xref: /openbsd-src/lib/libcrypto/stack/stack.c (revision 3015a2d49e68b9c975657613656a400cac39c1c2)
1 /* $OpenBSD: stack.c,v 1.33 2025/01/03 08:04:16 tb Exp $ */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3  * All rights reserved.
4  *
5  * This package is an SSL implementation written
6  * by Eric Young (eay@cryptsoft.com).
7  * The implementation was written so as to conform with Netscapes SSL.
8  *
9  * This library is free for commercial and non-commercial use as long as
10  * the following conditions are aheared to.  The following conditions
11  * apply to all code found in this distribution, be it the RC4, RSA,
12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13  * included with this distribution is covered by the same copyright terms
14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15  *
16  * Copyright remains Eric Young's, and as such any Copyright notices in
17  * the code are not to be removed.
18  * If this package is used in a product, Eric Young should be given attribution
19  * as the author of the parts of the library used.
20  * This can be in the form of a textual message at program startup or
21  * in documentation (online or textual) provided with the package.
22  *
23  * Redistribution and use in source and binary forms, with or without
24  * modification, are permitted provided that the following conditions
25  * are met:
26  * 1. Redistributions of source code must retain the copyright
27  *    notice, this list of conditions and the following disclaimer.
28  * 2. Redistributions in binary form must reproduce the above copyright
29  *    notice, this list of conditions and the following disclaimer in the
30  *    documentation and/or other materials provided with the distribution.
31  * 3. All advertising materials mentioning features or use of this software
32  *    must display the following acknowledgement:
33  *    "This product includes cryptographic software written by
34  *     Eric Young (eay@cryptsoft.com)"
35  *    The word 'cryptographic' can be left out if the rouines from the library
36  *    being used are not cryptographic related :-).
37  * 4. If you include any Windows specific code (or a derivative thereof) from
38  *    the apps directory (application code) you must include an acknowledgement:
39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40  *
41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51  * SUCH DAMAGE.
52  *
53  * The licence and distribution terms for any publically available version or
54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
55  * copied and put under another distribution licence
56  * [including the GNU Public Licence.]
57  */
58 
59 #include <errno.h>
60 #include <stdio.h>
61 #include <string.h>
62 
63 #include <openssl/objects.h>
64 #include <openssl/stack.h>
65 
66 #include "stack_local.h"
67 
68 #undef MIN_NODES
69 #define MIN_NODES	4
70 
71 int
72 (*sk_set_cmp_func(_STACK *sk, int (*c)(const void *, const void *)))(
73     const void *, const void *)
74 {
75 	int (*old)(const void *, const void *) = sk->comp;
76 
77 	if (sk->comp != c)
78 		sk->sorted = 0;
79 	sk->comp = c;
80 
81 	return old;
82 }
83 LCRYPTO_ALIAS(sk_set_cmp_func);
84 
85 _STACK *
86 sk_dup(_STACK *sk)
87 {
88 	_STACK *ret;
89 	char **s;
90 
91 	if ((ret = sk_new(sk->comp)) == NULL)
92 		goto err;
93 	s = reallocarray(ret->data, sk->num_alloc, sizeof(char *));
94 	if (s == NULL)
95 		goto err;
96 	ret->data = s;
97 
98 	ret->num = sk->num;
99 	memcpy(ret->data, sk->data, sizeof(char *) * sk->num);
100 	ret->sorted = sk->sorted;
101 	ret->num_alloc = sk->num_alloc;
102 	ret->comp = sk->comp;
103 	return (ret);
104 
105 err:
106 	if (ret)
107 		sk_free(ret);
108 	return (NULL);
109 }
110 LCRYPTO_ALIAS(sk_dup);
111 
112 _STACK *
113 sk_new_null(void)
114 {
115 	return sk_new((int (*)(const void *, const void *))0);
116 }
117 LCRYPTO_ALIAS(sk_new_null);
118 
119 _STACK *
120 sk_new(int (*c)(const void *, const void *))
121 {
122 	_STACK *ret;
123 	int i;
124 
125 	if ((ret = malloc(sizeof(_STACK))) == NULL)
126 		goto err;
127 	if ((ret->data = reallocarray(NULL, MIN_NODES, sizeof(char *))) == NULL)
128 		goto err;
129 	for (i = 0; i < MIN_NODES; i++)
130 		ret->data[i] = NULL;
131 	ret->comp = c;
132 	ret->num_alloc = MIN_NODES;
133 	ret->num = 0;
134 	ret->sorted = 0;
135 	return (ret);
136 
137 err:
138 	free(ret);
139 	return (NULL);
140 }
141 LCRYPTO_ALIAS(sk_new);
142 
143 int
144 sk_insert(_STACK *st, void *data, int loc)
145 {
146 	char **s;
147 
148 	if (st == NULL)
149 		return 0;
150 	if (st->num_alloc <= st->num + 1) {
151 		s = reallocarray(st->data, st->num_alloc, 2 * sizeof(char *));
152 		if (s == NULL)
153 			return (0);
154 		st->data = s;
155 		st->num_alloc *= 2;
156 	}
157 	if ((loc >= (int)st->num) || (loc < 0))
158 		st->data[st->num] = data;
159 	else {
160 		memmove(&(st->data[loc + 1]), &(st->data[loc]),
161 		    sizeof(char *)*(st->num - loc));
162 		st->data[loc] = data;
163 	}
164 	st->num++;
165 	st->sorted = 0;
166 	return (st->num);
167 }
168 LCRYPTO_ALIAS(sk_insert);
169 
170 void *
171 sk_delete_ptr(_STACK *st, void *p)
172 {
173 	int i;
174 
175 	for (i = 0; i < st->num; i++)
176 		if (st->data[i] == p)
177 			return (sk_delete(st, i));
178 	return (NULL);
179 }
180 LCRYPTO_ALIAS(sk_delete_ptr);
181 
182 void *
183 sk_delete(_STACK *st, int loc)
184 {
185 	char *ret;
186 
187 	if (!st || (loc < 0) || (loc >= st->num))
188 		return NULL;
189 
190 	ret = st->data[loc];
191 	if (loc != st->num - 1) {
192 		memmove(&(st->data[loc]), &(st->data[loc + 1]),
193 		    sizeof(char *)*(st->num - 1 - loc));
194 	}
195 	st->num--;
196 	return (ret);
197 }
198 LCRYPTO_ALIAS(sk_delete);
199 
200 static const void *
201 obj_bsearch_ex(const void *key, const void *base_, int num, int size,
202     int (*cmp)(const void *, const void *))
203 {
204 	const char *base = base_;
205 	int l, h, i, c;
206 
207 	l = 0;
208 	h = num;
209 	while (l < h) {
210 		i = (l + h) / 2;
211 		if ((c = cmp(key,  &base[i * size])) == 0) {
212 			/* Return first match. */
213 			while (i > 0 && cmp(key, &base[(i - 1) * size]) == 0)
214 				i--;
215 			return &base[i * size];
216 		}
217 		if (c < 0)
218 			h = i;
219 		else
220 			l = i + 1;
221 	}
222 
223 	return NULL;
224 }
225 
226 int
227 sk_find(_STACK *st, void *data)
228 {
229 	const void * const *r;
230 	int i;
231 
232 	if (st == NULL)
233 		return -1;
234 
235 	if (st->comp == NULL) {
236 		for (i = 0; i < st->num; i++)
237 			if (st->data[i] == data)
238 				return (i);
239 		return (-1);
240 	}
241 	sk_sort(st);
242 	if (data == NULL)
243 		return (-1);
244 	r = obj_bsearch_ex(&data, st->data, st->num, sizeof(void *), st->comp);
245 	if (r == NULL)
246 		return (-1);
247 	return (int)((char **)r - st->data);
248 }
249 LCRYPTO_ALIAS(sk_find);
250 
251 int
252 sk_push(_STACK *st, void *data)
253 {
254 	return (sk_insert(st, data, st->num));
255 }
256 LCRYPTO_ALIAS(sk_push);
257 
258 int
259 sk_unshift(_STACK *st, void *data)
260 {
261 	return (sk_insert(st, data, 0));
262 }
263 LCRYPTO_ALIAS(sk_unshift);
264 
265 void *
266 sk_shift(_STACK *st)
267 {
268 	if (st == NULL)
269 		return (NULL);
270 	if (st->num <= 0)
271 		return (NULL);
272 	return (sk_delete(st, 0));
273 }
274 LCRYPTO_ALIAS(sk_shift);
275 
276 void *
277 sk_pop(_STACK *st)
278 {
279 	if (st == NULL)
280 		return (NULL);
281 	if (st->num <= 0)
282 		return (NULL);
283 	return (sk_delete(st, st->num - 1));
284 }
285 LCRYPTO_ALIAS(sk_pop);
286 
287 void
288 sk_zero(_STACK *st)
289 {
290 	if (st == NULL)
291 		return;
292 	if (st->num <= 0)
293 		return;
294 	memset(st->data, 0, sizeof(st->data)*st->num);
295 	st->num = 0;
296 }
297 LCRYPTO_ALIAS(sk_zero);
298 
299 void
300 sk_pop_free(_STACK *st, void (*func)(void *))
301 {
302 	int i;
303 
304 	if (st == NULL)
305 		return;
306 	for (i = 0; i < st->num; i++)
307 		if (st->data[i] != NULL)
308 			func(st->data[i]);
309 	sk_free(st);
310 }
311 LCRYPTO_ALIAS(sk_pop_free);
312 
313 void
314 sk_free(_STACK *st)
315 {
316 	if (st == NULL)
317 		return;
318 	free(st->data);
319 	free(st);
320 }
321 LCRYPTO_ALIAS(sk_free);
322 
323 int
324 sk_num(const _STACK *st)
325 {
326 	if (st == NULL)
327 		return -1;
328 	return st->num;
329 }
330 LCRYPTO_ALIAS(sk_num);
331 
332 void *
333 sk_value(const _STACK *st, int i)
334 {
335 	if (!st || (i < 0) || (i >= st->num))
336 		return NULL;
337 	return st->data[i];
338 }
339 LCRYPTO_ALIAS(sk_value);
340 
341 void *
342 sk_set(_STACK *st, int i, void *value)
343 {
344 	if (!st || (i < 0) || (i >= st->num))
345 		return NULL;
346 	st->sorted = 0;
347 	return (st->data[i] = value);
348 }
349 LCRYPTO_ALIAS(sk_set);
350 
351 void
352 sk_sort(_STACK *st)
353 {
354 	if (st && !st->sorted) {
355 		int (*comp_func)(const void *, const void *);
356 
357 		/* same comment as in sk_find ... previously st->comp was declared
358 		 * as a (void*,void*) callback type, but this made the population
359 		 * of the callback pointer illogical - our callbacks compare
360 		 * type** with type**, so we leave the casting until absolutely
361 		 * necessary (ie. "now"). */
362 		comp_func = (int (*)(const void *, const void *))(st->comp);
363 		qsort(st->data, st->num, sizeof(char *), comp_func);
364 		st->sorted = 1;
365 	}
366 }
367 LCRYPTO_ALIAS(sk_sort);
368 
369 int
370 sk_is_sorted(const _STACK *st)
371 {
372 	if (st == NULL)
373 		return 1;
374 
375 	if (st->sorted)
376 		return 1;
377 
378 	/* If there is no comparison function we cannot sort. */
379 	if (st->comp == NULL)
380 		return 0;
381 
382 	/* Lists with zero or one elements are always sorted. */
383 	return st->num <= 1;
384 }
385 LCRYPTO_ALIAS(sk_is_sorted);
386