caddy/modules/caddyhttp/replacer.go
Cameron Moore b0a491aec8
Expose TLS placeholders (#2982)
* caddytls: Add CipherSuiteName and ProtocolName functions

The cipher_suites.go file is derived from a commit to the Go master
branch that's slated for Go 1.14.  Once Go 1.14 is released, this file
can be removed.

* caddyhttp: Use commonLogEmptyValue in common_log replacer

* caddyhttp: Add TLS placeholders

* caddytls: update unsupportedProtocols

Don't export unsupportedProtocols and update its godoc to mention that
it's used for logging only.

* caddyhttp: simplify getRegTLSReplacement signature

getRegTLSReplacement should receive a string instead of a pointer.

* caddyhttp: Remove http.request.tls.client.cert replacer

The previous behavior of printing the raw certificate bytes was ported
from Caddy 1, but the usefulness of that approach is suspect.  Remove
the client cert replacer from v2 until a use case is presented.

* caddyhttp: Use tls.CipherSuiteName from Go 1.14

Remove ported version of CipherSuiteName in the process.
2020-02-25 19:22:50 -07:00

294 lines
8.2 KiB
Go

// 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 caddyhttp
import (
"crypto/sha256"
"crypto/tls"
"crypto/x509"
"fmt"
"net"
"net/http"
"net/textproto"
"path"
"strconv"
"strings"
"github.com/caddyserver/caddy/v2"
"github.com/caddyserver/caddy/v2/modules/caddytls"
)
func addHTTPVarsToReplacer(repl *caddy.Replacer, req *http.Request, w http.ResponseWriter) {
httpVars := func(key string) (string, bool) {
if req != nil {
// query string parameters
if strings.HasPrefix(key, reqURIQueryReplPrefix) {
vals := req.URL.Query()[key[len(reqURIQueryReplPrefix):]]
// always return true, since the query param might
// be present only in some requests
return strings.Join(vals, ","), true
}
// request header fields
if strings.HasPrefix(key, reqHeaderReplPrefix) {
field := key[len(reqHeaderReplPrefix):]
vals := req.Header[textproto.CanonicalMIMEHeaderKey(field)]
// always return true, since the header field might
// be present only in some requests
return strings.Join(vals, ","), true
}
// cookies
if strings.HasPrefix(key, reqCookieReplPrefix) {
name := key[len(reqCookieReplPrefix):]
for _, cookie := range req.Cookies() {
if strings.EqualFold(name, cookie.Name) {
// always return true, since the cookie might
// be present only in some requests
return cookie.Value, true
}
}
}
// http.request.tls.
if strings.HasPrefix(key, reqTLSReplPrefix) {
return getReqTLSReplacement(req, key)
}
switch key {
case "http.request.method":
return req.Method, true
case "http.request.scheme":
if req.TLS != nil {
return "https", true
}
return "http", true
case "http.request.proto":
return req.Proto, true
case "http.request.host":
host, _, err := net.SplitHostPort(req.Host)
if err != nil {
return req.Host, true // OK; there probably was no port
}
return host, true
case "http.request.port":
_, port, _ := net.SplitHostPort(req.Host)
return port, true
case "http.request.hostport":
return req.Host, true
case "http.request.remote":
return req.RemoteAddr, true
case "http.request.remote.host":
host, _, err := net.SplitHostPort(req.RemoteAddr)
if err != nil {
return req.RemoteAddr, true
}
return host, true
case "http.request.remote.port":
_, port, _ := net.SplitHostPort(req.RemoteAddr)
return port, true
// current URI, including any internal rewrites
case "http.request.uri":
return req.URL.RequestURI(), true
case "http.request.uri.path":
return req.URL.Path, true
case "http.request.uri.path.file":
_, file := path.Split(req.URL.Path)
return file, true
case "http.request.uri.path.dir":
dir, _ := path.Split(req.URL.Path)
return dir, true
case "http.request.uri.query":
return req.URL.RawQuery, true
// original request, before any internal changes
case "http.request.orig_method":
or, _ := req.Context().Value(OriginalRequestCtxKey).(http.Request)
return or.Method, true
case "http.request.orig_uri":
or, _ := req.Context().Value(OriginalRequestCtxKey).(http.Request)
return or.RequestURI, true
case "http.request.orig_uri.path":
or, _ := req.Context().Value(OriginalRequestCtxKey).(http.Request)
return or.URL.Path, true
case "http.request.orig_uri.path.file":
or, _ := req.Context().Value(OriginalRequestCtxKey).(http.Request)
_, file := path.Split(or.URL.Path)
return file, true
case "http.request.orig_uri.path.dir":
or, _ := req.Context().Value(OriginalRequestCtxKey).(http.Request)
dir, _ := path.Split(or.URL.Path)
return dir, true
case "http.request.orig_uri.query":
or, _ := req.Context().Value(OriginalRequestCtxKey).(http.Request)
return or.URL.RawQuery, true
}
// hostname labels
if strings.HasPrefix(key, reqHostLabelsReplPrefix) {
idxStr := key[len(reqHostLabelsReplPrefix):]
idx, err := strconv.Atoi(idxStr)
if err != nil {
return "", false
}
reqHost, _, err := net.SplitHostPort(req.Host)
if err != nil {
reqHost = req.Host // OK; assume there was no port
}
hostLabels := strings.Split(reqHost, ".")
if idx < 0 {
return "", false
}
if idx > len(hostLabels) {
return "", true
}
return hostLabels[len(hostLabels)-idx-1], true
}
// path parts
if strings.HasPrefix(key, reqURIPathReplPrefix) {
idxStr := key[len(reqURIPathReplPrefix):]
idx, err := strconv.Atoi(idxStr)
if err != nil {
return "", false
}
pathParts := strings.Split(req.URL.Path, "/")
if len(pathParts) > 0 && pathParts[0] == "" {
pathParts = pathParts[1:]
}
if idx < 0 {
return "", false
}
if idx >= len(pathParts) {
return "", true
}
return pathParts[idx], true
}
// middleware variables
if strings.HasPrefix(key, varsReplPrefix) {
varName := key[len(varsReplPrefix):]
tbl := req.Context().Value(VarsCtxKey).(map[string]interface{})
raw, ok := tbl[varName]
if !ok {
// variables can be dynamic, so always return true
// even when it may not be set; treat as empty
return "", true
}
// do our best to convert it to a string efficiently
switch val := raw.(type) {
case string:
return val, true
case fmt.Stringer:
return val.String(), true
default:
return fmt.Sprintf("%s", val), true
}
}
}
if w != nil {
// response header fields
if strings.HasPrefix(key, respHeaderReplPrefix) {
field := key[len(respHeaderReplPrefix):]
vals := w.Header()[textproto.CanonicalMIMEHeaderKey(field)]
// always return true, since the header field might
// be present only in some responses
return strings.Join(vals, ","), true
}
}
return "", false
}
repl.Map(httpVars)
}
func getReqTLSReplacement(req *http.Request, key string) (string, bool) {
if req == nil || req.TLS == nil {
return "", false
}
if len(key) < len(reqTLSReplPrefix) {
return "", false
}
field := strings.ToLower(key[len(reqTLSReplPrefix):])
if strings.HasPrefix(field, "client.") {
cert := getTLSPeerCert(req.TLS)
if cert == nil {
return "", false
}
switch field {
case "client.fingerprint":
return fmt.Sprintf("%x", sha256.Sum256(cert.Raw)), true
case "client.issuer":
return cert.Issuer.String(), true
case "client.serial":
return fmt.Sprintf("%x", cert.SerialNumber), true
case "client.subject":
return cert.Subject.String(), true
default:
return "", false
}
}
switch field {
case "version":
return caddytls.ProtocolName(req.TLS.Version), true
case "cipher_suite":
return tls.CipherSuiteName(req.TLS.CipherSuite), true
case "resumed":
if req.TLS.DidResume {
return "true", true
}
return "false", true
case "proto":
return req.TLS.NegotiatedProtocol, true
case "proto_mutual":
if req.TLS.NegotiatedProtocolIsMutual {
return "true", true
}
return "false", true
case "server_name":
return req.TLS.ServerName, true
default:
return "", false
}
}
// getTLSPeerCert retrieves the first peer certificate from a TLS session.
// Returns nil if no peer cert is in use.
func getTLSPeerCert(cs *tls.ConnectionState) *x509.Certificate {
if len(cs.PeerCertificates) == 0 {
return nil
}
return cs.PeerCertificates[0]
}
const (
reqCookieReplPrefix = "http.request.cookie."
reqHeaderReplPrefix = "http.request.header."
reqHostLabelsReplPrefix = "http.request.host.labels."
reqTLSReplPrefix = "http.request.tls."
reqURIPathReplPrefix = "http.request.uri.path."
reqURIQueryReplPrefix = "http.request.uri.query."
respHeaderReplPrefix = "http.response.header."
varsReplPrefix = "http.vars."
)