5 DEFINE_STACK_OF, DEFINE_STACK_OF_CONST, DEFINE_SPECIAL_STACK_OF,
6 DEFINE_SPECIAL_STACK_OF_CONST,
7 sk_TYPE_num, sk_TYPE_value, sk_TYPE_new, sk_TYPE_new_null,
8 sk_TYPE_reserve, sk_TYPE_free, sk_TYPE_zero, sk_TYPE_delete,
9 sk_TYPE_delete_ptr, sk_TYPE_push, sk_TYPE_unshift, sk_TYPE_pop,
10 sk_TYPE_shift, sk_TYPE_pop_free, sk_TYPE_insert, sk_TYPE_set,
11 sk_TYPE_find, sk_TYPE_find_ex, sk_TYPE_find_all, sk_TYPE_sort,
12 sk_TYPE_is_sorted, sk_TYPE_dup, sk_TYPE_deep_copy, sk_TYPE_set_cmp_func,
14 OPENSSL_sk_deep_copy, OPENSSL_sk_delete, OPENSSL_sk_delete_ptr,
15 OPENSSL_sk_dup, OPENSSL_sk_find, OPENSSL_sk_find_ex, OPENSSL_sk_find_all,
16 OPENSSL_sk_free, OPENSSL_sk_insert, OPENSSL_sk_is_sorted, OPENSSL_sk_new,
17 OPENSSL_sk_new_null, OPENSSL_sk_new_reserve, OPENSSL_sk_num, OPENSSL_sk_pop,
18 OPENSSL_sk_pop_free, OPENSSL_sk_push, OPENSSL_sk_reserve, OPENSSL_sk_set,
19 OPENSSL_sk_set_cmp_func, OPENSSL_sk_shift, OPENSSL_sk_sort,
20 OPENSSL_sk_unshift, OPENSSL_sk_value, OPENSSL_sk_zero
27 #include <openssl/safestack.h>
31 DEFINE_STACK_OF_CONST(TYPE)
32 DEFINE_SPECIAL_STACK_OF(FUNCTYPE, TYPE)
33 DEFINE_SPECIAL_STACK_OF_CONST(FUNCTYPE, TYPE)
35 typedef int (*sk_TYPE_compfunc)(const TYPE *const *a, const TYPE *const *b);
36 typedef TYPE * (*sk_TYPE_copyfunc)(const TYPE *a);
37 typedef void (*sk_TYPE_freefunc)(TYPE *a);
39 int sk_TYPE_num(const STACK_OF(TYPE) *sk);
40 TYPE *sk_TYPE_value(const STACK_OF(TYPE) *sk, int idx);
41 STACK_OF(TYPE) *sk_TYPE_new(sk_TYPE_compfunc compare);
42 STACK_OF(TYPE) *sk_TYPE_new_null(void);
43 int sk_TYPE_reserve(STACK_OF(TYPE) *sk, int n);
44 void sk_TYPE_free(STACK_OF(TYPE) *sk);
45 void sk_TYPE_zero(STACK_OF(TYPE) *sk);
46 TYPE *sk_TYPE_delete(STACK_OF(TYPE) *sk, int i);
47 TYPE *sk_TYPE_delete_ptr(STACK_OF(TYPE) *sk, TYPE *ptr);
48 int sk_TYPE_push(STACK_OF(TYPE) *sk, const TYPE *ptr);
49 int sk_TYPE_unshift(STACK_OF(TYPE) *sk, const TYPE *ptr);
50 TYPE *sk_TYPE_pop(STACK_OF(TYPE) *sk);
51 TYPE *sk_TYPE_shift(STACK_OF(TYPE) *sk);
52 void sk_TYPE_pop_free(STACK_OF(TYPE) *sk, sk_TYPE_freefunc freefunc);
53 int sk_TYPE_insert(STACK_OF(TYPE) *sk, TYPE *ptr, int idx);
54 TYPE *sk_TYPE_set(STACK_OF(TYPE) *sk, int idx, const TYPE *ptr);
55 int sk_TYPE_find(STACK_OF(TYPE) *sk, TYPE *ptr);
56 int sk_TYPE_find_ex(STACK_OF(TYPE) *sk, TYPE *ptr);
57 int sk_TYPE_find_all(STACK_OF(TYPE) *sk, TYPE *ptr, int *pnum);
58 void sk_TYPE_sort(const STACK_OF(TYPE) *sk);
59 int sk_TYPE_is_sorted(const STACK_OF(TYPE) *sk);
60 STACK_OF(TYPE) *sk_TYPE_dup(const STACK_OF(TYPE) *sk);
61 STACK_OF(TYPE) *sk_TYPE_deep_copy(const STACK_OF(TYPE) *sk,
62 sk_TYPE_copyfunc copyfunc,
63 sk_TYPE_freefunc freefunc);
64 sk_TYPE_compfunc (*sk_TYPE_set_cmp_func(STACK_OF(TYPE) *sk,
65 sk_TYPE_compfunc compare));
66 STACK_OF(TYPE) *sk_TYPE_new_reserve(sk_TYPE_compfunc compare, int n);
70 Applications can create and use their own stacks by placing any of the macros
71 described below in a header file. These macros define typesafe inline
72 functions that wrap around the utility B<OPENSSL_sk_> API.
73 In the description here, B<I<TYPE>> is used
74 as a placeholder for any of the OpenSSL datatypes, such as B<X509>.
76 The STACK_OF() macro returns the name for a stack of the specified B<I<TYPE>>.
77 This is an opaque pointer to a structure declaration.
78 This can be used in every header file that references the stack.
79 There are several B<DEFINE...> macros that create static inline functions
80 for all of the functions described on this page.
81 This should normally be used in one source file, and the stack manipulation
82 is wrapped with application-specific functions.
84 DEFINE_STACK_OF() creates set of functions for a stack of B<I<TYPE>> elements.
85 The type is referenced by
86 B<STACK_OF>(B<I<TYPE>>) and each function name begins with B<sk_I<TYPE>_>.
87 DEFINE_STACK_OF_CONST() is identical to DEFINE_STACK_OF() except
88 each element is constant.
90 /* DEFINE_STACK_OF(TYPE) */
91 TYPE *sk_TYPE_value(STACK_OF(TYPE) *sk, int idx);
92 /* DEFINE_STACK_OF_CONST(TYPE) */
93 const TYPE *sk_TYPE_value(STACK_OF(TYPE) *sk, int idx);
95 DEFINE_SPECIAL_STACK_OF() and DEFINE_SPECIAL_STACK_OF_CONST() are similar
96 except B<FUNCNAME> is used in the function names:
98 /* DEFINE_SPECIAL_STACK_OF(TYPE, FUNCNAME) */
99 TYPE *sk_FUNCNAME_value(STACK_OF(TYPE) *sk, int idx);
100 /* DEFINE_SPECIAL_STACK_OF(TYPE, FUNCNAME) */
101 const TYPE *sk_FUNCNAME_value(STACK_OF(TYPE) *sk, int idx);
103 B<sk_I<TYPE>_num>() returns the number of elements in I<sk> or -1 if I<sk> is
106 B<sk_I<TYPE>_value>() returns element I<idx> in I<sk>, where I<idx> starts at
107 zero. If I<idx> is out of range then NULL is returned.
109 B<sk_I<TYPE>_new>() allocates a new empty stack using comparison function
110 I<compare>. If I<compare> is NULL then no comparison function is used. This
111 function is equivalent to B<sk_I<TYPE>_new_reserve>(I<compare>, 0).
113 B<sk_I<TYPE>_new_null>() allocates a new empty stack with no comparison
114 function. This function is equivalent to B<sk_I<TYPE>_new_reserve>(NULL, 0).
116 B<sk_I<TYPE>_reserve>() allocates additional memory in the I<sk> structure
117 such that the next I<n> calls to B<sk_I<TYPE>_insert>(), B<sk_I<TYPE>_push>()
118 or B<sk_I<TYPE>_unshift>() will not fail or cause memory to be allocated
119 or reallocated. If I<n> is zero, any excess space allocated in the
120 I<sk> structure is freed. On error I<sk> is unchanged.
122 B<sk_I<TYPE>_new_reserve>() allocates a new stack. The new stack will have
123 additional memory allocated to hold I<n> elements if I<n> is positive.
124 The next I<n> calls to B<sk_I<TYPE>_insert>(), B<sk_I<TYPE>_push>() or
125 B<sk_I<TYPE>_unshift>() will not fail or cause memory to be allocated or
126 reallocated. If I<n> is zero or less than zero, no memory is allocated.
127 B<sk_I<TYPE>_new_reserve>() also sets the comparison function I<compare>
128 to the newly created stack. If I<compare> is NULL then no comparison
131 B<sk_I<TYPE>_set_cmp_func>() sets the comparison function of I<sk> to
132 I<compare>. The previous comparison function is returned or NULL if there
133 was no previous comparison function.
135 B<sk_I<TYPE>_free>() frees up the I<sk> structure. It does I<not> free up any
136 elements of I<sk>. After this call I<sk> is no longer valid.
138 B<sk_I<TYPE>_zero>() sets the number of elements in I<sk> to zero. It does not
139 free I<sk> so after this call I<sk> is still valid.
141 B<sk_I<TYPE>_pop_free>() frees up all elements of I<sk> and I<sk> itself. The
142 free function freefunc() is called on each element to free it.
144 B<sk_I<TYPE>_delete>() deletes element I<i> from I<sk>. It returns the deleted
145 element or NULL if I<i> is out of range.
147 B<sk_I<TYPE>_delete_ptr>() deletes element matching I<ptr> from I<sk>. It
148 returns the deleted element or NULL if no element matching I<ptr> was found.
150 B<sk_I<TYPE>_insert>() inserts I<ptr> into I<sk> at position I<idx>. Any
151 existing elements at or after I<idx> are moved downwards. If I<idx> is out
152 of range the new element is appended to I<sk>. B<sk_I<TYPE>_insert>() either
153 returns the number of elements in I<sk> after the new element is inserted or
154 zero if an error (such as memory allocation failure) occurred.
156 B<sk_I<TYPE>_push>() appends I<ptr> to I<sk> it is equivalent to:
158 sk_TYPE_insert(sk, ptr, -1);
160 B<sk_I<TYPE>_unshift>() inserts I<ptr> at the start of I<sk> it is equivalent
163 sk_TYPE_insert(sk, ptr, 0);
165 B<sk_I<TYPE>_pop>() returns and removes the last element from I<sk>.
167 B<sk_I<TYPE>_shift>() returns and removes the first element from I<sk>.
169 B<sk_I<TYPE>_set>() sets element I<idx> of I<sk> to I<ptr> replacing the current
170 element. The new element value is returned or NULL if an error occurred:
171 this will only happen if I<sk> is NULL or I<idx> is out of range.
173 B<sk_I<TYPE>_find>() searches I<sk> for the element I<ptr>. In the case
174 where no comparison function has been specified, the function performs
175 a linear search for a pointer equal to I<ptr>. The index of the first
176 matching element is returned or B<-1> if there is no match. In the case
177 where a comparison function has been specified, I<sk> is sorted and
178 B<sk_I<TYPE>_find>() returns the index of a matching element or B<-1> if there
179 is no match. Note that, in this case the comparison function will usually
180 compare the values pointed to rather than the pointers themselves and
181 the order of elements in I<sk> can change.
183 B<sk_I<TYPE>_find_ex>() operates like B<sk_I<TYPE>_find>() except when a
184 comparison function has been specified and no matching element is found.
185 Instead of returning B<-1>, B<sk_I<TYPE>_find_ex>() returns the index of the
186 element either before or after the location where I<ptr> would be if it were
187 present in I<sk>. The function also does not guarantee that the first matching
188 element in the sorted stack is returned.
190 B<sk_I<TYPE>_find_all>() operates like B<sk_I<TYPE>_find>() but it also
191 sets the I<*pnum> to number of matching elements in the stack. In case
192 no comparison function has been specified the I<*pnum> will be always set
193 to 1 if matching element was found, 0 otherwise.
195 B<sk_I<TYPE>_sort>() sorts I<sk> using the supplied comparison function.
197 B<sk_I<TYPE>_is_sorted>() returns B<1> if I<sk> is sorted and B<0> otherwise.
199 B<sk_I<TYPE>_dup>() returns a shallow copy of I<sk>
200 or an empty stack if the passed stack is NULL.
201 Note the pointers in the copy are identical to the original.
203 B<sk_I<TYPE>_deep_copy>() returns a new stack where each element has been
204 copied or an empty stack if the passed stack is NULL.
205 Copying is performed by the supplied copyfunc() and freeing by freefunc().
206 The function freefunc() is only called if an error occurs.
210 Care should be taken when accessing stacks in multi-threaded environments.
211 Any operation which increases the size of a stack such as B<sk_I<TYPE>_insert>()
212 or B<sk_I<TYPE>_push>() can "grow" the size of an internal array and cause race
213 conditions if the same stack is accessed in a different thread. Operations such
214 as B<sk_I<TYPE>_find>() and B<sk_I<TYPE>_sort>() can also reorder the stack.
216 Any comparison function supplied should use a metric suitable
217 for use in a binary search operation. That is it should return zero, a
218 positive or negative value if I<a> is equal to, greater than
219 or less than I<b> respectively.
221 Care should be taken when checking the return values of the functions
222 B<sk_I<TYPE>_find>() and B<sk_I<TYPE>_find_ex>(). They return an index to the
223 matching element. In particular B<0> indicates a matching first element.
224 A failed search is indicated by a B<-1> return value.
226 STACK_OF(), DEFINE_STACK_OF(), DEFINE_STACK_OF_CONST(), and
227 DEFINE_SPECIAL_STACK_OF() are implemented as macros.
229 It is not an error to call B<sk_I<TYPE>_num>(), B<sk_I<TYPE>_value>(),
230 B<sk_I<TYPE>_free>(), B<sk_I<TYPE>_zero>(), B<sk_I<TYPE>_pop_free>(),
231 B<sk_I<TYPE>_delete>(), B<sk_I<TYPE>_delete_ptr>(), B<sk_I<TYPE>_pop>(),
232 B<sk_I<TYPE>_shift>(), B<sk_I<TYPE>_find>(), B<sk_I<TYPE>_find_ex>(),
233 and B<sk_I<TYPE>_find_all>() on a NULL stack, empty stack, or with
234 an invalid index. An error is not raised in these conditions.
236 The underlying utility B<OPENSSL_sk_> API should not be used directly.
237 It defines these functions: OPENSSL_sk_deep_copy(),
238 OPENSSL_sk_delete(), OPENSSL_sk_delete_ptr(), OPENSSL_sk_dup(),
239 OPENSSL_sk_find(), OPENSSL_sk_find_ex(), OPENSSL_sk_find_all(),
240 OPENSSL_sk_free(), OPENSSL_sk_insert(), OPENSSL_sk_is_sorted(),
241 OPENSSL_sk_new(), OPENSSL_sk_new_null(), OPENSSL_sk_new_reserve(),
242 OPENSSL_sk_num(), OPENSSL_sk_pop(), OPENSSL_sk_pop_free(), OPENSSL_sk_push(),
243 OPENSSL_sk_reserve(), OPENSSL_sk_set(), OPENSSL_sk_set_cmp_func(),
244 OPENSSL_sk_shift(), OPENSSL_sk_sort(), OPENSSL_sk_unshift(),
245 OPENSSL_sk_value(), OPENSSL_sk_zero().
249 B<sk_I<TYPE>_num>() returns the number of elements in the stack or B<-1> if the
250 passed stack is NULL.
252 B<sk_I<TYPE>_value>() returns a pointer to a stack element or NULL if the
253 index is out of range.
255 B<sk_I<TYPE>_new>(), B<sk_I<TYPE>_new_null>() and B<sk_I<TYPE>_new_reserve>()
256 return an empty stack or NULL if an error occurs.
258 B<sk_I<TYPE>_reserve>() returns B<1> on successful allocation of the required
259 memory or B<0> on error.
261 B<sk_I<TYPE>_set_cmp_func>() returns the old comparison function or NULL if
262 there was no old comparison function.
264 B<sk_I<TYPE>_free>(), B<sk_I<TYPE>_zero>(), B<sk_I<TYPE>_pop_free>() and
265 B<sk_I<TYPE>_sort>() do not return values.
267 B<sk_I<TYPE>_pop>(), B<sk_I<TYPE>_shift>(), B<sk_I<TYPE>_delete>() and
268 B<sk_I<TYPE>_delete_ptr>() return a pointer to the deleted element or NULL
271 B<sk_I<TYPE>_insert>(), B<sk_I<TYPE>_push>() and B<sk_I<TYPE>_unshift>() return
272 the total number of elements in the stack and 0 if an error occurred.
274 B<sk_I<TYPE>_set>() returns a pointer to the replacement element or NULL on
277 B<sk_I<TYPE>_find>() and B<sk_I<TYPE>_find_ex>() return an index to the found
278 element or B<-1> on error.
280 B<sk_I<TYPE>_is_sorted>() returns B<1> if the stack is sorted and B<0> if it is
283 B<sk_I<TYPE>_dup>() and B<sk_I<TYPE>_deep_copy>() return a pointer to the copy
284 of the stack or NULL on error.
288 Before OpenSSL 1.1.0, this was implemented via macros and not inline functions
289 and was not a public API.
291 B<sk_I<TYPE>_reserve>() and B<sk_I<TYPE>_new_reserve>() were added in OpenSSL
294 From OpenSSL 3.2.0, the B<sk_I<TYPE>_find>(), B<sk_I<TYPE>_find_ex>()
295 and B<sk_I<TYPE>_find_all>() calls are read-only and do not sort the
296 stack. To avoid any performance implications this change introduces,
297 B<sk_I<TYPE>_sort>() should be called before these find operations.
299 Before OpenSSL 3.3.0 B<sk_I<TYPE>_push>() returned -1 if I<sk> was NULL. It
300 was changed to return 0 in this condition as for other errors.
304 Copyright 2000-2023 The OpenSSL Project Authors. All Rights Reserved.
306 Licensed under the Apache License 2.0 (the "License"). You may not use
307 this file except in compliance with the License. You can obtain a copy
308 in the file LICENSE in the source distribution or at
309 L<https://www.openssl.org/source/license.html>.