Constify a bit more OPENSSL_sk_ API

Reviewed-by: NRichard Levitte <levitte@openssl.org>
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1244)

crypto/stack/stack.c

@@ -36,7 +36,7 @@ OPENSSL_sk_compfunc OPENSSL_sk_set_cmp_func(OPENSSL_STACK *sk, OPENSSL_sk_compfu
     return old;
 }
 
-OPENSSL_STACK *OPENSSL_sk_dup(OPENSSL_STACK *sk)
+OPENSSL_STACK *OPENSSL_sk_dup(const OPENSSL_STACK *sk)
 {
     OPENSSL_STACK *ret;
 
@@ -55,7 +55,8 @@ OPENSSL_STACK *OPENSSL_sk_dup(OPENSSL_STACK *sk)
     return NULL;
 }
 
-OPENSSL_STACK *OPENSSL_sk_deep_copy(OPENSSL_STACK *sk, OPENSSL_sk_copyfunc copy_func,
+OPENSSL_STACK *OPENSSL_sk_deep_copy(const OPENSSL_STACK *sk,
+                             OPENSSL_sk_copyfunc copy_func,
                              OPENSSL_sk_freefunc free_func)
 {
     OPENSSL_STACK *ret;

doc/crypto/DEFINE_STACK_OF.pod

@@ -50,8 +50,8 @@ stack container
  int sk_TYPE_find_ex(STACK_OF(TYPE) *sk, TYPE *ptr);
  void sk_TYPE_sort(const STACK_OF(TYPE) *sk);
  int sk_TYPE_is_sorted(const STACK_OF(TYPE) *sk);
- STACK_OF(TYPE) *sk_TYPE_dup(STACK_OF(TYPE) *sk);
- STACK_OF(TYPE) *sk_TYPE_deep_copy(STACK_OF(TYPE) *sk,
+ STACK_OF(TYPE) *sk_TYPE_dup(const STACK_OF(TYPE) *sk);
+ STACK_OF(TYPE) *sk_TYPE_deep_copy(const STACK_OF(TYPE) *sk,
                                    sk_TYPE_copyfunc copyfunc,
                                    sk_TYPE_freefunc freefunc);
  sk_TYPE_compfunc (*sk_TYPE_set_cmp_func(STACK_OF(TYPE) *sk, sk_TYPE_compfunc compare);

include/openssl/safestack.h

@@ -101,11 +101,11 @@ extern "C" {
     { \
         return OPENSSL_sk_is_sorted((const OPENSSL_STACK *)sk); \
     } \
-    static ossl_inline STACK_OF(t1) * sk_##t1##_dup(STACK_OF(t1) *sk) \
+    static ossl_inline STACK_OF(t1) * sk_##t1##_dup(const STACK_OF(t1) *sk) \
     { \
-        return (STACK_OF(t1) *)OPENSSL_sk_dup((OPENSSL_STACK *)sk); \
+        return (STACK_OF(t1) *)OPENSSL_sk_dup((const OPENSSL_STACK *)sk); \
     } \
-    static ossl_inline STACK_OF(t1) *sk_##t1##_deep_copy(STACK_OF(t1) *sk, \
+    static ossl_inline STACK_OF(t1) *sk_##t1##_deep_copy(const STACK_OF(t1) *sk, \
                                                     sk_##t1##_copyfunc copyfunc, \
                                                     sk_##t1##_freefunc freefunc) \
     { \

include/openssl/stack.h

@@ -29,7 +29,7 @@ OPENSSL_STACK *OPENSSL_sk_new(OPENSSL_sk_compfunc cmp);
 OPENSSL_STACK *OPENSSL_sk_new_null(void);
 void OPENSSL_sk_free(OPENSSL_STACK *);
 void OPENSSL_sk_pop_free(OPENSSL_STACK *st, void (*func) (void *));
-OPENSSL_STACK *OPENSSL_sk_deep_copy(OPENSSL_STACK *, OPENSSL_sk_copyfunc c, OPENSSL_sk_freefunc f);
+OPENSSL_STACK *OPENSSL_sk_deep_copy(const OPENSSL_STACK *, OPENSSL_sk_copyfunc c, OPENSSL_sk_freefunc f);
 int OPENSSL_sk_insert(OPENSSL_STACK *sk, void *data, int where);
 void *OPENSSL_sk_delete(OPENSSL_STACK *st, int loc);
 void *OPENSSL_sk_delete_ptr(OPENSSL_STACK *st, const void *p);
@@ -41,7 +41,7 @@ void *OPENSSL_sk_shift(OPENSSL_STACK *st);
 void *OPENSSL_sk_pop(OPENSSL_STACK *st);
 void OPENSSL_sk_zero(OPENSSL_STACK *st);
 OPENSSL_sk_compfunc OPENSSL_sk_set_cmp_func(OPENSSL_STACK *sk, OPENSSL_sk_compfunc cmp);
-OPENSSL_STACK *OPENSSL_sk_dup(OPENSSL_STACK *st);
+OPENSSL_STACK *OPENSSL_sk_dup(const OPENSSL_STACK *st);
 void OPENSSL_sk_sort(OPENSSL_STACK *st);
 int OPENSSL_sk_is_sorted(const OPENSSL_STACK *st);