[#286] client: Add TLS options

Add `WithTLSConfig` option to client.
If it is not nil then client will
try to open secured connection.

Signed-off-by: Pavel Karpy <carpawell@nspcc.ru>

pkg/client/opts.go

@@ -2,6 +2,7 @@ package client
 
 import (
 	"crypto/ecdsa"
+	"crypto/tls"
 	"time"
 
 	"github.com/nspcc-dev/neofs-api-go/pkg"
@@ -110,7 +111,7 @@ func v2MetaHeaderFromOpts(options *callOptions) *v2session.RequestMetaHeader {
 
 func defaultClientOptions() *clientOptions {
 	return &clientOptions{
-		rawOpts: make([]client.Option, 0, 3),
+		rawOpts: make([]client.Option, 0, 4),
 	}
 }
 
@@ -133,6 +134,13 @@ func WithDialTimeout(dur time.Duration) Option {
 	}
 }
 
+// WithTLSConfig returns option to set connection's TLS config to the remote node.
+func WithTLSConfig(cfg *tls.Config) Option {
+	return func(opts *clientOptions) {
+		opts.rawOpts = append(opts.rawOpts, client.WithTLSCfg(cfg))
+	}
+}
+
 // WithDefaultPrivateKey returns option to set default private key
 // used for the work.
 func WithDefaultPrivateKey(key *ecdsa.PrivateKey) Option {

rpc/client/connect.go

@@ -6,6 +6,7 @@ import (
 
 	"github.com/nspcc-dev/neofs-api-go/rpc/grpc"
 	grpcstd "google.golang.org/grpc"
+	"google.golang.org/grpc/credentials"
 )
 
 func (c *Client) createGRPCClient() (err error) {
@@ -33,8 +34,17 @@ func (c *Client) openGRPCConn() error {
 
 	var err error
 
+	var credOpt grpcstd.DialOption
+
+	if c.tlsCfg != nil {
+		creds := credentials.NewTLS(c.tlsCfg)
+		credOpt = grpcstd.WithTransportCredentials(creds)
+	} else {
+		credOpt = grpcstd.WithInsecure()
+	}
+
 	dialCtx, cancel := context.WithTimeout(context.Background(), c.dialTimeout)
-	c.conn, err = grpcstd.DialContext(dialCtx, c.addr, grpcstd.WithInsecure())
+	c.conn, err = grpcstd.DialContext(dialCtx, c.addr, credOpt)
 	cancel()
 
 	return err

rpc/client/options.go

@@ -1,6 +1,7 @@
 package client
 
 import (
+	"crypto/tls"
 	"time"
 
 	"google.golang.org/grpc"
@@ -14,6 +15,8 @@ type cfg struct {
 
 	dialTimeout time.Duration
 
+	tlsCfg *tls.Config
+
 	conn *grpc.ClientConn
 }
 
@@ -49,6 +52,18 @@ func WithDialTimeout(v time.Duration) Option {
 	}
 }
 
+// WithTLSCfg returns option to specify
+// TLS configuration.
+//
+// Ignored if WithGRPCConn is provided.
+func WithTLSCfg(v *tls.Config) Option {
+	return func(c *cfg) {
+		if v != nil {
+			c.tlsCfg = v
+		}
+	}
+}
+
 // WithGRPCConn returns option to specify
 // gRPC virtual connection.
 func WithGRPCConn(v *grpc.ClientConn) Option {