5 DEFINE_STACK_OF, DEFINE_STACK_OF_CONST, DEFINE_SPECIAL_STACK_OF,
6 DEFINE_SPECIAL_STACK_OF_CONST,
7 OPENSSL_sk_deep_copy, OPENSSL_sk_delete, OPENSSL_sk_delete_ptr,
8 OPENSSL_sk_dup, OPENSSL_sk_find, OPENSSL_sk_find_ex,
9 OPENSSL_sk_free, OPENSSL_sk_insert, OPENSSL_sk_is_sorted,
10 OPENSSL_sk_new, OPENSSL_sk_new_null, OPENSSL_sk_num, OPENSSL_sk_pop,
11 OPENSSL_sk_pop_free, OPENSSL_sk_push, OPENSSL_sk_reserve, OPENSSL_sk_set,
12 OPENSSL_sk_set_cmp_func, OPENSSL_sk_shift, OPENSSL_sk_sort,
13 OPENSSL_sk_unshift, OPENSSL_sk_value, OPENSSL_sk_zero,
14 sk_TYPE_num, sk_TYPE_value, sk_TYPE_new, sk_TYPE_new_null,
15 sk_TYPE_reserve, sk_TYPE_free, sk_TYPE_zero, sk_TYPE_delete,
16 sk_TYPE_delete_ptr, sk_TYPE_push, sk_TYPE_unshift, sk_TYPE_pop,
17 sk_TYPE_shift, sk_TYPE_pop_free, sk_TYPE_insert, sk_TYPE_set,
18 sk_TYPE_find, sk_TYPE_find_ex, sk_TYPE_sort, sk_TYPE_is_sorted,
19 sk_TYPE_dup, sk_TYPE_deep_copy, sk_TYPE_set_cmp_func - stack container
25 #include <openssl/safestack.h>
29 DEFINE_STACK_OF_CONST(TYPE)
30 DEFINE_SPECIAL_STACK_OF(FUNCTYPE, TYPE)
31 DEFINE_SPECIAL_STACK_OF_CONST(FUNCTYPE, TYPE)
33 typedef int (*sk_TYPE_compfunc)(const TYPE *const *a, const TYPE *const *b);
34 typedef TYPE * (*sk_TYPE_copyfunc)(const TYPE *a);
35 typedef void (*sk_TYPE_freefunc)(TYPE *a);
37 int sk_TYPE_num(const STACK_OF(TYPE) *sk);
38 TYPE *sk_TYPE_value(const STACK_OF(TYPE) *sk, int idx);
39 STACK_OF(TYPE) *sk_TYPE_new(sk_TYPE_compfunc compare);
40 STACK_OF(TYPE) *sk_TYPE_new_null(void);
41 int sk_TYPE_reserve(STACK_OF(TYPE) *sk, size_t n);
42 void sk_TYPE_free(const STACK_OF(TYPE) *sk);
43 void sk_TYPE_zero(const STACK_OF(TYPE) *sk);
44 TYPE *sk_TYPE_delete(STACK_OF(TYPE) *sk, int i);
45 TYPE *sk_TYPE_delete_ptr(STACK_OF(TYPE) *sk, TYPE *ptr);
46 int sk_TYPE_push(STACK_OF(TYPE) *sk, const TYPE *ptr);
47 int sk_TYPE_unshift(STACK_OF(TYPE) *sk, const TYPE *ptr);
48 TYPE *sk_TYPE_pop(STACK_OF(TYPE) *sk);
49 TYPE *sk_TYPE_shift(STACK_OF(TYPE) *sk);
50 void sk_TYPE_pop_free(STACK_OF(TYPE) *sk, sk_TYPE_freefunc freefunc);
51 int sk_TYPE_insert(STACK_OF(TYPE) *sk, TYPE *ptr, int idx);
52 TYPE *sk_TYPE_set(STACK_OF(TYPE) *sk, int idx, const TYPE *ptr);
53 int sk_TYPE_find(STACK_OF(TYPE) *sk, TYPE *ptr);
54 int sk_TYPE_find_ex(STACK_OF(TYPE) *sk, TYPE *ptr);
55 void sk_TYPE_sort(const STACK_OF(TYPE) *sk);
56 int sk_TYPE_is_sorted(const STACK_OF(TYPE) *sk);
57 STACK_OF(TYPE) *sk_TYPE_dup(const STACK_OF(TYPE) *sk);
58 STACK_OF(TYPE) *sk_TYPE_deep_copy(const STACK_OF(TYPE) *sk,
59 sk_TYPE_copyfunc copyfunc,
60 sk_TYPE_freefunc freefunc);
61 sk_TYPE_compfunc (*sk_TYPE_set_cmp_func(STACK_OF(TYPE) *sk,
62 sk_TYPE_compfunc compare));
66 Applications can create and use their own stacks by placing any of the macros
67 described below in a header file. These macros define typesafe inline
68 functions that wrap around the utility B<OPENSSL_sk_> API.
69 In the description here, I<TYPE> is used
70 as a placeholder for any of the OpenSSL datatypes, such as I<X509>.
72 STACK_OF() returns the name for a stack of the specified B<TYPE>.
73 DEFINE_STACK_OF() creates set of functions for a stack of B<TYPE>. This
74 will mean that type B<TYPE> is stored in each stack, the type is referenced by
75 STACK_OF(TYPE) and each function name begins with I<sk_TYPE_>. For example:
77 TYPE *sk_TYPE_value(STACK_OF(TYPE) *sk, int idx);
79 DEFINE_STACK_OF_CONST() is identical to DEFINE_STACK_OF() except
80 each element is constant. For example:
82 const TYPE *sk_TYPE_value(STACK_OF(TYPE) *sk, int idx);
84 DEFINE_SPECIAL_STACK_OF() defines a stack of B<TYPE> but
85 each function uses B<FUNCNAME> in the function name. For example:
87 TYPE *sk_FUNCNAME_value(STACK_OF(TYPE) *sk, int idx);
89 DEFINE_SPECIAL_STACK_OF_CONST() is similar except that each element is
92 const TYPE *sk_FUNCNAME_value(STACK_OF(TYPE) *sk, int idx);
94 sk_TYPE_num() returns the number of elements in B<sk> or -1 if B<sk> is
97 sk_TYPE_value() returns element B<idx> in B<sk>, where B<idx> starts at
98 zero. If B<idx> is out of range then B<NULL> is returned.
100 sk_TYPE_new() allocates a new empty stack using comparison function B<compar>.
101 If B<compar> is B<NULL> then no comparison function is used.
103 sk_TYPE_new_null() allocates a new empty stack with no comparison function.
105 sk_TYPE_reserve() allocates additional memory in the B<sk> structure
106 such that the next B<n> calls to sk_TYPE_insert(), sk_TYPE_push()
107 or sk_TYPE_unshift() will not fail or cause memory to be allocated
108 or reallocated. If B<n> is zero, any excess space allocated in the
109 B<sk> structure is freed. On error B<sk> is unchanged.
111 sk_TYPE_set_cmp_func() sets the comparison function of B<sk> to B<compar>.
112 The previous comparison function is returned or B<NULL> if there was
113 no previous comparison function.
115 sk_TYPE_free() frees up the B<sk> structure. It does B<not> free up any
116 elements of B<sk>. After this call B<sk> is no longer valid.
118 sk_TYPE_zero() sets the number of elements in B<sk> to zero. It does not free
119 B<sk> so after this call B<sk> is still valid.
121 sk_TYPE_pop_free() frees up all elements of B<sk> and B<sk> itself. The
122 free function freefunc() is called on each element to free it.
124 sk_TYPE_delete() deletes element B<i> from B<sk>. It returns the deleted
125 element or B<NULL> if B<i> is out of range.
127 sk_TYPE_delete_ptr() deletes element matching B<ptr> from B<sk>. It returns
128 the deleted element or B<NULL> if no element matching B<ptr> was found.
130 sk_TYPE_insert() inserts B<ptr> into B<sk> at position B<idx>. Any existing
131 elements at or after B<idx> are moved downwards. If B<idx> is out of range
132 the new element is appended to B<sk>. sk_TYPE_insert() either returns the
133 number of elements in B<sk> after the new element is inserted or zero if
134 an error (such as memory allocation failure) occurred.
136 sk_TYPE_push() appends B<ptr> to B<sk> it is equivalent to:
138 sk_TYPE_insert(sk, ptr, -1);
140 sk_TYPE_unshift() inserts B<ptr> at the start of B<sk> it is equivalent to:
142 sk_TYPE_insert(sk, ptr, 0);
144 sk_TYPE_pop() returns and removes the last element from B<sk>.
146 sk_TYPE_shift() returns and removes the first element from B<sk>.
148 sk_TYPE_set() sets element B<idx> of B<sk> to B<ptr> replacing the current
149 element. The new element value is returned or B<NULL> if an error occurred:
150 this will only happen if B<sk> is B<NULL> or B<idx> is out of range.
152 sk_TYPE_find() searches B<sk> for the element B<ptr>. In the case
153 where no comparison function has been specified, the function performs
154 a linear search for a pointer equal to B<ptr>. The index of the first
155 matching element is returned or B<-1> if there is no match. In the case
156 where a comparison function has been specified, B<sk> is sorted then
157 sk_TYPE_find() returns the index of a matching element or B<-1> if there
158 is no match. Note that, in this case, the matching element returned is
159 not guaranteed to be the first; the comparison function will usually
160 compare the values pointed to rather than the pointers themselves and
161 the order of elements in B<sk> could change.
163 sk_TYPE_find_ex() operates like sk_TYPE_find() except when a comparison
164 function has been specified and no matching element is found. Instead
165 of returning B<-1>, sk_TYPE_find_ex() returns the index of the element
166 either before or after the location where B<ptr> would be if it were
169 sk_TYPE_sort() sorts B<sk> using the supplied comparison function.
171 sk_TYPE_is_sorted() returns B<1> if B<sk> is sorted and B<0> otherwise.
173 sk_TYPE_dup() returns a copy of B<sk>. Note the pointers in the copy
174 are identical to the original.
176 sk_TYPE_deep_copy() returns a new stack where each element has been copied.
177 Copying is performed by the supplied copyfunc() and freeing by freefunc(). The
178 function freefunc() is only called if an error occurs.
182 Care should be taken when accessing stacks in multi-threaded environments.
183 Any operation which increases the size of a stack such as sk_TYPE_insert() or
184 sk_push() can "grow" the size of an internal array and cause race conditions
185 if the same stack is accessed in a different thread. Operations such as
186 sk_find() and sk_sort() can also reorder the stack.
188 Any comparison function supplied should use a metric suitable
189 for use in a binary search operation. That is it should return zero, a
190 positive or negative value if B<a> is equal to, greater than
191 or less than B<b> respectively.
193 Care should be taken when checking the return values of the functions
194 sk_TYPE_find() and sk_TYPE_find_ex(). They return an index to the
195 matching element. In particular B<0> indicates a matching first element.
196 A failed search is indicated by a B<-1> return value.
198 STACK_OF(), DEFINE_STACK_OF(), DEFINE_STACK_OF_CONST(), and
199 DEFINE_SPECIAL_STACK_OF() are implemented as macros.
203 sk_TYPE_num() returns the number of elements in the stack or B<-1> if the
204 passed stack is B<NULL>.
206 sk_TYPE_value() returns a pointer to a stack element or B<NULL> if the
207 index is out of range.
209 sk_TYPE_new() and sk_TYPE_new_null() return an empty stack or B<NULL> if
212 sk_TYPE_reserve() returns B<1> on successful allocation of the required memory
215 sk_TYPE_set_cmp_func() returns the old comparison function or B<NULL> if
216 there was no old comparison function.
218 sk_TYPE_free(), sk_TYPE_zero(), sk_TYPE_pop_free() and sk_TYPE_sort() do
221 sk_TYPE_pop(), sk_TYPE_shift(), sk_TYPE_delete() and sk_TYPE_delete_ptr()
222 return a pointer to the deleted element or B<NULL> on error.
224 sk_TYPE_insert(), sk_TYPE_push() and sk_TYPE_unshift() return the total
225 number of elements in the stack and 0 if an error occurred.
227 sk_TYPE_set() returns a pointer to the replacement element or B<NULL> on
230 sk_TYPE_find() and sk_TYPE_find_ex() return an index to the found element
233 sk_TYPE_is_sorted() returns B<1> if the stack is sorted and B<0> if it is
236 sk_TYPE_dup() and sk_TYPE_deep_copy() return a pointer to the copy of the
241 Before OpenSSL 1.1.0, this was implemented via macros and not inline functions
242 and was not a public API.
246 Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
248 Licensed under the OpenSSL license (the "License"). You may not use
249 this file except in compliance with the License. You can obtain a copy
250 in the file LICENSE in the source distribution or at
251 L<https://www.openssl.org/source/license.html>.