diff --git a/bin/Makefile.am b/bin/Makefile.am
index 2f62bd3..979a74e 100644
--- a/bin/Makefile.am
+++ b/bin/Makefile.am
@@ -1,5 +1,5 @@
 SUBDIRS =
 
-if OTP_UTIL
+if CRYB_CLI
 SUBDIRS += otpkey
-endif OTP_UTIL
+endif CRYB_CLI
diff --git a/configure.ac b/configure.ac
index 565495e..26903b2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1,5 +1,5 @@
 AC_PREREQ([2.63])
-AC_INIT([cryb.otp], [0.20180426], [des@des.no], [cryb-otp], [http://cryb.to/])
+AC_INIT([cryb.otp], [0.20180506], [des@des.no], [cryb-otp], [http://cryb.to/])
 AC_CONFIG_SRCDIR([include/cryb/otp.h])
 AC_CONFIG_MACRO_DIR([m4])
 AM_INIT_AUTOMAKE([foreign no-dist-gzip dist-xz])
@@ -75,31 +75,6 @@ AC_CHECK_DECLS([
 AC_CHECK_FUNCS([strlcat strlcmp strlcpy])
 AC_CHECK_FUNCS([wcslcat wcslcmp wcslcpy])
 
-############################################################################
-#
-# Extra libraries
-#
-
-# Cryb.to components
-AX_PKG_CONFIG_REQUIRE([cryb-core])
-AX_PKG_CONFIG_REQUIRE([cryb-oath])
-
-# Cryb.to test framework
-AX_PKG_CONFIG_CHECK([cryb-test],
-  [AC_MSG_NOTICE([Cryb test framework found, unit tests enabled.])],
-  [AC_MSG_WARN([Cryb test framework not found, unit tests disabled.])])
-
-# libpam
-save_LIBS="${LIBS}"
-LIBS=""
-AC_SEARCH_LIBS([pam_start], [pam], [
-  PAM_LIBS="${LIBS}"
-], [
-  PAM_LIBS=""
-])
-LIBS="${save_LIBS}"
-AC_SUBST(PAM_LIBS)
-
 ############################################################################
 #
 # Build options
@@ -143,77 +118,29 @@ AC_ARG_ENABLE([werror],
 #
 # Components
 #
+CRYB_INIT
 
-# Everything
-AC_ARG_ENABLE([all],
-    AS_HELP_STRING([--disable-all],
-        [disable all libraries and tools]),
-    [enable_all=$enableval],
-    [enable_all=yes])
+CRYB_LIB_REQUIRE([digest test])
 
-# Library
-elements="$elements lib"
-AC_ARG_ENABLE([otp-lib],
-    AS_HELP_STRING([--enable-otp-lib],
-	[build the OTP library]),
-    [enable_otp_lib=$enableval],
-    [enable_otp_lib=$enable_all])
-AM_CONDITIONAL([OTP_LIB], [test x"$enable_otp_lib" = x"yes"])
+CRYB_LIB_PROVIDE([otp], [core oath])
 
-# BSD Auth module
-elements="$elements bsdauth"
-requires="$requires bsdauth:lib"
-AC_ARG_ENABLE([otp-bsdauth],
-    AS_HELP_STRING([--enable-otp-bsdauth],
-	[build the BSD Auth module]),
-    [enable_otp_bsdauth=$enableval],
-    [enable_otp_bsdauth=$enable_all])
-AM_CONDITIONAL([OTP_BSDAUTH], [test x"$enable_otp_bsdauth" = x"yes"])
+CRYB_PROVIDE([bsdauth],	[otp])
+CRYB_PROVIDE([pam],	[otp])
+CRYB_PROVIDE([radius],	[otp])
+CRYB_PROVIDE([cli],	[otp])
 
-# PAM module
-elements="$elements pam"
-requires="$requires pam:lib"
-AC_ARG_ENABLE([otp-pam],
-    AS_HELP_STRING([--enable-otp-pam],
-	[build the PAM module]),
-    [enable_otp_pam=$enableval],
-    [enable_otp_pam=$enable_all])
-AM_CONDITIONAL([OTP_PAM], [test x"$enable_otp_pam" = x"yes"])
+if test x"$enable_cryb_pam" = x"yes" ; then
+    save_LIBS="${LIBS}"
+    LIBS=""
+    AC_CHECK_LIB([pam], [pam_start], [], [
+        AC_MSG_ERROR([libpam is required to build the PAM module])
+    ])
+    PAM_LIBS="${LIBS}"
+    LIBS="${save_LIBS}"
+    AC_SUBST(PAM_LIBS)
+fi
 
-# RADIUS server
-elements="$elements radius"
-requires="$requires radius:lib"
-AC_ARG_ENABLE([otp-radius],
-    AS_HELP_STRING([--enable-otp-radius],
-	[build the RADIUS server]),
-    [enable_otp_radius=$enableval],
-    [enable_otp_radius=$enable_all])
-AM_CONDITIONAL([OTP_RADIUS], [test x"$enable_otp_radius" = x"yes"])
-
-# Command-line utilities
-elements="$elements util"
-requires="$requires util:lib"
-AC_ARG_ENABLE([otp-util],
-    AS_HELP_STRING([--enable-otp-util],
-	[build the command-line utilities]),
-    [enable_otp_util=$enableval],
-    [enable_otp_util=$enable_all])
-AM_CONDITIONAL([OTP_UTIL], [test x"$enable_otp_util" = x"yes"])
-
-# Check dependencies
-AC_MSG_CHECKING([dependencies])
-for req in $requires ; do
-    lhs=${req%:*}
-    lhs_ena=`eval echo \\\$enable_otp_$lhs`
-    if test x"$lhs_ena" = x"yes" ; then
-        rhs=${req#*:}
-	rhs_ena=`eval echo \\\$enable_otp_$rhs`
-	if test x"$rhs_ena" != x"yes" ; then
-	    AC_MSG_ERROR([otp-$lhs requires otp-$rhs])
-	fi
-    fi
-done
-AC_MSG_RESULT([ok])
+CRYB_RESOLVE
 
 ############################################################################
 #
@@ -239,11 +166,4 @@ AC_CONFIG_FILES([
 ])
 AC_OUTPUT
 
-echo
-echo The following Cryb OTP components will be built:
-echo
-for elem in $elements ; do
-    enable=`eval echo \\\$enable_otp_$elem`
-    printf "%16s: %s\n" $elem ${enable:-no}
-done
-echo
+CRYB_SUMMARY
diff --git a/include/cryb/Makefile.am b/include/cryb/Makefile.am
index fb4466c..94124fb 100644
--- a/include/cryb/Makefile.am
+++ b/include/cryb/Makefile.am
@@ -2,9 +2,10 @@ crybdir = $(includedir)/cryb
 
 cryb_HEADERS =
 
-if OTP_LIB
-cryb_HEADERS += otp.h
-endif OTP_LIB
+if CRYB_OTP
+cryb_HEADERS += \
+	otp.h
+endif CRYB_OTP
 
 noinst_HEADERS = \
 	impl.h
diff --git a/lib/Makefile.am b/lib/Makefile.am
index 49a14af..27a1122 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -1,5 +1,5 @@
 SUBDIRS =
 
-if OTP_LIB
+if CRYB_OTP
 SUBDIRS += otp
-endif OTP_LIB
+endif CRYB_OTP
diff --git a/libexec/Makefile.am b/libexec/Makefile.am
index afd5240..6e5160f 100644
--- a/libexec/Makefile.am
+++ b/libexec/Makefile.am
@@ -1,5 +1,5 @@
 SUBDIRS =
 
-if OTP_BSDAUTH
+if CRYB_BSDAUTH
 SUBDIRS += login_otp
-endif
+endif CRYB_BSDAUTH
diff --git a/m4/ax_pkg_config.m4 b/m4/ax_pkg_config.m4
index a888c65..6be3dd2 100644
--- a/m4/ax_pkg_config.m4
+++ b/m4/ax_pkg_config.m4
@@ -28,7 +28,7 @@ dnl OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 dnl SUCH DAMAGE.
 dnl
 
-m4_define([AX_PKG_CONFIG_MACROS_VERSION], [0.20170404])
+m4_define([AX_PKG_CONFIG_MACROS_VERSION], [0.20180506])
 
 dnl
 dnl AX_PROG_PKG_CONFIG([min-version])
@@ -39,8 +39,10 @@ dnl
 AC_DEFUN([AX_PROG_PKG_CONFIG], [
     m4_pattern_forbid([^AX_PKG_CONFIG_[A-Z_]+$])
     AC_ARG_VAR([PKG_CONFIG], [path to pkg-config binary])
-    AC_ARG_VAR([PKG_CONFIG_PATH], [list of directories to prepend to default search path])
-    AC_ARG_VAR([PKG_CONFIG_LIBDIR], [list of directories to search instead of default search path])
+    AC_ARG_VAR([PKG_CONFIG_PATH],
+        [list of directories to prepend to default search path])
+    AC_ARG_VAR([PKG_CONFIG_LIBDIR],
+        [list of directories to search instead of default search path])
     if test x"${PKG_CONFIG}" = x"" ; then
         AC_PATH_PROGS([PKG_CONFIG], [pkgconf pkg-config]) >/dev/null
     else
@@ -97,12 +99,17 @@ AC_DEFUN([AX_PKG_CONFIG_VAR], [
 ])
 
 dnl
-dnl AX_PKG_CONFIG_CHECK(package-name,
+dnl AX_PKG_CONFIG_CHECK(package-name, [version-spec],
 dnl     [action-if-found], [action-if-not-found])
 dnl -------------------------------------------
 dnl
 dnl Check if the specified package is installed.  If it is, define
 dnl HAVE_PACKAGE, PACKAGE_VERSION, PACKAGE_CFLAGS and PACKAGE_LIBS.
+dnl
+dnl The second argument, if non-empty, specifies a minimum (>=1.2.3 or
+dnl >1.2.3), maximum (<=1.2.3 or <1.2.3) or exact (==1.2.3 or =1.2.3
+dnl or 1.2.3) version to look for.
+dnl
 dnl The specified actions are performed in addition to the standard
 dnl actions.
 dnl
@@ -110,10 +117,35 @@ AC_DEFUN([AX_PKG_CONFIG_CHECK], [
     AC_REQUIRE([AX_PROG_PKG_CONFIG])
     m4_define([_P], AS_TR_SH([m4_toupper([$1])]))
     m4_define([_p], AS_TR_SH([m4_tolower([$1])]))
+dnl
+    ver="$2"
+    ver="${ver##*\[<=>\]}"
+    case "$2" in
+    "")
+        vopt=""
+	vtext="$1"
+	;;
+    ">=$ver"|">$ver")
+	vopt="--atleast-version=$ver"
+	vtext="$1 $ver or newer"
+	;;
+    "<=$ver"|"<$ver")
+        vopt="--max-version=$ver"
+	vtext="$1 $ver or older"
+	;;
+    "==$ver"|"=$ver"|"$ver")
+        vopt="--exact-version=$ver"
+	vtext="$1 $ver"
+	;;
+    *)
+        AC_MSG_ERROR([invalid version specification: "$2"])
+	;;
+    esac
+dnl
     AC_ARG_VAR(_P[_CFLAGS], [C compiler flags for $1])
     AC_ARG_VAR(_P[_LIBS], [linker flags for $1])
-    AC_MSG_CHECKING([if $1 is installed])
-    if AC_RUN_LOG(["${PKG_CONFIG}" --exists --print-errors "$1"]) ; then
+    AC_MSG_CHECKING([if ${vtext} is installed])
+    if AC_RUN_LOG(["${PKG_CONFIG}" --exists $vopt --print-errors "$1"]) ; then
         AC_MSG_RESULT([yes])
         [ax_pc_cv_have_]_p=yes
         AC_DEFINE([HAVE_]_P, [1], [Define to 1 if you have $1])
@@ -133,11 +165,11 @@ dnl
         AC_SUBST(_P[_LIBS], [$ax_pc_cv_]_p[_libs])
         AC_MSG_RESULT([${ax_pc_cv_]_p[_libs:-none}])
 dnl
-        m4_default([$2], [:])
+        m4_default([$3], [:])
     else
         AC_MSG_RESULT([no])
         [ax_pc_cv_have_]_p=no
-        m4_default([$3], [:])
+        m4_default([$4], [:])
     fi
     m4_ifdef([AM_CONDITIONAL], [
         AM_CONDITIONAL([HAVE_]_P, [test x"$ax_pc_cv_have_]_p[" = x"yes"])
@@ -145,13 +177,13 @@ dnl
 ])
 
 dnl
-dnl AX_PKG_CONFIG_REQUIRE(package-name)
+dnl AX_PKG_CONFIG_REQUIRE(package-name, [version-spec])
 dnl -----------------------------------
 dnl
 dnl As above, but fail if the package is not installed.
 dnl
 AC_DEFUN([AX_PKG_CONFIG_REQUIRE], [
-    AX_PKG_CONFIG_CHECK([$1], [], [
+    AX_PKG_CONFIG_CHECK([$1], [$2], [], [
         AC_MSG_ERROR([cannot proceed without $1])
     ])
 ])
diff --git a/pam/Makefile.am b/pam/Makefile.am
index 8a3f53e..ea9d488 100644
--- a/pam/Makefile.am
+++ b/pam/Makefile.am
@@ -1,5 +1,5 @@
 SUBDIRS =
 
-if OTP_PAM
+if CRYB_PAM
 SUBDIRS += pam_otp
-endif OTP_PAM
+endif CRYB_PAM
diff --git a/sbin/Makefile.am b/sbin/Makefile.am
index 9863ee3..6fced73 100644
--- a/sbin/Makefile.am
+++ b/sbin/Makefile.am
@@ -1,5 +1,5 @@
 SUBDIRS =
 
-if OTP_RADIUS
+if CRYB_RADIUS
 SUBDIRS += otpradiusd
-endif OTP_RADIUS
+endif CRYB_RADIUS
diff --git a/sbin/otpradiusd/Makefile.am b/sbin/otpradiusd/Makefile.am
index 66b008d..438e383 100644
--- a/sbin/otpradiusd/Makefile.am
+++ b/sbin/otpradiusd/Makefile.am
@@ -7,8 +7,14 @@ sbin_PROGRAMS = otpradiusd
 otpradiusd_SOURCES = otpradiusd.c
 
 otpradiusd_CFLAGS = \
+	$(CRYB_OATH_CFLAGS) \
+	$(CRYB_DIGEST_CFLAGS) \
 	$(CRYB_CORE_CFLAGS)
 
-otpradiusd_LDADD = $(libotp)
+otpradiusd_LDADD = \
+	$(libotp) \
+	$(CRYB_OATH_CFLAGS) \
+	$(CRYB_DIGEST_CFLAGS) \
+	$(CRYB_CORE_CFLAGS)
 
 dist_man8_MANS = otpradiusd.8
diff --git a/t/Makefile.am b/t/Makefile.am
index 3558472..7941534 100644
--- a/t/Makefile.am
+++ b/t/Makefile.am
@@ -14,14 +14,14 @@ TESTS += t_cxx
 t_cxx_SOURCES = t_cxx.cc
 t_cxx_CPPFLAGS = $(AM_CPPFLAGS) $(CRYB_CORE_CFLAGS)
 t_cxx_LDADD =
-if OTP_LIB
-t_cxx_CPPFLAGS += -DWITH_OTP_LIB
+if CRYB_OTP
+t_cxx_CPPFLAGS += -DWITH_CRYB_OTP
 t_cxx_LDADD += $(libotp)
-endif OTP_LIB
+endif CRYB_OTP
 
 # libcryb-otp
-if OTP_LIB
-endif OTP_LIB
+if CRYB_OTP
+endif CRYB_OTP
 
 check_PROGRAMS = $(TESTS)
 
diff --git a/t/t_cxx.cc b/t/t_cxx.cc
index 69fbc02..80dffa6 100644
--- a/t/t_cxx.cc
+++ b/t/t_cxx.cc
@@ -57,7 +57,7 @@ public:
 		}							\
 	};
 
-#if WITH_OTP_LIB
+#if WITH_CRYB_OTP
 #include <cryb/otp.h>
 TEST(otp)
 #endif