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_sort, sk_TYPE_is_sorted,
12 sk_TYPE_dup, sk_TYPE_deep_copy, sk_TYPE_set_cmp_func, sk_TYPE_new_reserve
19 #include <openssl/safestack.h>
23 DEFINE_STACK_OF_CONST(TYPE)
24 DEFINE_SPECIAL_STACK_OF(FUNCTYPE, TYPE)
25 DEFINE_SPECIAL_STACK_OF_CONST(FUNCTYPE, TYPE)
27 typedef int (*sk_TYPE_compfunc)(const TYPE *const *a, const TYPE *const *b);
28 typedef TYPE * (*sk_TYPE_copyfunc)(const TYPE *a);
29 typedef void (*sk_TYPE_freefunc)(TYPE *a);
31 int sk_TYPE_num(const STACK_OF(TYPE) *sk);
32 TYPE *sk_TYPE_value(const STACK_OF(TYPE) *sk, int idx);
33 STACK_OF(TYPE) *sk_TYPE_new(sk_TYPE_compfunc compare);
34 STACK_OF(TYPE) *sk_TYPE_new_null(void);
35 int sk_TYPE_reserve(STACK_OF(TYPE) *sk, int n);
36 void sk_TYPE_free(const STACK_OF(TYPE) *sk);
37 void sk_TYPE_zero(const STACK_OF(TYPE) *sk);
38 TYPE *sk_TYPE_delete(STACK_OF(TYPE) *sk, int i);
39 TYPE *sk_TYPE_delete_ptr(STACK_OF(TYPE) *sk, TYPE *ptr);
40 int sk_TYPE_push(STACK_OF(TYPE) *sk, const TYPE *ptr);
41 int sk_TYPE_unshift(STACK_OF(TYPE) *sk, const TYPE *ptr);
42 TYPE *sk_TYPE_pop(STACK_OF(TYPE) *sk);
43 TYPE *sk_TYPE_shift(STACK_OF(TYPE) *sk);
44 void sk_TYPE_pop_free(STACK_OF(TYPE) *sk, sk_TYPE_freefunc freefunc);
45 int sk_TYPE_insert(STACK_OF(TYPE) *sk, TYPE *ptr, int idx);
46 TYPE *sk_TYPE_set(STACK_OF(TYPE) *sk, int idx, const TYPE *ptr);
47 int sk_TYPE_find(STACK_OF(TYPE) *sk, TYPE *ptr);
48 int sk_TYPE_find_ex(STACK_OF(TYPE) *sk, TYPE *ptr);
49 void sk_TYPE_sort(const STACK_OF(TYPE) *sk);
50 int sk_TYPE_is_sorted(const STACK_OF(TYPE) *sk);
51 STACK_OF(TYPE) *sk_TYPE_dup(const STACK_OF(TYPE) *sk);
52 STACK_OF(TYPE) *sk_TYPE_deep_copy(const STACK_OF(TYPE) *sk,
53 sk_TYPE_copyfunc copyfunc,
54 sk_TYPE_freefunc freefunc);
55 sk_TYPE_compfunc (*sk_TYPE_set_cmp_func(STACK_OF(TYPE) *sk,
56 sk_TYPE_compfunc compare));
57 STACK_OF(TYPE) *sk_TYPE_new_reserve(sk_TYPE_compfunc compare, int n);
61 Applications can create and use their own stacks by placing any of the macros
62 described below in a header file. These macros define typesafe inline
63 functions that wrap around the utility B<OPENSSL_sk_> API.
64 In the description here, B<I<TYPE>> is used
65 as a placeholder for any of the OpenSSL datatypes, such as B<X509>.
67 The STACK_OF() macro returns the name for a stack of the specified B<I<TYPE>>.
68 This is an opaque pointer to a structure declaration.
69 This can be used in every header file that references the stack.
70 There are several B<DEFINE...> macros that create static inline functions
71 for all of the functions described on this page.
72 This should normally be used in one source file, and the stack manipulation
73 is wrapped with application-specific functions.
75 DEFINE_STACK_OF() creates set of functions for a stack of B<I<TYPE>> elements.
76 The type is referenced by
77 B<STACK_OF>(B<I<TYPE>>) and each function name begins with B<sk_I<TYPE>_>.
78 DEFINE_STACK_OF_CONST() is identical to DEFINE_STACK_OF() except
79 each element is constant.
81 /* DEFINE_STACK_OF(TYPE) */
82 TYPE *sk_TYPE_value(STACK_OF(TYPE) *sk, int idx);
83 /* DEFINE_STACK_OF_CONST(TYPE) */
84 const TYPE *sk_TYPE_value(STACK_OF(TYPE) *sk, int idx);
86 DEFINE_SPECIAL_STACK_OF() and DEFINE_SPECIAL_STACK_OF_CONST() are similar
87 except B<FUNCNAME> is used in the function names:
89 /* DEFINE_SPECIAL_STACK_OF(TYPE, FUNCNAME) */
90 TYPE *sk_FUNCNAME_value(STACK_OF(TYPE) *sk, int idx);
91 /* DEFINE_SPECIAL_STACK_OF(TYPE, FUNCNAME) */
92 const TYPE *sk_FUNCNAME_value(STACK_OF(TYPE) *sk, int idx);
94 B<sk_I<TYPE>_num>() returns the number of elements in I<sk> or -1 if I<sk> is
97 B<sk_I<TYPE>_value>() returns element I<idx> in I<sk>, where I<idx> starts at
98 zero. If I<idx> is out of range then NULL is returned.
100 B<sk_I<TYPE>_new>() allocates a new empty stack using comparison function
101 I<compare>. If I<compare> is NULL then no comparison function is used. This
102 function is equivalent to B<sk_I<TYPE>_new_reserve>(I<compare>, 0).
104 B<sk_I<TYPE>_new_null>() allocates a new empty stack with no comparison
105 function. This function is equivalent to B<sk_I<TYPE>_new_reserve>(NULL, 0).
107 B<sk_I<TYPE>_reserve>() allocates additional memory in the I<sk> structure
108 such that the next I<n> calls to B<sk_I<TYPE>_insert>(), B<sk_I<TYPE>_push>()
109 or B<sk_I<TYPE>_unshift>() will not fail or cause memory to be allocated
110 or reallocated. If I<n> is zero, any excess space allocated in the
111 I<sk> structure is freed. On error I<sk> is unchanged.
113 B<sk_I<TYPE>_new_reserve>() allocates a new stack. The new stack will have
114 additional memory allocated to hold I<n> elements if I<n> is positive.
115 The next I<n> calls to B<sk_I<TYPE>_insert>(), B<sk_I<TYPE>_push>() or
116 B<sk_I<TYPE>_unshift>() will not fail or cause memory to be allocated or
117 reallocated. If I<n> is zero or less than zero, no memory is allocated.
118 B<sk_I<TYPE>_new_reserve>() also sets the comparison function I<compare>
119 to the newly created stack. If I<compare> is NULL then no comparison
122 B<sk_I<TYPE>_set_cmp_func>() sets the comparison function of I<sk> to
123 I<compare>. The previous comparison function is returned or NULL if there
124 was no previous comparison function.
126 B<sk_I<TYPE>_free>() frees up the I<sk> structure. It does I<not> free up any
127 elements of I<sk>. After this call I<sk> is no longer valid.
129 B<sk_I<TYPE>_zero>() sets the number of elements in I<sk> to zero. It does not
130 free I<sk> so after this call I<sk> is still valid.
132 B<sk_I<TYPE>_pop_free>() frees up all elements of I<sk> and I<sk> itself. The
133 free function freefunc() is called on each element to free it.
135 B<sk_I<TYPE>_delete>() deletes element I<i> from I<sk>. It returns the deleted
136 element or NULL if I<i> is out of range.
138 B<sk_I<TYPE>_delete_ptr>() deletes element matching I<ptr> from I<sk>. It
139 returns the deleted element or NULL if no element matching I<ptr> was found.
141 B<sk_I<TYPE>_insert>() inserts I<ptr> into I<sk> at position I<idx>. Any
142 existing elements at or after I<idx> are moved downwards. If I<idx> is out
143 of range the new element is appended to I<sk>. B<sk_I<TYPE>_insert>() either
144 returns the number of elements in I<sk> after the new element is inserted or
145 zero if an error (such as memory allocation failure) occurred.
147 B<sk_I<TYPE>_push>() appends I<ptr> to I<sk> it is equivalent to:
149 sk_TYPE_insert(sk, ptr, -1);
151 B<sk_I<TYPE>_unshift>() inserts I<ptr> at the start of I<sk> it is equivalent
154 sk_TYPE_insert(sk, ptr, 0);
156 B<sk_I<TYPE>_pop>() returns and removes the last element from I<sk>.
158 B<sk_I<TYPE>_shift>() returns and removes the first element from I<sk>.
160 B<sk_I<TYPE>_set>() sets element I<idx> of I<sk> to I<ptr> replacing the current
161 element. The new element value is returned or NULL if an error occurred:
162 this will only happen if I<sk> is NULL or I<idx> is out of range.
164 B<sk_I<TYPE>_find>() searches I<sk> for the element I<ptr>. In the case
165 where no comparison function has been specified, the function performs
166 a linear search for a pointer equal to I<ptr>. The index of the first
167 matching element is returned or B<-1> if there is no match. In the case
168 where a comparison function has been specified, I<sk> is sorted then
169 B<sk_I<TYPE>_find>() returns the index of a matching element or B<-1> if there
170 is no match. Note that, in this case, the matching element returned is
171 not guaranteed to be the first; the comparison function will usually
172 compare the values pointed to rather than the pointers themselves and
173 the order of elements in I<sk> could change.
175 B<sk_I<TYPE>_find_ex>() operates like B<sk_I<TYPE>_find>() except when a
176 comparison function has been specified and no matching element is found.
177 Instead of returning B<-1>, B<sk_I<TYPE>_find_ex>() returns the index of the
178 element either before or after the location where I<ptr> would be if it were
181 B<sk_I<TYPE>_sort>() sorts I<sk> using the supplied comparison function.
183 B<sk_I<TYPE>_is_sorted>() returns B<1> if I<sk> is sorted and B<0> otherwise.
185 B<sk_I<TYPE>_dup>() returns a copy of I<sk>. Note the pointers in the copy
186 are identical to the original.
188 B<sk_I<TYPE>_deep_copy>() returns a new stack where each element has been
189 copied. Copying is performed by the supplied copyfunc() and freeing by
190 freefunc(). The function freefunc() is only called if an error occurs.
194 Care should be taken when accessing stacks in multi-threaded environments.
195 Any operation which increases the size of a stack such as B<sk_I<TYPE>_insert>()
196 or B<sk_I<TYPE>_push>() can "grow" the size of an internal array and cause race
197 conditions if the same stack is accessed in a different thread. Operations such
198 as B<sk_I<TYPE>_find>() and B<sk_I<TYPE>_sort>() can also reorder the stack.
200 Any comparison function supplied should use a metric suitable
201 for use in a binary search operation. That is it should return zero, a
202 positive or negative value if I<a> is equal to, greater than
203 or less than I<b> respectively.
205 Care should be taken when checking the return values of the functions
206 B<sk_I<TYPE>_find>() and B<sk_I<TYPE>_find_ex>(). They return an index to the
207 matching element. In particular B<0> indicates a matching first element.
208 A failed search is indicated by a B<-1> return value.
210 STACK_OF(), DEFINE_STACK_OF(), DEFINE_STACK_OF_CONST(), and
211 DEFINE_SPECIAL_STACK_OF() are implemented as macros.
213 The underlying utility B<OPENSSL_sk_> API should not be used directly.
214 It defines these functions: OPENSSL_sk_deep_copy(),
215 OPENSSL_sk_delete(), OPENSSL_sk_delete_ptr(), OPENSSL_sk_dup(),
216 OPENSSL_sk_find(), OPENSSL_sk_find_ex(), OPENSSL_sk_free(),
217 OPENSSL_sk_insert(), OPENSSL_sk_is_sorted(), OPENSSL_sk_new(),
218 OPENSSL_sk_new_null(), OPENSSL_sk_num(), OPENSSL_sk_pop(),
219 OPENSSL_sk_pop_free(), OPENSSL_sk_push(), OPENSSL_sk_reserve(),
220 OPENSSL_sk_set(), OPENSSL_sk_set_cmp_func(), OPENSSL_sk_shift(),
221 OPENSSL_sk_sort(), OPENSSL_sk_unshift(), OPENSSL_sk_value(),
226 B<sk_I<TYPE>_num>() returns the number of elements in the stack or B<-1> if the
227 passed stack is NULL.
229 B<sk_I<TYPE>_value>() returns a pointer to a stack element or NULL if the
230 index is out of range.
232 B<sk_I<TYPE>_new>(), B<sk_I<TYPE>_new_null>() and B<sk_I<TYPE>_new_reserve>()
233 return an empty stack or NULL if an error occurs.
235 B<sk_I<TYPE>_reserve>() returns B<1> on successful allocation of the required
236 memory or B<0> on error.
238 B<sk_I<TYPE>_set_cmp_func>() returns the old comparison function or NULL if
239 there was no old comparison function.
241 B<sk_I<TYPE>_free>(), B<sk_I<TYPE>_zero>(), B<sk_I<TYPE>_pop_free>() and
242 B<sk_I<TYPE>_sort>() do not return values.
244 B<sk_I<TYPE>_pop>(), B<sk_I<TYPE>_shift>(), B<sk_I<TYPE>_delete>() and
245 B<sk_I<TYPE>_delete_ptr>() return a pointer to the deleted element or NULL
248 B<sk_I<TYPE>_insert>(), B<sk_I<TYPE>_push>() and B<sk_I<TYPE>_unshift>() return
249 the total number of elements in the stack and 0 if an error occurred.
251 B<sk_I<TYPE>_set>() returns a pointer to the replacement element or NULL on
254 B<sk_I<TYPE>_find>() and B<sk_I<TYPE>_find_ex>() return an index to the found
255 element or B<-1> on error.
257 B<sk_I<TYPE>_is_sorted>() returns B<1> if the stack is sorted and B<0> if it is
260 B<sk_I<TYPE>_dup>() and B<sk_I<TYPE>_deep_copy>() return a pointer to the copy
265 Before OpenSSL 1.1.0, this was implemented via macros and not inline functions
266 and was not a public API.
268 B<sk_I<TYPE>_reserve>() and B<sk_I<TYPE>_new_reserve>() were added in OpenSSL
273 Copyright 2000-2020 The OpenSSL Project Authors. All Rights Reserved.
275 Licensed under the Apache License 2.0 (the "License"). You may not use
276 this file except in compliance with the License. You can obtain a copy
277 in the file LICENSE in the source distribution or at
278 L<https://www.openssl.org/source/license.html>.