gost_pmeth.c: mitigate for constness difference in copy function

The second argument for the pkey_copy function has been constified in
OpenSSL to be 3.0.  This is normally not a problem, but when passing a
pointer to such a function, the compiler does complain.

This change solves the issue by looking at the macros
OPENSSL_VERSION_MAJOR, which is new in OpenSSL to be 3.0, and set
constness based on that.

Fixes #154

diff --git a/gost_pmeth.c b/gost_pmeth.c
index 7eded878bd08f4b0bfb580a8acf678f77a4e7a15..2b94e36298d3c3d71495fce6e422c485db7343da 100644 (file)
--- a/gost_pmeth.c
+++ b/gost_pmeth.c
@@ -12,12 +12,19 @@
 #include <openssl/ec.h>
 #include <openssl/err.h>
 #include <openssl/x509v3.h>     /* For string_to_hex */
+#include <openssl/opensslv.h>   /* For OPENSSL_VERSION_MAJOR */
 #include <stdlib.h>
 #include <string.h>
 #include <ctype.h>
 #include "gost_lcl.h"
 #include "e_gost_err.h"
 
+#define ossl3_const
+#ifdef OPENSSL_VERSION_MAJOR
+#undef ossl3_const
+#define ossl3_const const
+#endif
+
 /* -----init, cleanup, copy - uniform for all algs  --------------*/
 /* Allocates new gost_pmeth_data structure and assigns it as data */
 static int pkey_gost_init(EVP_PKEY_CTX *ctx)
@@ -53,7 +60,7 @@ static int pkey_gost_init(EVP_PKEY_CTX *ctx)
 }
 
 /* Copies contents of gost_pmeth_data structure */
-static int pkey_gost_copy(EVP_PKEY_CTX *dst, const EVP_PKEY_CTX *src)
+static int pkey_gost_copy(EVP_PKEY_CTX *dst, ossl3_const EVP_PKEY_CTX *src)
 {
     struct gost_pmeth_data *dst_data, *src_data;
     if (!pkey_gost_init(dst)) {
@@ -564,7 +571,7 @@ static void pkey_gost_mac_cleanup(EVP_PKEY_CTX *ctx)
         OPENSSL_free(data);
 }
 
-static int pkey_gost_mac_copy(EVP_PKEY_CTX *dst, const EVP_PKEY_CTX *src)
+static int pkey_gost_mac_copy(EVP_PKEY_CTX *dst, ossl3_const EVP_PKEY_CTX *src)
 {
     struct gost_mac_pmeth_data *dst_data, *src_data;
     if (!pkey_gost_mac_init(dst)) {