commit 18311d1be81d93350a406b641d501e3ced5a2662
Author: joerg.sonnenberger <joerg.sonnenberger@2e22974a-a639-11dd-bc7a-dd6b2ed99ab5>
Date:   Sun Feb 21 14:23:09 2010 +0000

    Improve detection of SHA2 functions in OpenSSL to deal with ancient
    versions like in Mac OS X and FreeBSD 6.x. Fixes #65 and should fix #55.
    
    
    git-svn-id: http://libarchive.googlecode.com/svn/trunk@1940 2e22974a-a639-11dd-bc7a-dd6b2ed99ab5

diff --git a/configure.ac b/configure.ac
index 45960ad..921ed87 100644
--- a/configure.ac
+++ b/configure.ac
@@ -281,30 +281,34 @@ if test "x$with_openssl" != "xno"; then
     AC_CHECK_HEADERS([openssl/sha.h])
     AC_SEARCH_LIBS([SHA1_Init], [crypto])
   fi
-  if test "$ac_cv_func_SHA256Init" != "yes" ||
-     test "$ac_cv_func_SHA384Init" != "yes" ||
-     test "$ac_cv_func_SHA512Init" != "yes"; then
-    if test "$ac_cv_func_SHA256_Init" != "yes" ||
-       test "$ac_cv_func_SHA384_Init" != "yes" ||
-       test "$ac_cv_func_SHA512_Init" != "yes"; then
-      AC_CHECK_HEADERS([openssl/sha.h])
-      # TODO: Does AC_SEARCH_LIBS support more than one function at once?
-      #       This appears to always fail.
-      AC_SEARCH_LIBS([SHA256_Init SHA384_Init SHA512_Init], [crypto])
-
-      # TODO: Actually test for these.  Previously our C code did not
-      # test for these at all and just assumed availability.  Now that
-      # the C code tests these macros we preserve previous behavior
-      # for the autotools build by hard-coding availability.
-      if test "$ac_cv_header_openssl_sha_h" = "yes"; then
+
+  AC_CHECK_HEADERS([openssl/sha.h])
+  if test "$ac_cv_func_SHA256Init" != "yes" &&
+    test "$ac_cv_func_SHA256_Init" != "yes"; then
+      AC_SEARCH_LIBS([SHA256_Init], [crypto])
+      if test "$ac_cv_func_SHA256_Init" = "yes" &&
+        test "$ac_cv_header_openssl_sha_h" = "yes"; then
         AC_DEFINE(HAVE_OPENSSL_SHA256_INIT, 1,
 	  [Define to 1 if your openssl has the `SHA256_Init' function.])
+      fi
+  fi
+  if test "$ac_cv_func_SHA384Init" != "yes" &&
+    test "$ac_cv_func_SHA384_Init" != "yes"; then
+      AC_SEARCH_LIBS([SHA384_Init], [crypto])
+      if test "$ac_cv_func_SHA384_Init" = "yes" &&
+        test "$ac_cv_header_openssl_sha_h" = "yes"; then
         AC_DEFINE(HAVE_OPENSSL_SHA384_INIT, 1,
 	  [Define to 1 if your openssl has the `SHA384_Init' function.])
+      fi
+  fi
+  if test "$ac_cv_func_SHA512Init" != "yes" &&
+    test "$ac_cv_func_SHA512_Init" != "yes"; then
+      AC_SEARCH_LIBS([SHA512_Init], [crypto])
+      if test "$ac_cv_func_SHA512_Init" = "yes" &&
+        test "$ac_cv_header_openssl_sha_h" = "yes"; then
         AC_DEFINE(HAVE_OPENSSL_SHA512_INIT, 1,
 	  [Define to 1 if your openssl has the `SHA512_Init' function.])
       fi
-    fi
   fi
 fi