feat: Extended Root CA for upstream connections (#181)

.schema/config.schema.json

@@ -1170,6 +1170,22 @@
             "timeout": {
               "$ref": "#/definitions/serverTimeout"
             },
+            "upstream": {
+              "type": "object",
+              "title": "HTTP Upstream",
+              "additionalProperties": false,
+              "properties": {
+                "ca_append_crt_path": {
+                  "type": "string",
+                  "default": "",
+                  "examples": [
+                    "./self-signed.crt"
+                  ],
+                  "title": "CA Certificate",
+                  "description": "The file containing the CA certificates to append to the Root CA when using upstream connections."
+                }
+              }
+            },
             "cors": {
               "$ref": "#/definitions/cors"
             },

docs/docs/reference/configuration.md

@@ -1498,6 +1498,28 @@ serve:
       #
       read: 5s
 
+    ## HTTP Upstream ##
+    #
+    # Control the HTTP upstream.
+    #
+    upstream:
+      ## Append Certificate To Root CA ##
+      #
+      # The path to a certificate file to append to the Root Certificate Authority for the upstream connection. Use this to accept self-signed certificates on the upstream only, keeping the host system certificate authority unaltered.
+      #
+      # Default value: ""
+      #
+      # Examples:
+      # - self-signed.crt      
+      #
+      # Set this value using environment variables on
+      # - Linux/macOS:
+      #    $ export SERVE_PROXY_UPSTREAM_CA_APPEND_CRT_PATH=<value>
+      # - Windows Command Line (CMD):
+      #    > set SERVE_PROXY_UPSTREAM_CA_APPEND_CRT_PATH=<value>
+      #
+      ca_append_crt_path: ""
+
     ## Cross Origin Resource Sharing (CORS) ##
     #
     # Configure [Cross Origin Resource Sharing (CORS)](http://www.w3.org/TR/cors/) using the following options.

driver/configuration/provider.go

@@ -5,7 +5,7 @@ import (
 	"net/url"
 	"time"
 
-	"github.com/gobuffalo/packr/v2"
+	packr "github.com/gobuffalo/packr/v2"
 
 	"github.com/ory/fosite"
 	"github.com/ory/x/tracing"
@@ -41,6 +41,7 @@ type Provider interface {
 	ProxyReadTimeout() time.Duration
 	ProxyWriteTimeout() time.Duration
 	ProxyIdleTimeout() time.Duration
+	ProxyServeUpstreamCaAppendCrtPath() string
 
 	APIReadTimeout() time.Duration
 	APIWriteTimeout() time.Duration

driver/configuration/provider_viper.go

@@ -43,6 +43,7 @@ const (
 	ViperKeyProxyIdleTimeout                    = "serve.proxy.timeout.idle"
 	ViperKeyProxyServeAddressHost               = "serve.proxy.host"
 	ViperKeyProxyServeAddressPort               = "serve.proxy.port"
+	ViperKeyProxyUpstreamCaAppendCrtPath        = "serve.proxy.upstream.ca_append_crt_path"
 	ViperKeyAPIServeAddressHost                 = "serve.api.host"
 	ViperKeyAPIServeAddressPort                 = "serve.api.port"
 	ViperKeyAPIReadTimeout                      = "serve.api.timeout.read"
@@ -177,6 +178,10 @@ func (v *ViperProvider) ProxyServeAddress() string {
 	)
 }
 
+func (v *ViperProvider) ProxyServeUpstreamCaAppendCrtPath() string {
+	return viperx.GetString(v.l, ViperKeyProxyUpstreamCaAppendCrtPath, "")
+}
+
 func (v *ViperProvider) APIReadTimeout() time.Duration {
 	return viperx.GetDuration(v.l, ViperKeyAPIReadTimeout, time.Second*5)
 }

driver/registry_memory.go

@@ -2,6 +2,10 @@ package driver
 
 import (
 	"context"
+	"crypto/tls"
+	"crypto/x509"
+	"io/ioutil"
+	"net/http"
 	"sync"
 	"time"
 
@@ -102,6 +106,41 @@ func (r *RegistryMemory) RuleMatcher() rule.Matcher {
 	return r.ruleRepository
 }
 
+func (r *RegistryMemory) UpstreamTransport(req *http.Request) (http.RoundTripper, error) {
+
+	// Use req to decide the transport per request iff need be.
+
+	certFile := r.c.ProxyServeUpstreamCaAppendCrtPath()
+	if certFile == "" {
+		return http.DefaultTransport, nil
+	}
+
+	transport := &(*http.DefaultTransport.(*http.Transport)) // shallow copy
+
+	// Get the SystemCertPool or continue with an empty pool on error
+	rootCAs, err := x509.SystemCertPool()
+	if err != nil {
+		return nil, err
+	}
+
+	certs, err := ioutil.ReadFile(certFile)
+	if err != nil {
+		return nil, err
+	}
+
+	// Append our cert to the system pool
+	if ok := rootCAs.AppendCertsFromPEM(certs); !ok {
+		return nil, errors.New("No certs appended, only system certs present, did you specify the correct cert file?")
+	}
+
+	transport.TLSClientConfig = &tls.Config{
+		InsecureSkipVerify: false,
+		RootCAs:            rootCAs,
+	}
+
+	return transport, nil
+}
+
 func NewRegistryMemory() *RegistryMemory {
 	return &RegistryMemory{}
 }

proxy/proxy.go

@@ -22,6 +22,8 @@ package proxy
 
 import (
 	"context"
+	"crypto/tls"
+	"crypto/x509"
 	"io/ioutil"
 	"net/http"
 	"net/url"
@@ -41,6 +43,7 @@ type proxyRegistry interface {
 
 	ProxyRequestHandler() *RequestHandler
 	RuleMatcher() rule.Matcher
+	UpstreamTransport(r *http.Request) (http.RoundTripper, error)
 }
 
 func NewProxy(r proxyRegistry) *Proxy {
@@ -88,7 +91,18 @@ func (d *Proxy) RoundTrip(r *http.Request) (*http.Response, error) {
 			Header:     rw.header,
 		}, nil
 	} else if err == nil {
-		res, err := http.DefaultTransport.RoundTrip(r)
+
+		transport, err := d.r.UpstreamTransport(r)
+		if err != nil {
+			d.r.Logger().
+				WithError(errors.WithStack(err)).
+				WithField("granted", false).
+				WithFields(fields).
+				Warn("Access request denied because upstream transport creation failed")
+			return nil, err
+		}
+
+		res, err := transport.RoundTrip(r)
 		if err != nil {
 			d.r.Logger().
 				WithError(errors.WithStack(err)).
@@ -194,3 +208,33 @@ func ConfigureBackendURL(r *http.Request, rl *rule.Rule) error {
 
 	return nil
 }
+
+// Allow for extending the Root CA chain
+// Use to avoid the error: "http: proxy error: x509: certificate signed by unknown authority" for self-signed
+// certificates upstream.
+func useTransportWithExtendedRootCa(certFile string) (transport *http.Transport, err error) {
+	transport = &(*http.DefaultTransport.(*http.Transport)) // shallow copy
+
+	// Get the SystemCertPool or continue with an empty pool on error
+	rootCAs, err := x509.SystemCertPool()
+	if err != nil {
+		return nil, err
+	}
+
+	certs, err := ioutil.ReadFile(certFile)
+	if err != nil {
+		return nil, err
+	}
+
+	// Append our cert to the system pool
+	if ok := rootCAs.AppendCertsFromPEM(certs); !ok {
+		return nil, errors.New("No certs appended, only system certs present, did you specifi the correct cert file?")
+	}
+
+	transport.TLSClientConfig = &tls.Config{
+		InsecureSkipVerify: false,
+		RootCAs:            rootCAs,
+	}
+
+	return transport, nil
+}