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 STACK_OF() returns the name for a stack of the specified B<I<TYPE>>.
68 DEFINE_STACK_OF() creates set of functions for a stack of B<I<TYPE>>. This
69 will mean that type B<I<TYPE>> is stored in each stack, the type is referenced by
70 B<STACK_OF>(B<I<TYPE>>) and each function name begins with B<sk_I<TYPE>_>.
73 TYPE *sk_TYPE_value(STACK_OF(TYPE) *sk, int idx);
75 DEFINE_STACK_OF_CONST() is identical to DEFINE_STACK_OF() except
76 each element is constant. For example:
78 const TYPE *sk_TYPE_value(STACK_OF(TYPE) *sk, int idx);
80 DEFINE_SPECIAL_STACK_OF() defines a stack of B<I<TYPE>> but
81 each function uses B<FUNCNAME> in the function name. For example:
83 TYPE *sk_FUNCNAME_value(STACK_OF(TYPE) *sk, int idx);
85 DEFINE_SPECIAL_STACK_OF_CONST() is similar except that each element is
88 const TYPE *sk_FUNCNAME_value(STACK_OF(TYPE) *sk, int idx);
90 B<sk_I<TYPE>_num>() returns the number of elements in I<sk> or -1 if I<sk> is
93 B<sk_I<TYPE>_value>() returns element I<idx> in I<sk>, where I<idx> starts at
94 zero. If I<idx> is out of range then NULL is returned.
96 B<sk_I<TYPE>_new>() allocates a new empty stack using comparison function
97 I<compare>. If I<compare> is NULL then no comparison function is used. This
98 function is equivalent to B<sk_I<TYPE>_new_reserve>(I<compare>, 0).
100 B<sk_I<TYPE>_new_null>() allocates a new empty stack with no comparison
101 function. This function is equivalent to B<sk_I<TYPE>_new_reserve>(NULL, 0).
103 B<sk_I<TYPE>_reserve>() allocates additional memory in the I<sk> structure
104 such that the next I<n> calls to B<sk_I<TYPE>_insert>(), B<sk_I<TYPE>_push>()
105 or B<sk_I<TYPE>_unshift>() will not fail or cause memory to be allocated
106 or reallocated. If I<n> is zero, any excess space allocated in the
107 I<sk> structure is freed. On error I<sk> is unchanged.
109 B<sk_I<TYPE>_new_reserve>() allocates a new stack. The new stack will have
110 additional memory allocated to hold I<n> elements if I<n> is positive.
111 The next I<n> calls to B<sk_I<TYPE>_insert>(), B<sk_I<TYPE>_push>() or
112 B<sk_I<TYPE>_unshift>() will not fail or cause memory to be allocated or
113 reallocated. If I<n> is zero or less than zero, no memory is allocated.
114 B<sk_I<TYPE>_new_reserve>() also sets the comparison function I<compare>
115 to the newly created stack. If I<compare> is NULL then no comparison
118 B<sk_I<TYPE>_set_cmp_func>() sets the comparison function of I<sk> to
119 I<compare>. The previous comparison function is returned or NULL if there
120 was no previous comparison function.
122 B<sk_I<TYPE>_free>() frees up the I<sk> structure. It does I<not> free up any
123 elements of I<sk>. After this call I<sk> is no longer valid.
125 B<sk_I<TYPE>_zero>() sets the number of elements in I<sk> to zero. It does not
126 free I<sk> so after this call I<sk> is still valid.
128 B<sk_I<TYPE>_pop_free>() frees up all elements of I<sk> and I<sk> itself. The
129 free function freefunc() is called on each element to free it.
131 B<sk_I<TYPE>_delete>() deletes element I<i> from I<sk>. It returns the deleted
132 element or NULL if I<i> is out of range.
134 B<sk_I<TYPE>_delete_ptr>() deletes element matching I<ptr> from I<sk>. It
135 returns the deleted element or NULL if no element matching I<ptr> was found.
137 B<sk_I<TYPE>_insert>() inserts I<ptr> into I<sk> at position I<idx>. Any
138 existing elements at or after I<idx> are moved downwards. If I<idx> is out
139 of range the new element is appended to I<sk>. B<sk_I<TYPE>_insert>() either
140 returns the number of elements in I<sk> after the new element is inserted or
141 zero if an error (such as memory allocation failure) occurred.
143 B<sk_I<TYPE>_push>() appends I<ptr> to I<sk> it is equivalent to:
145 sk_TYPE_insert(sk, ptr, -1);
147 B<sk_I<TYPE>_unshift>() inserts I<ptr> at the start of I<sk> it is equivalent
150 sk_TYPE_insert(sk, ptr, 0);
152 B<sk_I<TYPE>_pop>() returns and removes the last element from I<sk>.
154 B<sk_I<TYPE>_shift>() returns and removes the first element from I<sk>.
156 B<sk_I<TYPE>_set>() sets element I<idx> of I<sk> to I<ptr> replacing the current
157 element. The new element value is returned or NULL if an error occurred:
158 this will only happen if I<sk> is NULL or I<idx> is out of range.
160 B<sk_I<TYPE>_find>() searches I<sk> for the element I<ptr>. In the case
161 where no comparison function has been specified, the function performs
162 a linear search for a pointer equal to I<ptr>. The index of the first
163 matching element is returned or B<-1> if there is no match. In the case
164 where a comparison function has been specified, I<sk> is sorted then
165 B<sk_I<TYPE>_find>() returns the index of a matching element or B<-1> if there
166 is no match. Note that, in this case, the matching element returned is
167 not guaranteed to be the first; the comparison function will usually
168 compare the values pointed to rather than the pointers themselves and
169 the order of elements in I<sk> could change.
171 B<sk_I<TYPE>_find_ex>() operates like B<sk_I<TYPE>_find>() except when a
172 comparison function has been specified and no matching element is found.
173 Instead of returning B<-1>, B<sk_I<TYPE>_find_ex>() returns the index of the
174 element either before or after the location where I<ptr> would be if it were
177 B<sk_I<TYPE>_sort>() sorts I<sk> using the supplied comparison function.
179 B<sk_I<TYPE>_is_sorted>() returns B<1> if I<sk> is sorted and B<0> otherwise.
181 B<sk_I<TYPE>_dup>() returns a copy of I<sk>. Note the pointers in the copy
182 are identical to the original.
184 B<sk_I<TYPE>_deep_copy>() returns a new stack where each element has been
185 copied. Copying is performed by the supplied copyfunc() and freeing by
186 freefunc(). The function freefunc() is only called if an error occurs.
190 Care should be taken when accessing stacks in multi-threaded environments.
191 Any operation which increases the size of a stack such as B<sk_I<TYPE>_insert>()
192 or B<sk_I<TYPE>_push>() can "grow" the size of an internal array and cause race
193 conditions if the same stack is accessed in a different thread. Operations such
194 as B<sk_I<TYPE>_find>() and B<sk_I<TYPE>_sort>() can also reorder the stack.
196 Any comparison function supplied should use a metric suitable
197 for use in a binary search operation. That is it should return zero, a
198 positive or negative value if I<a> is equal to, greater than
199 or less than I<b> respectively.
201 Care should be taken when checking the return values of the functions
202 B<sk_I<TYPE>_find>() and B<sk_I<TYPE>_find_ex>(). They return an index to the
203 matching element. In particular B<0> indicates a matching first element.
204 A failed search is indicated by a B<-1> return value.
206 STACK_OF(), DEFINE_STACK_OF(), DEFINE_STACK_OF_CONST(), and
207 DEFINE_SPECIAL_STACK_OF() are implemented as macros.
209 The underlying utility B<OPENSSL_sk_> API should not be used directly.
210 It defines these functions: OPENSSL_sk_deep_copy(),
211 OPENSSL_sk_delete(), OPENSSL_sk_delete_ptr(), OPENSSL_sk_dup(),
212 OPENSSL_sk_find(), OPENSSL_sk_find_ex(), OPENSSL_sk_free(),
213 OPENSSL_sk_insert(), OPENSSL_sk_is_sorted(), OPENSSL_sk_new(),
214 OPENSSL_sk_new_null(), OPENSSL_sk_num(), OPENSSL_sk_pop(),
215 OPENSSL_sk_pop_free(), OPENSSL_sk_push(), OPENSSL_sk_reserve(),
216 OPENSSL_sk_set(), OPENSSL_sk_set_cmp_func(), OPENSSL_sk_shift(),
217 OPENSSL_sk_sort(), OPENSSL_sk_unshift(), OPENSSL_sk_value(),
222 B<sk_I<TYPE>_num>() returns the number of elements in the stack or B<-1> if the
223 passed stack is NULL.
225 B<sk_I<TYPE>_value>() returns a pointer to a stack element or NULL if the
226 index is out of range.
228 B<sk_I<TYPE>_new>(), B<sk_I<TYPE>_new_null>() and B<sk_I<TYPE>_new_reserve>()
229 return an empty stack or NULL if an error occurs.
231 B<sk_I<TYPE>_reserve>() returns B<1> on successful allocation of the required
232 memory or B<0> on error.
234 B<sk_I<TYPE>_set_cmp_func>() returns the old comparison function or NULL if
235 there was no old comparison function.
237 B<sk_I<TYPE>_free>(), B<sk_I<TYPE>_zero>(), B<sk_I<TYPE>_pop_free>() and
238 B<sk_I<TYPE>_sort>() do not return values.
240 B<sk_I<TYPE>_pop>(), B<sk_I<TYPE>_shift>(), B<sk_I<TYPE>_delete>() and
241 B<sk_I<TYPE>_delete_ptr>() return a pointer to the deleted element or NULL
244 B<sk_I<TYPE>_insert>(), B<sk_I<TYPE>_push>() and B<sk_I<TYPE>_unshift>() return
245 the total number of elements in the stack and 0 if an error occurred.
247 B<sk_I<TYPE>_set>() returns a pointer to the replacement element or NULL on
250 B<sk_I<TYPE>_find>() and B<sk_I<TYPE>_find_ex>() return an index to the found
251 element or B<-1> on error.
253 B<sk_I<TYPE>_is_sorted>() returns B<1> if the stack is sorted and B<0> if it is
256 B<sk_I<TYPE>_dup>() and B<sk_I<TYPE>_deep_copy>() return a pointer to the copy
261 Before OpenSSL 1.1.0, this was implemented via macros and not inline functions
262 and was not a public API.
264 B<sk_I<TYPE>_reserve>() and B<sk_I<TYPE>_new_reserve>() were added in OpenSSL
269 Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
271 Licensed under the Apache License 2.0 (the "License"). You may not use
272 this file except in compliance with the License. You can obtain a copy
273 in the file LICENSE in the source distribution or at
274 L<https://www.openssl.org/source/license.html>.