feat: add crd gen

Signed-off-by: runzexia <runzexia@yunify.com>

vendor/k8s.io/apiserver/pkg/authentication/request/anonymous/anonymous.go

@@ -0,0 +1,43 @@
+/*
+Copyright 2016 The Kubernetes 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 anonymous
+
+import (
+	"net/http"
+
+	"k8s.io/apiserver/pkg/authentication/authenticator"
+	"k8s.io/apiserver/pkg/authentication/user"
+)
+
+const (
+	anonymousUser = user.Anonymous
+
+	unauthenticatedGroup = user.AllUnauthenticated
+)
+
+func NewAuthenticator() authenticator.Request {
+	return authenticator.RequestFunc(func(req *http.Request) (*authenticator.Response, bool, error) {
+		auds, _ := authenticator.AudiencesFrom(req.Context())
+		return &authenticator.Response{
+			User: &user.DefaultInfo{
+				Name:   anonymousUser,
+				Groups: []string{unauthenticatedGroup},
+			},
+			Audiences: auds,
+		}, true, nil
+	})
+}

vendor/k8s.io/apiserver/pkg/authentication/request/bearertoken/bearertoken.go

@@ -0,0 +1,67 @@
+/*
+Copyright 2014 The Kubernetes 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 bearertoken
+
+import (
+	"errors"
+	"net/http"
+	"strings"
+
+	"k8s.io/apiserver/pkg/authentication/authenticator"
+)
+
+type Authenticator struct {
+	auth authenticator.Token
+}
+
+func New(auth authenticator.Token) *Authenticator {
+	return &Authenticator{auth}
+}
+
+var invalidToken = errors.New("invalid bearer token")
+
+func (a *Authenticator) AuthenticateRequest(req *http.Request) (*authenticator.Response, bool, error) {
+	auth := strings.TrimSpace(req.Header.Get("Authorization"))
+	if auth == "" {
+		return nil, false, nil
+	}
+	parts := strings.Split(auth, " ")
+	if len(parts) < 2 || strings.ToLower(parts[0]) != "bearer" {
+		return nil, false, nil
+	}
+
+	token := parts[1]
+
+	// Empty bearer tokens aren't valid
+	if len(token) == 0 {
+		return nil, false, nil
+	}
+
+	resp, ok, err := a.auth.AuthenticateToken(req.Context(), token)
+	// if we authenticated successfully, go ahead and remove the bearer token so that no one
+	// is ever tempted to use it inside of the API server
+	if ok {
+		req.Header.Del("Authorization")
+	}
+
+	// If the token authenticator didn't error, provide a default error
+	if !ok && err == nil {
+		err = invalidToken
+	}
+
+	return resp, ok, err
+}

vendor/k8s.io/apiserver/pkg/authentication/request/headerrequest/requestheader.go

@@ -0,0 +1,190 @@
+/*
+Copyright 2016 The Kubernetes 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 headerrequest
+
+import (
+	"crypto/x509"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"net/url"
+	"strings"
+
+	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/apiserver/pkg/authentication/authenticator"
+	x509request "k8s.io/apiserver/pkg/authentication/request/x509"
+	"k8s.io/apiserver/pkg/authentication/user"
+	utilcert "k8s.io/client-go/util/cert"
+)
+
+type requestHeaderAuthRequestHandler struct {
+	// nameHeaders are the headers to check (in order, case-insensitively) for an identity. The first header with a value wins.
+	nameHeaders []string
+
+	// groupHeaders are the headers to check (case-insensitively) for group membership.  All values of all headers will be added.
+	groupHeaders []string
+
+	// extraHeaderPrefixes are the head prefixes to check (case-insensitively) for filling in
+	// the user.Info.Extra.  All values of all matching headers will be added.
+	extraHeaderPrefixes []string
+}
+
+func New(nameHeaders []string, groupHeaders []string, extraHeaderPrefixes []string) (authenticator.Request, error) {
+	trimmedNameHeaders, err := trimHeaders(nameHeaders...)
+	if err != nil {
+		return nil, err
+	}
+	trimmedGroupHeaders, err := trimHeaders(groupHeaders...)
+	if err != nil {
+		return nil, err
+	}
+	trimmedExtraHeaderPrefixes, err := trimHeaders(extraHeaderPrefixes...)
+	if err != nil {
+		return nil, err
+	}
+
+	return &requestHeaderAuthRequestHandler{
+		nameHeaders:         trimmedNameHeaders,
+		groupHeaders:        trimmedGroupHeaders,
+		extraHeaderPrefixes: trimmedExtraHeaderPrefixes,
+	}, nil
+}
+
+func trimHeaders(headerNames ...string) ([]string, error) {
+	ret := []string{}
+	for _, headerName := range headerNames {
+		trimmedHeader := strings.TrimSpace(headerName)
+		if len(trimmedHeader) == 0 {
+			return nil, fmt.Errorf("empty header %q", headerName)
+		}
+		ret = append(ret, trimmedHeader)
+	}
+
+	return ret, nil
+}
+
+func NewSecure(clientCA string, proxyClientNames []string, nameHeaders []string, groupHeaders []string, extraHeaderPrefixes []string) (authenticator.Request, error) {
+	headerAuthenticator, err := New(nameHeaders, groupHeaders, extraHeaderPrefixes)
+	if err != nil {
+		return nil, err
+	}
+
+	if len(clientCA) == 0 {
+		return nil, fmt.Errorf("missing clientCA file")
+	}
+
+	// Wrap with an x509 verifier
+	caData, err := ioutil.ReadFile(clientCA)
+	if err != nil {
+		return nil, fmt.Errorf("error reading %s: %v", clientCA, err)
+	}
+	opts := x509request.DefaultVerifyOptions()
+	opts.Roots = x509.NewCertPool()
+	certs, err := utilcert.ParseCertsPEM(caData)
+	if err != nil {
+		return nil, fmt.Errorf("error loading certs from  %s: %v", clientCA, err)
+	}
+	for _, cert := range certs {
+		opts.Roots.AddCert(cert)
+	}
+
+	return x509request.NewVerifier(opts, headerAuthenticator, sets.NewString(proxyClientNames...)), nil
+}
+
+func (a *requestHeaderAuthRequestHandler) AuthenticateRequest(req *http.Request) (*authenticator.Response, bool, error) {
+	name := headerValue(req.Header, a.nameHeaders)
+	if len(name) == 0 {
+		return nil, false, nil
+	}
+	groups := allHeaderValues(req.Header, a.groupHeaders)
+	extra := newExtra(req.Header, a.extraHeaderPrefixes)
+
+	// clear headers used for authentication
+	for _, headerName := range a.nameHeaders {
+		req.Header.Del(headerName)
+	}
+	for _, headerName := range a.groupHeaders {
+		req.Header.Del(headerName)
+	}
+	for k := range extra {
+		for _, prefix := range a.extraHeaderPrefixes {
+			req.Header.Del(prefix + k)
+		}
+	}
+
+	return &authenticator.Response{
+		User: &user.DefaultInfo{
+			Name:   name,
+			Groups: groups,
+			Extra:  extra,
+		},
+	}, true, nil
+}
+
+func headerValue(h http.Header, headerNames []string) string {
+	for _, headerName := range headerNames {
+		headerValue := h.Get(headerName)
+		if len(headerValue) > 0 {
+			return headerValue
+		}
+	}
+	return ""
+}
+
+func allHeaderValues(h http.Header, headerNames []string) []string {
+	ret := []string{}
+	for _, headerName := range headerNames {
+		headerKey := http.CanonicalHeaderKey(headerName)
+		values, ok := h[headerKey]
+		if !ok {
+			continue
+		}
+
+		for _, headerValue := range values {
+			if len(headerValue) > 0 {
+				ret = append(ret, headerValue)
+			}
+		}
+	}
+	return ret
+}
+
+func unescapeExtraKey(encodedKey string) string {
+	key, err := url.PathUnescape(encodedKey) // Decode %-encoded bytes.
+	if err != nil {
+		return encodedKey // Always record extra strings, even if malformed/unencoded.
+	}
+	return key
+}
+
+func newExtra(h http.Header, headerPrefixes []string) map[string][]string {
+	ret := map[string][]string{}
+
+	// we have to iterate over prefixes first in order to have proper ordering inside the value slices
+	for _, prefix := range headerPrefixes {
+		for headerName, vv := range h {
+			if !strings.HasPrefix(strings.ToLower(headerName), strings.ToLower(prefix)) {
+				continue
+			}
+
+			extraKey := unescapeExtraKey(strings.ToLower(headerName[len(prefix):]))
+			ret[extraKey] = append(ret[extraKey], vv...)
+		}
+	}
+
+	return ret
+}

vendor/k8s.io/apiserver/pkg/authentication/request/union/union.go

@@ -0,0 +1,71 @@
+/*
+Copyright 2014 The Kubernetes 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 union
+
+import (
+	"net/http"
+
+	utilerrors "k8s.io/apimachinery/pkg/util/errors"
+	"k8s.io/apiserver/pkg/authentication/authenticator"
+)
+
+// unionAuthRequestHandler authenticates requests using a chain of authenticator.Requests
+type unionAuthRequestHandler struct {
+	// Handlers is a chain of request authenticators to delegate to
+	Handlers []authenticator.Request
+	// FailOnError determines whether an error returns short-circuits the chain
+	FailOnError bool
+}
+
+// New returns a request authenticator that validates credentials using a chain of authenticator.Request objects.
+// The entire chain is tried until one succeeds. If all fail, an aggregate error is returned.
+func New(authRequestHandlers ...authenticator.Request) authenticator.Request {
+	if len(authRequestHandlers) == 1 {
+		return authRequestHandlers[0]
+	}
+	return &unionAuthRequestHandler{Handlers: authRequestHandlers, FailOnError: false}
+}
+
+// NewFailOnError returns a request authenticator that validates credentials using a chain of authenticator.Request objects.
+// The first error short-circuits the chain.
+func NewFailOnError(authRequestHandlers ...authenticator.Request) authenticator.Request {
+	if len(authRequestHandlers) == 1 {
+		return authRequestHandlers[0]
+	}
+	return &unionAuthRequestHandler{Handlers: authRequestHandlers, FailOnError: true}
+}
+
+// AuthenticateRequest authenticates the request using a chain of authenticator.Request objects.
+func (authHandler *unionAuthRequestHandler) AuthenticateRequest(req *http.Request) (*authenticator.Response, bool, error) {
+	var errlist []error
+	for _, currAuthRequestHandler := range authHandler.Handlers {
+		resp, ok, err := currAuthRequestHandler.AuthenticateRequest(req)
+		if err != nil {
+			if authHandler.FailOnError {
+				return resp, ok, err
+			}
+			errlist = append(errlist, err)
+			continue
+		}
+
+		if ok {
+			return resp, ok, err
+		}
+	}
+
+	return nil, false, utilerrors.NewAggregate(errlist)
+}

vendor/k8s.io/apiserver/pkg/authentication/request/websocket/protocol.go

@@ -0,0 +1,108 @@
+/*
+Copyright 2017 The Kubernetes 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 websocket
+
+import (
+	"encoding/base64"
+	"errors"
+	"net/http"
+	"net/textproto"
+	"strings"
+	"unicode/utf8"
+
+	"k8s.io/apiserver/pkg/authentication/authenticator"
+	"k8s.io/apiserver/pkg/util/wsstream"
+)
+
+const bearerProtocolPrefix = "base64url.bearer.authorization.k8s.io."
+
+var protocolHeader = textproto.CanonicalMIMEHeaderKey("Sec-WebSocket-Protocol")
+
+var errInvalidToken = errors.New("invalid bearer token")
+
+// ProtocolAuthenticator allows a websocket connection to provide a bearer token as a subprotocol
+// in the format "base64url.bearer.authorization.<base64url-without-padding(bearer-token)>"
+type ProtocolAuthenticator struct {
+	// auth is the token authenticator to use to validate the token
+	auth authenticator.Token
+}
+
+func NewProtocolAuthenticator(auth authenticator.Token) *ProtocolAuthenticator {
+	return &ProtocolAuthenticator{auth}
+}
+
+func (a *ProtocolAuthenticator) AuthenticateRequest(req *http.Request) (*authenticator.Response, bool, error) {
+	// Only accept websocket connections
+	if !wsstream.IsWebSocketRequest(req) {
+		return nil, false, nil
+	}
+
+	token := ""
+	sawTokenProtocol := false
+	filteredProtocols := []string{}
+	for _, protocolHeader := range req.Header[protocolHeader] {
+		for _, protocol := range strings.Split(protocolHeader, ",") {
+			protocol = strings.TrimSpace(protocol)
+
+			if !strings.HasPrefix(protocol, bearerProtocolPrefix) {
+				filteredProtocols = append(filteredProtocols, protocol)
+				continue
+			}
+
+			if sawTokenProtocol {
+				return nil, false, errors.New("multiple base64.bearer.authorization tokens specified")
+			}
+			sawTokenProtocol = true
+
+			encodedToken := strings.TrimPrefix(protocol, bearerProtocolPrefix)
+			decodedToken, err := base64.RawURLEncoding.DecodeString(encodedToken)
+			if err != nil {
+				return nil, false, errors.New("invalid base64.bearer.authorization token encoding")
+			}
+			if !utf8.Valid(decodedToken) {
+				return nil, false, errors.New("invalid base64.bearer.authorization token")
+			}
+			token = string(decodedToken)
+		}
+	}
+
+	// Must pass at least one other subprotocol so that we can remove the one containing the bearer token,
+	// and there is at least one to echo back to the client
+	if len(token) > 0 && len(filteredProtocols) == 0 {
+		return nil, false, errors.New("missing additional subprotocol")
+	}
+
+	if len(token) == 0 {
+		return nil, false, nil
+	}
+
+	resp, ok, err := a.auth.AuthenticateToken(req.Context(), token)
+
+	// on success, remove the protocol with the token
+	if ok {
+		// https://tools.ietf.org/html/rfc6455#section-11.3.4 indicates the Sec-WebSocket-Protocol header may appear multiple times
+		// in a request, and is logically the same as a single Sec-WebSocket-Protocol header field that contains all values
+		req.Header.Set(protocolHeader, strings.Join(filteredProtocols, ","))
+	}
+
+	// If the token authenticator didn't error, provide a default error
+	if !ok && err == nil {
+		err = errInvalidToken
+	}
+
+	return resp, ok, err
+}

vendor/k8s.io/apiserver/pkg/authentication/request/x509/OWNERS

@@ -0,0 +1,7 @@
+approvers:
+- sig-auth-certificates-approvers
+reviewers:
+- sig-auth-certificates-reviewers
+labels:
+- sig/auth
+

vendor/k8s.io/apiserver/pkg/authentication/request/x509/doc.go

@@ -0,0 +1,19 @@
+/*
+Copyright 2014 The Kubernetes 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 x509 provides a request authenticator that validates and
+// extracts user information from client certificates
+package x509 // import "k8s.io/apiserver/pkg/authentication/request/x509"

vendor/k8s.io/apiserver/pkg/authentication/request/x509/x509.go

@@ -0,0 +1,192 @@
+/*
+Copyright 2014 The Kubernetes 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 x509
+
+import (
+	"crypto/x509"
+	"crypto/x509/pkix"
+	"fmt"
+	"net/http"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+
+	utilerrors "k8s.io/apimachinery/pkg/util/errors"
+	"k8s.io/apimachinery/pkg/util/sets"
+	"k8s.io/apiserver/pkg/authentication/authenticator"
+	"k8s.io/apiserver/pkg/authentication/user"
+)
+
+var clientCertificateExpirationHistogram = prometheus.NewHistogram(
+	prometheus.HistogramOpts{
+		Namespace: "apiserver",
+		Subsystem: "client",
+		Name:      "certificate_expiration_seconds",
+		Help:      "Distribution of the remaining lifetime on the certificate used to authenticate a request.",
+		Buckets: []float64{
+			0,
+			(6 * time.Hour).Seconds(),
+			(12 * time.Hour).Seconds(),
+			(24 * time.Hour).Seconds(),
+			(2 * 24 * time.Hour).Seconds(),
+			(4 * 24 * time.Hour).Seconds(),
+			(7 * 24 * time.Hour).Seconds(),
+			(30 * 24 * time.Hour).Seconds(),
+			(3 * 30 * 24 * time.Hour).Seconds(),
+			(6 * 30 * 24 * time.Hour).Seconds(),
+			(12 * 30 * 24 * time.Hour).Seconds(),
+		},
+	},
+)
+
+func init() {
+	prometheus.MustRegister(clientCertificateExpirationHistogram)
+}
+
+// UserConversion defines an interface for extracting user info from a client certificate chain
+type UserConversion interface {
+	User(chain []*x509.Certificate) (*authenticator.Response, bool, error)
+}
+
+// UserConversionFunc is a function that implements the UserConversion interface.
+type UserConversionFunc func(chain []*x509.Certificate) (*authenticator.Response, bool, error)
+
+// User implements x509.UserConversion
+func (f UserConversionFunc) User(chain []*x509.Certificate) (*authenticator.Response, bool, error) {
+	return f(chain)
+}
+
+// Authenticator implements request.Authenticator by extracting user info from verified client certificates
+type Authenticator struct {
+	opts x509.VerifyOptions
+	user UserConversion
+}
+
+// New returns a request.Authenticator that verifies client certificates using the provided
+// VerifyOptions, and converts valid certificate chains into user.Info using the provided UserConversion
+func New(opts x509.VerifyOptions, user UserConversion) *Authenticator {
+	return &Authenticator{opts, user}
+}
+
+// AuthenticateRequest authenticates the request using presented client certificates
+func (a *Authenticator) AuthenticateRequest(req *http.Request) (*authenticator.Response, bool, error) {
+	if req.TLS == nil || len(req.TLS.PeerCertificates) == 0 {
+		return nil, false, nil
+	}
+
+	// Use intermediates, if provided
+	optsCopy := a.opts
+	if optsCopy.Intermediates == nil && len(req.TLS.PeerCertificates) > 1 {
+		optsCopy.Intermediates = x509.NewCertPool()
+		for _, intermediate := range req.TLS.PeerCertificates[1:] {
+			optsCopy.Intermediates.AddCert(intermediate)
+		}
+	}
+
+	remaining := req.TLS.PeerCertificates[0].NotAfter.Sub(time.Now())
+	clientCertificateExpirationHistogram.Observe(remaining.Seconds())
+	chains, err := req.TLS.PeerCertificates[0].Verify(optsCopy)
+	if err != nil {
+		return nil, false, err
+	}
+
+	var errlist []error
+	for _, chain := range chains {
+		user, ok, err := a.user.User(chain)
+		if err != nil {
+			errlist = append(errlist, err)
+			continue
+		}
+
+		if ok {
+			return user, ok, err
+		}
+	}
+	return nil, false, utilerrors.NewAggregate(errlist)
+}
+
+// Verifier implements request.Authenticator by verifying a client cert on the request, then delegating to the wrapped auth
+type Verifier struct {
+	opts x509.VerifyOptions
+	auth authenticator.Request
+
+	// allowedCommonNames contains the common names which a verified certificate is allowed to have.
+	// If empty, all verified certificates are allowed.
+	allowedCommonNames sets.String
+}
+
+// NewVerifier create a request.Authenticator by verifying a client cert on the request, then delegating to the wrapped auth
+func NewVerifier(opts x509.VerifyOptions, auth authenticator.Request, allowedCommonNames sets.String) authenticator.Request {
+	return &Verifier{opts, auth, allowedCommonNames}
+}
+
+// AuthenticateRequest verifies the presented client certificate, then delegates to the wrapped auth
+func (a *Verifier) AuthenticateRequest(req *http.Request) (*authenticator.Response, bool, error) {
+	if req.TLS == nil || len(req.TLS.PeerCertificates) == 0 {
+		return nil, false, nil
+	}
+
+	// Use intermediates, if provided
+	optsCopy := a.opts
+	if optsCopy.Intermediates == nil && len(req.TLS.PeerCertificates) > 1 {
+		optsCopy.Intermediates = x509.NewCertPool()
+		for _, intermediate := range req.TLS.PeerCertificates[1:] {
+			optsCopy.Intermediates.AddCert(intermediate)
+		}
+	}
+
+	if _, err := req.TLS.PeerCertificates[0].Verify(optsCopy); err != nil {
+		return nil, false, err
+	}
+	if err := a.verifySubject(req.TLS.PeerCertificates[0].Subject); err != nil {
+		return nil, false, err
+	}
+	return a.auth.AuthenticateRequest(req)
+}
+
+func (a *Verifier) verifySubject(subject pkix.Name) error {
+	// No CN restrictions
+	if len(a.allowedCommonNames) == 0 {
+		return nil
+	}
+	// Enforce CN restrictions
+	if a.allowedCommonNames.Has(subject.CommonName) {
+		return nil
+	}
+	return fmt.Errorf("x509: subject with cn=%s is not in the allowed list", subject.CommonName)
+}
+
+// DefaultVerifyOptions returns VerifyOptions that use the system root certificates, current time,
+// and requires certificates to be valid for client auth (x509.ExtKeyUsageClientAuth)
+func DefaultVerifyOptions() x509.VerifyOptions {
+	return x509.VerifyOptions{
+		KeyUsages: []x509.ExtKeyUsage{x509.ExtKeyUsageClientAuth},
+	}
+}
+
+// CommonNameUserConversion builds user info from a certificate chain using the subject's CommonName
+var CommonNameUserConversion = UserConversionFunc(func(chain []*x509.Certificate) (*authenticator.Response, bool, error) {
+	if len(chain[0].Subject.CommonName) == 0 {
+		return nil, false, nil
+	}
+	return &authenticator.Response{
+		User: &user.DefaultInfo{
+			Name:   chain[0].Subject.CommonName,
+			Groups: chain[0].Subject.Organization,
+		},
+	}, true, nil
+})