build-sys: Implemet AX_CHECK_DEFINE and use for OpenSSL #define's

Some of the functions that OpenSSL uses are #define's for which
we need to check using a new AX_CHECK_DEFINE.

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>

configure.ac

@@ -205,6 +205,10 @@ AS_IF([test "x$enable_use_openssl_functions" != "xno"], [
 	AC_CHECK_LIB([crypto], [EVP_PKEY_verify_init],, not_found=1)
 	AC_CHECK_LIB([crypto], [EVP_PKEY_verify],, not_found=1)
 	AC_CHECK_LIB([crypto], [EVP_get_digestbyname],, not_found=1)
+	AX_CHECK_DEFINE([<openssl/rsa.h>], [EVP_PKEY_CTX_set0_rsa_oaep_label],, not_found=1)
+	AX_CHECK_DEFINE([<openssl/rsa.h>], [EVP_PKEY_CTX_set_rsa_padding],, not_found=1)
+	AX_CHECK_DEFINE([<openssl/rsa.h>], [EVP_PKEY_CTX_set_rsa_oaep_md],, not_found=1)
+	AX_CHECK_DEFINE([<openssl/evp.h>], [EVP_PKEY_CTX_set_signature_md],, not_found=1)
 	if test "x$not_found" = "x0"; then
 		use_openssl_functions_rsa=1
 		use_openssl_functions_for="${use_openssl_functions_for}RSA "

m4/ax_check_define.m4

@@ -0,0 +1,30 @@
+# SYNOPSIS
+#
+#   AX_CHECK_DEFINE(includefile, define, [ACTION-SUCCESS], [ACTION-FAILURE])
+#
+# DESCRIPTION
+#
+#    Check whether the given #define is available in the given #include file
+#
+# LICENSE
+#
+#    See the root directory of the libtpms project for the LICENSE
+#
+AC_DEFUN([AX_CHECK_DEFINE],
+[AC_PREREQ(2.64)
+ AC_MSG_CHECKING(whether $2 is defined in $1)
+ AC_COMPILE_IFELSE(
+  [AC_LANG_PROGRAM([[#include $1]],
+                   [[#ifndef $2
+                   #error $2 not defined
+                   #endif]])],
+                   [
+                      AC_MSG_RESULT([yes])
+                      [$3]
+                   ],
+                   [
+                      AC_MSG_RESULT([no])
+                      [$4]
+                   ])
+  ]
+)