Stop using the now deprecated ERR_load_CRYPTO_strings() to detect OpenSSL

And move to BN_new() instead, which has been present since at least
0.9.6 and is still in 3.1.

(cherry picked from commit 9fcef4932c9323b085984f8a087045fef70103f5)

diff --git a/m4/pdns_check_libcrypto.m4 b/m4/pdns_check_libcrypto.m4
index 8e1219a3e75bcb2566d457d82399b4a22fdb843e..1fa4f23bda9330aff85ed4322000252c34521a8e 100644 (file)
--- a/m4/pdns_check_libcrypto.m4
+++ b/m4/pdns_check_libcrypto.m4
@@ -108,7 +108,7 @@ AC_DEFUN([PDNS_CHECK_LIBCRYPTO], [
     LIBS="$LIBCRYPTO_LIBS $LIBS"
     CPPFLAGS="$LIBCRYPTO_INCLUDES $CPPFLAGS"
     AC_LINK_IFELSE(
-        [AC_LANG_PROGRAM([#include <openssl/crypto.h>], [ERR_load_CRYPTO_strings()])],
+        [AC_LANG_PROGRAM([#include <openssl/bn.h>], [BN_new()])],
         [
             AC_MSG_RESULT([yes])
             AC_CHECK_FUNCS([RAND_bytes RAND_pseudo_bytes CRYPTO_memcmp OPENSSL_init_crypto EVP_MD_CTX_new EVP_MD_CTX_free RSA_get0_key])