1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2  * All rights reserved.
3  *
4  * This package is an SSL implementation written
5  * by Eric Young (eay@cryptsoft.com).
6  * The implementation was written so as to conform with Netscapes SSL.
7  *
8  * This library is free for commercial and non-commercial use as long as
9  * the following conditions are aheared to.  The following conditions
10  * apply to all code found in this distribution, be it the RC4, RSA,
11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12  * included with this distribution is covered by the same copyright terms
13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14  *
15  * Copyright remains Eric Young's, and as such any Copyright notices in
16  * the code are not to be removed.
17  * If this package is used in a product, Eric Young should be given attribution
18  * as the author of the parts of the library used.
19  * This can be in the form of a textual message at program startup or
20  * in documentation (online or textual) provided with the package.
21  *
22  * Redistribution and use in source and binary forms, with or without
23  * modification, are permitted provided that the following conditions
24  * are met:
25  * 1. Redistributions of source code must retain the copyright
26  *    notice, this list of conditions and the following disclaimer.
27  * 2. Redistributions in binary form must reproduce the above copyright
28  *    notice, this list of conditions and the following disclaimer in the
29  *    documentation and/or other materials provided with the distribution.
30  * 3. All advertising materials mentioning features or use of this software
31  *    must display the following acknowledgement:
32  *    "This product includes cryptographic software written by
33  *     Eric Young (eay@cryptsoft.com)"
34  *    The word 'cryptographic' can be left out if the rouines from the library
35  *    being used are not cryptographic related :-).
36  * 4. If you include any Windows specific code (or a derivative thereof) from
37  *    the apps directory (application code) you must include an acknowledgement:
38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39  *
40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  *
52  * The licence and distribution terms for any publically available version or
53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
54  * copied and put under another distribution licence
55  * [including the GNU Public Licence.] */
56 
57 #ifndef OPENSSL_HEADER_STACK_H
58 #define OPENSSL_HEADER_STACK_H
59 
60 #include <openssl/base.h>
61 
62 #include <openssl/type_check.h>
63 
64 #if defined(__cplusplus)
65 extern "C" {
66 #endif
67 
68 
69 /* A stack, in OpenSSL, is an array of pointers. They are the most commonly
70  * used collection object.
71  *
72  * This file defines macros for type safe use of the stack functions. A stack
73  * of a specific type of object has type |STACK_OF(type)|. This can be defined
74  * (once) with |DEFINE_STACK_OF(type)| and declared where needed with
75  * |DECLARE_STACK_OF(type)|. For example:
76  *
77  *   struct foo {
78  *     int bar;
79  *   };
80  *
81  *   DEFINE_STACK_OF(struct foo);
82  *
83  * Although note that the stack will contain /pointers/ to |foo|.
84  *
85  * A macro will be defined for each of the sk_* functions below. For
86  * STACK_OF(foo), the macros would be sk_foo_new, sk_foo_pop etc. */
87 
88 
89 /* stack_cmp_func is a comparison function that returns a value < 0, 0 or > 0
90  * if |*a| is less than, equal to or greater than |*b|, respectively.  Note the
91  * extra indirection - the function is given a pointer to a pointer to the
92  * element. This differs from the usual qsort/bsearch comparison function. */
93 typedef int (*stack_cmp_func)(const void **a, const void **b);
94 
95 /* stack_st contains an array of pointers. It is not designed to be used
96  * directly, rather the wrapper macros should be used. */
97 typedef struct stack_st {
98   /* num contains the number of valid pointers in |data|. */
99   size_t num;
100   void **data;
101   /* sorted is non-zero if the values pointed to by |data| are in ascending
102    * order, based on |comp|. */
103   size_t sorted;
104   /* num_alloc contains the number of pointers allocated in the buffer pointed
105    * to by |data|, which may be larger than |num|. */
106   size_t num_alloc;
107   /* comp is an optional comparison function. */
108   stack_cmp_func comp;
109 } _STACK;
110 
111 
112 #define STACK_OF(type) struct stack_st_##type
113 
114 #define DECLARE_STACK_OF(type) STACK_OF(type);
115 
116 /* The make_macros.sh script in this directory parses the following lines and
117  * generates the stack_macros.h file that contains macros for the following
118  * types of stacks:
119  *
120  * STACK_OF:ACCESS_DESCRIPTION
121  * STACK_OF:ASN1_ADB_TABLE
122  * STACK_OF:ASN1_GENERALSTRING
123  * STACK_OF:ASN1_INTEGER
124  * STACK_OF:ASN1_OBJECT
125  * STACK_OF:ASN1_STRING_TABLE
126  * STACK_OF:ASN1_TYPE
127  * STACK_OF:ASN1_VALUE
128  * STACK_OF:BIO
129  * STACK_OF:BY_DIR_ENTRY
130  * STACK_OF:BY_DIR_HASH
131  * STACK_OF:CONF_VALUE
132  * STACK_OF:CRYPTO_EX_DATA_FUNCS
133  * STACK_OF:DIST_POINT
134  * STACK_OF:GENERAL_NAME
135  * STACK_OF:GENERAL_NAMES
136  * STACK_OF:GENERAL_SUBTREE
137  * STACK_OF:POLICYINFO
138  * STACK_OF:POLICYQUALINFO
139  * STACK_OF:POLICY_MAPPING
140  * STACK_OF:RSA_additional_prime
141  * STACK_OF:SSL_COMP
142  * STACK_OF:SSL_CUSTOM_EXTENSION
143  * STACK_OF:STACK_OF_X509_NAME_ENTRY
144  * STACK_OF:SXNETID
145  * STACK_OF:X509
146  * STACK_OF:X509V3_EXT_METHOD
147  * STACK_OF:X509_ALGOR
148  * STACK_OF:X509_ATTRIBUTE
149  * STACK_OF:X509_CRL
150  * STACK_OF:X509_EXTENSION
151  * STACK_OF:X509_INFO
152  * STACK_OF:X509_LOOKUP
153  * STACK_OF:X509_NAME
154  * STACK_OF:X509_NAME_ENTRY
155  * STACK_OF:X509_OBJECT
156  * STACK_OF:X509_POLICY_DATA
157  * STACK_OF:X509_POLICY_NODE
158  * STACK_OF:X509_PURPOSE
159  * STACK_OF:X509_REVOKED
160  * STACK_OF:X509_TRUST
161  * STACK_OF:X509_VERIFY_PARAM
162  * STACK_OF:void
163  *
164  * Some stacks contain only const structures, so the stack should return const
165  * pointers to retain type-checking.
166  *
167  * CONST_STACK_OF:SRTP_PROTECTION_PROFILE
168  * CONST_STACK_OF:SSL_CIPHER */
169 
170 
171 /* Some stacks are special because, although we would like STACK_OF(char *),
172  * that would actually be a stack of pointers to char*, but we just want to
173  * point to the string directly. In this case we call them "special" and use
174  * |DEFINE_SPECIAL_STACK_OF(type)| */
175 #define DEFINE_SPECIAL_STACK_OF(type, inner)             \
176   STACK_OF(type) { _STACK special_stack; };              \
177   OPENSSL_COMPILE_ASSERT(sizeof(type) == sizeof(void *), \
178                          special_stack_of_non_pointer_##type);
179 
180 typedef char *OPENSSL_STRING;
181 
182 DEFINE_SPECIAL_STACK_OF(OPENSSL_STRING, char)
183 DEFINE_SPECIAL_STACK_OF(OPENSSL_BLOCK, uint8_t)
184 
185 /* The make_macros.sh script in this directory parses the following lines and
186  * generates the stack_macros.h file that contains macros for the following
187  * types of stacks:
188  *
189  * SPECIAL_STACK_OF:OPENSSL_STRING
190  * SPECIAL_STACK_OF:OPENSSL_BLOCK */
191 
192 #define IN_STACK_H
193 #include <openssl/stack_macros.h>
194 #undef IN_STACK_H
195 
196 
197 /* These are the raw stack functions, you shouldn't be using them. Rather you
198  * should be using the type stack macros implemented above. */
199 
200 /* sk_new creates a new, empty stack with the given comparison function, which
201  * may be zero. It returns the new stack or NULL on allocation failure. */
202 OPENSSL_EXPORT _STACK *sk_new(stack_cmp_func comp);
203 
204 /* sk_new_null creates a new, empty stack. It returns the new stack or NULL on
205  * allocation failure. */
206 OPENSSL_EXPORT _STACK *sk_new_null(void);
207 
208 /* sk_num returns the number of elements in |s|. */
209 OPENSSL_EXPORT size_t sk_num(const _STACK *sk);
210 
211 /* sk_zero resets |sk| to the empty state but does nothing to free the
212  * individual elements themselves. */
213 OPENSSL_EXPORT void sk_zero(_STACK *sk);
214 
215 /* sk_value returns the |i|th pointer in |sk|, or NULL if |i| is out of
216  * range. */
217 OPENSSL_EXPORT void *sk_value(const _STACK *sk, size_t i);
218 
219 /* sk_set sets the |i|th pointer in |sk| to |p| and returns |p|. If |i| is out
220  * of range, it returns NULL. */
221 OPENSSL_EXPORT void *sk_set(_STACK *sk, size_t i, void *p);
222 
223 /* sk_free frees the given stack and array of pointers, but does nothing to
224  * free the individual elements. Also see |sk_pop_free|. */
225 OPENSSL_EXPORT void sk_free(_STACK *sk);
226 
227 /* sk_pop_free calls |free_func| on each element in the stack and then frees
228  * the stack itself. */
229 OPENSSL_EXPORT void sk_pop_free(_STACK *sk, void (*free_func)(void *));
230 
231 /* sk_insert inserts |p| into the stack at index |where|, moving existing
232  * elements if needed. It returns the length of the new stack, or zero on
233  * error. */
234 OPENSSL_EXPORT size_t sk_insert(_STACK *sk, void *p, size_t where);
235 
236 /* sk_delete removes the pointer at index |where|, moving other elements down
237  * if needed. It returns the removed pointer, or NULL if |where| is out of
238  * range. */
239 OPENSSL_EXPORT void *sk_delete(_STACK *sk, size_t where);
240 
241 /* sk_delete_ptr removes, at most, one instance of |p| from the stack based on
242  * pointer equality. If an instance of |p| is found then |p| is returned,
243  * otherwise it returns NULL. */
244 OPENSSL_EXPORT void *sk_delete_ptr(_STACK *sk, void *p);
245 
246 /* sk_find returns the first value in the stack equal to |p|. If a comparison
247  * function has been set on the stack, then equality is defined by it and the
248  * stack will be sorted if need be so that a binary search can be used.
249  * Otherwise pointer equality is used. If a matching element is found, its
250  * index is written to |*out_index| (if |out_index| is not NULL) and one is
251  * returned. Otherwise zero is returned. */
252 OPENSSL_EXPORT int sk_find(_STACK *sk, size_t *out_index, void *p);
253 
254 /* sk_shift removes and returns the first element in the stack, or returns NULL
255  * if the stack is empty. */
256 OPENSSL_EXPORT void *sk_shift(_STACK *sk);
257 
258 /* sk_push appends |p| to the stack and returns the length of the new stack, or
259  * 0 on allocation failure. */
260 OPENSSL_EXPORT size_t sk_push(_STACK *sk, void *p);
261 
262 /* sk_pop returns and removes the last element on the stack, or NULL if the
263  * stack is empty. */
264 OPENSSL_EXPORT void *sk_pop(_STACK *sk);
265 
266 /* sk_dup performs a shallow copy of a stack and returns the new stack, or NULL
267  * on error. */
268 OPENSSL_EXPORT _STACK *sk_dup(const _STACK *sk);
269 
270 /* sk_sort sorts the elements of |sk| into ascending order based on the
271  * comparison function. The stack maintains a |sorted| flag and sorting an
272  * already sorted stack is a no-op. */
273 OPENSSL_EXPORT void sk_sort(_STACK *sk);
274 
275 /* sk_is_sorted returns one if |sk| is known to be sorted and zero
276  * otherwise. */
277 OPENSSL_EXPORT int sk_is_sorted(const _STACK *sk);
278 
279 /* sk_set_cmp_func sets the comparison function to be used by |sk| and returns
280  * the previous one. */
281 OPENSSL_EXPORT stack_cmp_func sk_set_cmp_func(_STACK *sk, stack_cmp_func comp);
282 
283 /* sk_deep_copy performs a copy of |sk| and of each of the non-NULL elements in
284  * |sk| by using |copy_func|. If an error occurs, |free_func| is used to free
285  * any copies already made and NULL is returned. */
286 OPENSSL_EXPORT _STACK *sk_deep_copy(const _STACK *sk,
287                                     void *(*copy_func)(void *),
288                                     void (*free_func)(void *));
289 
290 
291 #if defined(__cplusplus)
292 }  /* extern C */
293 #endif
294 
295 #endif  /* OPENSSL_HEADER_STACK_H */
296