istio

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// Copyright Istio Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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//     http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package security
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import (
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	"context"
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	"errors"
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	"google.golang.org/grpc/credentials"
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	"google.golang.org/grpc/peer"
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	"istio.io/istio/pilot/pkg/features"
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	"istio.io/istio/pkg/env"
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)
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var AuthPlaintext = env.Register("XDS_AUTH_PLAINTEXT", false,
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	"authenticate plain text requests - used if Istiod is running on a secure/trusted network").Get()
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// Authenticate authenticates the ADS request using the configured authenticators.
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// Returns the validated principals or an error.
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// If no authenticators are configured, or if the request is on a non-secure
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// stream ( 15010 ) - returns amn empty caller and no errors.
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func Authenticate(ctx context.Context, authenticators []Authenticator) (*Caller, error) {
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	if !features.XDSAuth {
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		return nil, nil
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	}
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	// authenticate - currently just checks that request has a certificate signed with the our key.
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	// Protected by flag to avoid breaking upgrades - should be enabled in multi-cluster/meshexpansion where
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	// XDS is exposed.
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	peerInfo, ok := peer.FromContext(ctx)
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	if !ok {
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		return nil, errors.New("invalid context")
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	}
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	// Not a TLS connection, we will not perform authentication
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	// TODO: add a flag to prevent unauthenticated requests ( 15010 )
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	// request not over TLS on the insecure port
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	if _, ok := peerInfo.AuthInfo.(credentials.TLSInfo); !ok && !AuthPlaintext {
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		return nil, nil
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	}
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	am := authenticationManager{
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		Authenticators: authenticators,
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	}
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	if u := am.authenticate(ctx); u != nil {
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		return u, nil
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	}
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	securityLog.Errorf("Failed to authenticate client from %s: %s", peerInfo.Addr.String(), am.FailedMessages())
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	return nil, errors.New("authentication failure")
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}
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