add build constraints to not support <= go 1.9

credentials/go10.go

@@ -0,0 +1,69 @@
+// +build go1.10
+
+/*
+ *
+ * Copyright 2020 gRPC 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 credentials
+
+import (
+	"fmt"
+	"net/url"
+
+	"google.golang.org/grpc/grpclog"
+)
+
+// ParseSpiffeID parses the Spiffe ID from State and fill it into SpiffeID.
+// An error is returned only when we are sure Spiffe ID is used but the format
+// is wrong.
+// This function can only be used with go version 1.10 and onwards. When used
+// with a prior version, no error will be returned, but the field
+// TLSInfo.SpiffeID wouldn't be plumbed.
+func (t *TLSInfo) ParseSpiffeID() error {
+	if len(t.State.PeerCertificates) == 0 || len(t.State.PeerCertificates[0].URIs) == 0 {
+		return nil
+	}
+	spiffeIDCnt := 0
+	var spiffeID url.URL
+	for _, uri := range t.State.PeerCertificates[0].URIs {
+		if uri == nil || uri.Scheme != "spiffe" || uri.Opaque != "" || (uri.User != nil && uri.User.Username() != "") {
+			continue
+		}
+		// From this point, we assume the uri is intended for a Spiffe ID.
+		if len(uri.Host)+len(uri.Scheme)+len(uri.RawPath)+4 > 2048 ||
+			len(uri.Host)+len(uri.Scheme)+len(uri.Path)+4 > 2048 {
+			return fmt.Errorf("invalid SPIFFE ID: total ID length larger than 2048 bytes")
+		}
+		if len(uri.Host) == 0 || len(uri.RawPath) == 0 || len(uri.Path) == 0 {
+			return fmt.Errorf("invalid SPIFFE ID: domain or workload ID is empty")
+		}
+		if len(uri.Host) > 255 {
+			return fmt.Errorf("invalid SPIFFE ID: domain length larger than 255 characters")
+		}
+		// We use a default deep copy since we know the User field of a SPIFFE ID is empty.
+		spiffeID = *uri
+		spiffeIDCnt++
+	}
+	if spiffeIDCnt == 1 {
+		t.SpiffeID = &spiffeID
+	} else {
+		// A standard SPIFFE ID should be unique. If there are more, we log this
+		// mis-behavior and not plumb any of them.
+		grpclog.Info("invalid SPIFFE ID: multiple SPIFFE IDs")
+	}
+	return nil
+}

credentials/gobefore10.go

@@ -0,0 +1,30 @@
+// +build !go1.10
+
+/*
+ *
+ * Copyright 2020 gRPC 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 credentials
+
+import (
+	"google.golang.org/grpc/grpclog"
+)
+
+func (t *TLSInfo) ParseSpiffeID() error {
+	grpclog.Info("go version prior to 1.10 doesn't support parsing URIs in certificates. Please consider a newer version")
+	return nil
+}

credentials/tls.go

@@ -55,42 +55,6 @@ func (t TLSInfo) GetSecurityValue() ChannelzSecurityValue {
 	return v
 }
 
-// ParseSpiffeID parses the Spiffe ID from State and fill it into SpiffeID.
-// An error is returned only when we are sure Spiffe ID is used but the format
-// is wrong.
-func (t *TLSInfo) ParseSpiffeID() error {
-	if len(t.State.PeerCertificates) == 0 || len(t.State.PeerCertificates[0].URIs) == 0 {
-		return nil
-	}
-	spiffeIDCnt := 0
-	var spiffeID url.URL
-	for _, uri := range t.State.PeerCertificates[0].URIs {
-		if uri == nil || uri.Scheme != "spiffe" || uri.Opaque != "" || (uri.User != nil && uri.User.Username() != "") {
-			continue
-		}
-		// From this point, we assume the uri is intended for a Spiffe ID.
-		if len(uri.Host)+len(uri.Scheme)+len(uri.RawPath)+4 > 2048 ||
-			len(uri.Host)+len(uri.Scheme)+len(uri.Path)+4 > 2048 {
-			return fmt.Errorf("invalid SPIFFE ID: total ID length larger than 2048 bytes")
-		}
-		if len(uri.Host) == 0 || len(uri.RawPath) == 0 || len(uri.Path) == 0 {
-			return fmt.Errorf("invalid SPIFFE ID: domain or workload ID is empty")
-		}
-		if len(uri.Host) > 255 {
-			return fmt.Errorf("invalid SPIFFE ID: domain length larger than 255 characters")
-		}
-		// We use a default deep copy since we know the User field of a SPIFFE ID is empty.
-		spiffeID = *uri
-		spiffeIDCnt++
-	}
-	// A standard SPIFFE ID should be unique. If there are more, we don't raise
-	// any errors but simply not plumbing any of them.
-	if spiffeIDCnt == 1 {
-		t.SpiffeID = &spiffeID
-	}
-	return nil
-}
-
 // tlsCreds is the credentials required for authenticating a connection using TLS.
 type tlsCreds struct {
 	// TLS configuration