Bump the minimal OpenSSL version to 1.1.1

As BIND 9.20 does not support RHEL/CentOS 7 which just reach
end-of-life, we can safely bump the OpenSSL requirements to version
1.1.1, which in turn will allow us to simplify our OpenSSL integration.

configure.ac

@@ -653,7 +653,7 @@ CRYPTO=OpenSSL
 #
 # OpenSSL/LibreSSL is mandatory
 #
-PKG_CHECK_MODULES([OPENSSL], [libssl libcrypto], [PKG_CHECK_VERSION([OPENSSL_VERSION], [openssl])],
+PKG_CHECK_MODULES([OPENSSL], [libssl >= 1.1.1 libcrypto >= 1.1.1], [PKG_CHECK_VERSION([OPENSSL_VERSION], [openssl])],
 		  [AX_CHECK_OPENSSL([:], [AC_MSG_FAILURE([OpenSSL/LibreSSL not found])])])
 
 AX_SAVE_FLAGS([openssl])
@@ -661,12 +661,12 @@ AX_SAVE_FLAGS([openssl])
 CFLAGS="$OPENSSL_CFLAGS $CFLAGS"
 LIBS="$OPENSSL_LIBS $LIBS"
 
-AC_MSG_CHECKING([for OpenSSL >= 1.0.0 or LibreSSL >= 2.7.0])
+AC_MSG_CHECKING([for OpenSSL >= 1.1.1 or LibreSSL >= 2.7.0])
 AC_COMPILE_IFELSE(
     [AC_LANG_PROGRAM([[#include <openssl/opensslv.h>]],
-		     [[#if (!defined(LIBRESSL_VERSION_NUMBER) && (OPENSSL_VERSION_NUMBER < 0x1000000fL)) || \\
+		     [[#if (!defined(LIBRESSL_VERSION_NUMBER) && (OPENSSL_VERSION_NUMBER < 0x01010100fL)) || \\
 			   (defined(LIBRESSL_VERSION_NUMBER) && (LIBRESSL_VERSION_NUMBER < 0x02070000fL))
-		       #error OpenSSL >= 1.0.0 or LibreSSL >= 2.7.0 required
+		       #error OpenSSL >= 1.1.1 or LibreSSL >= 2.7.0 required
 		       #endif
 		      ]])],
     [AC_MSG_RESULT([yes])],

doc/arm/platforms.inc.rst

@@ -99,7 +99,7 @@ Unsupported Platforms
 
 These are platforms on which current versions of BIND 9 are known *not* to build or run:
 
--  Platforms without at least OpenSSL 1.0.2
+-  Platforms without at least OpenSSL 1.1.1
 -  Windows
 -  Solaris 10 and older
 -  Platforms that do not support IPv6 Advanced Socket API (:rfc:`3542`)

m4/ax_check_openssl.m4

@@ -1,133 +0,0 @@
-# SPDX-License-Identifier: FSFAP
-#
-# ===========================================================================
-#     https://www.gnu.org/software/autoconf-archive/ax_check_openssl.html
-# ===========================================================================
-#
-# SYNOPSIS
-#
-#   AX_CHECK_OPENSSL([action-if-found[, action-if-not-found]])
-#
-# DESCRIPTION
-#
-#   Look for OpenSSL in a number of default spots, or in a user-selected
-#   spot (via --with-openssl).  Sets
-#
-#     OPENSSL_CFLAGS to the include directives required
-#     OPENSSL_LIBS to the -l directives required
-#     OPENSSL_LDFLAGS to the -L or -R flags required
-#
-#   and calls ACTION-IF-FOUND or ACTION-IF-NOT-FOUND appropriately
-#
-#   This macro sets OPENSSL_CFLAGS such that source files should use the
-#   openssl/ directory in include directives:
-#
-#     #include <openssl/hmac.h>
-#
-# LICENSE
-#
-#   Copyright (c) 2009,2010 Zmanda Inc. <http://www.zmanda.com/>
-#   Copyright (c) 2009,2010 Dustin J. Mitchell <dustin@zmanda.com>
-#
-#   Copying and distribution of this file, with or without modification, are
-#   permitted in any medium without royalty provided the copyright notice
-#   and this notice are preserved. This file is offered as-is, without any
-#   warranty.
-
-#serial 11
-
-AU_ALIAS([CHECK_SSL], [AX_CHECK_OPENSSL])
-AC_DEFUN([AX_CHECK_OPENSSL], [
-    found=false
-    AC_PROG_SED
-    AC_ARG_WITH([openssl],
-        [AS_HELP_STRING([--with-openssl=DIR],
-            [root of the OpenSSL directory])],
-        [
-            case "$withval" in
-            "" | y | ye | yes | n | no)
-            AC_MSG_ERROR([Invalid --with-openssl value])
-              ;;
-            *) ssldirs="$withval"
-              ;;
-            esac
-        ], [
-            # if pkg-config is installed and openssl has installed a .pc file,
-            # then use that information and don't search ssldirs
-            AC_CHECK_TOOL([PKG_CONFIG], [pkg-config])
-            if test x"$PKG_CONFIG" != x""; then
-                OPENSSL_LDFLAGS=`$PKG_CONFIG openssl --libs-only-L 2>/dev/null`
-                if test $? = 0; then
-                    OPENSSL_LIBS=`$PKG_CONFIG openssl --libs-only-l 2>/dev/null`
-                    OPENSSL_CFLAGS=`$PKG_CONFIG openssl --cflags-only-I 2>/dev/null`
-                    OPENSSL_VERSION=`$PKG_CONFIG openssl --modversion 2>/dev/null`
-                    found=true
-                fi
-            fi
-
-            # no such luck; use some default ssldirs
-            if ! $found; then
-                ssldirs="/usr/local/ssl /usr/lib/ssl /usr/ssl /usr/pkg /usr/local /usr"
-            fi
-        ]
-        )
-
-
-    # note that we #include <openssl/foo.h>, so the OpenSSL headers have to be in
-    # an 'openssl' subdirectory
-
-    if ! $found; then
-        OPENSSL_CFLAGS=
-        for ssldir in $ssldirs; do
-            AC_MSG_CHECKING([for include/openssl/ssl.h in $ssldir])
-            if test -f "$ssldir/include/openssl/ssl.h"; then
-                OPENSSL_CFLAGS="-I$ssldir/include"
-                OPENSSL_LDFLAGS="-L$ssldir/lib"
-                OPENSSL_LIBS="-lssl -lcrypto"
-                OPENSSL_VERSION=`$SED -ne 's/.*OPENSSL_VERSION_STR[^"]*"\([^"]*\)".*/\1/p;' $ssldir/include/openssl/opensslv.h`
-                if test -z "$OPENSSL_VERSION"; then
-                  OPENSSL_VERSION=`$SED -ne 's/.*OPENSSL_VERSION_TEXT[^"]*"\([^"]*\)".*/\1/p;' $ssldir/include/openssl/opensslv.h`
-                fi
-                found=true
-                AC_MSG_RESULT([yes])
-                break
-            else
-                AC_MSG_RESULT([no])
-            fi
-        done
-
-        # if the file wasn't found, well, go ahead and try the link anyway -- maybe
-        # it will just work!
-    fi
-
-    # try the preprocessor and linker with our new flags,
-    # being careful not to pollute the global LIBS, LDFLAGS, and CPPFLAGS
-
-    AC_MSG_CHECKING([whether compiling and linking against OpenSSL works])
-    echo "Trying link with OPENSSL_LDFLAGS=$OPENSSL_LDFLAGS;" \
-        "OPENSSL_LIBS=$OPENSSL_LIBS; OPENSSL_CFLAGS=$OPENSSL_CFLAGS" >&AS_MESSAGE_LOG_FD
-
-    save_LIBS="$LIBS"
-    save_LDFLAGS="$LDFLAGS"
-    save_CPPFLAGS="$CPPFLAGS"
-    LDFLAGS="$LDFLAGS $OPENSSL_LDFLAGS"
-    LIBS="$OPENSSL_LIBS $LIBS"
-    CPPFLAGS="$OPENSSL_CFLAGS $CPPFLAGS"
-    AC_LINK_IFELSE(
-        [AC_LANG_PROGRAM([#include <openssl/ssl.h>], [SSL_new(NULL)])],
-        [
-            AC_MSG_RESULT([yes])
-            $1
-        ], [
-            AC_MSG_RESULT([no])
-            $2
-        ])
-    CPPFLAGS="$save_CPPFLAGS"
-    LDFLAGS="$save_LDFLAGS"
-    LIBS="$save_LIBS"
-
-    AC_SUBST([OPENSSL_CFLAGS])
-    AC_SUBST([OPENSSL_LIBS])
-    AC_SUBST([OPENSSL_LDFLAGS])
-    AC_SUBST([OPENSSL_VERSION])
-])