feat: auto tls sni

Signed-off-by: Steven Kreitzer <skre@skre.me>

config/configuration.go

@@ -205,6 +205,8 @@ type OriginRequestConfig struct {
 	HTTPHostHeader *string `yaml:"httpHostHeader" json:"httpHostHeader,omitempty"`
 	// Hostname on the origin server certificate.
 	OriginServerName *string `yaml:"originServerName" json:"originServerName,omitempty"`
+	// Auto configure the Hostname on the origin server certificate.
+	MatchSNIToHost *bool `yaml:"matchSNItoHost" json:"matchSNItoHost,omitempty"`
 	// Path to the CA for the certificate of your origin.
 	// This option should be used only if your certificate is not signed by Cloudflare.
 	CAPool *string `yaml:"caPool" json:"caPool,omitempty"`

ingress/config.go

@@ -32,6 +32,7 @@ const (
 	ProxyKeepAliveTimeoutFlag     = "proxy-keepalive-timeout"
 	HTTPHostHeaderFlag            = "http-host-header"
 	OriginServerNameFlag          = "origin-server-name"
+	MatchSNIToHostFlag            = "match-sni-to-host"
 	NoTLSVerifyFlag               = "no-tls-verify"
 	NoChunkedEncodingFlag         = "no-chunked-encoding"
 	ProxyAddressFlag              = "proxy-address"
@@ -118,6 +119,7 @@ func originRequestFromSingleRule(c *cli.Context) OriginRequestConfig {
 	var keepAliveTimeout = defaultKeepAliveTimeout
 	var httpHostHeader string
 	var originServerName string
+	var matchSNItoHost bool
 	var caPool string
 	var noTLSVerify bool
 	var disableChunkedEncoding bool
@@ -150,6 +152,9 @@ func originRequestFromSingleRule(c *cli.Context) OriginRequestConfig {
 	if flag := OriginServerNameFlag; c.IsSet(flag) {
 		originServerName = c.String(flag)
 	}
+	if flag := MatchSNIToHostFlag; c.IsSet(flag) {
+		matchSNItoHost = c.Bool(flag)
+	}
 	if flag := tlsconfig.OriginCAPoolFlag; c.IsSet(flag) {
 		caPool = c.String(flag)
 	}
@@ -185,6 +190,7 @@ func originRequestFromSingleRule(c *cli.Context) OriginRequestConfig {
 		KeepAliveTimeout:       keepAliveTimeout,
 		HTTPHostHeader:         httpHostHeader,
 		OriginServerName:       originServerName,
+		MatchSNIToHost:         matchSNItoHost,
 		CAPool:                 caPool,
 		NoTLSVerify:            noTLSVerify,
 		DisableChunkedEncoding: disableChunkedEncoding,
@@ -229,6 +235,9 @@ func originRequestFromConfig(c config.OriginRequestConfig) OriginRequestConfig {
 	if c.OriginServerName != nil {
 		out.OriginServerName = *c.OriginServerName
 	}
+	if c.MatchSNIToHost != nil {
+		out.MatchSNIToHost = *c.MatchSNIToHost
+	}
 	if c.CAPool != nil {
 		out.CAPool = *c.CAPool
 	}
@@ -287,6 +296,8 @@ type OriginRequestConfig struct {
 	HTTPHostHeader string `yaml:"httpHostHeader" json:"httpHostHeader"`
 	// Hostname on the origin server certificate.
 	OriginServerName string `yaml:"originServerName" json:"originServerName"`
+	// Auto configure the Hostname on the origin server certificate.
+	MatchSNIToHost bool `yaml:"matchSNItoHost" json:"matchSNItoHost"`
 	// Path to the CA for the certificate of your origin.
 	// This option should be used only if your certificate is not signed by Cloudflare.
 	CAPool string `yaml:"caPool" json:"caPool"`
@@ -362,6 +373,12 @@ func (defaults *OriginRequestConfig) setOriginServerName(overrides config.Origin
 	}
 }
 
+func (defaults *OriginRequestConfig) setMatchSNIToHost(overrides config.OriginRequestConfig) {
+	if val := overrides.MatchSNIToHost; val != nil {
+		defaults.MatchSNIToHost = *val
+	}
+}
+
 func (defaults *OriginRequestConfig) setCAPool(overrides config.OriginRequestConfig) {
 	if val := overrides.CAPool; val != nil {
 		defaults.CAPool = *val
@@ -447,6 +464,7 @@ func setConfig(defaults OriginRequestConfig, overrides config.OriginRequestConfi
 	cfg.setTCPKeepAlive(overrides)
 	cfg.setHTTPHostHeader(overrides)
 	cfg.setOriginServerName(overrides)
+	cfg.setMatchSNIToHost(overrides)
 	cfg.setCAPool(overrides)
 	cfg.setNoTLSVerify(overrides)
 	cfg.setDisableChunkedEncoding(overrides)
@@ -501,6 +519,7 @@ func ConvertToRawOriginConfig(c OriginRequestConfig) config.OriginRequestConfig
 		KeepAliveTimeout:       keepAliveTimeout,
 		HTTPHostHeader:         emptyStringToNil(c.HTTPHostHeader),
 		OriginServerName:       emptyStringToNil(c.OriginServerName),
+		MatchSNIToHost:         defaultBoolToNil(c.MatchSNIToHost),
 		CAPool:                 emptyStringToNil(c.CAPool),
 		NoTLSVerify:            defaultBoolToNil(c.NoTLSVerify),
 		DisableChunkedEncoding: defaultBoolToNil(c.DisableChunkedEncoding),

ingress/origin_proxy.go

@@ -2,7 +2,9 @@ package ingress
 
 import (
 	"context"
+	"crypto/tls"
 	"fmt"
+	"net"
 	"net/http"
 
 	"github.com/rs/zerolog"
@@ -48,9 +50,28 @@ func (o *httpService) RoundTrip(req *http.Request) (*http.Response, error) {
 		req.Header.Set("X-Forwarded-Host", req.Host)
 		req.Host = o.hostHeader
 	}
+
+	if o.matchSNIToHost {
+		o.SetOriginServerName(req)
+	}
+
 	return o.transport.RoundTrip(req)
 }
 
+func (o *httpService) SetOriginServerName(req *http.Request) {
+	o.transport.DialTLSContext = func(ctx context.Context, network, addr string) (net.Conn, error) {
+		conn, err := o.transport.DialContext(ctx, network, addr)
+		if err != nil {
+			return nil, err
+		}
+		return tls.Client(conn, &tls.Config{
+			RootCAs:            o.transport.TLSClientConfig.RootCAs,
+			InsecureSkipVerify: o.transport.TLSClientConfig.InsecureSkipVerify,
+			ServerName:         req.Host,
+		}), nil
+	}
+}
+
 func (o *statusCode) RoundTrip(_ *http.Request) (*http.Response, error) {
 	if o.defaultResp {
 		o.log.Warn().Msgf(ErrNoIngressRulesCLI.Error())

ingress/origin_service.go

@@ -71,6 +71,7 @@ type httpService struct {
 	url            *url.URL
 	hostHeader     string
 	transport      *http.Transport
+	matchSNIToHost bool
 }
 
 func (o *httpService) start(log *zerolog.Logger, _ <-chan struct{}, cfg OriginRequestConfig) error {
@@ -80,6 +81,7 @@ func (o *httpService) start(log *zerolog.Logger, _ <-chan struct{}, cfg OriginRe
 	}
 	o.hostHeader = cfg.HTTPHostHeader
 	o.transport = transport
+	o.matchSNIToHost = cfg.MatchSNIToHost
 	return nil
 }
 

ingress/rule_test.go

@@ -204,25 +204,25 @@ func TestMarshalJSON(t *testing.T) {
 		{
 			name:     "Nil",
 			path:     nil,
-			expected: `{"hostname":"example.com","path":null,"service":"https://localhost:8000","Handlers":null,"originRequest":{"connectTimeout":30,"tlsTimeout":10,"tcpKeepAlive":30,"noHappyEyeballs":false,"keepAliveTimeout":90,"keepAliveConnections":100,"httpHostHeader":"","originServerName":"","caPool":"","noTLSVerify":false,"disableChunkedEncoding":false,"bastionMode":false,"proxyAddress":"127.0.0.1","proxyPort":0,"proxyType":"","ipRules":null,"http2Origin":false,"access":{"teamName":"","audTag":null}}}`,
+			expected: `{"hostname":"example.com","path":null,"service":"https://localhost:8000","Handlers":null,"originRequest":{"connectTimeout":30,"tlsTimeout":10,"tcpKeepAlive":30,"noHappyEyeballs":false,"keepAliveTimeout":90,"keepAliveConnections":100,"httpHostHeader":"","originServerName":"","matchSNItoHost":false,"caPool":"","noTLSVerify":false,"disableChunkedEncoding":false,"bastionMode":false,"proxyAddress":"127.0.0.1","proxyPort":0,"proxyType":"","ipRules":null,"http2Origin":false,"access":{"teamName":"","audTag":null}}}`,
 			want:     true,
 		},
 		{
 			name:     "Nil regex",
 			path:     &Regexp{Regexp: nil},
-			expected: `{"hostname":"example.com","path":null,"service":"https://localhost:8000","Handlers":null,"originRequest":{"connectTimeout":30,"tlsTimeout":10,"tcpKeepAlive":30,"noHappyEyeballs":false,"keepAliveTimeout":90,"keepAliveConnections":100,"httpHostHeader":"","originServerName":"","caPool":"","noTLSVerify":false,"disableChunkedEncoding":false,"bastionMode":false,"proxyAddress":"127.0.0.1","proxyPort":0,"proxyType":"","ipRules":null,"http2Origin":false,"access":{"teamName":"","audTag":null}}}`,
+			expected: `{"hostname":"example.com","path":null,"service":"https://localhost:8000","Handlers":null,"originRequest":{"connectTimeout":30,"tlsTimeout":10,"tcpKeepAlive":30,"noHappyEyeballs":false,"keepAliveTimeout":90,"keepAliveConnections":100,"httpHostHeader":"","originServerName":"","matchSNItoHost":false,"caPool":"","noTLSVerify":false,"disableChunkedEncoding":false,"bastionMode":false,"proxyAddress":"127.0.0.1","proxyPort":0,"proxyType":"","ipRules":null,"http2Origin":false,"access":{"teamName":"","audTag":null}}}`,
 			want:     true,
 		},
 		{
 			name:     "Empty",
 			path:     &Regexp{Regexp: regexp.MustCompile("")},
-			expected: `{"hostname":"example.com","path":"","service":"https://localhost:8000","Handlers":null,"originRequest":{"connectTimeout":30,"tlsTimeout":10,"tcpKeepAlive":30,"noHappyEyeballs":false,"keepAliveTimeout":90,"keepAliveConnections":100,"httpHostHeader":"","originServerName":"","caPool":"","noTLSVerify":false,"disableChunkedEncoding":false,"bastionMode":false,"proxyAddress":"127.0.0.1","proxyPort":0,"proxyType":"","ipRules":null,"http2Origin":false,"access":{"teamName":"","audTag":null}}}`,
+			expected: `{"hostname":"example.com","path":"","service":"https://localhost:8000","Handlers":null,"originRequest":{"connectTimeout":30,"tlsTimeout":10,"tcpKeepAlive":30,"noHappyEyeballs":false,"keepAliveTimeout":90,"keepAliveConnections":100,"httpHostHeader":"","originServerName":"","matchSNItoHost":false,"caPool":"","noTLSVerify":false,"disableChunkedEncoding":false,"bastionMode":false,"proxyAddress":"127.0.0.1","proxyPort":0,"proxyType":"","ipRules":null,"http2Origin":false,"access":{"teamName":"","audTag":null}}}`,
 			want:     true,
 		},
 		{
 			name:     "Basic",
 			path:     &Regexp{Regexp: regexp.MustCompile("/echo")},
-			expected: `{"hostname":"example.com","path":"/echo","service":"https://localhost:8000","Handlers":null,"originRequest":{"connectTimeout":30,"tlsTimeout":10,"tcpKeepAlive":30,"noHappyEyeballs":false,"keepAliveTimeout":90,"keepAliveConnections":100,"httpHostHeader":"","originServerName":"","caPool":"","noTLSVerify":false,"disableChunkedEncoding":false,"bastionMode":false,"proxyAddress":"127.0.0.1","proxyPort":0,"proxyType":"","ipRules":null,"http2Origin":false,"access":{"teamName":"","audTag":null}}}`,
+			expected: `{"hostname":"example.com","path":"/echo","service":"https://localhost:8000","Handlers":null,"originRequest":{"connectTimeout":30,"tlsTimeout":10,"tcpKeepAlive":30,"noHappyEyeballs":false,"keepAliveTimeout":90,"keepAliveConnections":100,"httpHostHeader":"","originServerName":"","matchSNItoHost":false,"caPool":"","noTLSVerify":false,"disableChunkedEncoding":false,"bastionMode":false,"proxyAddress":"127.0.0.1","proxyPort":0,"proxyType":"","ipRules":null,"http2Origin":false,"access":{"teamName":"","audTag":null}}}`,
 			want:     true,
 		},
 	}