diff --git a/m4/gpg-error.m4 b/m4/gpg-error.m4
index 8ba24b71..a9d572fb 100644
--- a/m4/gpg-error.m4
+++ b/m4/gpg-error.m4
@@ -1,5 +1,5 @@
 # gpg-error.m4 - autoconf macro to detect libgpg-error.
-# Copyright (C) 2002, 2003, 2004, 2011, 2014 g10 Code GmbH
+# Copyright (C) 2002, 2003, 2004, 2011, 2014, 2018 g10 Code GmbH
 #
 # This file is free software; as a special exception the author gives
 # unlimited permission to copy and/or distribute it, with or without
@@ -9,7 +9,7 @@
 # WITHOUT ANY WARRANTY, to the extent permitted by law; without even the
 # implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
 #
-# Last-changed: 2014-10-02
+# Last-changed: 2018-11-02
 
 
 dnl AM_PATH_GPG_ERROR([MINIMUM-VERSION,
@@ -17,7 +17,7 @@ dnl                   [ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND ]]])
 dnl
 dnl Test for libgpg-error and define GPG_ERROR_CFLAGS, GPG_ERROR_LIBS,
 dnl GPG_ERROR_MT_CFLAGS, and GPG_ERROR_MT_LIBS.  The _MT_ variants are
-dnl used for programs requiring real multi thread support.
+dnl used for programs requireing real multi thread support.
 dnl
 dnl If a prefix option is not used, the config script is first
 dnl searched in $SYSROOT/bin and then along $PATH.  If the used
@@ -61,16 +61,55 @@ AC_DEFUN([AM_PATH_GPG_ERROR],
   fi
 
   AC_PATH_PROG(GPG_ERROR_CONFIG, gpg-error-config, no)
-  min_gpg_error_version=ifelse([$1], ,0.0,$1)
-  AC_MSG_CHECKING(for GPG Error - version >= $min_gpg_error_version)
+  min_gpg_error_version=ifelse([$1], ,1.33,$1)
   ok=no
-  if test "$GPG_ERROR_CONFIG" != "no" \
-     && test -f "$GPG_ERROR_CONFIG" ; then
+
+  if test "$prefix" = NONE ; then
+    prefix_option_expanded=/usr/local
+  else
+    prefix_option_expanded="$prefix"
+  fi
+  if test "$exec_prefix" = NONE ; then
+    exec_prefix_option_expanded=$prefix_option_expanded
+  else
+    exec_prefix_option_expanded=$(prefix=$prefix_option_expanded eval echo $exec_prefix)
+  fi
+  libdir_option_expanded=$(prefix=$prefix_option_expanded exec_prefix=$exec_prefix_option_expanded eval echo $libdir)
+
+  if test -f $libdir_option_expanded/pkgconfig/gpg-error.pc; then
+    gpgrt_libdir=$libdir_option_expanded
+  else
+    if crt1_path=$(${CC:-cc} -print-file-name=crt1.o 2>/dev/null); then
+      if possible_libdir=$(cd ${crt1_path%/*} && pwd 2>/dev/null); then
+        if test -f $possible_libdir/pkgconfig/gpg-error.pc; then
+          gpgrt_libdir=$possible_libdir
+        fi
+      fi
+    fi
+  fi
+
+  if test "$GPG_ERROR_CONFIG" = "no" -a -n "$gpgrt_libdir"; then
+    AC_PATH_PROG(GPGRT_CONFIG, gpgrt-config, no)
+    if test "$GPGRT_CONFIG" = "no"; then
+      unset GPGRT_CONFIG
+    else
+      GPGRT_CONFIG="$GPGRT_CONFIG --libdir=$gpgrt_libdir"
+      if $GPGRT_CONFIG gpg-error >/dev/null 2>&1; then
+        GPG_ERROR_CONFIG="$GPGRT_CONFIG gpg-error"
+        AC_MSG_NOTICE([Use gpgrt-config with $gpgrt_libdir as gpg-error-config])
+        gpg_error_config_version=`$GPG_ERROR_CONFIG --modversion`
+      else
+        unset GPGRT_CONFIG
+      fi
+    fi
+  else
+    gpg_error_config_version=`$GPG_ERROR_CONFIG --version`
+  fi
+  if test "$GPG_ERROR_CONFIG" != "no"; then
     req_major=`echo $min_gpg_error_version | \
                sed 's/\([[0-9]]*\)\.\([[0-9]]*\)/\1/'`
     req_minor=`echo $min_gpg_error_version | \
                sed 's/\([[0-9]]*\)\.\([[0-9]]*\)/\2/'`
-    gpg_error_config_version=`$GPG_ERROR_CONFIG $gpg_error_config_args --version`
     major=`echo $gpg_error_config_version | \
                sed 's/\([[0-9]]*\)\.\([[0-9]]*\).*/\1/'`
     minor=`echo $gpg_error_config_version | \
@@ -84,23 +123,51 @@ AC_DEFUN([AM_PATH_GPG_ERROR],
             fi
         fi
     fi
+    if test -z "$GPGRT_CONFIG" -a -n "$gpgrt_libdir"; then
+      if test "$major" -gt 1 -o "$major" -eq 1 -a "$minor" -ge 33; then
+        AC_PATH_PROG(GPGRT_CONFIG, gpgrt-config, no)
+        if test "$GPGRT_CONFIG" = "no"; then
+          unset GPGRT_CONFIG
+        else
+          GPGRT_CONFIG="$GPGRT_CONFIG --libdir=$gpgrt_libdir"
+          if $GPGRT_CONFIG gpg-error >/dev/null 2>&1; then
+            GPG_ERROR_CONFIG="$GPGRT_CONFIG gpg-error"
+            AC_MSG_NOTICE([Use gpgrt-config with $gpgrt_libdir as gpg-error-config])
+          else
+            unset GPGRT_CONFIG
+          fi
+        fi
+      fi
+    fi
   fi
+  AC_MSG_CHECKING(for GPG Error - version >= $min_gpg_error_version)
   if test $ok = yes; then
-    GPG_ERROR_CFLAGS=`$GPG_ERROR_CONFIG $gpg_error_config_args --cflags`
-    GPG_ERROR_LIBS=`$GPG_ERROR_CONFIG $gpg_error_config_args --libs`
-    GPG_ERROR_MT_CFLAGS=`$GPG_ERROR_CONFIG $gpg_error_config_args --mt --cflags 2>/dev/null`
-    GPG_ERROR_MT_LIBS=`$GPG_ERROR_CONFIG $gpg_error_config_args --mt --libs 2>/dev/null`
+    GPG_ERROR_CFLAGS=`$GPG_ERROR_CONFIG --cflags`
+    GPG_ERROR_LIBS=`$GPG_ERROR_CONFIG --libs`
+    if test -z "$GPGRT_CONFIG"; then
+      GPG_ERROR_MT_CFLAGS=`$GPG_ERROR_CONFIG --mt --cflags 2>/dev/null`
+      GPG_ERROR_MT_LIBS=`$GPG_ERROR_CONFIG --mt --libs 2>/dev/null`
+    else
+      GPG_ERROR_MT_CFLAGS=`$GPG_ERROR_CONFIG --variable=mtcflags 2>/dev/null`
+      GPG_ERROR_MT_CFLAGS="$GPG_ERROR_CFLAGS${GPG_ERROR_CFLAGS:+ }$GPG_ERROR_MT_CFLAGS"
+      GPG_ERROR_MT_LIBS=`$GPG_ERROR_CONFIG --variable=mtlibs 2>/dev/null`
+      GPG_ERROR_MT_LIBS="$GPG_ERROR_LIBS${GPG_ERROR_LIBS:+ }$GPG_ERROR_MT_LIBS"
+    fi
     AC_MSG_RESULT([yes ($gpg_error_config_version)])
     ifelse([$2], , :, [$2])
-    gpg_error_config_host=`$GPG_ERROR_CONFIG $gpg_error_config_args --host 2>/dev/null || echo none`
+    if test -z "$GPGRT_CONFIG"; then
+      gpg_error_config_host=`$GPG_ERROR_CONFIG --host 2>/dev/null || echo none`
+    else
+      gpg_error_config_host=`$GPG_ERROR_CONFIG --variable=host 2>/dev/null || echo none`
+    fi
     if test x"$gpg_error_config_host" != xnone ; then
       if test x"$gpg_error_config_host" != x"$host" ; then
   AC_MSG_WARN([[
 ***
-*** The config script $GPG_ERROR_CONFIG was
+*** The config script "$GPG_ERROR_CONFIG" was
 *** built for $gpg_error_config_host and thus may not match the
 *** used host $host.
-*** You may want to use the configure option --with-gpg-error-prefix
+*** You may want to use the configure option --with-libgpg-error-prefix
 *** to specify a matching config script or use \$SYSROOT.
 ***]])
         gpg_config_script_warn="$gpg_config_script_warn libgpg-error"
diff --git a/m4/libassuan.m4 b/m4/libassuan.m4
index 4b196a5c..4af2d04f 100644
--- a/m4/libassuan.m4
+++ b/m4/libassuan.m4
@@ -8,6 +8,7 @@ dnl
 dnl This file is distributed in the hope that it will be useful, but
 dnl WITHOUT ANY WARRANTY, to the extent permitted by law; without even the
 dnl implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+dnl SPDX-License-Identifier: FSFULLR
 
 dnl
 dnl Common code used for libassuan detection [internal]
@@ -20,13 +21,22 @@ AC_DEFUN([_AM_PATH_LIBASSUAN_COMMON],
                              [prefix where LIBASSUAN is installed (optional)]),
      libassuan_config_prefix="$withval", libassuan_config_prefix="")
   if test x$libassuan_config_prefix != x ; then
-    libassuan_config_args="$libassuan_config_args --prefix=$libassuan_config_prefix"
     if test x${LIBASSUAN_CONFIG+set} != xset ; then
       LIBASSUAN_CONFIG=$libassuan_config_prefix/bin/libassuan-config
     fi
   fi
 
-  AC_PATH_TOOL(LIBASSUAN_CONFIG, libassuan-config, no)
+  use_gpgrt_config=""
+  if test x"${LIBASSUAN_CONFIG}" = x -a x"$GPGRT_CONFIG" != x -a "$GPGRT_CONFIG" != "no"; then
+    if $GPGRT_CONFIG libassuan --exists; then
+      LIBASSUAN_CONFIG="$GPGRT_CONFIG libassuan"
+      AC_MSG_NOTICE([Use gpgrt-config as libassuan-config])
+      use_gpgrt_config=yes
+    fi
+  fi
+  if test -z "$use_gpgrt_config"; then
+    AC_PATH_PROG(LIBASSUAN_CONFIG, libassuan-config, no)
+  fi
 
   tmp=ifelse([$1], ,1:0.9.2,$1)
   if echo "$tmp" | grep ':' >/dev/null 2>/dev/null ; then
@@ -39,8 +49,7 @@ AC_DEFUN([_AM_PATH_LIBASSUAN_COMMON],
 
   AC_MSG_CHECKING(for LIBASSUAN - version >= $min_libassuan_version)
   ok=no
-  if test "$LIBASSUAN_CONFIG" != "no" \
-     && test -f "$LIBASSUAN_CONFIG" ; then
+  if test "$LIBASSUAN_CONFIG" != "no"; then
     req_major=`echo $min_libassuan_version | \
                sed 's/\([[0-9]]*\)\.\([[0-9]]*\)\.\([[0-9]]*\)/\1/'`
     req_minor=`echo $min_libassuan_version | \
@@ -48,7 +57,11 @@ AC_DEFUN([_AM_PATH_LIBASSUAN_COMMON],
     req_micro=`echo $min_libassuan_version | \
                sed 's/\([[0-9]]*\)\.\([[0-9]]*\)\.\([[0-9]]*\)/\3/'`
 
-    libassuan_config_version=`$LIBASSUAN_CONFIG --version`
+    if test -z "$use_gpgrt_config"; then
+      libassuan_config_version=`$LIBASSUAN_CONFIG --version`
+    else
+      libassuan_config_version=`$LIBASSUAN_CONFIG --modversion`
+    fi
     major=`echo $libassuan_config_version | \
                sed 's/\([[0-9]]*\)\.\([[0-9]]*\)\.\([[0-9]]*\).*/\1/'`
     minor=`echo $libassuan_config_version | \
@@ -58,7 +71,7 @@ AC_DEFUN([_AM_PATH_LIBASSUAN_COMMON],
 
     if test "$major" -gt "$req_major"; then
         ok=yes
-    else 
+    else
         if test "$major" -eq "$req_major"; then
             if test "$minor" -gt "$req_minor"; then
                ok=yes
@@ -81,7 +94,11 @@ AC_DEFUN([_AM_PATH_LIBASSUAN_COMMON],
 
   if test $ok = yes; then
     if test "$req_libassuan_api" -gt 0 ; then
-      tmp=`$LIBASSUAN_CONFIG --api-version 2>/dev/null || echo 0`
+      if test -z "$use_gpgrt_config"; then
+        tmp=`$LIBASSUAN_CONFIG --api-version 2>/dev/null || echo 0`
+      else
+        tmp=`$LIBASSUAN_CONFIG --variable=api_version 2>/dev/null || echo 0`
+      fi
       if test "$tmp" -gt 0 ; then
         AC_MSG_CHECKING([LIBASSUAN API version])
         if test "$req_libassuan_api" -eq "$tmp" ; then
@@ -96,12 +113,16 @@ AC_DEFUN([_AM_PATH_LIBASSUAN_COMMON],
 
   if test $ok = yes; then
     if test x"$host" != x ; then
-      libassuan_config_host=`$LIBASSUAN_CONFIG --host 2>/dev/null || echo none`
+      if test -z "$use_gpgrt_config"; then
+        libassuan_config_host=`$LIBASSUAN_CONFIG --host 2>/dev/null || echo none`
+      else
+        libassuan_config_host=`$LIBASSUAN_CONFIG --variable=host 2>/dev/null || echo none`
+      fi
       if test x"$libassuan_config_host" != xnone ; then
         if test x"$libassuan_config_host" != x"$host" ; then
   AC_MSG_WARN([[
 ***
-*** The config script $LIBASSUAN_CONFIG was
+*** The config script "$LIBASSUAN_CONFIG" was
 *** built for $libassuan_config_host and thus may not match the
 *** used host $host.
 *** You may want to use the configure option --with-libassuan-prefix
@@ -137,8 +158,8 @@ dnl
 AC_DEFUN([AM_PATH_LIBASSUAN],
 [ _AM_PATH_LIBASSUAN_COMMON($1)
   if test $ok = yes; then
-    LIBASSUAN_CFLAGS=`$LIBASSUAN_CONFIG $libassuan_config_args --cflags`
-    LIBASSUAN_LIBS=`$LIBASSUAN_CONFIG $libassuan_config_args --libs`
+    LIBASSUAN_CFLAGS=`$LIBASSUAN_CONFIG --cflags`
+    LIBASSUAN_LIBS=`$LIBASSUAN_CONFIG --libs`
     ifelse([$2], , :, [$2])
   else
     LIBASSUAN_CFLAGS=""