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// Copyright 2015 Matthew Holt and The Caddy Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package caddytls
import (
"crypto/tls"
"fmt"
"net"
"net/netip"
"strings"
"github.com/caddyserver/certmagic"
"go.uber.org/zap"
"github.com/caddyserver/caddy/v2"
)
func init() {
caddy.RegisterModule(MatchServerName{})
caddy.RegisterModule(MatchRemoteIP{})
caddy.RegisterModule(MatchLocalIP{})
}
// MatchServerName matches based on SNI. Names in
// this list may use left-most-label wildcards,
// similar to wildcard certificates.
type MatchServerName []string
// CaddyModule returns the Caddy module information.
func (MatchServerName) CaddyModule() caddy.ModuleInfo {
return caddy.ModuleInfo{
ID: "tls.handshake_match.sni",
New: func() caddy.Module { return new(MatchServerName) },
}
}
// Match matches hello based on SNI.
func (m MatchServerName) Match(hello *tls.ClientHelloInfo) bool {
for _, name := range m {
if certmagic.MatchWildcard(hello.ServerName, name) {
return true
}
}
return false
}
// MatchRemoteIP matches based on the remote IP of the
// connection. Specific IPs or CIDR ranges can be specified.
//
// Note that IPs can sometimes be spoofed, so do not rely
// on this as a replacement for actual authentication.
type MatchRemoteIP struct {
// The IPs or CIDR ranges to match.
Ranges []string `json:"ranges,omitempty"`
// The IPs or CIDR ranges to *NOT* match.
NotRanges []string `json:"not_ranges,omitempty"`
cidrs []netip.Prefix
notCidrs []netip.Prefix
logger *zap.Logger
}
// CaddyModule returns the Caddy module information.
func (MatchRemoteIP) CaddyModule() caddy.ModuleInfo {
return caddy.ModuleInfo{
ID: "tls.handshake_match.remote_ip",
New: func() caddy.Module { return new(MatchRemoteIP) },
}
}
// Provision parses m's IP ranges, either from IP or CIDR expressions.
func (m *MatchRemoteIP) Provision(ctx caddy.Context) error {
m.logger = ctx.Logger()
for _, str := range m.Ranges {
cidrs, err := m.parseIPRange(str)
if err != nil {
return err
}
m.cidrs = append(m.cidrs, cidrs...)
}
for _, str := range m.NotRanges {
cidrs, err := m.parseIPRange(str)
if err != nil {
return err
}
m.notCidrs = append(m.notCidrs, cidrs...)
}
return nil
}
// Match matches hello based on the connection's remote IP.
func (m MatchRemoteIP) Match(hello *tls.ClientHelloInfo) bool {
remoteAddr := hello.Conn.RemoteAddr().String()
ipStr, _, err := net.SplitHostPort(remoteAddr)
if err != nil {
ipStr = remoteAddr // weird; maybe no port?
}
ipAddr, err := netip.ParseAddr(ipStr)
if err != nil {
m.logger.Error("invalid client IP address", zap.String("ip", ipStr))
return false
}
return (len(m.cidrs) == 0 || m.matches(ipAddr, m.cidrs)) &&
(len(m.notCidrs) == 0 || !m.matches(ipAddr, m.notCidrs))
}
func (MatchRemoteIP) parseIPRange(str string) ([]netip.Prefix, error) {
var cidrs []netip.Prefix
if strings.Contains(str, "/") {
ipNet, err := netip.ParsePrefix(str)
if err != nil {
return nil, fmt.Errorf("parsing CIDR expression: %v", err)
}
cidrs = append(cidrs, ipNet)
} else {
ipAddr, err := netip.ParseAddr(str)
if err != nil {
return nil, fmt.Errorf("invalid IP address: '%s': %v", str, err)
}
ip := netip.PrefixFrom(ipAddr, ipAddr.BitLen())
cidrs = append(cidrs, ip)
}
return cidrs, nil
}
func (MatchRemoteIP) matches(ip netip.Addr, ranges []netip.Prefix) bool {
for _, ipRange := range ranges {
if ipRange.Contains(ip) {
return true
}
}
return false
}
// MatchLocalIP matches based on the IP address of the interface
// receiving the connection. Specific IPs or CIDR ranges can be specified.
type MatchLocalIP struct {
// The IPs or CIDR ranges to match.
Ranges []string `json:"ranges,omitempty"`
cidrs []netip.Prefix
logger *zap.Logger
}
// CaddyModule returns the Caddy module information.
func (MatchLocalIP) CaddyModule() caddy.ModuleInfo {
return caddy.ModuleInfo{
ID: "tls.handshake_match.local_ip",
New: func() caddy.Module { return new(MatchLocalIP) },
}
}
// Provision parses m's IP ranges, either from IP or CIDR expressions.
func (m *MatchLocalIP) Provision(ctx caddy.Context) error {
m.logger = ctx.Logger()
for _, str := range m.Ranges {
cidrs, err := m.parseIPRange(str)
if err != nil {
return err
}
m.cidrs = append(m.cidrs, cidrs...)
}
return nil
}
// Match matches hello based on the connection's remote IP.
func (m MatchLocalIP) Match(hello *tls.ClientHelloInfo) bool {
localAddr := hello.Conn.LocalAddr().String()
ipStr, _, err := net.SplitHostPort(localAddr)
if err != nil {
ipStr = localAddr // weird; maybe no port?
}
ipAddr, err := netip.ParseAddr(ipStr)
if err != nil {
m.logger.Error("invalid local IP address", zap.String("ip", ipStr))
return false
}
return (len(m.cidrs) == 0 || m.matches(ipAddr, m.cidrs))
}
func (MatchLocalIP) parseIPRange(str string) ([]netip.Prefix, error) {
var cidrs []netip.Prefix
if strings.Contains(str, "/") {
ipNet, err := netip.ParsePrefix(str)
if err != nil {
return nil, fmt.Errorf("parsing CIDR expression: %v", err)
}
cidrs = append(cidrs, ipNet)
} else {
ipAddr, err := netip.ParseAddr(str)
if err != nil {
return nil, fmt.Errorf("invalid IP address: '%s': %v", str, err)
}
ip := netip.PrefixFrom(ipAddr, ipAddr.BitLen())
cidrs = append(cidrs, ip)
}
return cidrs, nil
}
func (MatchLocalIP) matches(ip netip.Addr, ranges []netip.Prefix) bool {
for _, ipRange := range ranges {
if ipRange.Contains(ip) {
return true
}
}
return false
}
// Interface guards
var (
_ ConnectionMatcher = (*MatchServerName)(nil)
_ ConnectionMatcher = (*MatchRemoteIP)(nil)
_ caddy.Provisioner = (*MatchLocalIP)(nil)
_ ConnectionMatcher = (*MatchLocalIP)(nil)
)
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