minefield_size = 0;
228static long minefield_npages = 0;
229static long minefield_curpos = 0;
230static unsigned short *minefield_admin = NULL;
231static void *minefield_pages = NULL;
232
233static void minefield_admin_hide(int hide)
234{
235 int access = hide ? PAGE_NOACCESS : PAGE_READWRITE;
236 VirtualProtect(minefield_admin, minefield_npages * 2, access, NULL);
237}
238
239static void minefield_init(void)
240{
241 int size;
242 int admin_size;
243 int i;
244
245 for (size = 0x40000000; size > 0; size = ((size >> 3) * 7) & ~0xFFF) {
246 minefield_region = VirtualAlloc(NULL, size,
247 MEM_RESERVE, PAGE_NOACCESS);
248 if (minefield_region)
249 break;
250 }
251 minefield_size = size;
252
253 /*
254 * Firstly, allocate a section of that to be the admin block.
255 * We'll need a two-byte field for each page.
256 */
257 minefield_admin = minefield_region;
258 minefield_npages = minefield_size / PAGESIZE;
259 admin_size = (minefield_npages * 2 + PAGESIZE - 1) & ~(PAGESIZE - 1);
260 minefield_npages = (minefield_size - admin_size) / PAGESIZE;
261 minefield_pages = (char *) minefield_region + admin_size;
262
263 /*
264 * Commit the admin region.
265 */
266 VirtualAlloc(minefield_admin, minefield_npages * 2,
267 MEM_COMMIT, PAGE_READWRITE);
268
269 /*
270 * Mark all pages as unused (0xFFFF).
271 */
272 for (i = 0; i < minefield_npages; i++)
273 minefield_admin[i] = 0xFFFF;
274
275 /*
276 * Hide the admin region.
277 */
278 minefield_admin_hide(1);
279
280 minefield_initialised = 1;
281}
282
283static void minefield_bomb(void)
284{
285 div(1, *(int *) minefield_pages);
286}
287
288static void *minefield_alloc(int size)
289{
290 int npages;
291 int pos, lim, region_end, region_start;
292 int start;
293 int i;
294
295 npages = (size + PAGESIZE - 1) / PAGESIZE;
296
297 minefield_admin_hide(0);
298
299 /*
300 * Search from current position until we find a contiguous
301 * bunch of npages+2 unused pages.
302 */
303 pos = minefield_curpos;
304 lim = minefield_npages;
305 while (1) {
306 /* Skip over used pages. */
307 while (pos < lim && minefield_admin[pos] != 0xFFFF)
308 pos++;
309 /* Count unused pages. */
310 start = pos;
311 while (pos < lim && pos - start < npages + 2 &&
312 minefield_admin[pos] == 0xFFFF)
313 pos++;
314 if (pos - start == npages + 2)
315 break;
316 /* If we've reached the limit, reset the limit or stop. */
317 if (pos >= lim) {
318 if (lim == minefield_npages) {
319 /* go round and start again at zero */
320 lim = minefield_curpos;
321 pos = 0;
322 } else {
323 minefield_admin_hide(1);
324 return NULL;
325 }
326 }
327 }
328
329 minefield_curpos = pos - 1;
330
331 /*
332 * We have npages+2 unused pages starting at start. We leave
333 * the first and last of these alone and use the rest.
334 */
335 region_end = (start + npages + 1) * PAGESIZE;
336 region_start = region_end - size;
337 /* FIXME: could align here if we wanted */
338
339 /*
340 * Update the admin region.
341 */
342 for (i = start + 2; i < start + npages + 1; i++)
343 minefield_admin[i] = 0xFFFE; /* used but no region starts here */
344 minefield_admin[start + 1] = region_start % PAGESIZE;
345
346 minefield_admin_hide(1);
347
348 VirtualAlloc((char *) minefield_pages + region_start, size,
349 MEM_COMMIT, PAGE_READWRITE);
350 return (char *) minefield_pages + region_start;
351}
352
353static void minefield_free(void *ptr)
354{
355 int region_start, i, j;
356
357 minefield_admin_hide(0);
358
359 region_start = (char *) ptr - (char *) minefield_pages;
360 i = region_start / PAGESIZE;
361 if (i < 0 || i >= minefield_npages ||
362 minefield_admin[i] != region_start % PAGESIZE)
363 minefield_bomb();
364 for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++) {
365 minefield_admin[j] = 0xFFFF;
366 }
367
368 VirtualFree(ptr, j * PAGESIZE - region_start, MEM_DECOMMIT);
369
370 minefield_admin_hide(1);
371}
372
373static int minefield_get_size(void *ptr)
374{
375 int region_start, i, j;
376
377 minefield_admin_hide(0);
378
379 region_start = (char *) ptr - (char *) minefield_pages;
380 i = region_start / PAGESIZE;
381 if (i < 0 || i >= minefield_npages ||
382 minefield_admin[i] != region_start % PAGESIZE)
383 minefield_bomb();
384 for (j = i; j < minefield_npages && minefield_admin[j] != 0xFFFF; j++);
385
386 minefield_admin_hide(1);
387
388 return j * PAGESIZE - region_start;
389}
390
391void *minefield_c_malloc(size_t size)
392{
393 if (!minefield_initialised)
394 minefield_init();
395 return minefield_alloc(size);
396}
397
398void minefield_c_free(void *p)
399{
400 if (!minefield_initialised)
401 minefield_init();
402 minefield_free(p);
403}
404
405/*
406 * realloc _always_ moves the chunk, for rapid detection of code
407 * that assumes it won't.
408 */
409void *minefield_c_realloc(void *p, size_t size)
410{
411 size_t oldsize;
412 void *q;
413 if (!minefield_initialised)
414 minefield_init();
415 q = minefield_alloc(size);
416 oldsize = minefield_get_size(p);
417 memcpy(q, p, (oldsize < size ? oldsize : size));
418 minefield_free(p);
419 return q;
420}
421
422#endif /* MINEFIELD */
ae62eaeb 423
424FontSpec *fontspec_new(const char *name,
425 int bold, int height, int charset)
426{
427 FontSpec *f = snew(FontSpec);
428 f->name = dupstr(name);
429 f->isbold = bold;
430 f->height = height;
431 f->charset = charset;
432 return f;
433}
434FontSpec *fontspec_copy(const FontSpec *f)
435{
436 return fontspec_new(f->name, f->isbold, f->height, f->charset);
437}
438void fontspec_free(FontSpec *f)
439{
440 sfree(f->name);
441 sfree(f);
442}
443int fontspec_serialise(FontSpec *f, void *vdata)
444{
445 char *data = (char *)vdata;
446 int len = strlen(f->name) + 1; /* include trailing NUL */
447 if (data) {
448 strcpy(data, f->name);
449 PUT_32BIT_MSB_FIRST(data + len, f->isbold);
450 PUT_32BIT_MSB_FIRST(data + len + 4, f->height);
451 PUT_32BIT_MSB_FIRST(data + len + 8, f->charset);
452 }
453 return len + 12; /* also include three 4-byte ints */
454}
455FontSpec *fontspec_deserialise(void *vdata, int maxsize, int *used)
456{
457 char *data = (char *)vdata;
458 char *end;
459 if (maxsize < 13)
460 return NULL;
461 end = memchr(data, '\0', maxsize-12);
462 if (!end)
463 return NULL;
464 end++;
465 *used = end - data + 12;
466 return fontspec_new(data,
467 GET_32BIT_MSB_FIRST(end),
468 GET_32BIT_MSB_FIRST(end + 4),
469 GET_32BIT_MSB_FIRST(end + 8));
470}