istio.io/istio@v0.0.0-20240520182934-d79c90f27776/security/pkg/server/ca/authenticate/cert_authenticator.go (about)

     1  // Copyright Istio Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package authenticate
    16  
    17  import (
    18  	"context"
    19  	"fmt"
    20  	"net/http"
    21  
    22  	"google.golang.org/grpc/credentials"
    23  	"google.golang.org/grpc/peer"
    24  
    25  	"istio.io/istio/pkg/security"
    26  	"istio.io/istio/security/pkg/pki/util"
    27  )
    28  
    29  const (
    30  	ClientCertAuthenticatorType = "ClientCertAuthenticator"
    31  )
    32  
    33  // ClientCertAuthenticator extracts identities from client certificate.
    34  type ClientCertAuthenticator struct{}
    35  
    36  var _ security.Authenticator = &ClientCertAuthenticator{}
    37  
    38  func (cca *ClientCertAuthenticator) AuthenticatorType() string {
    39  	return ClientCertAuthenticatorType
    40  }
    41  
    42  // Authenticate extracts identities from presented client certificates. This
    43  // method assumes that certificate chain has been properly validated before
    44  // this method is called. In other words, this method does not do certificate
    45  // chain validation itself.
    46  func (cca *ClientCertAuthenticator) Authenticate(authCtx security.AuthContext) (*security.Caller, error) {
    47  	if authCtx.GrpcContext != nil {
    48  		return cca.authenticateGrpc(authCtx.GrpcContext)
    49  	}
    50  	if authCtx.Request != nil {
    51  		return cca.authenticateHTTP(authCtx.Request)
    52  	}
    53  	return nil, nil
    54  }
    55  
    56  func (cca *ClientCertAuthenticator) authenticateGrpc(ctx context.Context) (*security.Caller, error) {
    57  	peer, ok := peer.FromContext(ctx)
    58  	if !ok || peer.AuthInfo == nil {
    59  		return nil, fmt.Errorf("no client certificate is presented")
    60  	}
    61  
    62  	if authType := peer.AuthInfo.AuthType(); authType != "tls" {
    63  		return nil, fmt.Errorf("unsupported auth type: %q", authType)
    64  	}
    65  
    66  	tlsInfo := peer.AuthInfo.(credentials.TLSInfo)
    67  	chains := tlsInfo.State.VerifiedChains
    68  	if len(chains) == 0 || len(chains[0]) == 0 {
    69  		return nil, fmt.Errorf("no verified chain is found")
    70  	}
    71  
    72  	ids, err := util.ExtractIDs(chains[0][0].Extensions)
    73  	if err != nil {
    74  		return nil, err
    75  	}
    76  
    77  	return &security.Caller{
    78  		AuthSource: security.AuthSourceClientCertificate,
    79  		Identities: ids,
    80  	}, nil
    81  }
    82  
    83  // authenticateHTTP performs mTLS authentication for http requests. Requires having the endpoints on a listener
    84  // with proper TLS configuration.
    85  func (cca *ClientCertAuthenticator) authenticateHTTP(req *http.Request) (*security.Caller, error) {
    86  	if req.TLS == nil || req.TLS.VerifiedChains == nil {
    87  		return nil, fmt.Errorf("no client certificate is presented")
    88  	}
    89  
    90  	chains := req.TLS.VerifiedChains
    91  	if len(chains) == 0 || len(chains[0]) == 0 {
    92  		return nil, fmt.Errorf("no verified chain is found")
    93  	}
    94  
    95  	ids, err := util.ExtractIDs(chains[0][0].Extensions)
    96  	if err != nil {
    97  		return nil, err
    98  	}
    99  
   100  	return &security.Caller{
   101  		AuthSource: security.AuthSourceClientCertificate,
   102  		Identities: ids,
   103  	}, nil
   104  }