| blob | 77738a4fd93d36a444b251b78b37f38e521e4a5c |
1 /*\r
2 * Platform-independent routines shared between all PuTTY programs.\r
3 */\r
4 \r
5 #include <stdio.h>\r
6 #include <stdlib.h>\r
7 #include <stdarg.h>\r
8 #include <limits.h>\r
9 #include <ctype.h>\r
10 #include <assert.h>\r
11 #include "putty.h"\r
12 \r
13 /*\r
14 * Parse a string block size specification. This is approximately a\r
15 * subset of the block size specs supported by GNU fileutils:\r
16 * "nk" = n kilobytes\r
17 * "nM" = n megabytes\r
18 * "nG" = n gigabytes\r
19 * All numbers are decimal, and suffixes refer to powers of two.\r
20 * Case-insensitive.\r
21 */\r
22 unsigned long parse_blocksize(const char *bs)\r
23 {\r
24 char *suf;\r
25 unsigned long r = strtoul(bs, &suf, 10);\r
26 if (*suf != '\0') {\r
27 while (*suf && isspace((unsigned char)*suf)) suf++;\r
28 switch (*suf) {\r
29 case 'k': case 'K':\r
30 r *= 1024ul;\r
31 break;\r
32 case 'm': case 'M':\r
33 r *= 1024ul * 1024ul;\r
34 break;\r
35 case 'g': case 'G':\r
36 r *= 1024ul * 1024ul * 1024ul;\r
37 break;\r
38 case '\0':\r
39 default:\r
40 break;\r
41 }\r
42 }\r
43 return r;\r
44 }\r
45 \r
46 /*\r
47 * Parse a ^C style character specification.\r
48 * Returns NULL in `next' if we didn't recognise it as a control character,\r
49 * in which case `c' should be ignored.\r
50 * The precise current parsing is an oddity inherited from the terminal\r
51 * answerback-string parsing code. All sequences start with ^; all except\r
52 * ^<123> are two characters. The ones that are worth keeping are probably:\r
53 * ^? 127\r
54 * ^@A-Z[\]^_ 0-31\r
55 * a-z 1-26\r
56 * <num> specified by number (decimal, 0octal, 0xHEX)\r
57 * ~ ^ escape\r
58 */\r
59 char ctrlparse(char *s, char **next)\r
60 {\r
61 char c = 0;\r
62 if (*s != '^') {\r
63 *next = NULL;\r
64 } else {\r
65 s++;\r
66 if (*s == '\0') {\r
67 *next = NULL;\r
68 } else if (*s == '<') {\r
69 s++;\r
70 c = (char)strtol(s, next, 0);\r
71 if ((*next == s) || (**next != '>')) {\r
72 c = 0;\r
73 *next = NULL;\r
74 } else\r
75 (*next)++;\r
76 } else if (*s >= 'a' && *s <= 'z') {\r
77 c = (*s - ('a' - 1));\r
78 *next = s+1;\r
79 } else if ((*s >= '@' && *s <= '_') || *s == '?' || (*s & 0x80)) {\r
80 c = ('@' ^ *s);\r
81 *next = s+1;\r
82 } else if (*s == '~') {\r
83 c = '^';\r
84 *next = s+1;\r
85 }\r
86 }\r
87 return c;\r
88 }\r
89 \r
90 /*\r
91 * Find a character in a string, unless it's a colon contained within\r
92 * square brackets. Used for untangling strings of the form\r
93 * 'host:port', where host can be an IPv6 literal.\r
94 *\r
95 * We provide several variants of this function, with semantics like\r
96 * various standard string.h functions.\r
97 */\r
98 static const char *host_strchr_internal(const char *s, const char *set,\r
99 int first)\r
100 {\r
101 int brackets = 0;\r
102 const char *ret = NULL;\r
103 \r
104 while (1) {\r
105 if (!*s)\r
106 return ret;\r
107 \r
108 if (*s == '[')\r
109 brackets++;\r
110 else if (*s == ']' && brackets > 0)\r
111 brackets--;\r
112 else if (brackets && *s == ':')\r
113 /* never match */ ;\r
114 else if (strchr(set, *s)) {\r
115 ret = s;\r
116 if (first)\r
117 return ret;\r
118 }\r
119 \r
120 s++;\r
121 }\r
122 }\r
123 size_t host_strcspn(const char *s, const char *set)\r
124 {\r
125 const char *answer = host_strchr_internal(s, set, TRUE);\r
126 if (answer)\r
127 return answer - s;\r
128 else\r
129 return strlen(s);\r
130 }\r
131 char *host_strchr(const char *s, int c)\r
132 {\r
133 char set[2];\r
134 set[0] = c;\r
135 set[1] = '\0';\r
136 return (char *) host_strchr_internal(s, set, TRUE);\r
137 }\r
138 char *host_strrchr(const char *s, int c)\r
139 {\r
140 char set[2];\r
141 set[0] = c;\r
142 set[1] = '\0';\r
143 return (char *) host_strchr_internal(s, set, FALSE);\r
144 }\r
145 \r
146 #ifdef TEST_HOST_STRFOO\r
147 int main(void)\r
148 {\r
149 int passes = 0, fails = 0;\r
150 \r
151 #define TEST1(func, string, arg2, suffix, result) do \\r
152 { \\r
153 const char *str = string; \\r
154 unsigned ret = func(string, arg2) suffix; \\r
155 if (ret == result) { \\r
156 passes++; \\r
157 } else { \\r
158 printf("fail: %s(%s,%s)%s = %u, expected %u\n", \\r
159 #func, #string, #arg2, #suffix, ret, result); \\r
160 fails++; \\r
161 } \\r
162 } while (0)\r
163 \r
164 TEST1(host_strchr, "[1:2:3]:4:5", ':', -str, 7);\r
165 TEST1(host_strrchr, "[1:2:3]:4:5", ':', -str, 9);\r
166 TEST1(host_strcspn, "[1:2:3]:4:5", "/:",, 7);\r
167 TEST1(host_strchr, "[1:2:3]", ':', == NULL, 1);\r
168 TEST1(host_strrchr, "[1:2:3]", ':', == NULL, 1);\r
169 TEST1(host_strcspn, "[1:2:3]", "/:",, 7);\r
170 TEST1(host_strcspn, "[1:2/3]", "/:",, 4);\r
171 TEST1(host_strcspn, "[1:2:3]/", "/:",, 7);\r
172 \r
173 printf("passed %d failed %d total %d\n", passes, fails, passes+fails);\r
174 return fails != 0 ? 1 : 0;\r
175 }\r
176 /* Stubs to stop the rest of this module causing compile failures. */\r
177 void modalfatalbox(char *fmt, ...) {}\r
178 int conf_get_int(Conf *conf, int primary) { return 0; }\r
179 char *conf_get_str(Conf *conf, int primary) { return NULL; }\r
180 #endif /* TEST_HOST_STRFOO */\r
181 \r
182 /*\r
183 * Trim square brackets off the outside of an IPv6 address literal.\r
184 * Leave all other strings unchanged. Returns a fresh dynamically\r
185 * allocated string.\r
186 */\r
187 char *host_strduptrim(const char *s)\r
188 {\r
189 if (s[0] == '[') {\r
190 const char *p = s+1;\r
191 int colons = 0;\r
192 while (*p && *p != ']') {\r
193 if (isxdigit((unsigned char)*p))\r
194 /* OK */;\r
195 else if (*p == ':')\r
196 colons++;\r
197 else\r
198 break;\r
199 p++;\r
200 }\r
201 if (*p == ']' && !p[1] && colons > 1) {\r
202 /*\r
203 * This looks like an IPv6 address literal (hex digits and\r
204 * at least two colons, contained in square brackets).\r
205 * Trim off the brackets.\r
206 */\r
207 return dupprintf("%.*s", (int)(p - (s+1)), s+1);\r
208 }\r
209 }\r
210 \r
211 /*\r
212 * Any other shape of string is simply duplicated.\r
213 */\r
214 return dupstr(s);\r
215 }\r
216 \r
217 prompts_t *new_prompts(void *frontend)\r
218 {\r
219 prompts_t *p = snew(prompts_t);\r
220 p->prompts = NULL;\r
221 p->n_prompts = 0;\r
222 p->frontend = frontend;\r
223 p->data = NULL;\r
224 p->to_server = TRUE; /* to be on the safe side */\r
225 p->name = p->instruction = NULL;\r
226 p->name_reqd = p->instr_reqd = FALSE;\r
227 return p;\r
228 }\r
229 void add_prompt(prompts_t *p, char *promptstr, int echo)\r
230 {\r
231 prompt_t *pr = snew(prompt_t);\r
232 pr->prompt = promptstr;\r
233 pr->echo = echo;\r
234 pr->result = NULL;\r
235 pr->resultsize = 0;\r
236 p->n_prompts++;\r
237 p->prompts = sresize(p->prompts, p->n_prompts, prompt_t *);\r
238 p->prompts[p->n_prompts-1] = pr;\r
239 }\r
240 void prompt_ensure_result_size(prompt_t *pr, int newlen)\r
241 {\r
242 if ((int)pr->resultsize < newlen) {\r
243 char *newbuf;\r
244 newlen = newlen * 5 / 4 + 512; /* avoid too many small allocs */\r
245 \r
246 /*\r
247 * We don't use sresize / realloc here, because we will be\r
248 * storing sensitive stuff like passwords in here, and we want\r
249 * to make sure that the data doesn't get copied around in\r
250 * memory without the old copy being destroyed.\r
251 */\r
252 newbuf = snewn(newlen, char);\r
253 memcpy(newbuf, pr->result, pr->resultsize);\r
254 smemclr(pr->result, pr->resultsize);\r
255 sfree(pr->result);\r
256 pr->result = newbuf;\r
257 pr->resultsize = newlen;\r
258 }\r
259 }\r
260 void prompt_set_result(prompt_t *pr, const char *newstr)\r
261 {\r
262 prompt_ensure_result_size(pr, strlen(newstr) + 1);\r
263 strcpy(pr->result, newstr);\r
264 }\r
265 void free_prompts(prompts_t *p)\r
266 {\r
267 size_t i;\r
268 for (i=0; i < p->n_prompts; i++) {\r
269 prompt_t *pr = p->prompts[i];\r
270 smemclr(pr->result, pr->resultsize); /* burn the evidence */\r
271 sfree(pr->result);\r
272 sfree(pr->prompt);\r
273 sfree(pr);\r
274 }\r
275 sfree(p->prompts);\r
276 sfree(p->name);\r
277 sfree(p->instruction);\r
278 sfree(p);\r
279 }\r
280 \r
281 /* ----------------------------------------------------------------------\r
282 * String handling routines.\r
283 */\r
284 \r
285 char *dupstr(const char *s)\r
286 {\r
287 char *p = NULL;\r
288 if (s) {\r
289 int len = strlen(s);\r
290 p = snewn(len + 1, char);\r
291 strcpy(p, s);\r
292 }\r
293 return p;\r
294 }\r
295 \r
296 /* Allocate the concatenation of N strings. Terminate arg list with NULL. */\r
297 char *dupcat(const char *s1, ...)\r
298 {\r
299 int len;\r
300 char *p, *q, *sn;\r
301 va_list ap;\r
302 \r
303 len = strlen(s1);\r
304 va_start(ap, s1);\r
305 while (1) {\r
306 sn = va_arg(ap, char *);\r
307 if (!sn)\r
308 break;\r
309 len += strlen(sn);\r
310 }\r
311 va_end(ap);\r
312 \r
313 p = snewn(len + 1, char);\r
314 strcpy(p, s1);\r
315 q = p + strlen(p);\r
316 \r
317 va_start(ap, s1);\r
318 while (1) {\r
319 sn = va_arg(ap, char *);\r
320 if (!sn)\r
321 break;\r
322 strcpy(q, sn);\r
323 q += strlen(q);\r
324 }\r
325 va_end(ap);\r
326 \r
327 return p;\r
328 }\r
329 \r
330 void burnstr(char *string) /* sfree(str), only clear it first */\r
331 {\r
332 if (string) {\r
333 smemclr(string, strlen(string));\r
334 sfree(string);\r
335 }\r
336 }\r
337 \r
338 int toint(unsigned u)\r
339 {\r
340 /*\r
341 * Convert an unsigned to an int, without running into the\r
342 * undefined behaviour which happens by the strict C standard if\r
343 * the value overflows. You'd hope that sensible compilers would\r
344 * do the sensible thing in response to a cast, but actually I\r
345 * don't trust modern compilers not to do silly things like\r
346 * assuming that _obviously_ you wouldn't have caused an overflow\r
347 * and so they can elide an 'if (i < 0)' test immediately after\r
348 * the cast.\r
349 *\r
350 * Sensible compilers ought of course to optimise this entire\r
351 * function into 'just return the input value'!\r
352 */\r
353 if (u <= (unsigned)INT_MAX)\r
354 return (int)u;\r
355 else if (u >= (unsigned)INT_MIN) /* wrap in cast _to_ unsigned is OK */\r
356 return INT_MIN + (int)(u - (unsigned)INT_MIN);\r
357 else\r
358 return INT_MIN; /* fallback; should never occur on binary machines */\r
359 }\r
360 \r
361 /*\r
362 * Do an sprintf(), but into a custom-allocated buffer.\r
363 * \r
364 * Currently I'm doing this via vsnprintf. This has worked so far,\r
365 * but it's not good, because vsnprintf is not available on all\r
366 * platforms. There's an ifdef to use `_vsnprintf', which seems\r
367 * to be the local name for it on Windows. Other platforms may\r
368 * lack it completely, in which case it'll be time to rewrite\r
369 * this function in a totally different way.\r
370 * \r
371 * The only `properly' portable solution I can think of is to\r
372 * implement my own format string scanner, which figures out an\r
373 * upper bound for the length of each formatting directive,\r
374 * allocates the buffer as it goes along, and calls sprintf() to\r
375 * actually process each directive. If I ever need to actually do\r
376 * this, some caveats:\r
377 * \r
378 * - It's very hard to find a reliable upper bound for\r
379 * floating-point values. %f, in particular, when supplied with\r
380 * a number near to the upper or lower limit of representable\r
381 * numbers, could easily take several hundred characters. It's\r
382 * probably feasible to predict this statically using the\r
383 * constants in <float.h>, or even to predict it dynamically by\r
384 * looking at the exponent of the specific float provided, but\r
385 * it won't be fun.\r
386 * \r
387 * - Don't forget to _check_, after calling sprintf, that it's\r
388 * used at most the amount of space we had available.\r
389 * \r
390 * - Fault any formatting directive we don't fully understand. The\r
391 * aim here is to _guarantee_ that we never overflow the buffer,\r
392 * because this is a security-critical function. If we see a\r
393 * directive we don't know about, we should panic and die rather\r
394 * than run any risk.\r
395 */\r
396 char *dupprintf(const char *fmt, ...)\r
397 {\r
398 char *ret;\r
399 va_list ap;\r
400 va_start(ap, fmt);\r
401 ret = dupvprintf(fmt, ap);\r
402 va_end(ap);\r
403 return ret;\r
404 }\r
405 char *dupvprintf(const char *fmt, va_list ap)\r
406 {\r
407 char *buf;\r
408 int len, size;\r
409 \r
410 buf = snewn(512, char);\r
411 size = 512;\r
412 \r
413 while (1) {\r
414 #ifdef _WINDOWS\r
415 #define vsnprintf _vsnprintf\r
416 #endif\r
417 #ifdef va_copy\r
418 /* Use the `va_copy' macro mandated by C99, if present.\r
419 * XXX some environments may have this as __va_copy() */\r
420 va_list aq;\r
421 va_copy(aq, ap);\r
422 len = vsnprintf(buf, size, fmt, aq);\r
423 va_end(aq);\r
424 #else\r
425 /* Ugh. No va_copy macro, so do something nasty.\r
426 * Technically, you can't reuse a va_list like this: it is left\r
427 * unspecified whether advancing a va_list pointer modifies its\r
428 * value or something it points to, so on some platforms calling\r
429 * vsnprintf twice on the same va_list might fail hideously\r
430 * (indeed, it has been observed to).\r
431 * XXX the autoconf manual suggests that using memcpy() will give\r
432 * "maximum portability". */\r
433 len = vsnprintf(buf, size, fmt, ap);\r
434 #endif\r
435 if (len >= 0 && len < size) {\r
436 /* This is the C99-specified criterion for snprintf to have\r
437 * been completely successful. */\r
438 return buf;\r
439 } else if (len > 0) {\r
440 /* This is the C99 error condition: the returned length is\r
441 * the required buffer size not counting the NUL. */\r
442 size = len + 1;\r
443 } else {\r
444 /* This is the pre-C99 glibc error condition: <0 means the\r
445 * buffer wasn't big enough, so we enlarge it a bit and hope. */\r
446 size += 512;\r
447 }\r
448 buf = sresize(buf, size, char);\r
449 }\r
450 }\r
451 \r
452 /*\r
453 * Read an entire line of text from a file. Return a buffer\r
454 * malloced to be as big as necessary (caller must free).\r
455 */\r
456 char *fgetline(FILE *fp)\r
457 {\r
458 char *ret = snewn(512, char);\r
459 int size = 512, len = 0;\r
460 while (fgets(ret + len, size - len, fp)) {\r
461 len += strlen(ret + len);\r
462 if (len > 0 && ret[len-1] == '\n')\r
463 break; /* got a newline, we're done */\r
464 size = len + 512;\r
465 ret = sresize(ret, size, char);\r
466 }\r
467 if (len == 0) { /* first fgets returned NULL */\r
468 sfree(ret);\r
469 return NULL;\r
470 }\r
471 ret[len] = '\0';\r
472 return ret;\r
473 }\r
474 \r
475 /* ----------------------------------------------------------------------\r
476 * Core base64 encoding and decoding routines.\r
477 */\r
478 \r
479 void base64_encode_atom(unsigned char *data, int n, char *out)\r
480 {\r
481 static const char base64_chars[] =\r
482 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";\r
483 \r
484 unsigned word;\r
485 \r
486 word = data[0] << 16;\r
487 if (n > 1)\r
488 word |= data[1] << 8;\r
489 if (n > 2)\r
490 word |= data[2];\r
491 out[0] = base64_chars[(word >> 18) & 0x3F];\r
492 out[1] = base64_chars[(word >> 12) & 0x3F];\r
493 if (n > 1)\r
494 out[2] = base64_chars[(word >> 6) & 0x3F];\r
495 else\r
496 out[2] = '=';\r
497 if (n > 2)\r
498 out[3] = base64_chars[word & 0x3F];\r
499 else\r
500 out[3] = '=';\r
501 }\r
502 \r
503 int base64_decode_atom(char *atom, unsigned char *out)\r
504 {\r
505 int vals[4];\r
506 int i, v, len;\r
507 unsigned word;\r
508 char c;\r
509 \r
510 for (i = 0; i < 4; i++) {\r
511 c = atom[i];\r
512 if (c >= 'A' && c <= 'Z')\r
513 v = c - 'A';\r
514 else if (c >= 'a' && c <= 'z')\r
515 v = c - 'a' + 26;\r
516 else if (c >= '0' && c <= '9')\r
517 v = c - '0' + 52;\r
518 else if (c == '+')\r
519 v = 62;\r
520 else if (c == '/')\r
521 v = 63;\r
522 else if (c == '=')\r
523 v = -1;\r
524 else\r
525 return 0; /* invalid atom */\r
526 vals[i] = v;\r
527 }\r
528 \r
529 if (vals[0] == -1 || vals[1] == -1)\r
530 return 0;\r
531 if (vals[2] == -1 && vals[3] != -1)\r
532 return 0;\r
533 \r
534 if (vals[3] != -1)\r
535 len = 3;\r
536 else if (vals[2] != -1)\r
537 len = 2;\r
538 else\r
539 len = 1;\r
540 \r
541 word = ((vals[0] << 18) |\r
542 (vals[1] << 12) | ((vals[2] & 0x3F) << 6) | (vals[3] & 0x3F));\r
543 out[0] = (word >> 16) & 0xFF;\r
544 if (len > 1)\r
545 out[1] = (word >> 8) & 0xFF;\r
546 if (len > 2)\r
547 out[2] = word & 0xFF;\r
548 return len;\r
549 }\r
550 \r
551 /* ----------------------------------------------------------------------\r
552 * Generic routines to deal with send buffers: a linked list of\r
553 * smallish blocks, with the operations\r
554 * \r
555 * - add an arbitrary amount of data to the end of the list\r
556 * - remove the first N bytes from the list\r
557 * - return a (pointer,length) pair giving some initial data in\r
558 * the list, suitable for passing to a send or write system\r
559 * call\r
560 * - retrieve a larger amount of initial data from the list\r
561 * - return the current size of the buffer chain in bytes\r
562 */\r
563 \r
564 #define BUFFER_MIN_GRANULE 512\r
565 \r
566 struct bufchain_granule {\r
567 struct bufchain_granule *next;\r
568 char *bufpos, *bufend, *bufmax;\r
569 };\r
570 \r
571 void bufchain_init(bufchain *ch)\r
572 {\r
573 ch->head = ch->tail = NULL;\r
574 ch->buffersize = 0;\r
575 }\r
576 \r
577 void bufchain_clear(bufchain *ch)\r
578 {\r
579 struct bufchain_granule *b;\r
580 while (ch->head) {\r
581 b = ch->head;\r
582 ch->head = ch->head->next;\r
583 sfree(b);\r
584 }\r
585 ch->tail = NULL;\r
586 ch->buffersize = 0;\r
587 }\r
588 \r
589 int bufchain_size(bufchain *ch)\r
590 {\r
591 return ch->buffersize;\r
592 }\r
593 \r
594 void bufchain_add(bufchain *ch, const void *data, int len)\r
595 {\r
596 const char *buf = (const char *)data;\r
597 \r
598 if (len == 0) return;\r
599 \r
600 ch->buffersize += len;\r
601 \r
602 while (len > 0) {\r
603 if (ch->tail && ch->tail->bufend < ch->tail->bufmax) {\r
604 int copylen = min(len, ch->tail->bufmax - ch->tail->bufend);\r
605 memcpy(ch->tail->bufend, buf, copylen);\r
606 buf += copylen;\r
607 len -= copylen;\r
608 ch->tail->bufend += copylen;\r
609 }\r
610 if (len > 0) {\r
611 int grainlen =\r
612 max(sizeof(struct bufchain_granule) + len, BUFFER_MIN_GRANULE);\r
613 struct bufchain_granule *newbuf;\r
614 newbuf = smalloc(grainlen);\r
615 newbuf->bufpos = newbuf->bufend =\r
616 (char *)newbuf + sizeof(struct bufchain_granule);\r
617 newbuf->bufmax = (char *)newbuf + grainlen;\r
618 newbuf->next = NULL;\r
619 if (ch->tail)\r
620 ch->tail->next = newbuf;\r
621 else\r
622 ch->head = newbuf;\r
623 ch->tail = newbuf;\r
624 }\r
625 }\r
626 }\r
627 \r
628 void bufchain_consume(bufchain *ch, int len)\r
629 {\r
630 struct bufchain_granule *tmp;\r
631 \r
632 assert(ch->buffersize >= len);\r
633 while (len > 0) {\r
634 int remlen = len;\r
635 assert(ch->head != NULL);\r
636 if (remlen >= ch->head->bufend - ch->head->bufpos) {\r
637 remlen = ch->head->bufend - ch->head->bufpos;\r
638 tmp = ch->head;\r
639 ch->head = tmp->next;\r
640 if (!ch->head)\r
641 ch->tail = NULL;\r
642 sfree(tmp);\r
643 } else\r
644 ch->head->bufpos += remlen;\r
645 ch->buffersize -= remlen;\r
646 len -= remlen;\r
647 }\r
648 }\r
649 \r
650 void bufchain_prefix(bufchain *ch, void **data, int *len)\r
651 {\r
652 *len = ch->head->bufend - ch->head->bufpos;\r
653 *data = ch->head->bufpos;\r
654 }\r
655 \r
656 void bufchain_fetch(bufchain *ch, void *data, int len)\r
657 {\r
658 struct bufchain_granule *tmp;\r
659 char *data_c = (char *)data;\r
660 \r
661 tmp = ch->head;\r
662 \r
663 assert(ch->buffersize >= len);\r
664 while (len > 0) {\r
665 int remlen = len;\r
666 \r
667 assert(tmp != NULL);\r
668 if (remlen >= tmp->bufend - tmp->bufpos)\r
669 remlen = tmp->bufend - tmp->bufpos;\r
670 memcpy(data_c, tmp->bufpos, remlen);\r
671 \r
672 tmp = tmp->next;\r
673 len -= remlen;\r
674 data_c += remlen;\r
675 }\r
676 }\r
677 \r
678 /* ----------------------------------------------------------------------\r
679 * My own versions of malloc, realloc and free. Because I want\r
680 * malloc and realloc to bomb out and exit the program if they run\r
681 * out of memory, realloc to reliably call malloc if passed a NULL\r
682 * pointer, and free to reliably do nothing if passed a NULL\r
683 * pointer. We can also put trace printouts in, if we need to; and\r
684 * we can also replace the allocator with an ElectricFence-like\r
685 * one.\r
686 */\r
687 \r
688 #ifdef MINEFIELD\r
689 void *minefield_c_malloc(size_t size);\r
690 void minefield_c_free(void *p);\r
691 void *minefield_c_realloc(void *p, size_t size);\r
692 #endif\r
693 \r
694 #ifdef MALLOC_LOG\r
695 static FILE *fp = NULL;\r
696 \r
697 static char *mlog_file = NULL;\r
698 static int mlog_line = 0;\r
699 \r
700 void mlog(char *file, int line)\r
701 {\r
702 mlog_file = file;\r
703 mlog_line = line;\r
704 if (!fp) {\r
705 fp = fopen("putty_mem.log", "w");\r
706 setvbuf(fp, NULL, _IONBF, BUFSIZ);\r
707 }\r
708 if (fp)\r
709 fprintf(fp, "%s:%d: ", file, line);\r
710 }\r
711 #endif\r
712 \r
713 void *safemalloc(size_t n, size_t size)\r
714 {\r
715 void *p;\r
716 \r
717 if (n > INT_MAX / size) {\r
718 p = NULL;\r
719 } else {\r
720 size *= n;\r
721 if (size == 0) size = 1;\r
722 #ifdef MINEFIELD\r
723 p = minefield_c_malloc(size);\r
724 #else\r
725 p = malloc(size);\r
726 #endif\r
727 }\r
728 \r
729 if (!p) {\r
730 char str[200];\r
731 #ifdef MALLOC_LOG\r
732 sprintf(str, "Out of memory! (%s:%d, size=%d)",\r
733 mlog_file, mlog_line, size);\r
734 fprintf(fp, "*** %s\n", str);\r
735 fclose(fp);\r
736 #else\r
737 strcpy(str, "Out of memory!");\r
738 #endif\r
739 modalfatalbox("%s", str);\r
740 }\r
741 #ifdef MALLOC_LOG\r
742 if (fp)\r
743 fprintf(fp, "malloc(%d) returns %p\n", size, p);\r
744 #endif\r
745 return p;\r
746 }\r
747 \r
748 void *saferealloc(void *ptr, size_t n, size_t size)\r
749 {\r
750 void *p;\r
751 \r
752 if (n > INT_MAX / size) {\r
753 p = NULL;\r
754 } else {\r
755 size *= n;\r
756 if (!ptr) {\r
757 #ifdef MINEFIELD\r
758 p = minefield_c_malloc(size);\r
759 #else\r
760 p = malloc(size);\r
761 #endif\r
762 } else {\r
763 #ifdef MINEFIELD\r
764 p = minefield_c_realloc(ptr, size);\r
765 #else\r
766 p = realloc(ptr, size);\r
767 #endif\r
768 }\r
769 }\r
770 \r
771 if (!p) {\r
772 char str[200];\r
773 #ifdef MALLOC_LOG\r
774 sprintf(str, "Out of memory! (%s:%d, size=%d)",\r
775 mlog_file, mlog_line, size);\r
776 fprintf(fp, "*** %s\n", str);\r
777 fclose(fp);\r
778 #else\r
779 strcpy(str, "Out of memory!");\r
780 #endif\r
781 modalfatalbox("%s", str);\r
782 }\r
783 #ifdef MALLOC_LOG\r
784 if (fp)\r
785 fprintf(fp, "realloc(%p,%d) returns %p\n", ptr, size, p);\r
786 #endif\r
787 return p;\r
788 }\r
789 \r
790 void safefree(void *ptr)\r
791 {\r
792 if (ptr) {\r
793 #ifdef MALLOC_LOG\r
794 if (fp)\r
795 fprintf(fp, "free(%p)\n", ptr);\r
796 #endif\r
797 #ifdef MINEFIELD\r
798 minefield_c_free(ptr);\r
799 #else\r
800 free(ptr);\r
801 #endif\r
802 }\r
803 #ifdef MALLOC_LOG\r
804 else if (fp)\r
805 fprintf(fp, "freeing null pointer - no action taken\n");\r
806 #endif\r
807 }\r
808 \r
809 /* ----------------------------------------------------------------------\r
810 * Debugging routines.\r
811 */\r
812 \r
813 #ifdef DEBUG\r
814 extern void dputs(char *); /* defined in per-platform *misc.c */\r
815 \r
816 void debug_printf(char *fmt, ...)\r
817 {\r
818 char *buf;\r
819 va_list ap;\r
820 \r
821 va_start(ap, fmt);\r
822 buf = dupvprintf(fmt, ap);\r
823 dputs(buf);\r
824 sfree(buf);\r
825 va_end(ap);\r
826 }\r
827 \r
828 \r
829 void debug_memdump(void *buf, int len, int L)\r
830 {\r
831 int i;\r
832 unsigned char *p = buf;\r
833 char foo[17];\r
834 if (L) {\r
835 int delta;\r
836 debug_printf("\t%d (0x%x) bytes:\n", len, len);\r
837 delta = 15 & (unsigned long int) p;\r
838 p -= delta;\r
839 len += delta;\r
840 }\r
841 for (; 0 < len; p += 16, len -= 16) {\r
842 dputs(" ");\r
843 if (L)\r
844 debug_printf("%p: ", p);\r
845 strcpy(foo, "................"); /* sixteen dots */\r
846 for (i = 0; i < 16 && i < len; ++i) {\r
847 if (&p[i] < (unsigned char *) buf) {\r
848 dputs(" "); /* 3 spaces */\r
849 foo[i] = ' ';\r
850 } else {\r
851 debug_printf("%c%02.2x",\r
852 &p[i] != (unsigned char *) buf\r
853 && i % 4 ? '.' : ' ', p[i]\r
854 );\r
855 if (p[i] >= ' ' && p[i] <= '~')\r
856 foo[i] = (char) p[i];\r
857 }\r
858 }\r
859 foo[i] = '\0';\r
860 debug_printf("%*s%s\n", (16 - i) * 3 + 2, "", foo);\r
861 }\r
862 }\r
863 \r
864 #endif /* def DEBUG */\r
865 \r
866 /*\r
867 * Determine whether or not a Conf represents a session which can\r
868 * sensibly be launched right now.\r
869 */\r
870 int conf_launchable(Conf *conf)\r
871 {\r
872 if (conf_get_int(conf, CONF_protocol) == PROT_SERIAL)\r
873 return conf_get_str(conf, CONF_serline)[0] != 0;\r
874 else\r
875 return conf_get_str(conf, CONF_host)[0] != 0;\r
876 }\r
877 \r
878 char const *conf_dest(Conf *conf)\r
879 {\r
880 if (conf_get_int(conf, CONF_protocol) == PROT_SERIAL)\r
881 return conf_get_str(conf, CONF_serline);\r
882 else\r
883 return conf_get_str(conf, CONF_host);\r
884 }\r
885 \r
886 #ifndef PLATFORM_HAS_SMEMCLR\r
887 /*\r
888 * Securely wipe memory.\r
889 *\r
890 * The actual wiping is no different from what memset would do: the\r
891 * point of 'securely' is to try to be sure over-clever compilers\r
892 * won't optimise away memsets on variables that are about to be freed\r
893 * or go out of scope. See\r
894 * https://buildsecurityin.us-cert.gov/bsi-rules/home/g1/771-BSI.html\r
895 *\r
896 * Some platforms (e.g. Windows) may provide their own version of this\r
897 * function.\r
898 */\r
899 void smemclr(void *b, size_t n) {\r
900 volatile char *vp;\r
901 \r
902 if (b && n > 0) {\r
903 /*\r
904 * Zero out the memory.\r
905 */\r
906 memset(b, 0, n);\r
907 \r
908 /*\r
909 * Perform a volatile access to the object, forcing the\r
910 * compiler to admit that the previous memset was important.\r
911 *\r
912 * This while loop should in practice run for zero iterations\r
913 * (since we know we just zeroed the object out), but in\r
914 * theory (as far as the compiler knows) it might range over\r
915 * the whole object. (If we had just written, say, '*vp =\r
916 * *vp;', a compiler could in principle have 'helpfully'\r
917 * optimised the memset into only zeroing out the first byte.\r
918 * This should be robust.)\r
919 */\r
920 vp = b;\r
921 while (*vp) vp++;\r
922 }\r
923 }\r
924 #endif\r
925 \r
926 /*\r
927 * Validate a manual host key specification (either entered in the\r
928 * GUI, or via -hostkey). If valid, we return TRUE, and update 'key'\r
929 * to contain a canonicalised version of the key string in 'key'\r
930 * (which is guaranteed to take up at most as much space as the\r
931 * original version), suitable for putting into the Conf. If not\r
932 * valid, we return FALSE.\r
933 */\r
934 int validate_manual_hostkey(char *key)\r
935 {\r
936 char *p, *q, *r, *s;\r
937 \r
938 /*\r
939 * Step through the string word by word, looking for a word that's\r
940 * in one of the formats we like.\r
941 */\r
942 p = key;\r
943 while ((p += strspn(p, " \t"))[0]) {\r
944 q = p;\r
945 p += strcspn(p, " \t");\r
946 if (*p) *p++ = '\0';\r
947 \r
948 /*\r
949 * Now q is our word.\r
950 */\r
951 \r
952 if (strlen(q) == 16*3 - 1 &&\r
953 q[strspn(q, "0123456789abcdefABCDEF:")] == 0) {\r
954 /*\r
955 * Might be a key fingerprint. Check the colons are in the\r
956 * right places, and if so, return the same fingerprint\r
957 * canonicalised into lowercase.\r
958 */\r
959 int i;\r
960 for (i = 0; i < 16; i++)\r
961 if (q[3*i] == ':' || q[3*i+1] == ':')\r
962 goto not_fingerprint; /* sorry */\r
963 for (i = 0; i < 15; i++)\r
964 if (q[3*i+2] != ':')\r
965 goto not_fingerprint; /* sorry */\r
966 for (i = 0; i < 16*3 - 1; i++)\r
967 key[i] = tolower(q[i]);\r
968 key[16*3 - 1] = '\0';\r
969 return TRUE;\r
970 }\r
971 not_fingerprint:;\r
972 \r
973 /*\r
974 * Before we check for a public-key blob, trim newlines out of\r
975 * the middle of the word, in case someone's managed to paste\r
976 * in a public-key blob _with_ them.\r
977 */\r
978 for (r = s = q; *r; r++)\r
979 if (*r != '\n' && *r != '\r')\r
980 *s++ = *r;\r
981 *s = '\0';\r
982 \r
983 if (strlen(q) % 4 == 0 && strlen(q) > 2*4 &&\r
984 q[strspn(q, "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"\r
985 "abcdefghijklmnopqrstuvwxyz+/=")] == 0) {\r
986 /*\r
987 * Might be a base64-encoded SSH-2 public key blob. Check\r
988 * that it starts with a sensible algorithm string. No\r
989 * canonicalisation is necessary for this string type.\r
990 *\r
991 * The algorithm string must be at most 64 characters long\r
992 * (RFC 4251 section 6).\r
993 */\r
994 unsigned char decoded[6];\r
995 unsigned alglen;\r
996 int minlen;\r
997 int len = 0;\r
998 \r
999 len += base64_decode_atom(q, decoded+len);\r
1000 if (len < 3)\r
1001 goto not_ssh2_blob; /* sorry */\r
1002 len += base64_decode_atom(q+4, decoded+len);\r
1003 if (len < 4)\r
1004 goto not_ssh2_blob; /* sorry */\r
1005 \r
1006 alglen = GET_32BIT_MSB_FIRST(decoded);\r
1007 if (alglen > 64)\r
1008 goto not_ssh2_blob; /* sorry */\r
1009 \r
1010 minlen = ((alglen + 4) + 2) / 3;\r
1011 if (strlen(q) < minlen)\r
1012 goto not_ssh2_blob; /* sorry */\r
1013 \r
1014 strcpy(key, q);\r
1015 return TRUE;\r
1016 }\r
1017 not_ssh2_blob:;\r
1018 }\r
1019 \r
1020 return FALSE;\r
1021 }\r
1022 \r
1023 int smemeq(const void *av, const void *bv, size_t len)\r
1024 {\r
1025 const unsigned char *a = (const unsigned char *)av;\r
1026 const unsigned char *b = (const unsigned char *)bv;\r
1027 unsigned val = 0;\r
1028 \r
1029 while (len-- > 0) {\r
1030 val |= *a++ ^ *b++;\r
1031 }\r
1032 /* Now val is 0 iff we want to return 1, and in the range\r
1033 * 0x01..0xFF iff we want to return 0. So subtracting from 0x100\r
1034 * will clear bit 8 iff we want to return 0, and leave it set iff\r
1035 * we want to return 1, so then we can just shift down. */\r
1036 return (0x100 - val) >> 8;\r
1037 }\r
1038 \r
1039 int strstartswith(const char *s, const char *t)\r
1040 {\r
1041 return !memcmp(s, t, strlen(t));\r
1042 }\r
1043 \r
1044 int strendswith(const char *s, const char *t)\r
1045 {\r
1046 size_t slen = strlen(s), tlen = strlen(t);\r
1047 return slen >= tlen && !strcmp(s + (slen - tlen), t);\r
1048 }\r