diff --git a/Makefile.am b/Makefile.am
index 0a702e7..97fe1fe 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -12,5 +12,6 @@ EXTRA_DIST = \
 	autogen.sh \
 	m4/ax_gcc_builtin.m4 \
 	m4/ax_pkg_config.m4 \
+	m4/cryb_to.m4 \
 	tools/coverage.sh.in \
 	tools/setprops.sh
diff --git a/configure.ac b/configure.ac
index 8141f2b..39e5174 100644
--- a/configure.ac
+++ b/configure.ac
@@ -186,136 +186,21 @@ unset XFLAGS
 # Components
 #
 
-# Everything
-AC_ARG_ENABLE([all],
-    AS_HELP_STRING([--disable-all],
-        [disable all libraries and tools]),
-    [enable_all=$enableval],
-    [enable_all=yes])
+CRYB_INIT
 
-# Ciphers
-elements="$elements cipher"
-requires="$requires cipher:core"
-AC_ARG_ENABLE([cryb-cipher],
-    AS_HELP_STRING([--enable-cryb-cipher],
-	[build the cipher library]),
-    [enable_cryb_cipher=$enableval],
-    [enable_cryb_cipher=$enable_all])
-AM_CONDITIONAL([CRYB_CIPHER], [test x"$enable_cryb_cipher" = x"yes"])
+CRYB_LIB_PROVIDE([cipher],	[core])
+CRYB_LIB_PROVIDE([core],	[])
+CRYB_LIB_PROVIDE([cpe],		[core])
+CRYB_LIB_PROVIDE([digest],	[core])
+CRYB_LIB_PROVIDE([enc],		[core])
+CRYB_LIB_PROVIDE([hash],	[core])
+CRYB_LIB_PROVIDE([mac],		[core digest])
+CRYB_LIB_PROVIDE([mpi],		[core])
+CRYB_LIB_PROVIDE([oath],	[core digest enc mac rand])
+CRYB_LIB_PROVIDE([rand],	[core])
+CRYB_LIB_PROVIDE([test],	[core])
 
-# Core
-elements="$elements core"
-AC_ARG_ENABLE([cryb-core],
-    AS_HELP_STRING([--enable-cryb-core],
-	[build the core library]),
-    [enable_cryb_core=$enableval],
-    [enable_cryb_core=$enable_all])
-AM_CONDITIONAL([CRYB_CORE], [test x"$enable_cryb_core" = x"yes"])
-
-# CPE
-elements="$elements cpe"
-requires="$requires cpe:core"
-AC_ARG_ENABLE([cryb-cpe],
-    AS_HELP_STRING([--enable-cryb-cpe],
-	[build the CPE library]),
-    [enable_cryb_cpe=$enableval],
-    [enable_cryb_cpe=$enable_all])
-AM_CONDITIONAL([CRYB_CPE], [test x"$enable_cryb_cpe" = x"yes"])
-
-# Message digests
-elements="$elements digest"
-requires="$requires digests:core"
-AC_ARG_ENABLE([cryb-digest],
-    AS_HELP_STRING([--enable-cryb-digest],
-	[build the message digest library]),
-    [enable_cryb_digest=$enableval],
-    [enable_cryb_digest=$enable_all])
-AM_CONDITIONAL([CRYB_DIGEST], [test x"$enable_cryb_digest" = x"yes"])
-
-# Encodings
-elements="$elements enc"
-requires="$requires enc:core"
-AC_ARG_ENABLE([cryb-enc],
-    AS_HELP_STRING([--enable-cryb-enc],
-	[build the encoding library]),
-    [enable_cryb_enc=$enableval],
-    [enable_cryb_enc=$enable_all])
-AM_CONDITIONAL([CRYB_ENC], [test x"$enable_cryb_enc" = x"yes"])
-
-# Non-cryptographic hashes
-elements="$elements hash"
-requires="$requires hash:core"
-AC_ARG_ENABLE([cryb-hash],
-    AS_HELP_STRING([--enable-cryb-hash],
-	[build the non-cryptographic hash library]),
-    [enable_cryb_hash=$enableval],
-    [enable_cryb_hash=$enable_all])
-AM_CONDITIONAL([CRYB_HASH], [test x"$enable_cryb_hash" = x"yes"])
-
-# Message authentication codes
-elements="$elements mac"
-requires="$requires mac:core mac:digest"
-AC_ARG_ENABLE([cryb-mac],
-    AS_HELP_STRING([--enable-cryb-mac],
-	[build the message authentication code library]),
-    [enable_cryb_mac=$enableval],
-    [enable_cryb_mac=$enable_all])
-AM_CONDITIONAL([CRYB_MAC], [test x"$enable_cryb_digest" = x"yes"])
-
-# Multiple-precision integers
-elements="$elements mpi"
-requires="$requires mpi:core"
-AC_ARG_ENABLE([cryb-mpi],
-    AS_HELP_STRING([--enable-cryb-mpi],
-	[build the multiple-precision math library]),
-    [enable_cryb_mpi=$enableval],
-    [enable_cryb_mpi=$enable_all])
-AM_CONDITIONAL([CRYB_MPI], [test x"$enable_cryb_mpi" = x"yes"])
-
-# OATH
-elements="$elements oath"
-requires="$requires oath:core oath:digest oath:enc oath:mac oath:rand"
-AC_ARG_ENABLE([cryb-oath],
-    AS_HELP_STRING([--enable-cryb-oath],
-	[build the OATH library]),
-    [enable_cryb_oath=$enableval],
-    [enable_cryb_oath=$enable_all])
-AM_CONDITIONAL([CRYB_OATH], [test x"$enable_cryb_oath" = x"yes"])
-
-# Pseudo-randomness
-elements="$elements rand"
-requires="$requires rand:core"
-AC_ARG_ENABLE([cryb-rand],
-    AS_HELP_STRING([--enable-cryb-rand],
-	[build the pseudo-randomness library]),
-    [enable_cryb_rand=$enableval],
-    [enable_cryb_rand=$enable_all])
-AM_CONDITIONAL([CRYB_RAND], [test x"$enable_cryb_rand" = x"yes"])
-
-# Test framework
-elements="$elements test"
-requires="$requires test:core"
-AC_ARG_ENABLE([cryb-test],
-    AS_HELP_STRING([--enable-cryb-test],
-	[build the test framework]),
-    [enable_cryb_test=$enableval],
-    [enable_cryb_test=$enable_all])
-AM_CONDITIONAL([CRYB_TEST], [test x"$enable_cryb_test" = x"yes"])
-
-# Check dependencies
-AC_MSG_CHECKING([dependencies])
-for req in $requires ; do
-    lhs=${req%:*}
-    lhs_ena=`eval echo \\\$enable_cryb_$lhs`
-    if test x"$lhs_ena" = x"yes" ; then
-        rhs=${req#*:}
-    	rhs_ena=`eval echo \\\$enable_cryb_$rhs`
-	if test x"$rhs_ena" != x"yes" ; then
-	    AC_MSG_ERROR([cryb-$lhs requires cryb-$rhs])
-	fi
-    fi
-done
-AC_MSG_RESULT([ok])
+CRYB_CHECK_DEPENDENCIES
 
 ############################################################################
 #
@@ -356,11 +241,4 @@ AC_CONFIG_FILES([
 AC_CONFIG_FILES([tools/coverage.sh], [chmod +x tools/coverage.sh])
 AC_OUTPUT
 
-echo
-echo The following Cryb components will be built:
-echo
-for elem in $elements ; do
-    enable=`eval echo \\\$enable_cryb_$elem`
-    printf "%16s: %s\n" $elem ${enable:-no}
-done
-echo
+CRYB_SUMMARY
diff --git a/m4/.gitignore b/m4/.gitignore
index 1ed7cfe..56d9f93 100644
--- a/m4/.gitignore
+++ b/m4/.gitignore
@@ -1,3 +1,4 @@
 /*.m4
 !/ax_gcc_builtin.m4
 !/ax_pkg_config.m4
+!/cryb_to.m4
diff --git a/m4/cryb_to.m4 b/m4/cryb_to.m4
new file mode 100644
index 0000000..7410165
--- /dev/null
+++ b/m4/cryb_to.m4
@@ -0,0 +1,116 @@
+dnl -*- autoconf -*-
+dnl
+dnl Copyright (c) 2018 The University of Oslo
+dnl All rights reserved.
+dnl
+dnl Redistribution and use in source and binary forms, with or without
+dnl modification, are permitted provided that the following conditions
+dnl are met:
+dnl 1. Redistributions of source code must retain the above copyright
+dnl    notice, this list of conditions and the following disclaimer.
+dnl 2. Redistributions in binary form must reproduce the above copyright
+dnl    notice, this list of conditions and the following disclaimer in the
+dnl    documentation and/or other materials provided with the distribution.
+dnl 3. The name of the author may not be used to endorse or promote
+dnl    products derived from this software without specific prior written
+dnl    permission.
+dnl
+dnl THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+dnl ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+dnl IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+dnl ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+dnl FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+dnl DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+dnl OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+dnl HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+dnl LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+dnl OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+dnl SUCH DAMAGE.
+dnl
+
+m4_define([CRYB_MACROS_VERSION], [0.20180506])
+
+dnl
+dnl CRYB_INIT
+dnl ---------
+dnl
+dnl Initialize.
+dnl
+AC_DEFUN([CRYB_INIT], [
+    AC_ARG_ENABLE([all],
+        AS_HELP_STRING([--disable-all],
+            [disable all components]),
+        [enable_all=$enableval],
+        [enable_all=yes])
+])
+
+dnl
+dnl CRYB_LIB_PROVIDE(library-name, [dependencies])
+dnl ----------------------------------------------
+dnl
+dnl Declare a Cryb library that we provide, and its dependencies.
+dnl
+AC_DEFUN([CRYB_LIB_PROVIDE], [
+    m4_define([COMP], m4_toupper([$1]))
+    m4_define([comp], m4_tolower([$1]))
+    m4_set_add([cryb_provides], comp)
+    m4_foreach_w([req], [$2], [m4_set_add([cryb_requires], req)])
+    AC_ARG_ENABLE([cryb-]comp,
+	AS_HELP_STRING([--enable-cryb-]comp,
+	    [build the ]comp[ library]),
+        [enable_cryb_]comp[=$enableval],
+        [enable_cryb_]comp[=$enable_all])
+    if test [x"$enable_cryb_]comp[" = x"yes"] ; then
+	AC_DEFINE([HAVE_CRYB_]COMP, [1], [Define to 1 if you have $1])
+	AC_SUBST([CRYB_]COMP[_VERSION], [$PACKAGE_VERSION])
+        AC_SUBST([CRYB_]COMP[_CFLAGS], [])
+        AC_SUBST([CRYB_]COMP[_LIBS],
+	    ['\$(top_builddir)/lib/]comp[/libcryb-]comp[.la]')
+        AM_CONDITIONAL([HAVE_CRYB_]COMP, [true])
+    else
+        AX_PKG_CONFIG_CHECK([cryb-]comp, [$PACKAGE_VERSION])
+    fi
+    AM_CONDITIONAL([CRYB_]COMP, [test [x"$enable_cryb_]comp[" = x"yes"]])
+])
+
+dnl
+dnl CRYB_LIB_REQUIRE(library-name)
+dnl ------------------------------
+dnl
+dnl Declare a Cryb library that we require.
+dnl
+AC_DEFUN([CRYB_LIB_REQUIRE], [
+    m4_foreach_w([req], [$1], [m4_set_add([cryb_requires], req)])
+])
+
+dnl
+dnl CRYB_CHECK_DEPENDENCIES
+dnl -----------------------
+dnl
+dnl Verify that all dependencies have been satisfied.
+dnl
+AC_DEFUN([CRYB_CHECK_DEPENDENCIES], [
+    AC_MSG_CHECKING([required Cryb elements])
+    m4_set_foreach([cryb_requires], [req], [
+        if test [x"$enable_cryb_]req[" != x"yes"] && \
+	   test [x"$ax_pc_cv_have_cryb_]req[" != x"yes"] ; then
+            AC_MSG_ERROR([missing cryb-]req)
+	fi
+    ])
+    AC_MSG_RESULT([ok])
+])
+
+dnl
+dnl CRYB_SUMMARY
+dnl ------------
+dnl
+dnl Print a summary of enabled components.
+dnl
+AC_DEFUN([CRYB_SUMMARY], [
+    AS_ECHO([])
+    AS_ECHO(["The following Cryb components will be built:"])
+    AS_ECHO([])
+    m4_set_foreach([cryb_provides], [comp], [
+        [printf "%16s: %s\n" ]comp[ ${enable_cryb_]comp[:-no}]
+    ])
+])