Merge pull request #3762 from Security-Onion-Solutions/foxtrot

Refactor so-ssh-harden

salt/common/tools/sbin/so-ssh-harden

@@ -4,90 +4,184 @@
 
 if [[ $1 =~ ^(-q|--quiet) ]]; then
 	quiet=true
+elif [[ $1 =~ ^(-v|--verbose) ]]; then
+	verbose=true
 fi
 
+sshd_config=/etc/ssh/sshd_config
+temp_config=/tmp/sshd_config
+
 before=
 after=
 reload_required=false
+change_header_printed=false
 
-print_sshd_t() {
+check_sshd_t() {
 	local string=$1
-	local state=$2
-	echo "${state}:"
 
 	local grep_out
 	grep_out=$(sshd -T | grep "^${string}")
 
-	if [[ $state == "Before" ]]; then
+	before=$grep_out
-		before=$grep_out
+}
+
+print_diff() {
+	local diff
+	diff=$(diff -dbB <(echo $before) <(echo $after) | awk 'NR>1')
+
+	if [[ -n $diff ]]; then
+		if [[ $change_header_printed == false ]]; then
+			printf '%s\n' '' "Changes" '-------' ''
+			change_header_printed=true
+		fi
+		echo -e "$diff\n"
+	fi
+}
+
+replace_or_add() {
+	local type=$1
+	local string=$2
+	if grep -q "$type" $temp_config; then
+		sed -i "/$type .*/d" $temp_config
+	fi
+	printf "%s\n\n" "$string" >> $temp_config
+	reload_required=true
+}
+
+test_config() {
+	local msg
+	msg=$(sshd -t -f $temp_config)
+	local ret=$?
+
+	if [[ -n $msg ]]; then
+		echo "Error found in temp sshd config:"
+		echo $msg
+	fi
+
+	return $ret
+}
+
+main() {
+	if ! [[ $quiet ]]; then echo "Copying current config to $temp_config"; fi
+	cp $sshd_config $temp_config
+
+	# Add newline to ssh for legibility
+	echo "" >> $temp_config
+
+	# Ciphers
+	check_sshd_t "ciphers"
+
+	local bad_ciphers=(
+		"3des-cbc"
+		"aes128-cbc"
+		"aes192-cbc"
+		"aes256-cbc"
+		"arcfour"
+		"arcfour128"
+		"arcfour256"
+		"blowfish-cbc"
+		"cast128-cbc"
+	)
+
+	local cipher_string=$before
+	for cipher in "${bad_ciphers[@]}"; do
+		cipher_string=$(echo "$cipher_string" | sed "s/${cipher}\(,\|\$\)//g" | sed 's/,$//')
+	done
+
+	after=$cipher_string
+
+	if [[ $verbose ]]; then print_diff; fi
+
+	if [[ $before != "$after" ]]; then
+		replace_or_add "ciphers" "$cipher_string" && test_config || exit 1
+	fi
+
+	# KexAlgorithms
+	check_sshd_t "kexalgorithms"
+
+	local bad_kexalgs=(
+		"diffie-hellman-group-exchange-sha1"
+		"diffie-hellman-group-exchange-sha256"
+		"diffie-hellman-group1-sha1"
+		"diffie-hellman-group14-sha1"
+		"ecdh-sha2-nistp256"
+		"ecdh-sha2-nistp521"
+		"ecdh-sha2-nistp384"
+	)
+
+	local kexalg_string=$before
+	for kexalg in "${bad_kexalgs[@]}"; do
+		kexalg_string=$(echo "$kexalg_string" | sed "s/${kexalg}\(,\|\$\)//g" | sed 's/,$//')
+	done
+
+	after=$kexalg_string
+
+	if [[ $verbose ]]; then print_diff; fi
+
+	if [[ $before != "$after" ]]; then
+		replace_or_add "kexalgorithms" "$kexalg_string" && test_config || exit 1
+	fi
+
+	# Macs
+	check_sshd_t "macs"
+	
+	local bad_macs=(
+		"hmac-sha2-512"
+		"umac-128@openssh.com"
+		"hmac-sha2-256"
+		"umac-64@openssh.com"
+		"hmac-sha1"
+		"hmac-sha1-etm@openssh.com"
+		"umac-64-etm@openssh.com"
+	)
+
+	local macs_string=$before
+	for mac in "${bad_macs[@]}"; do
+		macs_string=$(echo "$macs_string" | sed "s/${mac}\(,\|\$\)//g" | sed 's/,$//')
+	done
+
+	after=$macs_string
+
+	if [[ $verbose ]]; then print_diff; fi
+
+	if [[ $before != "$after" ]]; then
+		replace_or_add "macs" "$macs_string" && test_config || exit 1
+	fi
+
+	# HostKeyAlgorithms
+	check_sshd_t "hostkeyalgorithms"
+	
+	local optional_suffix_regex_hka="\(-cert-v01@openssh.com\)\?"
+	local bad_hostkeyalg_list=(
+		"ecdsa-sha2-nistp256"
+		"ecdsa-sha2-nistp384"
+		"ecdsa-sha2-nistp521"
+		"ssh-rsa"
+		"ssh-dss"
+	)
+
+	local hostkeyalg_string=$before
+	for alg in "${bad_hostkeyalg_list[@]}"; do
+		hostkeyalg_string=$(echo "$hostkeyalg_string" | sed "s/${alg}${optional_suffix_regex_hka}\(,\|\$\)//g" | sed 's/,$//')
+	done
+
+	after=$hostkeyalg_string
+	
+	if [[ $verbose ]]; then print_diff; fi
+	
+	if [[ $before != "$after" ]]; then
+		replace_or_add "hostkeyalgorithms" "$hostkeyalg_string" && test_config || exit 1
+	fi
+
+	if [[ $reload_required == true ]]; then
+		mv -f $temp_config $sshd_config
+		if ! [[ $quiet ]]; then echo "Reloading sshd to load config changes"; fi
+		systemctl reload sshd
+		echo "[ WARNING ] Any new ssh sessions will need to remove and reaccept the host key fingerprint for this server before reconnecting."
 	else
-		after=$grep_out
+		if ! [[ $quiet ]]; then echo "No changes made to temp file, cleaning up"; fi
-	fi
+		rm -f $temp_config
-
-	echo $grep_out
-}
-
-print_msg() {
-	local msg=$1
-	if ! [[ $quiet ]]; then
-	printf "%s\n" \
-		"----" \
-		"$msg" \
-		"----" \
-		""
 	fi
 }
 
-if ! [[ $quiet ]]; then print_sshd_t "ciphers" "Before"; fi
+main
-sshd -T | grep "^ciphers" | sed -e "s/\(3des-cbc\|aes128-cbc\|aes192-cbc\|aes256-cbc\|arcfour\|arcfour128\|arcfour256\|blowfish-cbc\|cast128-cbc\|rijndael-cbc@lysator.liu.se\)\,\?//g" >> /etc/ssh/sshd_config
-if ! [[ $quiet ]]; then
-	print_sshd_t "ciphers" "After"
-	echo ""
-fi
-
-if [[ $before != $after ]]; then
-	reload_required=true
-fi
-
-if ! [[ $quiet ]]; then print_sshd_t "kexalgorithms" "Before"; fi
-sshd -T | grep "^kexalgorithms" | sed -e "s/\(diffie-hellman-group14-sha1\|ecdh-sha2-nistp256\|diffie-hellman-group-exchange-sha256\|diffie-hellman-group1-sha1\|diffie-hellman-group-exchange-sha1\|ecdh-sha2-nistp521\|ecdh-sha2-nistp384\)\,\?//g" >> /etc/ssh/sshd_config
-if ! [[ $quiet ]]; then
-	print_sshd_t "kexalgorithms" "After"
-	echo ""
-fi
-
-if [[ $before != $after ]]; then
-	reload_required=true
-fi
-
-if ! [[ $quiet ]]; then print_sshd_t "macs" "Before"; fi
-sshd -T | grep "^macs" | sed -e "s/\(hmac-sha2-512,\|umac-128@openssh.com,\|hmac-sha2-256,\|umac-64@openssh.com,\|hmac-sha1,\|hmac-sha1-etm@openssh.com,\|umac-64-etm@openssh.com,\|hmac-sha1\)//g" >> /etc/ssh/sshd_config
-if ! [[ $quiet ]]; then
-	print_sshd_t "macs" "After"
-	echo ""
-fi
-
-if [[ $before != $after ]]; then
-	reload_required=true
-fi
-
-if ! [[ $quiet ]]; then print_sshd_t "hostkeyalgorithms" "Before"; fi
-sshd -T | grep "^hostkeyalgorithms" | sed "s|ecdsa-sha2-nistp256,||g" | sed "s|ssh-rsa,||g" >> /etc/ssh/sshd_config
-if ! [[ $quiet ]]; then
-	print_sshd_t "hostkeyalgorithms" "After"
-	echo ""
-fi
-
-if [[ $before != $after ]]; then
-	reload_required=true
-fi
-
-if [[ $reload_required == true ]]; then
-	print_msg "Reloading sshd to load config changes..."
-	systemctl reload sshd
-fi
-
-{% if grains['os'] != 'CentOS' %}
-print_msg "[ WARNING ] Any new ssh sessions will need to remove and reaccept the ECDSA key for this server before reconnecting."
-{% endif %}
-

setup/so-functions

@@ -1454,8 +1454,6 @@ install_cleanup() {
 		info "Removing so-setup permission entry from sudoers file"
 		sed -i '/so-setup/d' /etc/sudoers
 	fi
-
-	so-ssh-harden -q
 }
 
 import_registry_docker() {

setup/so-setup

@@ -906,6 +906,7 @@ set_redirect >> $setup_log 2>&1
 	set_progress_str 85 'Applying finishing touches'
 	filter_unused_nics >> $setup_log 2>&1
 	network_setup >> $setup_log 2>&1
+	so-ssh-harden >> $setup_log 2>&1
 
 	if [[ $is_manager || $is_import ]]; then
 		set_progress_str 87 'Adding user to SOC'