Create ENABLE_OPENSSL CMake option

This option tells libarchive whether to check for OpenSSL and use it.
We enable it by default since we previously did this unconditionally.
This provides the CMake equivalent to the --without-openssl option,
spelled as -DENABLE_OPENSSL=OFF.  See issue #22.

SVN-Revision: 1750

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 059df17dfff48545c9dbc7e3be70835972eca3de..a19391b2ffa1a0c8e5ca6fa6117d364b223deadc 100644 (file)
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -35,6 +35,7 @@ include(CTest)
 # TODO: Require CMake 2.8 and drop this workaround (perhaps late 2010).
 INCLUDE(AddTest28)
 
+OPTION(ENABLE_OPENSSL "Enable use of OpenSSL" ON)
 OPTION(ENABLE_TAR "Enable tar building" ON)
 OPTION(ENABLE_TAR_SHARED "Enable dynamic build of tar" OFF)
 OPTION(ENABLE_CPIO "Enable cpio building" ON)
@@ -259,11 +260,23 @@ LA_CHECK_INCLUDE_FILE("windows.h" HAVE_WINDOWS_H)
 #
 # Find OpenSSL
 #
-FIND_PACKAGE(OpenSSL)
+IF(ENABLE_OPENSSL)
+  FIND_PACKAGE(OpenSSL)
+ELSE()
+  SET(OPENSSL_FOUND 0)
+ENDIF()
 IF(OPENSSL_FOUND)
   INCLUDE_DIRECTORIES(${OPENSSL_INCLUDE_DIR})
   LIST(APPEND ADDITIONAL_LIBS ${OPENSSL_LIBRARIES})
-ENDIF(OPENSSL_FOUND)
+ELSE()
+  # Block OpenSSL checks and override cached results.
+  SET(HAVE_OPENSSL_MD5_H 0)
+  SET(HAVE_OPENSSL_RIPEMD_H 0)
+  SET(HAVE_OPENSSL_SHA_H 0)
+  SET(HAVE_OPENSSL_SHA256_INIT 0)
+  SET(HAVE_OPENSSL_SHA384_INIT 0)
+  SET(HAVE_OPENSSL_SHA512_INIT 0)
+ENDIF()
 #
 # Check MD5/RMD160/SHA headers
 #