Check for the existence of openssl version funcs.

Check for the existence of openssl version functions and use the ones
detected instead of trying to guess based on the int32 version
identifier.  Fixes builds with LibreSSL.

configure.ac

@@ -2585,6 +2585,9 @@ if test "x$openssl" = "xyes" ; then
 		]
 	)
 
+	# Determining OpenSSL library version is version dependent.
+	AC_CHECK_FUNCS([OpenSSL_version OpenSSL_version_num])
+
 	# Determine OpenSSL library version
 	AC_MSG_CHECKING([OpenSSL library version])
 	AC_RUN_IFELSE(
@@ -2601,10 +2604,14 @@ if test "x$openssl" = "xyes" ; then
 		fd = fopen(DATA,"w");
 		if(fd == NULL)
 			exit(1);
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
-# define OpenSSL_version_num	SSLeay
+#ifndef OPENSSL_VERSION
+# define OPENSSL_VERSION SSLEAY_VERSION
+#endif
+#ifndef HAVE_OPENSSL_VERSION
 # define OpenSSL_version	SSLeay_version
-# define OPENSSL_VERSION	SSLEAY_VERSION
+#endif
+#ifndef HAVE_OPENSSL_VERSION_NUM
+# define OpenSSL_version_num	SSLeay
 #endif
 		if ((rc = fprintf(fd, "%08lx (%s)\n",
 		    (unsigned long)OpenSSL_version_num(),
@@ -2650,8 +2657,8 @@ if test "x$openssl" = "xyes" ; then
 	#include <openssl/opensslv.h>
 	#include <openssl/crypto.h>
 		]], [[
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
-# define OpenSSL_version_num SSLeay
+#ifndef HAVE_OPENSSL_VERSION_NUM
+# define OpenSSL_version_num	SSLeay
 #endif
 		exit(OpenSSL_version_num() == OPENSSL_VERSION_NUMBER ? 0 : 1);
 		]])],