5 DEFINE_STACK_OF, DEFINE_STACK_OF_CONST, DEFINE_SPECIAL_STACK_OF,
6 sk_TYPE_num, sk_TYPE_value, sk_TYPE_new, sk_TYPE_new_null, sk_TYPE_free,
7 sk_TYPE_zero, sk_TYPE_delete, sk_TYPE_delete_ptr, sk_TYPE_push,
8 sk_TYPE_unshift, sk_TYPE_pop, sk_TYPE_shift, sk_TYPE_pop_free,
9 sk_TYPE_insert, sk_TYPE_set, sk_TYPE_find, sk_TYPE_find_ex, sk_TYPE_sort,
10 sk_TYPE_is_sorted, sk_TYPE_dup, sk_TYPE_deep_copy, sk_TYPE_set_cmp_func -
17 #include <openssl/safestack.h>
19 #define STACK_OF(TYPE)
20 #define DEFINE_STACK_OF
21 #define DEFINE_STACK_OF_CONST
22 #define DEFINE_SPECIAL_STACK_OF
24 typedef int (*sk_TYPE_compfunc)(const TYPE *const *a, const TYPE *const *b);
25 typedef TYPE * (*sk_TYPE_copyfunc)(const TYPE *a);
26 typedef void (*sk_TYPE_freefunc)(TYPE *a);
28 int sk_TYPE_num(const STACK_OF(TYPE) *sk);
29 TYPE *sk_TYPE_value(const STACK_OF(TYPE) *sk, int idx);
30 STACK_OF(TYPE) *sk_TYPE_new(sk_TYPE_compfunc compare);
31 STACK_OF(TYPE) *sk_TYPE_new_null(void);
32 void sk_TYPE_free(const STACK_OF(TYPE) *sk);
33 void sk_TYPE_zero(const STACK_OF(TYPE) *sk);
34 TYPE *sk_TYPE_delete(STACK_OF(TYPE) *sk, int i);
35 TYPE *sk_TYPE_delete_ptr(STACK_OF(TYPE) *sk, TYPE *ptr);
36 int sk_TYPE_push(STACK_OF(TYPE) *sk, TYPE *ptr);
37 int sk_TYPE_unshift(STACK_OF(TYPE) *sk, TYPE *ptr);
38 TYPE *sk_TYPE_pop(STACK_OF(TYPE) *sk);
39 TYPE *sk_TYPE_shift(STACK_OF(TYPE) *sk);
40 void sk_TYPE_pop_free(STACK_OF(TYPE) *sk, sk_TYPE_freefunc freefunc);
41 int sk_TYPE_insert(STACK_OF(TYPE) *sk, TYPE *ptr, int idx);
42 TYPE *sk_TYPE_set(STACK_OF(TYPE) *sk, int idx, TYPE *ptr);
43 int sk_TYPE_find(STACK_OF(TYPE) *sk, TYPE *ptr);
44 int sk_TYPE_find_ex(STACK_OF(TYPE) *sk, TYPE *ptr);
45 void sk_TYPE_sort(const STACK_OF(TYPE) *sk);
46 int sk_TYPE_is_sorted(const STACK_OF(TYPE) *sk);
47 STACK_OF(TYPE) *sk_TYPE_dup(STACK_OF(TYPE) *sk);
48 STACK_OF(TYPE) *sk_TYPE_deep_copy(STACK_OF(TYPE) *sk,
49 sk_TYPE_copyfunc copyfunc,
50 sk_TYPE_freefunc freefunc);
51 sk_TYPE_compfunc (*sk_TYPE_set_cmp_func(STACK_OF(TYPE) *sk, sk_TYPE_compfunc compare);
55 Applications can create and use their own stacks by placing any of the macros
56 described below in a header file. In the description below, I<TYPE> is used
57 as a placeholder for any of the OpenSSL datatypes, such as I<X509>.
59 DEFINE_STACK_OF(TYPE) creates set of functions for a stack of B<TYPE>. This
60 will mean that type B<TYPE> is stored in each stack, the type is referenced by
61 STACK_OF(TYPE) and each function name begins with I<sk_TYPE_>. For example:
63 TYPE *sk_TYPE_value(STACK_OF(TYPE) *sk, int idx);
65 DEFINE_STACK_OF_CONST(TYPE) is identical to DEFINE_STACK_OF(TYPE) except
66 each element is constant. For example:
68 const TYPE *sk_TYPE_value(STACK_OF(TYPE) *sk, int idx);
70 DEFINE_SPECIAL_STACK_OF(FUNCNAME, TYPE) defines a stack of B<TYPE> but
71 each function uses B<FUNCNAME> in the function name. For example:
73 TYPE *sk_FUNCNAME_value(STACK_OF(TYPE) *sk, int idx);
75 sk_TYPE_num() returns the number of elements in B<sk> or -1 if B<sk> is
78 sk_TYPE_value() returns element B<idx> in B<sk>, where B<idx> starts at
79 zero. If B<idx> is out of range then B<NULL> is returned.
81 sk_TYPE_new() allocates a new empty stack using comparison function B<compar>.
82 If B<compar> is B<NULL> then no comparison function is used.
84 sk_TYPE_new_null() allocates a new empty stack with no comparison function.
86 sk_TYPE_set_cmp_func() sets the comparison function of B<sk> to B<compar>.
87 The previous comparison function is returned or B<NULL> if there was
88 no previous comparison function.
90 sk_TYPE_free() frees up the B<sk> structure. It does B<not> free up any
91 elements of B<sk>. After this call B<sk> is no longer valid.
93 sk_TYPE_zero() sets the number of elements in B<sk> to zero. It does not free
94 B<sk> so after this call B<sk> is still valid.
96 sk_TYPE_pop_free() frees up all elements of B<sk> and B<sk> itself. The
97 free function freefunc() is called on each element to free it.
99 sk_TYPE_delete() deletes element B<i> from B<sk>. It returns the deleted
100 element or B<NULL> if B<i> is out of range.
102 sk_TYPE_delete_ptr() deletes element matching B<ptr> from B<sk>. It returns
103 the deleted element or B<NULL> if no element matching B<ptr> was found.
105 sk_TYPE_insert() inserts B<ptr> into B<sk> at position B<idx>. Any existing
106 elements at or after B<idx> are moved downwards. If B<idx> is out of range
107 the new element is appended to B<sk>. sk_TYPE_insert() either returns the
108 number of elements in B<sk> after the new element is inserted or zero if
109 an error (such as memory allocation failure) occurred.
111 sk_TYPE_push() appends B<ptr> to B<sk> it is equivalent to:
113 sk_TYPE_insert(sk, ptr, -1);
115 sk_TYPE_unshift() inserts B<ptr> at the start of B<sk> it is equivalent to:
117 sk_TYPE_insert(sk, ptr, 0);
119 sk_TYPE_pop() returns and removes the last element from B<sk>.
121 sk_TYPE_shift() returns and removes the first element from B<sk>.
123 sk_TYPE_set() sets element B<idx> of B<sk> to B<ptr> replacing the current
124 element. The new element value is returned or B<NULL> if an error occurred:
125 this will only happen if B<sk> is B<NULL> or B<idx> is out of range.
127 sk_TYPE_find() and sk_TYPE_find_ex() search B<sk> using the supplied
128 comparison function for an element matching B<ptr>. sk_TYPE_find() returns
129 the index of the first matching element or B<-1> if there is no match.
130 sk_TYPE_find_ex() returns a matching element or the nearest element that
131 does not match B<ptr>. Note: if a comparison function is set then B<sk> is
132 sorted before the search which may change its order. If no comparison
133 function is set then a linear search is made for a pointer matching B<ptr>
134 and the stack is not reordered.
136 sk_TYPE_sort() sorts B<sk> using the supplied comparison function.
138 sk_TYPE_is_sorted() returns B<1> if B<sk> is sorted and B<0> otherwise.
140 sk_TYPE_dup() returns a copy of B<sk>. Note the pointers in the copy
141 are identical to the original.
143 sk_TYPE_deep_copy() returns a new stack where each element has been copied.
144 Copying is performed by the supplied copyfunc() and freeing by freefunc(). The
145 function freefunc() is only called if an error occurs.
149 Care should be taken when accessing stacks in multi-threaded environments.
150 Any operation which increases the size of a stack such as sk_TYPE_insert() or
151 sk_push() can "grow" the size of an internal array and cause race conditions
152 if the same stack is accessed in a different thread. Operations such as
153 sk_find() and sk_sort() can also reorder the stack.
155 Any comparison function supplied should use a metric suitable
156 for use in a binary search operation. That is it should return zero, a
157 positive or negative value if B<a> is equal to, greater than
158 or less than B<b> respectively.
160 Care should be taken when checking the return values of the functions
161 sk_TYPE_find() and sk_TYPE_find_ex(). They return an index to the
162 matching element. In particular B<0> indicates a matching first element.
163 A failed search is indicated by a B<-1> return value.
167 sk_TYPE_num() returns the number of elements in the stack or B<-1> if the
168 passed stack is B<NULL>.
170 sk_TYPE_value() returns a pointer to a stack element or B<NULL> if the
171 index is out of range.
173 sk_TYPE_new() and sk_TYPE_new_null() return an empty stack or B<NULL> if
176 sk_TYPE_set_cmp_func() returns the old comparison function or B<NULL> if
177 there was no old comparison function.
179 sk_TYPE_free(), sk_TYPE_zero(), sk_TYPE_pop_free() and sk_TYPE_sort() do
182 sk_TYPE_pop(), sk_TYPE_shift(), sk_TYPE_delete() and sk_TYPE_delete_ptr()
183 return a pointer to the deleted element or B<NULL> on error.
185 sk_TYPE_insert(), sk_TYPE_push() and sk_TYPE_unshift() return the total
186 number of elements in the stack and 0 if an error occurred.
188 sk_TYPE_set() returns a pointer to the replacement element or B<NULL> on
191 sk_TYPE_find() and sk_TYPE_find_ex() return an index to the found element
194 sk_TYPE_is_sorted() returns B<1> if the stack is sorted and B<0> if it is
197 sk_TYPE_dup() and sk_TYPE_deep_copy() return a pointer to the copy of the
202 Before OpenSSL 1.1.0, this was implemented via macros and not inline functions
203 and was not a public API.
207 Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
209 Licensed under the OpenSSL license (the "License"). You may not use
210 this file except in compliance with the License. You can obtain a copy
211 in the file LICENSE in the source distribution or at
212 L<https://www.openssl.org/source/license.html>.