feat: add skip_mtls_uri_regex support for ApisixTls (#1915)

* Add `skip_mtls_uri_regex` support


---------

Signed-off-by: Ashish Tiwari <ashishjaitiwari15112000@gmail.com>
Co-authored-by: Jintao Zhang <zhangjintao9020@gmail.com>
Co-authored-by: Ashish Tiwari <ashishjaitiwari15112000@gmail.com>

docs/en/latest/concepts/apisix_tls.md

@@ -51,3 +51,33 @@ Make sure that the `hosts` field is accurate. APISIX uses the `host` field to ma
 :::
 
 APISIX Ingress will watch the secret resources referred by `ApisixTls` objects and re-translates it to APISIX resources if they are changed.
+
+## Bypassing MTLS based on regular expression matching against URI
+
+::: note
+This feature is only supported with APISIX version 3.4 or above.
+:::
+
+APISIX allows configuring an URI whitelist to bypass MTLS. If the URI of a request is in the whitelist, then the client certificate will not be checked. Note that other URIs of the associated SNI will get HTTP 400 response instead of alert error in the SSL handshake phase, if the client certificate is missing or invalid.
+
+The below example creates an APISIX ssl resource where MTLS is bypassed for any route that starts with `/ip`.
+
+```yaml
+apiVersion: %s
+kind: ApisixTls
+metadata:
+  name: my-tls
+spec:
+  hosts:
+  - httpbin.org
+  secret:
+    name: my-secret
+    namespace: default
+  client:
+    caSecret:
+      name: ca-secret
+      namespace: default
+    depth: 10
+    skip_mtls_uri_regex:
+    - /ip.*
+```

docs/en/latest/references/apisix_tls_v2.md

@@ -42,3 +42,4 @@ See the [definition](https://github.com/apache/apisix-ingress-controller/blob/ma
 | client.caSecret.name      | string | Name of the Secret related to the certificate provided by the client.                   |
 | client.caSecret.namespace | string | Namespace of the Secret related to the certificate.                                     |
 | client.depth              | int    | The maximum length of the certificate chain.                                            |
+| client.skip_mtls_uri_regex              | array    | List of uri regular expression to skip mtls.                                            |

docs/en/latest/tutorials/mtls-bypass.md

@@ -0,0 +1,50 @@
+---
+title: MTLS bypass based on regular expression matching against URI
+---
+
+<!--
+#
+# Licensed to the Apache Software Foundation (ASF) under one or more
+# contributor license agreements.  See the NOTICE file distributed with
+# this work for additional information regarding copyright ownership.
+# The ASF licenses this file to You 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.
+#
+-->
+
+APISIX allows configuring an URI whitelist to bypass MTLS. If the URI of a request is in the whitelist, then the client certificate will not be checked. Note that other URIs of the associated SNI will get HTTP 400 response instead of alert error in the SSL handshake phase, if the client certificate is missing or invalid.
+
+::: note
+This feature is only available in APISIX version 3.4 and above.
+:::
+
+The below example creates an APISIX ssl resource where MTLS is bypassed for any route that starts with `/ip`.
+
+```yaml
+apiVersion: %s
+kind: ApisixTls
+metadata:
+  name: my-tls
+spec:
+  hosts:
+  - httpbin.org
+  secret:
+    name: my-secret
+    namespace: default
+  client:
+    caSecret:
+      name: ca-secret
+      namespace: default
+    depth: 10
+    skip_mtls_uri_regex:
+    - /ip.*
+```

pkg/kube/apisix/apis/config/v2/types.go

@@ -784,8 +784,9 @@ type ApisixSecret struct {
 
 // ApisixMutualTlsClientConfig describes the mutual TLS CA and verify depth
 type ApisixMutualTlsClientConfig struct {
-	CASecret ApisixSecret `json:"caSecret,omitempty" yaml:"caSecret,omitempty"`
-	Depth    int          `json:"depth,omitempty" yaml:"depth,omitempty"`
+	CASecret         ApisixSecret `json:"caSecret,omitempty" yaml:"caSecret,omitempty"`
+	Depth            int          `json:"depth,omitempty" yaml:"depth,omitempty"`
+	SkipMTLSUriRegex []string     `json:"skip_mtls_uri_regex,omitempty" yaml:"skip_mtls_uri_regex, omitempty"`
 }
 
 // +genclient

pkg/providers/apisix/translation/apisix_ssl.go

@@ -57,8 +57,9 @@ func (t *translator) TranslateSSLV2(tls *configv2.ApisixTls) (*apisixv1.Ssl, err
 			return nil, err
 		}
 		ssl.Client = &apisixv1.MutualTLSClientConfig{
-			CA:    string(ca),
-			Depth: tls.Spec.Client.Depth,
+			CA:               string(ca),
+			Depth:            tls.Spec.Client.Depth,
+			SkipMTLSUriRegex: tls.Spec.Client.SkipMTLSUriRegex,
 		}
 	}
 

pkg/types/apisix/v1/types.go

@@ -470,8 +470,9 @@ type Ssl struct {
 // MutualTLSClientConfig apisix SSL client field
 // +k8s:deepcopy-gen=true
 type MutualTLSClientConfig struct {
-	CA    string `json:"ca,omitempty" yaml:"ca,omitempty"`
-	Depth int    `json:"depth,omitempty" yaml:"depth,omitempty"`
+	CA               string   `json:"ca,omitempty" yaml:"ca,omitempty"`
+	Depth            int      `json:"depth,omitempty" yaml:"depth,omitempty"`
+	SkipMTLSUriRegex []string `json:"skip_mtls_uri_regex,omitempty" yaml:"skip_mtls_uri_regex, omitempty"`
 }
 
 // StreamRoute represents the stream_route object in APISIX.

samples/deploy/crd/v1/ApisixTls.yaml

@@ -96,6 +96,10 @@ spec:
                           minLength: 1
                     depth:
                       type: integer
+                    skip_mtls_uri_regex:
+                      type: array
+                      items:
+                        type: string
                 hosts:
                   type: array
                   minItems: 1

test/e2e/scaffold/ssl.go

@@ -88,6 +88,8 @@ spec:
       name: %s
       namespace: %s
     depth: 10
+    skip_mtls_uri_regex:
+    - %s
 `
 )
 
@@ -137,8 +139,8 @@ func (s *Scaffold) NewApisixTls(name, host, secretName string, ingressClassName
 }
 
 // NewApisixTlsWithClientCA new a ApisixTls CRD
-func (s *Scaffold) NewApisixTlsWithClientCA(name, host, secretName, clientCASecret string) error {
-	tls := fmt.Sprintf(_api6tlsWithClientCATemplate, s.opts.ApisixResourceVersion, name, host, secretName, s.kubectlOptions.Namespace, clientCASecret, s.kubectlOptions.Namespace)
+func (s *Scaffold) NewApisixTlsWithClientCA(name, host, secretName, clientCASecret, skipMtlsUriRegex string) error {
+	tls := fmt.Sprintf(_api6tlsWithClientCATemplate, s.opts.ApisixResourceVersion, name, host, secretName, s.kubectlOptions.Namespace, clientCASecret, s.kubectlOptions.Namespace, skipMtlsUriRegex)
 	if err := s.CreateResourceFromString(tls); err != nil {
 		return err
 	}

test/e2e/suite-ingress/suite-ingress-resource/ssl.go

@@ -251,6 +251,48 @@ var _ = ginkgo.Describe("suite-ingress-resource: ApisixTls mTLS Test", func() {
 
 	suites := func(scaffoldFunc func() *scaffold.Scaffold) {
 		s := scaffoldFunc()
+		ginkgo.It("create a SSL without client CA and bypass mTLS", func() {
+			// Without client cert
+
+			// When skip_mtls_uri_regex is set for a route, it won't require a client cert
+			// update ApisixTls `skip_mtls_uri_regex`
+			skipMtlsUriRegex := "/ip.*"
+			tlsName := "tls-with-client-ca"
+			// create secrets
+			host := "mtls.httpbin.local"
+			rootCA, serverCert, serverKey, _, _ := s.GenerateMACert(ginkgo.GinkgoT(), []string{host})
+			err := s.NewSecret(serverCertSecret, serverCert.String(), serverKey.String())
+			assert.Nil(ginkgo.GinkgoT(), err, "create server cert secret error")
+			err = s.NewClientCASecret(clientCASecret, rootCA.String(), "")
+			assert.Nil(ginkgo.GinkgoT(), err, "create client CA cert secret error")
+
+			err = s.NewApisixTlsWithClientCA(tlsName, host, serverCertSecret, clientCASecret, skipMtlsUriRegex)
+			assert.Nil(ginkgo.GinkgoT(), err, "Update ApisixTls with client CA error")
+
+			// create route
+			backendSvc, backendSvcPort := s.DefaultHTTPBackend()
+			apisixRoute := fmt.Sprintf(`
+apiVersion: apisix.apache.org/v2
+kind: ApisixRoute
+metadata:
+  name: httpbin-route
+spec:
+  http:
+  - name: rule1
+    match:
+      hosts:
+      - mtls.httpbin.local
+      paths:
+      - /*
+    backends:
+    - serviceName: %s
+      servicePort: %d
+`, backendSvc, backendSvcPort[0])
+			assert.Nil(ginkgo.GinkgoT(), s.CreateVersionedApisixResource(apisixRoute))
+			assert.Nil(ginkgo.GinkgoT(), s.EnsureNumApisixRoutesCreated(1))
+
+			s.NewAPISIXHttpsClient(host).GET("/ip").WithHeader("Host", host).Expect().Status(http.StatusOK)
+		})
 		ginkgo.It("create a SSL with client CA", func() {
 			// create secrets
 			host := "mtls.httpbin.local"
@@ -263,7 +305,8 @@ var _ = ginkgo.Describe("suite-ingress-resource: ApisixTls mTLS Test", func() {
 
 			// create ApisixTls resource
 			tlsName := "tls-with-client-ca"
-			err = s.NewApisixTlsWithClientCA(tlsName, host, serverCertSecret, clientCASecret)
+			skipMtlsUriRegex := "/unused-route"
+			err = s.NewApisixTlsWithClientCA(tlsName, host, serverCertSecret, clientCASecret, skipMtlsUriRegex)
 			assert.Nil(ginkgo.GinkgoT(), err, "create ApisixTls with client CA error")
 			// check ssl in APISIX
 			assert.Nil(ginkgo.GinkgoT(), s.EnsureNumApisixTlsCreated(1))
@@ -290,11 +333,6 @@ spec:
 			assert.Nil(ginkgo.GinkgoT(), s.CreateVersionedApisixResource(apisixRoute))
 			assert.Nil(ginkgo.GinkgoT(), s.EnsureNumApisixRoutesCreated(1))
 
-			// Without Client Cert
-			// From APISIX v2.14, If the client does not carry a certificate request, it will fail directly.
-			// Previous versions would return 400.
-			// s.NewAPISIXHttpsClient(host).GET("/ip").WithHeader("Host", host).Expect().Status(http.StatusBadRequest).Body().Raw()
-
 			// With client cert
 			caCertPool := x509.NewCertPool()
 			ok := caCertPool.AppendCertsFromPEM([]byte(rootCA.String()))