--- a/Makefile.in
+++ b/Makefile.in
@@ -35,7 +35,7 @@
 	config \
 	config.h.in \
 	configure \
-	configure.in \
+	configure.ac \
 	COPYING \
 	INSTALL \
 	install-sh \
@@ -82,13 +82,13 @@
 	tar cfj $(distdir).tar.bz2 $(distdir)
 	rm -rf $(distdir)
 
-# automatic re-running of configure if the configure.in file has changed
-configure: configure.in aclocal.m4
+# automatic re-running of configure if the configure.ac file has changed
+configure: configure.ac aclocal.m4
 	autoconf
 
 # autoheader might not change config.h.in, so touch a stamp file
 config.h.in: stamp-h.in
-stamp-h.in: configure.in aclocal.m4
+stamp-h.in: configure.ac aclocal.m4
 	autoheader
 	echo timestamp > stamp-h.in
 
--- a/configure.in
+++ b/configure.in
@@ -68,7 +68,7 @@
 AC_PROG_INSTALL
 AC_PROG_LN_S
 AC_PROG_MAKE_SET
-AC_PROG_RANLIB
+AC_CHECK_TOOL([AR], [ar])
 
 if test "$GCC" = "yes"; then
    CFLAGS="$CFLAGS -Wall -std=gnu9x -pedantic -I.."
@@ -167,55 +167,8 @@
    AC_CHECK_LIB([pthread], [pthread_mutex_init], [], [AC_MSG_ERROR([ophcrack requires libpthread.])])
 fi
 
-
-AC_MSG_CHECKING(for libssl)
-with_ssl=no
-AC_ARG_WITH(libssl, AC_HELP_STRING(--with-libssl=DIR,use libssl in DIR),
-[ case "$withval" in
-  no)
-     AC_MSG_RESULT(no)
-     ;;
-  *)
-     AC_MSG_RESULT(yes)
-     with_ssl=$withval
-     CFLAGS="$CFLAGS -I$with_ssl/include"
-     CXXFLAGS="$CXXFLAGS -I$with_ssl/include"
-	   LIBS="$LIBS -L$with_ssl/lib -lssl -lcrypto"
-     ;;
-  esac ]
-)
-
-if test "x$with_ssl" = "xno"; then
-   CHECK_SSL
-fi
-
-with_expat=no
-AC_ARG_WITH(libexpat, AC_HELP_STRING(--with-libexpat=DIR,use libexpat in DIR),
-[ AC_MSG_CHECKING(for libexpat)
-  case "$withval" in
-  no)
-     AC_MSG_RESULT(no)
-     ;;
-  *)
-     AC_MSG_RESULT(yes)
-     with_expat=$withval
-     if test "x$enable_win32" = "xyes"; then	
-     	CFLAGS="$CFLAGS -I$with_expat/lib"
-     	CXXFLAGS="$CXXFLAGS -I$with_expat/lib"
-     	LIBS="$LIBS -L$with_expat"
-	LIBS_END="$LIBS_END -lexpat"
-     else
-	CFLAGS="$CFLAGS -I$with_expat/include"
-	CXXFLAGS="$CXXFLAGS -I$with_expat/include"
-	LIBS="$LIBS -L$with_expat/lib -lexpat"
-     fi
-     ;;
-  esac ]
-)
-
-if test "x$with_expat" = "xno"; then
-   AC_CHECK_LIB([expat], [XML_ParserCreate], [], [AC_MSG_ERROR([ophcrack requires libexpat.])])
-fi
+PKG_CHECK_MODULES([EXPAT], [expat])
+PKG_CHECK_MODULES([CRYPTO], [libcrypto])
 
 AC_CHECK_LIB([m], [sqrt], [], [AC_MSG_ERROR([ophcrack requires libmath.])])
 
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -20,9 +20,16 @@
 
 CC = @CC@
 
-CPPFLAGS  = @CPPFLAGS@
-CFLAGS  = @CFLAGS@ -Icore -Intproba
-LDFLAGS = @LDFLAGS@ @LIBS@
+CPPFLAGS = @CPPFLAGS@ -Icore -Intproba
+CFLAGS = @CFLAGS@
+LIBS = @LIBS@
+LDFLAGS = @LDFLAGS@
+
+EXPAT_CFLAGS = @EXPAT_CFLAGS@
+EXPAT_LIBS = @EXPAT_LIBS@
+
+CRYPTO_CFLAGS = @CRYPTO_CFLAGS@
+CRYPTO_LIBS = @CRYPTO_LIBS@
 
 SUBDIRS = core ntproba samdump2 test
 @HAVE_GUI_TRUE@SUBDIRS += gui
@@ -48,7 +55,7 @@
 ophcrack: gui/main.cpp core ntproba samdump2
 	cp $< main.c
 	$(CC) $(CPPFLAGS) $(CFLAGS) -c main.c -o main.o
-	$(CC) main.o $(ARCHIVES) -o $@ $(LDFLAGS)
+	$(CC) $(CFLAGS) $(LDFLAGS) main.o $(ARCHIVES) -o $@ $(EXPAT_LIBS) $(CRYPTO_LIBS) $(LIBS)
 	rm main.c main.o
 
 gui: core ntproba samdump2
--- a/src/common.mk.in
+++ b/src/common.mk.in
@@ -23,7 +23,14 @@
 
 CFLAGS  = @CFLAGS@
 CPPFLAGS  = @CPPFLAGS@
-LDFLAGS = @LDFLAGS@ @LIBS@
+LDFLAGS = @LDFLAGS@
+LIBS = @LIBS@
+
+EXPAT_CFLAGS = @EXPAT_CFLAGS@
+EXPAT_LIBS = @EXPAT_LIBS@
+
+CRYPTO_CFLAGS = @CRYPTO_CFLAGS@
+CRYPTO_LIBS = @CRYPTO_LIBS@
 
 HEADERS = $(wildcard *.h)
 SOURCES = $(wildcard *.c)
@@ -32,11 +39,7 @@
 all:
 
 %.a:
-	ar r $@ $^
-	$(RANLIB) $@
-
-%.o: %.c
-	$(CC) $(CPPFLAGS) $(CFLAGS) -c $< -o $@
+	$(AR) rcs $@ $^
 
 clean_:
 	rm -f *.o *~
--- a/src/core/Makefile.in
+++ b/src/core/Makefile.in
@@ -17,7 +17,7 @@
 
 include ../common.mk
 
-CFLAGS += -I../.. -I../samdump2 -I../ntproba
+CPPFLAGS += -I../.. -I../samdump2 -I../ntproba $(CRYPTO_CFLAGS)
 
 all: libophcrack.a
 
--- a/src/gui/gui.pro.in
+++ b/src/gui/gui.pro.in
@@ -30,7 +30,7 @@
   ../ntproba/libntproba.a
 
 PRE_TARGETDEPS += $$ARCHIVES
-LIBS += $$ARCHIVES @LDFLAGS@ @LIBS@
+LIBS += $$ARCHIVES @LDFLAGS@ @EXPAT_LIBS@ @CRYPTO_LIBS@ @LIBS@
 
 QMAKE_CC = @CC@
 QMAKE_CXX = @CXX@
--- a/src/ntproba/Makefile.in
+++ b/src/ntproba/Makefile.in
@@ -17,6 +17,8 @@
 
 include ../common.mk
 
+CPPFLAGS += $(EXPAT_CFLAGS) $(CRYPTO_CFLAGS)
+
 all: libntproba.a
 
 libntproba.a: $(OBJECTS)
--- a/src/samdump2/Makefile.in
+++ b/src/samdump2/Makefile.in
@@ -17,7 +17,7 @@
 
 include ../common.mk
 
-CFLAGS += -I../core
+CPPFLAGS += -I../core $(CRYPTO_CFLAGS)
 
 all: libsamdump2.a
 
--- a/src/test/Makefile.in
+++ b/src/test/Makefile.in
@@ -17,7 +17,7 @@
 
 include ../common.mk
 
-CFLAGS += -I../.. -I../core -I../ntproba
+CPPFLAGS += -I../.. -I../core -I../ntproba
 
 ARCHIVES = \
 	../core/libophcrack.a \
@@ -32,7 +32,7 @@
 %.a:
 
 test_%: test_%.o $(ARCHIVES)
-	$(CC) $^ -o $@ $(LDFLAGS)
+	$(CC) $(CFLAGS) $(LDFLAGS) $^ -o $@ $(EXPAT_LIBS) $(CRYPTO_LIBS) $(LIBS)
 
 clean: clean_
 	rm -f $(TARGETS)