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, OPENSSL_sk_free,
9 OPENSSL_sk_insert, OPENSSL_sk_is_sorted, OPENSSL_sk_new, OPENSSL_sk_new_null,
10 OPENSSL_sk_num, OPENSSL_sk_pop, OPENSSL_sk_pop_free, OPENSSL_sk_push,
11 OPENSSL_sk_set, OPENSSL_sk_set_cmp_func, OPENSSL_sk_shift, OPENSSL_sk_sort,
12 OPENSSL_sk_unshift, OPENSSL_sk_value, OPENSSL_sk_zero,
13 sk_TYPE_num, sk_TYPE_value, sk_TYPE_new, sk_TYPE_new_null, sk_TYPE_free,
14 sk_TYPE_zero, sk_TYPE_delete, sk_TYPE_delete_ptr, sk_TYPE_push,
15 sk_TYPE_unshift, sk_TYPE_pop, sk_TYPE_shift, sk_TYPE_pop_free,
16 sk_TYPE_insert, sk_TYPE_set, sk_TYPE_find, sk_TYPE_find_ex, sk_TYPE_sort,
17 sk_TYPE_is_sorted, sk_TYPE_dup, sk_TYPE_deep_copy, sk_TYPE_set_cmp_func -
24 #include <openssl/safestack.h>
28 DEFINE_STACK_OF_CONST(TYPE)
29 DEFINE_SPECIAL_STACK_OF(FUNCTYPE, TYPE)
30 DEFINE_SPECIAL_STACK_OF_CONST(FUNCTYPE, TYPE)
32 typedef int (*sk_TYPE_compfunc)(const TYPE *const *a, const TYPE *const *b);
33 typedef TYPE * (*sk_TYPE_copyfunc)(const TYPE *a);
34 typedef void (*sk_TYPE_freefunc)(TYPE *a);
36 int sk_TYPE_num(const STACK_OF(TYPE) *sk);
37 TYPE *sk_TYPE_value(const STACK_OF(TYPE) *sk, int idx);
38 STACK_OF(TYPE) *sk_TYPE_new(sk_TYPE_compfunc compare);
39 STACK_OF(TYPE) *sk_TYPE_new_null(void);
40 void sk_TYPE_free(const STACK_OF(TYPE) *sk);
41 void sk_TYPE_zero(const STACK_OF(TYPE) *sk);
42 TYPE *sk_TYPE_delete(STACK_OF(TYPE) *sk, int i);
43 TYPE *sk_TYPE_delete_ptr(STACK_OF(TYPE) *sk, TYPE *ptr);
44 int sk_TYPE_push(STACK_OF(TYPE) *sk, const TYPE *ptr);
45 int sk_TYPE_unshift(STACK_OF(TYPE) *sk, const TYPE *ptr);
46 TYPE *sk_TYPE_pop(STACK_OF(TYPE) *sk);
47 TYPE *sk_TYPE_shift(STACK_OF(TYPE) *sk);
48 void sk_TYPE_pop_free(STACK_OF(TYPE) *sk, sk_TYPE_freefunc freefunc);
49 int sk_TYPE_insert(STACK_OF(TYPE) *sk, TYPE *ptr, int idx);
50 TYPE *sk_TYPE_set(STACK_OF(TYPE) *sk, int idx, const TYPE *ptr);
51 int sk_TYPE_find(STACK_OF(TYPE) *sk, TYPE *ptr);
52 int sk_TYPE_find_ex(STACK_OF(TYPE) *sk, TYPE *ptr);
53 void sk_TYPE_sort(const STACK_OF(TYPE) *sk);
54 int sk_TYPE_is_sorted(const STACK_OF(TYPE) *sk);
55 STACK_OF(TYPE) *sk_TYPE_dup(const STACK_OF(TYPE) *sk);
56 STACK_OF(TYPE) *sk_TYPE_deep_copy(const STACK_OF(TYPE) *sk,
57 sk_TYPE_copyfunc copyfunc,
58 sk_TYPE_freefunc freefunc);
59 sk_TYPE_compfunc (*sk_TYPE_set_cmp_func(STACK_OF(TYPE) *sk,
60 sk_TYPE_compfunc compare));
64 Applications can create and use their own stacks by placing any of the macros
65 described below in a header file. These macros define typesafe inline
66 functions that wrap around the utility B<OPENSSL_sk_> API.
67 In the description here, I<TYPE> is used
68 as a placeholder for any of the OpenSSL datatypes, such as I<X509>.
70 STACK_OF() returns the name for a stack of the specified B<TYPE>.
71 DEFINE_STACK_OF() creates set of functions for a stack of B<TYPE>. This
72 will mean that type B<TYPE> is stored in each stack, the type is referenced by
73 STACK_OF(TYPE) and each function name begins with I<sk_TYPE_>. For example:
75 TYPE *sk_TYPE_value(STACK_OF(TYPE) *sk, int idx);
77 DEFINE_STACK_OF_CONST() is identical to DEFINE_STACK_OF() except
78 each element is constant. For example:
80 const TYPE *sk_TYPE_value(STACK_OF(TYPE) *sk, int idx);
82 DEFINE_SPECIAL_STACK_OF() defines a stack of B<TYPE> but
83 each function uses B<FUNCNAME> in the function name. For example:
85 TYPE *sk_FUNCNAME_value(STACK_OF(TYPE) *sk, int idx);
87 DEFINE_SPECIAL_STACK_OF_CONST() is similar except that each element is
90 const TYPE *sk_FUNCNAME_value(STACK_OF(TYPE) *sk, int idx);
92 sk_TYPE_num() returns the number of elements in B<sk> or -1 if B<sk> is
95 sk_TYPE_value() returns element B<idx> in B<sk>, where B<idx> starts at
96 zero. If B<idx> is out of range then B<NULL> is returned.
98 sk_TYPE_new() allocates a new empty stack using comparison function B<compar>.
99 If B<compar> is B<NULL> then no comparison function is used.
101 sk_TYPE_new_null() allocates a new empty stack with no comparison function.
103 sk_TYPE_set_cmp_func() sets the comparison function of B<sk> to B<compar>.
104 The previous comparison function is returned or B<NULL> if there was
105 no previous comparison function.
107 sk_TYPE_free() frees up the B<sk> structure. It does B<not> free up any
108 elements of B<sk>. After this call B<sk> is no longer valid.
110 sk_TYPE_zero() sets the number of elements in B<sk> to zero. It does not free
111 B<sk> so after this call B<sk> is still valid.
113 sk_TYPE_pop_free() frees up all elements of B<sk> and B<sk> itself. The
114 free function freefunc() is called on each element to free it.
116 sk_TYPE_delete() deletes element B<i> from B<sk>. It returns the deleted
117 element or B<NULL> if B<i> is out of range.
119 sk_TYPE_delete_ptr() deletes element matching B<ptr> from B<sk>. It returns
120 the deleted element or B<NULL> if no element matching B<ptr> was found.
122 sk_TYPE_insert() inserts B<ptr> into B<sk> at position B<idx>. Any existing
123 elements at or after B<idx> are moved downwards. If B<idx> is out of range
124 the new element is appended to B<sk>. sk_TYPE_insert() either returns the
125 number of elements in B<sk> after the new element is inserted or zero if
126 an error (such as memory allocation failure) occurred.
128 sk_TYPE_push() appends B<ptr> to B<sk> it is equivalent to:
130 sk_TYPE_insert(sk, ptr, -1);
132 sk_TYPE_unshift() inserts B<ptr> at the start of B<sk> it is equivalent to:
134 sk_TYPE_insert(sk, ptr, 0);
136 sk_TYPE_pop() returns and removes the last element from B<sk>.
138 sk_TYPE_shift() returns and removes the first element from B<sk>.
140 sk_TYPE_set() sets element B<idx> of B<sk> to B<ptr> replacing the current
141 element. The new element value is returned or B<NULL> if an error occurred:
142 this will only happen if B<sk> is B<NULL> or B<idx> is out of range.
144 sk_TYPE_find() searches B<sk> for the element B<ptr>. In the case
145 where no comparison function has been specified, the function performs
146 a linear search for a pointer equal to B<ptr>. The index of the first
147 matching element is returned or B<-1> if there is no match. In the case
148 where a comparison function has been specified, B<sk> is sorted then
149 sk_TYPE_find() returns the index of a matching element or B<-1> if there
150 is no match. Note that, in this case, the matching element returned is
151 not guaranteed to be the first; the comparison function will usually
152 compare the values pointed to rather than the pointers themselves and
153 the order of elements in B<sk> could change.
155 sk_TYPE_find_ex() operates like sk_TYPE_find() except when a comparison
156 function has been specified and no matching element is found. Instead
157 of returning B<-1>, sk_TYPE_find_ex() returns the index of the element
158 either before or after the location where B<ptr> would be if it were
161 sk_TYPE_sort() sorts B<sk> using the supplied comparison function.
163 sk_TYPE_is_sorted() returns B<1> if B<sk> is sorted and B<0> otherwise.
165 sk_TYPE_dup() returns a copy of B<sk>. Note the pointers in the copy
166 are identical to the original.
168 sk_TYPE_deep_copy() returns a new stack where each element has been copied.
169 Copying is performed by the supplied copyfunc() and freeing by freefunc(). The
170 function freefunc() is only called if an error occurs.
174 Care should be taken when accessing stacks in multi-threaded environments.
175 Any operation which increases the size of a stack such as sk_TYPE_insert() or
176 sk_push() can "grow" the size of an internal array and cause race conditions
177 if the same stack is accessed in a different thread. Operations such as
178 sk_find() and sk_sort() can also reorder the stack.
180 Any comparison function supplied should use a metric suitable
181 for use in a binary search operation. That is it should return zero, a
182 positive or negative value if B<a> is equal to, greater than
183 or less than B<b> respectively.
185 Care should be taken when checking the return values of the functions
186 sk_TYPE_find() and sk_TYPE_find_ex(). They return an index to the
187 matching element. In particular B<0> indicates a matching first element.
188 A failed search is indicated by a B<-1> return value.
190 STACK_OF(), DEFINE_STACK_OF(), DEFINE_STACK_OF_CONST(), and
191 DEFINE_SPECIAL_STACK_OF() are implemented as macros.
195 sk_TYPE_num() returns the number of elements in the stack or B<-1> if the
196 passed stack is B<NULL>.
198 sk_TYPE_value() returns a pointer to a stack element or B<NULL> if the
199 index is out of range.
201 sk_TYPE_new() and sk_TYPE_new_null() return an empty stack or B<NULL> if
204 sk_TYPE_set_cmp_func() returns the old comparison function or B<NULL> if
205 there was no old comparison function.
207 sk_TYPE_free(), sk_TYPE_zero(), sk_TYPE_pop_free() and sk_TYPE_sort() do
210 sk_TYPE_pop(), sk_TYPE_shift(), sk_TYPE_delete() and sk_TYPE_delete_ptr()
211 return a pointer to the deleted element or B<NULL> on error.
213 sk_TYPE_insert(), sk_TYPE_push() and sk_TYPE_unshift() return the total
214 number of elements in the stack and 0 if an error occurred.
216 sk_TYPE_set() returns a pointer to the replacement element or B<NULL> on
219 sk_TYPE_find() and sk_TYPE_find_ex() return an index to the found element
222 sk_TYPE_is_sorted() returns B<1> if the stack is sorted and B<0> if it is
225 sk_TYPE_dup() and sk_TYPE_deep_copy() return a pointer to the copy of the
230 Before OpenSSL 1.1.0, this was implemented via macros and not inline functions
231 and was not a public API.
235 Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
237 Licensed under the OpenSSL license (the "License"). You may not use
238 this file except in compliance with the License. You can obtain a copy
239 in the file LICENSE in the source distribution or at
240 L<https://www.openssl.org/source/license.html>.