libidn 1.43

stringprep.c
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1/* stringprep.c --- Core stringprep implementation.
2 Copyright (C) 2002-2025 Simon Josefsson
3
4 This file is part of GNU Libidn.
5
6 GNU Libidn is free software: you can redistribute it and/or
7 modify it under the terms of either:
8
9 * the GNU Lesser General Public License as published by the Free
10 Software Foundation; either version 3 of the License, or (at
11 your option) any later version.
12
13 or
14
15 * the GNU General Public License as published by the Free
16 Software Foundation; either version 2 of the License, or (at
17 your option) any later version.
18
19 or both in parallel, as here.
20
21 GNU Libidn is distributed in the hope that it will be useful,
22 but WITHOUT ANY WARRANTY; without even the implied warranty of
23 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
24 General Public License for more details.
25
26 You should have received copies of the GNU General Public License and
27 the GNU Lesser General Public License along with this program. If
28 not, see <https://www.gnu.org/licenses/>. */
29
30#ifdef HAVE_CONFIG_H
31# include "config.h"
32#endif
33
34#include <stdlib.h>
35#include <string.h>
36
37#include "stringprep.h"
38
39 static int
40_compare_table_element (const uint32_t *c, const Stringprep_table_element *e)
41{
42 if (*c < e->start)
43 return -1;
44 if (*c > e->end)
45 return 1;
46 return 0;
47}
48
49 static ssize_t
50stringprep_find_character_in_table (uint32_t ucs4,
51 const Stringprep_table_element *table,
52 size_t table_size)
53{
54 /* This is where typical uses of Libidn spends very close to all CPU
55 time and causes most cache misses. One could easily do a binary
56 search instead. Before rewriting this, I want hard evidence this
57 slowness is at all relevant in typical applications. (I don't
58 dispute optimization may improve matters significantly, I'm
59 mostly interested in having someone give real-world benchmark on
60 the impact of libidn.)
61 *
62 * Answer (Tim Rühsen rockdaboot@gmx.de):
63 * Testing the fuzz corpora just once via make check takes ~54 billion CPU cycles.
64 * That is almost 20s on my Intel i3 3.1GHz !!!
65 * That even makes fuzzing almost useless, eating up CPU cycles for nothing.
66 *
67 * The bsearch() approach takes ~3 billion CPU cycles.
68 * Almost a factor of 20 faster (but still pretty slow).
69 * There are still ~2 million calls to bsearch() which make ~30% of CPU time used.
70 * Most time is spent in _g_utf8_normalize_wc().
71
72 ssize_t i;
73
74 for (i = 0; table[i].start || table[i].end; i++)
75 if (ucs4 >= table[i].start &&
76 ucs4 <= (table[i].end ? table[i].end : table[i].start))
77 return i;
78 */
79
80 const Stringprep_table_element *p =
81 bsearch (&ucs4, table, table_size, sizeof (Stringprep_table_element),
82 (int (*)(const void *, const void *)) _compare_table_element);
83
84 return p ? (p - table) : -1;
85}
86
87 static ssize_t
88stringprep_find_string_in_table (uint32_t *ucs4,
89 size_t ucs4len,
90 size_t *tablepos,
91 const Stringprep_table_element *table,
92 size_t table_size)
93{
94 size_t j;
95 ssize_t pos;
96
97 for (j = 0; j < ucs4len; j++)
98 if ((pos =
99 stringprep_find_character_in_table (ucs4[j], table,
100 table_size)) != -1)
101 {
102 if (tablepos)
103 *tablepos = pos;
104 return j;
105 }
106
107 return -1;
108}
109
110 static int
111stringprep_apply_table_to_string (uint32_t *ucs4,
112 size_t *ucs4len,
113 size_t maxucs4len,
114 const Stringprep_table_element *table,
115 size_t table_size)
116{
117 ssize_t pos;
118 size_t i, maplen;
119 uint32_t *src = ucs4; /* points to unprocessed data */
120 size_t srclen = *ucs4len; /* length of unprocessed data */
121
122 while ((pos = stringprep_find_string_in_table (src, srclen,
123 &i, table,
124 table_size)) != -1)
125 {
126 for (maplen = STRINGPREP_MAX_MAP_CHARS;
127 maplen > 0 && table[i].map[maplen - 1] == 0; maplen--)
128 ;
129
130 if (*ucs4len - 1 + maplen >= maxucs4len)
131 return STRINGPREP_TOO_SMALL_BUFFER;
132
133 memmove (src + pos + maplen, src + pos + 1,
134 sizeof (uint32_t) * (srclen - pos - 1));
135 memcpy (src + pos, table[i].map, sizeof (uint32_t) * maplen);
136 *ucs4len = *ucs4len - 1 + maplen;
137 src += pos + maplen;
138 srclen -= pos + 1;
139 }
140
141 return STRINGPREP_OK;
142}
143
144#define INVERTED(x) ((x) & ((~0UL) >> 1))
145#define UNAPPLICAPLEFLAGS(flags, profileflags) \
146 ((!INVERTED(profileflags) && !(profileflags & flags) && profileflags) || \
147 ( INVERTED(profileflags) && (profileflags & flags)))
148
180 int
181 stringprep_4i (uint32_t *ucs4, size_t *len, size_t maxucs4len,
182 Stringprep_profile_flags flags,
183 const Stringprep_profile *profile)
184{
185 size_t i, j;
186 ssize_t k;
187 size_t ucs4len = *len;
188 int rc;
189
190 for (i = 0; profile[i].operation; i++)
191 {
192 switch (profile[i].operation)
193 {
194 case STRINGPREP_NFKC:
195 {
196 uint32_t *q = 0;
197
198 if (UNAPPLICAPLEFLAGS (flags, profile[i].flags))
199 break;
200
201 if (flags & STRINGPREP_NO_NFKC && !profile[i].flags)
202 /* Profile requires NFKC, but callee asked for no NFKC. */
203 return STRINGPREP_FLAG_ERROR;
204
205 q = stringprep_ucs4_nfkc_normalize (ucs4, ucs4len);
206 if (!q)
207 return STRINGPREP_NFKC_FAILED;
208
209 for (ucs4len = 0; q[ucs4len]; ucs4len++)
210 ;
211
212 if (ucs4len >= maxucs4len)
213 {
214 free (q);
215 return STRINGPREP_TOO_SMALL_BUFFER;
216 }
217
218 memcpy (ucs4, q, ucs4len * sizeof (ucs4[0]));
219
220 free (q);
221 }
222 break;
223
224 case STRINGPREP_PROHIBIT_TABLE:
225 k = stringprep_find_string_in_table (ucs4, ucs4len,
226 NULL, profile[i].table,
227 profile[i].table_size);
228 if (k != -1)
229 return STRINGPREP_CONTAINS_PROHIBITED;
230 break;
231
232 case STRINGPREP_UNASSIGNED_TABLE:
233 if (UNAPPLICAPLEFLAGS (flags, profile[i].flags))
234 break;
235 if (flags & STRINGPREP_NO_UNASSIGNED)
236 {
237 k = stringprep_find_string_in_table
238 (ucs4, ucs4len, NULL, profile[i].table,
239 profile[i].table_size);
240 if (k != -1)
241 return STRINGPREP_CONTAINS_UNASSIGNED;
242 }
243 break;
244
245 case STRINGPREP_MAP_TABLE:
246 if (UNAPPLICAPLEFLAGS (flags, profile[i].flags))
247 break;
248 rc = stringprep_apply_table_to_string
249 (ucs4, &ucs4len, maxucs4len, profile[i].table,
250 profile[i].table_size);
251 if (rc != STRINGPREP_OK)
252 return rc;
253 break;
254
255 case STRINGPREP_BIDI_PROHIBIT_TABLE:
256 case STRINGPREP_BIDI_RAL_TABLE:
257 case STRINGPREP_BIDI_L_TABLE:
258 break;
259
260 case STRINGPREP_BIDI:
261 {
262 int done_prohibited = 0;
263 int done_ral = 0;
264 int done_l = 0;
265 size_t contains_ral = SIZE_MAX;
266 size_t contains_l = SIZE_MAX;
267
268 for (j = 0; profile[j].operation; j++)
269 if (profile[j].operation == STRINGPREP_BIDI_PROHIBIT_TABLE)
270 {
271 done_prohibited = 1;
272 k = stringprep_find_string_in_table (ucs4, ucs4len,
273 NULL,
274 profile[j].table,
275 profile[j].table_size);
276 if (k != -1)
277 return STRINGPREP_BIDI_CONTAINS_PROHIBITED;
278 }
279 else if (profile[j].operation == STRINGPREP_BIDI_RAL_TABLE)
280 {
281 done_ral = 1;
282 if (stringprep_find_string_in_table
283 (ucs4, ucs4len, NULL, profile[j].table,
284 profile[j].table_size) != -1)
285 contains_ral = j;
286 }
287 else if (profile[j].operation == STRINGPREP_BIDI_L_TABLE)
288 {
289 done_l = 1;
290 if (stringprep_find_string_in_table
291 (ucs4, ucs4len, NULL, profile[j].table,
292 profile[j].table_size) != -1)
293 contains_l = j;
294 }
295
296 if (!done_prohibited || !done_ral || !done_l)
297 return STRINGPREP_PROFILE_ERROR;
298
299 if (contains_ral != SIZE_MAX && contains_l != SIZE_MAX)
300 return STRINGPREP_BIDI_BOTH_L_AND_RAL;
301
302 if (contains_ral != SIZE_MAX)
303 {
304 if (!(stringprep_find_character_in_table
305 (ucs4[0], profile[contains_ral].table,
306 profile[contains_ral].table_size) != -1
307 &&
308 stringprep_find_character_in_table (ucs4[ucs4len - 1],
309 profile
310 [contains_ral].table,
311 profile
312 [contains_ral].table_size)
313 != -1))
314 return STRINGPREP_BIDI_LEADTRAIL_NOT_RAL;
315 }
316 }
317 break;
318
319 default:
320 return STRINGPREP_PROFILE_ERROR;
321 break;
322 }
323 }
324
325 *len = ucs4len;
326
327 return STRINGPREP_OK;
328}
329
330 static int
331stringprep_4zi_1 (uint32_t *ucs4, size_t ucs4len, size_t maxucs4len,
332 Stringprep_profile_flags flags,
333 const Stringprep_profile *profile)
334{
335 int rc;
336
337 rc = stringprep_4i (ucs4, &ucs4len, maxucs4len, flags, profile);
338 if (rc != STRINGPREP_OK)
339 return rc;
340
341 if (ucs4len >= maxucs4len)
342 return STRINGPREP_TOO_SMALL_BUFFER;
343
344 ucs4[ucs4len] = 0;
345
346 return STRINGPREP_OK;
347}
348
373 int
374 stringprep_4zi (uint32_t *ucs4, size_t maxucs4len,
375 Stringprep_profile_flags flags,
376 const Stringprep_profile *profile)
377{
378 size_t ucs4len;
379
380 for (ucs4len = 0; ucs4len < maxucs4len && ucs4[ucs4len] != 0; ucs4len++)
381 ;
382
383 return stringprep_4zi_1 (ucs4, ucs4len, maxucs4len, flags, profile);
384}
385
413 int
414 stringprep (char *in,
415 size_t maxlen,
416 Stringprep_profile_flags flags, const Stringprep_profile *profile)
417{
418 int rc;
419 char *utf8 = NULL;
420 uint32_t *ucs4 = NULL;
421 size_t ucs4len, maxucs4len, adducs4len = strlen (in) / 10 + 1;
422
423 do
424 {
425 uint32_t *newp;
426
427 free (ucs4);
428 ucs4 = stringprep_utf8_to_ucs4 (in, -1, &ucs4len);
429 if (ucs4 == NULL)
430 return STRINGPREP_ICONV_ERROR;
431 maxucs4len = ucs4len + adducs4len;
432 newp = realloc (ucs4, maxucs4len * sizeof (uint32_t));
433 if (!newp)
434 {
435 free (ucs4);
436 return STRINGPREP_MALLOC_ERROR;
437 }
438 ucs4 = newp;
439
440 rc = stringprep_4i (ucs4, &ucs4len, maxucs4len, flags, profile);
441 adducs4len *= 2;
442 }
443 while (rc == STRINGPREP_TOO_SMALL_BUFFER);
444 if (rc != STRINGPREP_OK)
445 {
446 free (ucs4);
447 return rc;
448 }
449
450 utf8 = stringprep_ucs4_to_utf8 (ucs4, ucs4len, 0, 0);
451 free (ucs4);
452 if (!utf8)
453 return STRINGPREP_ICONV_ERROR;
454
455 if (strlen (utf8) >= maxlen)
456 {
457 free (utf8);
458 return STRINGPREP_TOO_SMALL_BUFFER;
459 }
460
461 strcpy (in, utf8); /* flawfinder: ignore */
462
463 free (utf8);
464
465 return STRINGPREP_OK;
466}
467
492 int
493 stringprep_profile (const char *in,
494 char **out,
495 const char *profile, Stringprep_profile_flags flags)
496{
497 const Stringprep_profiles *p;
498 char *str = NULL;
499 size_t len = strlen (in) + 1, addlen = len / 10 + 1;
500 int rc;
501
502 for (p = &stringprep_profiles[0]; p->name; p++)
503 if (strcmp (p->name, profile) == 0)
504 break;
505
506 if (!p || !p->name || !p->tables)
507 return STRINGPREP_UNKNOWN_PROFILE;
508
509 do
510 {
511 free (str);
512 str = (char *) malloc (len);
513 if (str == NULL)
514 return STRINGPREP_MALLOC_ERROR;
515
516 strcpy (str, in);
517
518 rc = stringprep (str, len, flags, p->tables);
519 len += addlen;
520 addlen *= 2;
521 }
522 while (rc == STRINGPREP_TOO_SMALL_BUFFER);
523
524 if (rc == STRINGPREP_OK)
525 *out = str;
526 else
527 free (str);
528
529 return rc;
530}
531
stringprep_ucs4_to_utf8
char * stringprep_ucs4_to_utf8(const uint32_t *str, ssize_t len, size_t *items_read, size_t *items_written)
Definition nfkc.c:1019
stringprep_ucs4_nfkc_normalize
uint32_t * stringprep_ucs4_nfkc_normalize(const uint32_t *str, ssize_t len)
Definition nfkc.c:1076
stringprep_utf8_to_ucs4
uint32_t * stringprep_utf8_to_ucs4(const char *str, ssize_t len, size_t *items_written)
Definition nfkc.c:986
stringprep_profiles
const Stringprep_profiles stringprep_profiles[]
Definition profiles.c:34
stringprep_4zi
int stringprep_4zi(uint32_t *ucs4, size_t maxucs4len, Stringprep_profile_flags flags, const Stringprep_profile *profile)
Definition stringprep.c:374
stringprep_4i
int stringprep_4i(uint32_t *ucs4, size_t *len, size_t maxucs4len, Stringprep_profile_flags flags, const Stringprep_profile *profile)
Definition stringprep.c:181
stringprep_profile
int stringprep_profile(const char *in, char **out, const char *profile, Stringprep_profile_flags flags)
Definition stringprep.c:493
UNAPPLICAPLEFLAGS
#define UNAPPLICAPLEFLAGS(flags, profileflags)
Definition stringprep.c:145
stringprep
int stringprep(char *in, size_t maxlen, Stringprep_profile_flags flags, const Stringprep_profile *profile)
Definition stringprep.c:414
stringprep.h
STRINGPREP_BIDI_PROHIBIT_TABLE
@ STRINGPREP_BIDI_PROHIBIT_TABLE
Definition stringprep.h:101
STRINGPREP_BIDI_RAL_TABLE
@ STRINGPREP_BIDI_RAL_TABLE
Definition stringprep.h:102
STRINGPREP_NFKC
@ STRINGPREP_NFKC
Definition stringprep.h:96
STRINGPREP_PROHIBIT_TABLE
@ STRINGPREP_PROHIBIT_TABLE
Definition stringprep.h:100
STRINGPREP_UNASSIGNED_TABLE
@ STRINGPREP_UNASSIGNED_TABLE
Definition stringprep.h:99
STRINGPREP_BIDI
@ STRINGPREP_BIDI
Definition stringprep.h:97
STRINGPREP_MAP_TABLE
@ STRINGPREP_MAP_TABLE
Definition stringprep.h:98
STRINGPREP_BIDI_L_TABLE
@ STRINGPREP_BIDI_L_TABLE
Definition stringprep.h:103
Stringprep_profile_flags
Stringprep_profile_flags
Definition stringprep.h:87
STRINGPREP_NO_NFKC
@ STRINGPREP_NO_NFKC
Definition stringprep.h:88
STRINGPREP_NO_UNASSIGNED
@ STRINGPREP_NO_UNASSIGNED
Definition stringprep.h:90
STRINGPREP_UNKNOWN_PROFILE
@ STRINGPREP_UNKNOWN_PROFILE
Definition stringprep.h:78
STRINGPREP_NFKC_FAILED
@ STRINGPREP_NFKC_FAILED
Definition stringprep.h:81
STRINGPREP_TOO_SMALL_BUFFER
@ STRINGPREP_TOO_SMALL_BUFFER
Definition stringprep.h:75
STRINGPREP_ICONV_ERROR
@ STRINGPREP_ICONV_ERROR
Definition stringprep.h:79
STRINGPREP_MALLOC_ERROR
@ STRINGPREP_MALLOC_ERROR
Definition stringprep.h:82
STRINGPREP_FLAG_ERROR
@ STRINGPREP_FLAG_ERROR
Definition stringprep.h:77
STRINGPREP_OK
@ STRINGPREP_OK
Definition stringprep.h:67
STRINGPREP_CONTAINS_UNASSIGNED
@ STRINGPREP_CONTAINS_UNASSIGNED
Definition stringprep.h:69
STRINGPREP_CONTAINS_PROHIBITED
@ STRINGPREP_CONTAINS_PROHIBITED
Definition stringprep.h:70
STRINGPREP_BIDI_CONTAINS_PROHIBITED
@ STRINGPREP_BIDI_CONTAINS_PROHIBITED
Definition stringprep.h:73
STRINGPREP_BIDI_BOTH_L_AND_RAL
@ STRINGPREP_BIDI_BOTH_L_AND_RAL
Definition stringprep.h:71
STRINGPREP_BIDI_LEADTRAIL_NOT_RAL
@ STRINGPREP_BIDI_LEADTRAIL_NOT_RAL
Definition stringprep.h:72
STRINGPREP_PROFILE_ERROR
@ STRINGPREP_PROFILE_ERROR
Definition stringprep.h:76
STRINGPREP_MAX_MAP_CHARS
#define STRINGPREP_MAX_MAP_CHARS
Definition stringprep.h:106
Stringprep_profiles
Definition stringprep.h:170
Stringprep_profiles::name
const char * name
Definition stringprep.h:171
Stringprep_profiles::tables
const Stringprep_profile * tables
Definition stringprep.h:172
Stringprep_table_element
Definition stringprep.h:132
Stringprep_table_element::end
uint32_t end
Definition stringprep.h:134
Stringprep_table_element::map
uint32_t map[STRINGPREP_MAX_MAP_CHARS]
Definition stringprep.h:135
Stringprep_table
Definition stringprep.h:149
Stringprep_table::operation
Stringprep_profile_steps operation
Definition stringprep.h:150