working-config-otel

Signed-off-by: Davanum Srinivas <davanum@gmail.com>

vendor/github.com/google/s2a-go/s2a_options.go

@@ -0,0 +1,215 @@
+/*
+ *
+ * Copyright 2021 Google LLC
+ *
+ * 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
+ *
+ *     https://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 s2a
+
+import (
+	"context"
+	"crypto/tls"
+	"errors"
+	"sync"
+
+	"github.com/google/s2a-go/fallback"
+	"github.com/google/s2a-go/stream"
+	"google.golang.org/grpc/credentials"
+
+	s2apb "github.com/google/s2a-go/internal/proto/common_go_proto"
+)
+
+// Identity is the interface for S2A identities.
+type Identity interface {
+	// Name returns the name of the identity.
+	Name() string
+}
+
+type spiffeID struct {
+	spiffeID string
+}
+
+func (s *spiffeID) Name() string { return s.spiffeID }
+
+// NewSpiffeID creates a SPIFFE ID from id.
+func NewSpiffeID(id string) Identity {
+	return &spiffeID{spiffeID: id}
+}
+
+type hostname struct {
+	hostname string
+}
+
+func (h *hostname) Name() string { return h.hostname }
+
+// NewHostname creates a hostname from name.
+func NewHostname(name string) Identity {
+	return &hostname{hostname: name}
+}
+
+type uid struct {
+	uid string
+}
+
+func (h *uid) Name() string { return h.uid }
+
+// NewUID creates a UID from name.
+func NewUID(name string) Identity {
+	return &uid{uid: name}
+}
+
+// VerificationModeType specifies the mode that S2A must use to verify the peer
+// certificate chain.
+type VerificationModeType int
+
+// Three types of verification modes.
+const (
+	Unspecified = iota
+	ConnectToGoogle
+	Spiffe
+)
+
+// ClientOptions contains the client-side options used to establish a secure
+// channel using the S2A handshaker service.
+type ClientOptions struct {
+	// TargetIdentities contains a list of allowed server identities. One of the
+	// target identities should match the peer identity in the handshake
+	// result; otherwise, the handshake fails.
+	TargetIdentities []Identity
+	// LocalIdentity is the local identity of the client application. If none is
+	// provided, then the S2A will choose the default identity, if one exists.
+	LocalIdentity Identity
+	// S2AAddress is the address of the S2A.
+	S2AAddress string
+	// Optional transport credentials.
+	// If set, this will be used for the gRPC connection to the S2A server.
+	TransportCreds credentials.TransportCredentials
+	// EnsureProcessSessionTickets waits for all session tickets to be sent to
+	// S2A before a process completes.
+	//
+	// This functionality is crucial for processes that complete very soon after
+	// using S2A to establish a TLS connection, but it can be ignored for longer
+	// lived processes.
+	//
+	// Usage example:
+	//   func main() {
+	//     var ensureProcessSessionTickets sync.WaitGroup
+	//     clientOpts := &s2a.ClientOptions{
+	//       EnsureProcessSessionTickets: &ensureProcessSessionTickets,
+	//       // Set other members.
+	//     }
+	//     creds, _ := s2a.NewClientCreds(clientOpts)
+	//     conn, _ := grpc.Dial(serverAddr, grpc.WithTransportCredentials(creds))
+	//     defer conn.Close()
+	//
+	//     // Make RPC call.
+	//
+	//     // The process terminates right after the RPC call ends.
+	//     // ensureProcessSessionTickets can be used to ensure resumption
+	//     // tickets are fully processed. If the process is long-lived, using
+	//     // ensureProcessSessionTickets is not necessary.
+	//     ensureProcessSessionTickets.Wait()
+	//   }
+	EnsureProcessSessionTickets *sync.WaitGroup
+	// If true, enables the use of legacy S2Av1.
+	EnableLegacyMode bool
+	// VerificationMode specifies the mode that S2A must use to verify the
+	// peer certificate chain.
+	VerificationMode VerificationModeType
+
+	// Optional fallback after dialing with S2A fails.
+	FallbackOpts *FallbackOptions
+
+	// Generates an S2AStream interface for talking to the S2A server.
+	getS2AStream func(ctx context.Context, s2av2Address string) (stream.S2AStream, error)
+
+	// Serialized user specified policy for server authorization.
+	serverAuthorizationPolicy []byte
+}
+
+// FallbackOptions prescribes the fallback logic that should be taken if the application fails to connect with S2A.
+type FallbackOptions struct {
+	// FallbackClientHandshakeFunc is used to specify fallback behavior when calling s2a.NewClientCreds().
+	// It will be called by ClientHandshake function, after handshake with S2A fails.
+	// s2a.NewClientCreds() ignores the other FallbackDialer field.
+	FallbackClientHandshakeFunc fallback.ClientHandshake
+
+	// FallbackDialer is used to specify fallback behavior when calling s2a.NewS2aDialTLSContextFunc().
+	// It passes in a custom fallback dialer and server address to use after dialing with S2A fails.
+	// s2a.NewS2aDialTLSContextFunc() ignores the other FallbackClientHandshakeFunc field.
+	FallbackDialer *FallbackDialer
+}
+
+// FallbackDialer contains a fallback tls.Dialer and a server address to connect to.
+type FallbackDialer struct {
+	// Dialer specifies a fallback tls.Dialer.
+	Dialer *tls.Dialer
+	// ServerAddr is used by Dialer to establish fallback connection.
+	ServerAddr string
+}
+
+// DefaultClientOptions returns the default client options.
+func DefaultClientOptions(s2aAddress string) *ClientOptions {
+	return &ClientOptions{
+		S2AAddress:       s2aAddress,
+		VerificationMode: ConnectToGoogle,
+	}
+}
+
+// ServerOptions contains the server-side options used to establish a secure
+// channel using the S2A handshaker service.
+type ServerOptions struct {
+	// LocalIdentities is the list of local identities that may be assumed by
+	// the server. If no local identity is specified, then the S2A chooses a
+	// default local identity, if one exists.
+	LocalIdentities []Identity
+	// S2AAddress is the address of the S2A.
+	S2AAddress string
+	// Optional transport credentials.
+	// If set, this will be used for the gRPC connection to the S2A server.
+	TransportCreds credentials.TransportCredentials
+	// If true, enables the use of legacy S2Av1.
+	EnableLegacyMode bool
+	// VerificationMode specifies the mode that S2A must use to verify the
+	// peer certificate chain.
+	VerificationMode VerificationModeType
+
+	// Generates an S2AStream interface for talking to the S2A server.
+	getS2AStream func(ctx context.Context, s2av2Address string) (stream.S2AStream, error)
+}
+
+// DefaultServerOptions returns the default server options.
+func DefaultServerOptions(s2aAddress string) *ServerOptions {
+	return &ServerOptions{
+		S2AAddress:       s2aAddress,
+		VerificationMode: ConnectToGoogle,
+	}
+}
+
+func toProtoIdentity(identity Identity) (*s2apb.Identity, error) {
+	if identity == nil {
+		return nil, nil
+	}
+	switch id := identity.(type) {
+	case *spiffeID:
+		return &s2apb.Identity{IdentityOneof: &s2apb.Identity_SpiffeId{SpiffeId: id.Name()}}, nil
+	case *hostname:
+		return &s2apb.Identity{IdentityOneof: &s2apb.Identity_Hostname{Hostname: id.Name()}}, nil
+	case *uid:
+		return &s2apb.Identity{IdentityOneof: &s2apb.Identity_Uid{Uid: id.Name()}}, nil
+	default:
+		return nil, errors.New("unrecognized identity type")
+	}
+}